JAVA Spring MyBatis DAY02
1 注入参数值
1.1 问题
使用Spring创建bean，并且为bean注入各种类型的参数值。
1.2 方案
使用Spring为一个bean注入以下类型的参数值：
1.3 步骤
步骤一：创建项目，导入jar包
创建项目Spring02，导入Spring开发包，如下图：
图-1
步骤二： 创建bean
将Spring01项目中的Computer类复制到当前项目下，代码如下：
package com.tarena.bean;
import java.io.Serializable;
public class Computer implements Serializable {
private String mainboard; // 主板
private String hdd; // 硬盘
private String ram; // 内存
public String getMainboard() {
return mainboard;
}
public void setMainboard(String mainboard) {
this.mainboard = mainboard;
}
public String getHdd() {
return hdd;
}
public void setHdd(String hdd) {
this.hdd = hdd;
}
public String getRam() {
return ram;
}
public void setRam(String ram) {
this.ram = ram;
}
}
创建一个消息类MessageBean，代码如下：
package com.tarena.bean;
import java.io.Serializable;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.Set;
public class MessageBean implements Serializable {
// 基本值
private String name;
private int age;
// bean对象
private Computer computer;
//集合
private List<String> langs;
private Set<String> cities;
private Map<String, Object> score;
private Properties props;
public void execute() {
System.out.println("基本值：");
System.out.println(name);
System.out.println(age);
System.out.println("bean对象：");
if(computer != null) {
System.out.println(computer.getMainboard());
System.out.println(computer.getHdd());
System.out.println(computer.getRam());
}
System.out.println("编程语言：");
if(langs != null) {
for(String lang : langs) {
System.out.println(lang);
}
}
System.out.println("城市：");
if(cities != null) {
for(String city : cities) {
System.out.println(city);
}
}
System.out.println("分数：");
if(score != null) {
Set<String> set = score.keySet();
for(String key : set) {
System.out.println(
key + " : " + score.get(key));
}
}
System.out.println("参数：");
if(props != null) {
Set<Object> propKeySet = props.keySet();
for(Object key : propKeySet) {
System.out.println(
key + " : " + props.getProperty(key.toString()));
}
}
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public Computer getComputer() {
return computer;
}
public void setComputer(Computer computer) {
this.computer = computer;
}
public List<String> getLangs() {
return langs;
}
public void setLangs(List<String> langs) {
this.langs = langs;
}
public Set<String> getCities() {
return cities;
}
public void setCities(Set<String> cities) {
this.cities = cities;
}
public Map<String, Object> getScore() {
return score;
}
public void setScore(Map<String, Object> score) {
this.score = score;
}
public Properties getProps() {
return props;
}
public void setProps(Properties props) {
this.props = props;
}
}
步骤三：声明bean
导入applicationContext.xml，在该配置文件中声明这2个bean，并将Computer注入给MessageBean，代码如下：
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:jdbc="http://www.springframework.org/schema/jdbc" xmlns:jee="http://www.springframework.org/schema/jee" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:util="http://www.springframework.org/schema/util" xmlns:jpa="http://www.springframework.org/schema/data/jpa" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.2.xsd http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.2.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.2.xsd"> <bean id="computer" class="com.tarena.bean.Computer"> <property name="mainboard" value="技嘉"/> <property name="hdd" value="希捷"/> <property name="ram" value="金士顿"/> </bean> <!-- 注入参数值 --> <bean id="msg" class="com.tarena.bean.MessageBean"> <property name="name"> <value>张三</value> </property> <property name="age" value="25"/> <property name="computer" ref="computer"/> <property name="langs"> <list> <value>Java</value> <value>php</value> <value>.net</value> </list> </property> <property name="cities"> <set> <value>北京</value> <value>上海</value> <value>广州</value> </set> </property> <property name="score"> <map> <entry key="JSD1412001" value="78"/> <entry key="JSD1412002" value="68"/> <entry key="JSD1412003" value="94"/> </map> </property> <property name="props"> <props> <prop key="user">lhh</prop> <prop key="password">123456</prop> </props> </property> </bean> </beans>
步骤四：写测试代码
创建TestCase测试类，增加测试方法test1，代码如下：
package com.tarena.test;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.tarena.bean.DemoBean;
import com.tarena.bean.MessageBean;
public class TestCase {
/**
* 注入参数值
*/
@Test
public void test1() {
String cfg = "applicationContext.xml";
ApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
MessageBean bean = ctx.getBean("msg", MessageBean.class);
bean.execute();
}
}
步骤五：执行测试
执行测试方法test1，效果如下图：
图-2
1.4 完整代码
Computer类完整代码如下：
package com.tarena.bean;
import java.io.Serializable;
public class Computer implements Serializable {
private String mainboard; // 主板
private String hdd; // 硬盘
private String ram; // 内存
public String getMainboard() {
return mainboard;
}
public void setMainboard(String mainboard) {
this.mainboard = mainboard;
}
public String getHdd() {
return hdd;
}
public void setHdd(String hdd) {
this.hdd = hdd;
}
public String getRam() {
return ram;
}
public void setRam(String ram) {
this.ram = ram;
}
}
MessageBean类完整代码如下：
package com.tarena.bean;
import java.io.Serializable;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.Set;
public class MessageBean implements Serializable {
// 基本值
private String name;
private int age;
// bean对象
private Computer computer;
//集合
private List<String> langs;
private Set<String> cities;
private Map<String, Object> score;
private Properties props;
public void execute() {
System.out.println("基本值：");
System.out.println(name);
System.out.println(age);
System.out.println("bean对象：");
if(computer != null) {
System.out.println(computer.getMainboard());
System.out.println(computer.getHdd());
System.out.println(computer.getRam());
}
System.out.println("编程语言：");
if(langs != null) {
for(String lang : langs) {
System.out.println(lang);
}
}
System.out.println("城市：");
if(cities != null) {
for(String city : cities) {
System.out.println(city);
}
}
System.out.println("分数：");
if(score != null) {
Set<String> set = score.keySet();
for(String key : set) {
System.out.println(
key + " : " + score.get(key));
}
}
System.out.println("参数：");
if(props != null) {
Set<Object> propKeySet = props.keySet();
for(Object key : propKeySet) {
System.out.println(
key + " : " + props.getProperty(key.toString()));
}
}
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public Computer getComputer() {
return computer;
}
public void setComputer(Computer computer) {
this.computer = computer;
}
public List<String> getLangs() {
return langs;
}
public void setLangs(List<String> langs) {
this.langs = langs;
}
public Set<String> getCities() {
return cities;
}
public void setCities(Set<String> cities) {
this.cities = cities;
}
public Map<String, Object> getScore() {
return score;
}
public void setScore(Map<String, Object> score) {
this.score = score;
}
public Properties getProps() {
return props;
}
public void setProps(Properties props) {
this.props = props;
}
}
applicationContext.xml完整代码如下：
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:jdbc="http://www.springframework.org/schema/jdbc" xmlns:jee="http://www.springframework.org/schema/jee" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:util="http://www.springframework.org/schema/util" xmlns:jpa="http://www.springframework.org/schema/data/jpa" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.2.xsd http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.2.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.2.xsd"> <bean id="computer" class="com.tarena.bean.Computer"> <property name="mainboard" value="技嘉"/> <property name="hdd" value="希捷"/> <property name="ram" value="金士顿"/> </bean> <!-- 注入参数值 --> <bean id="msg" class="com.tarena.bean.MessageBean"> <property name="name"> <value>张三</value> </property> <property name="age" value="25"/> <property name="computer" ref="computer"/> <property name="langs"> <list> <value>Java</value> <value>php</value> <value>.net</value> </list> </property> <property name="cities"> <set> <value>北京</value> <value>上海</value> <value>广州</value> </set> </property> <property name="score"> <map> <entry key="JSD1412001" value="78"/> <entry key="JSD1412002" value="68"/> <entry key="JSD1412003" value="94"/> </map> </property> <property name="props"> <props> <prop key="user">lhh</prop> <prop key="password">123456</prop> </props> </property> </bean> </beans>
TestCase类完整代码如下：
package com.tarena.test;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.tarena.bean.DemoBean;
import com.tarena.bean.MessageBean;
public class TestCase {
/**
* 注入参数值
*/
@Test
public void test1() {
String cfg = "applicationContext.xml";
ApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
MessageBean bean = ctx.getBean("msg", MessageBean.class);
bean.execute();
}
}
2 采用引用的方式注入集合
2.1 问题
先声明集合bean，然后采用引用的方式将这些bean注入给MessageBean。
2.2 方案
使用<util>标签声明集合bean，然后在MessageBean下使用<property>标签引用这些集合bean。
2.3 步骤
步骤一：声明bean
在applicationContext.xml中声明集合bean，然后新声明一个MessageBean类型的bean，让这个bean引用集合bean，追加代码如下：
<!-- 声明集合bean --> <util:list id="langList"> <value>c++</value> <value>python</value> </util:list> <util:set id="citySet"> <value>重庆</value> <value>天津</value> </util:set> <util:map id="scoreMap"> <entry key="JSD1412004" value="90"/> <entry key="JSD1412005" value="85"/> </util:map> <util:properties id="paramProp"> <prop key="user">tarena</prop> <prop key="password">123456</prop> </util:properties> <!-- 采用引用的方式注入集合 --> <bean id="msg2" class="com.tarena.bean.MessageBean"> <property name="langs" ref="langList"/> <property name="cities" ref="citySet"/> <property name="score" ref="scoreMap"/> <property name="props" ref="paramProp"/> </bean>
步骤二： 写测试代码
在TestCase中增加测试方法test2，追加代码如下：
/**
* 采用引用的方式注入集合
*/
@Test
public void test2() {
String cfg = "applicationContext.xml";
ApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
MessageBean bean = ctx.getBean("msg2", MessageBean.class);
bean.execute();
}
步骤三：执行测试
执行test2方法，效果如下图：
图-3
2.4 完整代码
applicationContext.xml完整代码如下：
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:jdbc="http://www.springframework.org/schema/jdbc" xmlns:jee="http://www.springframework.org/schema/jee" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:util="http://www.springframework.org/schema/util" xmlns:jpa="http://www.springframework.org/schema/data/jpa" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.2.xsd http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.2.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.2.xsd"> <bean id="computer" class="com.tarena.bean.Computer"> <property name="mainboard" value="技嘉"/> <property name="hdd" value="希捷"/> <property name="ram" value="金士顿"/> </bean> <!-- 注入参数值 --> <bean id="msg" class="com.tarena.bean.MessageBean"> <property name="name"> <value>张三</value> </property> <property name="age" value="25"/> <property name="computer" ref="computer"/> <property name="langs"> <list> <value>Java</value> <value>php</value> <value>.net</value> </list> </property> <property name="cities"> <set> <value>北京</value> <value>上海</value> <value>广州</value> </set> </property> <property name="score"> <map> <entry key="JSD1412001" value="78"/> <entry key="JSD1412002" value="68"/> <entry key="JSD1412003" value="94"/> </map> </property> <property name="props"> <props> <prop key="user">lhh</prop> <prop key="password">123456</prop> </props> </property> </bean> <!-- 声明集合bean --> <util:list id="langList"> <value>c++</value> <value>python</value> </util:list> <util:set id="citySet"> <value>重庆</value> <value>天津</value> </util:set> <util:map id="scoreMap"> <entry key="JSD1412004" value="90"/> <entry key="JSD1412005" value="85"/> </util:map> <util:properties id="paramProp"> <prop key="user">tarena</prop> <prop key="password">123456</prop> </util:properties> <!-- 采用引用的方式注入集合 --> <bean id="msg2" class="com.tarena.bean.MessageBean"> <property name="langs" ref="langList"/> <property name="cities" ref="citySet"/> <property name="score" ref="scoreMap"/> <property name="props" ref="paramProp"/> </bean> </beans>
TestCase类完整代码如下：
package com.tarena.test;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.tarena.bean.DemoBean;
import com.tarena.bean.MessageBean;
public class TestCase {
/**
* 注入参数值
*/
@Test
public void test1() {
String cfg = "applicationContext.xml";
ApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
MessageBean bean = ctx.getBean("msg", MessageBean.class);
bean.execute();
}
/**
* 采用引用的方式注入集合
*/
@Test
public void test2() {
String cfg = "applicationContext.xml";
ApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
MessageBean bean = ctx.getBean("msg2", MessageBean.class);
bean.execute();
}
}
3 注入表达式
3.1 问题
通过表达式的方式，给bean注入值。
3.2 方案
新建一个bean，通过表达式的方式引用MessageBean等bean的数据，注入给这个新建的bean。
3.3 步骤
步骤一：创建bean
创建DemoBean，代码如下：
package com.tarena.bean;
import java.io.Serializable;
public class DemoBean implements Serializable {
private String name;
private String lang;
private String score;
private int pageSize;
public void execute() {
System.out.println("name:" + name);
System.out.println("lang:" + lang);
System.out.println("score:" + score);
System.out.println("pageSize:" + pageSize);
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getLang() {
return lang;
}
public void setLang(String lang) {
this.lang = lang;
}
public String getScore() {
return score;
}
public void setScore(String score) {
this.score = score;
}
public int getPageSize() {
return pageSize;
}
public void setPageSize(int pageSize) {
this.pageSize = pageSize;
}
}
步骤二： 创建资源文件
创建一个资源文件const.properties，用来封装系统常量，代码如下：
#max rows in one page PAGE_SIZE=10
步骤三：声明bean
在applicationContext.xml中，通过<util:properties>标签声明一个id=”const”的bean，加载const.properties中的信息。然后再声明DemoBean，使用表达式读取MessageBean和id=”const”的bean，将值注入给DemoBean，追加代码如下：
<!-- 声明Properties集合，读取const.properties参数 -->
<util:properties id="const" location="classpath:const.properties"/>
<!-- 注入表达式 -->
<bean id="demo" class="com.tarena.bean.DemoBean">
<property name="name" value="#{msg.name}"/>
<property name="lang" value="#{msg.langs[0]}"/>
<property name="score" value="#{msg.score.JSD1412001}"/>
<property name="pageSize" value="#{const.PAGE_SIZE}"/>
</bean>
步骤四：写测试代码
在TestCase中增加测试方法test3，追加代码如下：
/**
* 注入表达式
*/
@Test
public void test3() {
String cfg = "applicationContext.xml";
ApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
DemoBean bean = ctx.getBean("demo", DemoBean.class);
bean.execute();
}
步骤五：执行测试
执行test3方法，效果如下图：
图-4
3.4 完整代码
DemoBean完整代码如下：
package com.tarena.bean;
import java.io.Serializable;
public class DemoBean implements Serializable {
private String name;
private String lang;
private String score;
private int pageSize;
public void execute() {
System.out.println("name:" + name);
System.out.println("lang:" + lang);
System.out.println("score:" + score);
System.out.println("pageSize:" + pageSize);
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getLang() {
return lang;
}
public void setLang(String lang) {
this.lang = lang;
}
public String getScore() {
return score;
}
public void setScore(String score) {
this.score = score;
}
public int getPageSize() {
return pageSize;
}
public void setPageSize(int pageSize) {
this.pageSize = pageSize;
}
}
const.properties完整代码如下：
#max rows in one page PAGE_SIZE=10
applicationContext.xml完整代码如下：
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:jdbc="http://www.springframework.org/schema/jdbc"
xmlns:jee="http://www.springframework.org/schema/jee"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:util="http://www.springframework.org/schema/util"
xmlns:jpa="http://www.springframework.org/schema/data/jpa"
xsi:schemaLocation="
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd
http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.2.xsd
http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.2.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd
http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd
http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd
http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.2.xsd">
<bean id="computer" class="com.tarena.bean.Computer">
<property name="mainboard" value="技嘉"/>
<property name="hdd" value="希捷"/>
<property name="ram" value="金士顿"/>
</bean>
<!-- 注入参数值 -->
<bean id="msg" class="com.tarena.bean.MessageBean">
<property name="name">
<value>张三</value>
</property>
<property name="age" value="25"/>
<property name="computer" ref="computer"/>
<property name="langs">
<list>
<value>Java</value>
<value>php</value>
<value>.net</value>
</list>
</property>
<property name="cities">
<set>
<value>北京</value>
<value>上海</value>
<value>广州</value>
</set>
</property>
<property name="score">
<map>
<entry key="JSD1412001" value="78"/>
<entry key="JSD1412002" value="68"/>
<entry key="JSD1412003" value="94"/>
</map>
</property>
<property name="props">
<props>
<prop key="user">lhh</prop>
<prop key="password">123456</prop>
</props>
</property>
</bean>
<!-- 声明集合bean -->
<util:list id="langList">
<value>c++</value>
<value>python</value>
</util:list>
<util:set id="citySet">
<value>重庆</value>
<value>天津</value>
</util:set>
<util:map id="scoreMap">
<entry key="JSD1412004" value="90"/>
<entry key="JSD1412005" value="85"/>
</util:map>
<util:properties id="paramProp">
<prop key="user">tarena</prop>
<prop key="password">123456</prop>
</util:properties>
<!-- 采用引用的方式注入集合 -->
<bean id="msg2" class="com.tarena.bean.MessageBean">
<property name="langs" ref="langList"/>
<property name="cities" ref="citySet"/>
<property name="score" ref="scoreMap"/>
<property name="props" ref="paramProp"/>
</bean>
<!-- 声明Properties集合，读取const.properties参数 -->
<util:properties id="const" location="classpath:const.properties"/>
<!-- 注入表达式 -->
<bean id="demo" class="com.tarena.bean.DemoBean">
<property name="name" value="#{msg.name}"/>
<property name="lang" value="#{msg.langs[0]}"/>
<property name="score" value="#{msg.score.JSD1412001}"/>
<property name="pageSize" value="#{const.PAGE_SIZE}"/>
</bean>
</beans>
4 使用注解声明bean
4.1 问题
使用Spring注解代替XML配置来声明bean，并使用注解管理bean的作用域和生命周期。
4.2 方案
4.3 步骤
步骤一：创建项目，导入jar包
创建项目Spring02-2，导入Spring开发包，如下图：
图-5
步骤二： 导入配置文件
导入Spring配置文件applicationContext.xml，开启注解扫描，代码如下：
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:jdbc="http://www.springframework.org/schema/jdbc" xmlns:jee="http://www.springframework.org/schema/jee" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:util="http://www.springframework.org/schema/util" xmlns:jpa="http://www.springframework.org/schema/data/jpa" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.2.xsd http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.2.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.2.xsd"> <!-- 开启注解扫描 --> <context:component-scan base-package="com.tarena"/> </beans>
步骤三：创建并声明bean
创建ExampleBean，并使用@Component注解声明这个bean，代码如下：
package com.tarena.bean;
import java.io.Serializable;
import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Component;
@Component("example")
public class ExampleBean implements Serializable {
public ExampleBean() {
System.out.println("实例化ExampleBean：" + this);
}
public void init() {
System.out.println("初始化ExampleBean");
}
public void destroy() {
System.out.println("销毁ExampleBean");
}
public void execute() {
System.out.println("执行execute方法");
}
}
步骤四：测试使用注解声明bean
创建测试类TestCase，增加测试方法test1，代码如下：
package com.tarena.test;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.AbstractApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.tarena.bean.DemoBean;
import com.tarena.bean.ExampleBean;
import com.tarena.bean.Manager;
import com.tarena.bean.Programmer;
import com.tarena.bean.Salesman;
import com.tarena.bean.Student;
import com.tarena.bean.Teacher;
public class TestCase {
/**
* 使用注解声明bean
*/
@Test
public void test1() {
String cfg = "applicationContext.xml";
ApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
ExampleBean bean =
ctx.getBean("example", ExampleBean.class);
System.out.println(bean);
}
}
执行test1方法，效果如下图：
图-6
步骤五：测试bean的作用域
在TestCase中增加test2方法，追加代码如下：
/**
* 使用注解声明bean的作用域
*/
@Test
public void test2() {
String cfg = "applicationContext.xml";
ApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
ExampleBean bean1 =
ctx.getBean("example", ExampleBean.class);
ExampleBean bean2 =
ctx.getBean("example", ExampleBean.class);
System.out.println(bean1==bean2);
}
执行该方法，效果如下图：
图-7
在ExampleBean类上增加@scope(“prototype”)，追加代码如下：
@Component("example")
@Scope("prototype")
public class ExampleBean implements Serializable {
再次执行test2方法，效果如下图：
图-8
步骤六：测试bean的生命周期
在ExampleBean上使用注解声明其初始化方法和销毁方法，并将该bean改为单例的，代码如下：
package com.tarena.bean;
import java.io.Serializable;
import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Component;
@Component("example")
@Scope("singleton")
public class ExampleBean implements Serializable {
public ExampleBean() {
System.out.println("实例化ExampleBean：" + this);
}
@PostConstruct
public void init() {
System.out.println("初始化ExampleBean");
}
@PreDestroy
public void destroy() {
System.out.println("销毁ExampleBean");
}
public void execute() {
System.out.println("执行execute方法");
}
}
在TestCase中增加测试方法test3，追加代码如下：
/**
* 使用注解声明bean的生命周期
*/
@Test
public void test3() {
String cfg = "applicationContext.xml";
AbstractApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
ExampleBean bean =
ctx.getBean("example", ExampleBean.class);
bean.execute();
ctx.close();
}
执行该测试方法，效果如下图：
图-9
4.4 完整代码
applicationContext.xml完整代码如下：
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:jdbc="http://www.springframework.org/schema/jdbc" xmlns:jee="http://www.springframework.org/schema/jee" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:util="http://www.springframework.org/schema/util" xmlns:jpa="http://www.springframework.org/schema/data/jpa" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.2.xsd http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.2.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.2.xsd"> <!-- 开启注解扫描 --> <context:component-scan base-package="com.tarena"/> </beans>
ExampleBean完整代码如下：
package com.tarena.bean;
import java.io.Serializable;
import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Component;
@Component("example")
@Scope("singleton")
public class ExampleBean implements Serializable {
public ExampleBean() {
System.out.println("实例化ExampleBean：" + this);
}
@PostConstruct
public void init() {
System.out.println("初始化ExampleBean");
}
@PreDestroy
public void destroy() {
System.out.println("销毁ExampleBean");
}
public void execute() {
System.out.println("执行execute方法");
}
}
TestCase完整代码如下：
package com.tarena.test;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.AbstractApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.tarena.bean.DemoBean;
import com.tarena.bean.ExampleBean;
import com.tarena.bean.Manager;
import com.tarena.bean.Programmer;
import com.tarena.bean.Salesman;
import com.tarena.bean.Student;
import com.tarena.bean.Teacher;
public class TestCase {
/**
* 使用注解声明bean
*/
@Test
public void test1() {
String cfg = "applicationContext.xml";
ApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
ExampleBean bean =
ctx.getBean("example", ExampleBean.class);
System.out.println(bean);
}
/**
* 使用注解声明bean的作用域
*/
@Test
public void test2() {
String cfg = "applicationContext.xml";
ApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
ExampleBean bean1 =
ctx.getBean("example", ExampleBean.class);
ExampleBean bean2 =
ctx.getBean("example", ExampleBean.class);
System.out.println(bean1==bean2);
}
/**
* 使用注解声明bean的生命周期
*/
@Test
public void test3() {
String cfg = "applicationContext.xml";
AbstractApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
ExampleBean bean =
ctx.getBean("example", ExampleBean.class);
bean.execute();
ctx.close();
}
}
5 使用@Autowired注解
5.1 问题
使用@Autowired注解注入依赖的bean。
5.2 方案
5.3 步骤
步骤一：创建并声明bean
创建Computer类，并使用@Component注解将其声明到容器中，代码如下：
package com.tarena.bean;
import java.io.Serializable;
import org.springframework.stereotype.Component;
@Component
public class Computer implements Serializable {
private String mainboard; // 主板
private String hdd; // 硬盘
private String ram; // 内存
public String getMainboard() {
return mainboard;
}
public void setMainboard(String mainboard) {
this.mainboard = mainboard;
}
public String getHdd() {
return hdd;
}
public void setHdd(String hdd) {
this.hdd = hdd;
}
public String getRam() {
return ram;
}
public void setRam(String ram) {
this.ram = ram;
}
}
创建Programmer类，并使用@Component注解将其声明到容器中，然后使用@Autowired注解在构造器上将Computer注入进来，代码如下：
package com.tarena.bean;
import java.io.Serializable;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Component;
@Component
public class Programmer implements Serializable {
private Computer computer;
@Autowired
public Programmer(
@Qualifier("computer") Computer computer) {
this.computer = computer;
}
public Computer getComputer() {
return computer;
}
public void setComputer(Computer computer) {
this.computer = computer;
}
}
步骤二： 测试以构造方式注入bean
在TestCase中增加测试方法test4，追加代码如下：
/**
* 使用@Autowired，以构造方式注入bean
*/
@Test
public void test4() {
String cfg = "applicationContext.xml";
ApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
Programmer prog =
ctx.getBean("programmer", Programmer.class);
System.out.println(prog);
System.out.println(prog.getComputer());
}
执行该测试方法，效果如下图：
图-10
步骤三：创建并声明bean
创建Teacher类，并使用注解将其声明到容器中，然后使用@Autowired注解在set方法上将Computer注入，代码如下：
package com.tarena.bean;
import java.io.Serializable;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Component;
@Component
public class Teacher implements Serializable {
private Computer computer;
@Autowired
public void setComputer(
@Qualifier("computer") Computer computer) {
this.computer = computer;
System.out.println("Teacher");
}
public Computer getComputer() {
return computer;
}
}
步骤四：测试在setter上加注解的方式注入bean
在TestCase里增加测试方法test5，追加代码如下：
/**
* 在setter上使用@Autowired，以setter方式注入bean
*/
@Test
public void test5() {
String cfg = "applicationContext.xml";
ApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
Teacher teacher =
ctx.getBean("teacher", Teacher.class);
System.out.println(teacher);
System.out.println(teacher.getComputer());
}
执行该测试方法，效果如下图：
图-11
步骤五：创建并声明bean
创建Student类，并使用注解将其声明到容器中，然后在属性上加注解将Computer注入，代码如下：
package com.tarena.bean;
import java.io.Serializable;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Component;
@Component
public class Student implements Serializable {
@Autowired
@Qualifier("computer")
private Computer computer;
public Computer getComputer() {
return computer;
}
public void setComputer(Computer computer) {
this.computer = computer;
System.out.println("Student");
}
}
步骤六：测试在属性上加注解的方式注入bean
在TestCase中增加测试方法test6，追加代码如下：
/**
* 在属性上使用@Autowired，以setter方式注入bean
*/
@Test
public void test6() {
String cfg = "applicationContext.xml";
ApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
Student student =
ctx.getBean("student", Student.class);
System.out.println(student);
System.out.println(student.getComputer());
}
执行该测试方法，效果如下图：
图-12
5.4 完整代码
Computer类完整代码如下：
package com.tarena.bean;
import java.io.Serializable;
import org.springframework.stereotype.Component;
@Component
public class Computer implements Serializable {
private String mainboard; // 主板
private String hdd; // 硬盘
private String ram; // 内存
public String getMainboard() {
return mainboard;
}
public void setMainboard(String mainboard) {
this.mainboard = mainboard;
}
public String getHdd() {
return hdd;
}
public void setHdd(String hdd) {
this.hdd = hdd;
}
public String getRam() {
return ram;
}
public void setRam(String ram) {
this.ram = ram;
}
}
Programmer类完整代码如下：
package com.tarena.bean;
import java.io.Serializable;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Component;
@Component
public class Programmer implements Serializable {
private Computer computer;
@Autowired
public Programmer(
@Qualifier("computer") Computer computer) {
this.computer = computer;
}
public Computer getComputer() {
return computer;
}
public void setComputer(Computer computer) {
this.computer = computer;
}
}
Teacher类完整代码如下：
package com.tarena.bean;
import java.io.Serializable;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Component;
@Component
public class Teacher implements Serializable {
private Computer computer;
@Autowired
public void setComputer(
@Qualifier("computer") Computer computer) {
this.computer = computer;
System.out.println("Teacher");
}
public Computer getComputer() {
return computer;
}
}
Student类完整代码如下：
package com.tarena.bean;
import java.io.Serializable;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Component;
@Component
public class Student implements Serializable {
@Autowired
@Qualifier("computer")
private Computer computer;
public Computer getComputer() {
return computer;
}
public void setComputer(Computer computer) {
this.computer = computer;
System.out.println("Student");
}
}
TestCase类完整代码如下：
package com.tarena.test;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.AbstractApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.tarena.bean.DemoBean;
import com.tarena.bean.ExampleBean;
import com.tarena.bean.Manager;
import com.tarena.bean.Programmer;
import com.tarena.bean.Salesman;
import com.tarena.bean.Student;
import com.tarena.bean.Teacher;
public class TestCase {
/**
* 使用注解声明bean
*/
@Test
public void test1() {
String cfg = "applicationContext.xml";
ApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
ExampleBean bean =
ctx.getBean("example", ExampleBean.class);
System.out.println(bean);
}
/**
* 使用注解声明bean的作用域
*/
@Test
public void test2() {
String cfg = "applicationContext.xml";
ApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
ExampleBean bean1 =
ctx.getBean("example", ExampleBean.class);
ExampleBean bean2 =
ctx.getBean("example", ExampleBean.class);
System.out.println(bean1==bean2);
}
/**
* 使用注解声明bean的生命周期
*/
@Test
public void test3() {
String cfg = "applicationContext.xml";
AbstractApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
ExampleBean bean =
ctx.getBean("example", ExampleBean.class);
bean.execute();
ctx.close();
}
/**
* 使用@Autowired，以构造方式注入bean
*/
@Test
public void test4() {
String cfg = "applicationContext.xml";
ApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
Programmer prog =
ctx.getBean("programmer", Programmer.class);
System.out.println(prog);
System.out.println(prog.getComputer());
}
/**
* 在setter上使用@Autowired，以setter方式注入bean
*/
@Test
public void test5() {
String cfg = "applicationContext.xml";
ApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
Teacher teacher =
ctx.getBean("teacher", Teacher.class);
System.out.println(teacher);
System.out.println(teacher.getComputer());
}
/**
* 在属性上使用@Autowired，以setter方式注入bean
*/
@Test
public void test6() {
String cfg = "applicationContext.xml";
ApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
Student student =
ctx.getBean("student", Student.class);
System.out.println(student);
System.out.println(student.getComputer());
}
}
6 使用@Resource注解
6.1 问题
使用@Resource注解注入依赖的bean。
6.2 方案
6.3 步骤
步骤一：创建并声明bean
创建Manager类，代码如下：
package com.tarena.bean;
import java.io.Serializable;
import javax.annotation.Resource;
import org.springframework.stereotype.Component;
@Component
public class Manager implements Serializable {
private Computer computer;
@Resource(name="computer")
public void setComputer(Computer computer) {
this.computer = computer;
System.out.println("Manager");
}
public Computer getComputer() {
return computer;
}
}
步骤二： 测试在setter上加注解的方式注入bean
在TestCase中增加测试方法test7，追加代码如下：
/**
* 在setter上使用@Resource，以setter方式注入bean
*/
@Test
public void test7() {
String cfg = "applicationContext.xml";
ApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
Manager manager =
ctx.getBean("manager", Manager.class);
System.out.println(manager);
System.out.println(manager.getComputer());
}
执行该测试方法，效果如下图：
图-13
步骤三：创建并声明bean
创建Salesman类，代码如下：
package com.tarena.bean;
import java.io.Serializable;
import javax.annotation.Resource;
import org.springframework.stereotype.Component;
@Component
public class Salesman implements Serializable {
@Resource
private Computer computer;
public Computer getComputer() {
return computer;
}
public void setComputer(Computer computer) {
this.computer = computer;
System.out.println("Salesman");
}
}
步骤四：测试在属性上加注解的方式注入bean
在TestCase中增加测试方法test8，追加代码如下：
/**
* 在属性上使用@Resource，以setter方式注入bean
*/
@Test
public void test8() {
String cfg = "applicationContext.xml";
ApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
Salesman man =
ctx.getBean("salesman", Salesman.class);
System.out.println(man);
System.out.println(man.getComputer());
}
执行该测试方法，效果如下图：
图-14
6.4 完整代码
Manager类完整代码如下：
package com.tarena.bean;
import java.io.Serializable;
import javax.annotation.Resource;
import org.springframework.stereotype.Component;
@Component
public class Manager implements Serializable {
private Computer computer;
@Resource(name="computer")
public void setComputer(Computer computer) {
this.computer = computer;
System.out.println("Manager");
}
public Computer getComputer() {
return computer;
}
}
Salesman类完整代码如下：
package com.tarena.bean;
import java.io.Serializable;
import javax.annotation.Resource;
import org.springframework.stereotype.Component;
@Component
public class Salesman implements Serializable {
@Resource
private Computer computer;
public Computer getComputer() {
return computer;
}
public void setComputer(Computer computer) {
this.computer = computer;
System.out.println("Salesman");
}
}
TestCase类完整代码如下：
package com.tarena.test;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.AbstractApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.tarena.bean.DemoBean;
import com.tarena.bean.ExampleBean;
import com.tarena.bean.Manager;
import com.tarena.bean.Programmer;
import com.tarena.bean.Salesman;
import com.tarena.bean.Student;
import com.tarena.bean.Teacher;
public class TestCase {
/**
* 使用注解声明bean
*/
@Test
public void test1() {
String cfg = "applicationContext.xml";
ApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
ExampleBean bean =
ctx.getBean("example", ExampleBean.class);
System.out.println(bean);
}
/**
* 使用注解声明bean的作用域
*/
@Test
public void test2() {
String cfg = "applicationContext.xml";
ApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
ExampleBean bean1 =
ctx.getBean("example", ExampleBean.class);
ExampleBean bean2 =
ctx.getBean("example", ExampleBean.class);
System.out.println(bean1==bean2);
}
/**
* 使用注解声明bean的生命周期
*/
@Test
public void test3() {
String cfg = "applicationContext.xml";
AbstractApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
ExampleBean bean =
ctx.getBean("example", ExampleBean.class);
bean.execute();
ctx.close();
}
/**
* 使用@Autowired，以构造方式注入bean
*/
@Test
public void test4() {
String cfg = "applicationContext.xml";
ApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
Programmer prog =
ctx.getBean("programmer", Programmer.class);
System.out.println(prog);
System.out.println(prog.getComputer());
}
/**
* 在setter上使用@Autowired，以setter方式注入bean
*/
@Test
public void test5() {
String cfg = "applicationContext.xml";
ApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
Teacher teacher =
ctx.getBean("teacher", Teacher.class);
System.out.println(teacher);
System.out.println(teacher.getComputer());
}
/**
* 在属性上使用@Autowired，以setter方式注入bean
*/
@Test
public void test6() {
String cfg = "applicationContext.xml";
ApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
Student student =
ctx.getBean("student", Student.class);
System.out.println(student);
System.out.println(student.getComputer());
}
/**
* 在setter上使用@Resource，以setter方式注入bean
*/
@Test
public void test7() {
String cfg = "applicationContext.xml";
ApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
Manager manager =
ctx.getBean("manager", Manager.class);
System.out.println(manager);
System.out.println(manager.getComputer());
}
/**
* 在属性上使用@Resource，以setter方式注入bean
*/
@Test
public void test8() {
String cfg = "applicationContext.xml";
ApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
Salesman man =
ctx.getBean("salesman", Salesman.class);
System.out.println(man);
System.out.println(man.getComputer());
}
}
7 使用注解注入表达式
7.1 问题
使用注解，通过表达式给一个bean注入数据。
7.2 方案
在@Value注解上写表达式，可以给bean注入数据。
7.3 步骤
步骤一：创建资源文件
创建资源文件const.properties，代码如下：
#max rows in one page PAGE_SIZE=10
步骤二： 读取资源文件信息
在applicationContext.xml中，使用<util>标签声明一个bean，读取资源文件的信息，追加代码如下：
<!-- 声明Properties集合，读取const.properties参数 --> <util:properties id="const" location="classpath:const.properties"/>
步骤三：将读取到的信息注入bean
创建DemoBean类，并使用注解将读取的资源文件数据注入到这个bean中，代码如下：
package com.tarena.bean;
import java.io.Serializable;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
@Component
public class DemoBean implements Serializable {
private String name;
private String lang;
private String score;
@Value("#{const.PAGE_SIZE}")
private int pageSize;
public void execute() {
System.out.println("name:" + name);
System.out.println("lang:" + lang);
System.out.println("score:" + score);
System.out.println("pageSize:" + pageSize);
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getLang() {
return lang;
}
public void setLang(String lang) {
this.lang = lang;
}
public String getScore() {
return score;
}
public void setScore(String score) {
this.score = score;
}
public int getPageSize() {
return pageSize;
}
public void setPageSize(int pageSize) {
this.pageSize = pageSize;
}
}
步骤四：写测试代码
在TestCase类中增加测试方法test9，追加代码如下：
/**
* 使用注解注入表达式
*/
@Test
public void test9() {
String cfg = "applicationContext.xml";
ApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
DemoBean demo =
ctx.getBean("demoBean", DemoBean.class);
demo.execute();
}
步骤五：执行测试
执行test9，效果如下图：
图-15
7.4 完整代码
const.properties完整代码如下：
#max rows in one page PAGE_SIZE=10
applicationContext.xml完整代码如下：
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:jdbc="http://www.springframework.org/schema/jdbc" xmlns:jee="http://www.springframework.org/schema/jee" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:util="http://www.springframework.org/schema/util" xmlns:jpa="http://www.springframework.org/schema/data/jpa" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.2.xsd http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.2.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.2.xsd"> <!-- 开启注解扫描 --> <context:component-scan base-package="com.tarena"/> <!-- 声明Properties集合，读取const.properties参数 --> <util:properties id="const" location="classpath:const.properties"/> </beans>
DemoBean完整代码如下：
package com.tarena.bean;
import java.io.Serializable;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
@Component
public class DemoBean implements Serializable {
private String name;
private String lang;
private String score;
@Value("#{const.PAGE_SIZE}")
private int pageSize;
public void execute() {
System.out.println("name:" + name);
System.out.println("lang:" + lang);
System.out.println("score:" + score);
System.out.println("pageSize:" + pageSize);
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getLang() {
return lang;
}
public void setLang(String lang) {
this.lang = lang;
}
public String getScore() {
return score;
}
public void setScore(String score) {
this.score = score;
}
public int getPageSize() {
return pageSize;
}
public void setPageSize(int pageSize) {
this.pageSize = pageSize;
}
}
TestCase完整代码如下：
package com.tarena.test;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.AbstractApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.tarena.bean.DemoBean;
import com.tarena.bean.ExampleBean;
import com.tarena.bean.Manager;
import com.tarena.bean.Programmer;
import com.tarena.bean.Salesman;
import com.tarena.bean.Student;
import com.tarena.bean.Teacher;
public class TestCase {
/**
* 使用注解声明bean
*/
@Test
public void test1() {
String cfg = "applicationContext.xml";
ApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
ExampleBean bean =
ctx.getBean("example", ExampleBean.class);
System.out.println(bean);
}
/**
* 使用注解声明bean的作用域
*/
@Test
public void test2() {
String cfg = "applicationContext.xml";
ApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
ExampleBean bean1 =
ctx.getBean("example", ExampleBean.class);
ExampleBean bean2 =
ctx.getBean("example", ExampleBean.class);
System.out.println(bean1==bean2);
}
/**
* 使用注解声明bean的生命周期
*/
@Test
public void test3() {
String cfg = "applicationContext.xml";
AbstractApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
ExampleBean bean =
ctx.getBean("example", ExampleBean.class);
bean.execute();
ctx.close();
}
/**
* 使用@Autowired，以构造方式注入bean
*/
@Test
public void test4() {
String cfg = "applicationContext.xml";
ApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
Programmer prog =
ctx.getBean("programmer", Programmer.class);
System.out.println(prog);
System.out.println(prog.getComputer());
}
/**
* 在setter上使用@Autowired，以setter方式注入bean
*/
@Test
public void test5() {
String cfg = "applicationContext.xml";
ApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
Teacher teacher =
ctx.getBean("teacher", Teacher.class);
System.out.println(teacher);
System.out.println(teacher.getComputer());
}
/**
* 在属性上使用@Autowired，以setter方式注入bean
*/
@Test
public void test6() {
String cfg = "applicationContext.xml";
ApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
Student student =
ctx.getBean("student", Student.class);
System.out.println(student);
System.out.println(student.getComputer());
}
/**
* 在setter上使用@Resource，以setter方式注入bean
*/
@Test
public void test7() {
String cfg = "applicationContext.xml";
ApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
Manager manager =
ctx.getBean("manager", Manager.class);
System.out.println(manager);
System.out.println(manager.getComputer());
}
/**
* 在属性上使用@Resource，以setter方式注入bean
*/
@Test
public void test8() {
String cfg = "applicationContext.xml";
ApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
Salesman man =
ctx.getBean("salesman", Salesman.class);
System.out.println(man);
System.out.println(man.getComputer());
}
/**
* 使用注解注入表达式
*/
@Test
public void test9() {
String cfg = "applicationContext.xml";
ApplicationContext ctx =
new ClassPathXmlApplicationContext(cfg);
DemoBean demo =
ctx.getBean("demoBean", DemoBean.class);
demo.execute();
}
}