Spring学习笔记之 Spring IOC容器(二)

本节主要内容： 1. 给MessageBean注入参数值 2. 测试Spring自动组件扫描方式 3. 如何控制ExampleBean实例化方式 4. 使用注解方式重构JdbcDataSource, UserDAO, UserService

Spring可以通过配置文件为bean注入多种类型的属性, MessageBean类用于演示Spring的多种类型数据的注入方式, 这些类型数据和注入方式包括：

1. 注入基本值。

2. 注入Bean对象(请参考Unit 1案例)。

3. 直接集合注入。

4. 引用方式集合注入

5. 注入Spring表达式值。

6. 注入null或空字符串。

步骤一：新建工程，导入Spring API jar包

新建名为SouvcSpringIoC_02的web工程，在该工程导入5个jar包。

步骤二：新建Spring配置文件

在src目录下，新建Spring配置文件applicationContext.xml。该文件名为Spring默认的配置文件名，也可以自由定义名称。

applicationContext.xml文件中的代码如下所示：

<?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: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"></beans>

步骤三：新建类MessageBean 添加基本值属性

新建类MessageBean，在该类中添加如下代码中的四个属性，并生成这几个属性对应的getter和setter方法；最后在execute方法获取这几个属性的信息，代码如下所示：

package com.souvc.bean;public class MessageBean {    private String moduleName;    private int pageSize;    private String username;    private String passWord = "";    public String getUsername() {        return username;    }    public void setUsername(String username) {        this.username = username;    }    public String getPassword() {        return password;    }    public void setPassword(String password) {        this.password = password;    }    public String getModuleName() {        return moduleName;    }    public void setModuleName(String moduleName) {        this.moduleName = moduleName;    }    public int getPageSize() {        return pageSize;    }    public void setPageSize(int pageSize) {        this.pageSize = pageSize;    }    public String execute() {        System.out.println("moduleName=" + moduleName);        System.out.println("pageSize=" + pageSize);        System.out.println("username=" + username);        System.out.println("password=" + password);        System.out.println("---List信息如下---");        return "success";    }}

步骤四：修改applicationContext.xml文件, 增加属性基本值注入

修改applicationContext.xml文件，为MessageBean的四个属性注入基本参数值，代码如图-3所示：

    <bean id="messagebean" class="com.souvc.bean.MessageBean">        <property name="moduleName" value="测试基本属性"></property>        <property name="pageSize" value="5"></property>        <property name="username" value="daliu_it"></property>        <property name="password" value="123456"></property>    </bean>

步骤五：新建类Test1, 添加测试方法获取MessageBean对象测试注入结果

新建类Test1，在类中使用ApplicationContext的方式实例化Spring容器，获取MessageBean对象，并调用execute方法。

@Test    public void test1() {        String conf = "applicationContext.xml";        ApplicationContext ac = new ClassPathXmlApplicationContext(conf);        System.out.println(ac);        MessageBean messagebean = ac.getBean("messagebean", MessageBean.class);        System.out.println(messagebean.toString());        messagebean.execute();    }

步骤六：运行Test1类, 测试注入结果

运行Test1类，控制台输入结果

org.springframework.context.support.ClassPathXmlApplicationContext@65b4fad5: startup date [Wed Jun 17 11:16:13 CST 2015]; root of context hierarchycom.souvc.bean.MessageBean@5d3e754fmoduleName=测试基本属性pageSize=5username=daliu_itpassword=123456---List信息如下---

控制台输出所示的信息，说明获取到了注入的基本属性值。

步骤七：为MessageBean添加集合属性,用于注入集合测试

1. 修改类MessageBean，在该类中添加如下加粗代码中的四个属性，并生成这几个属性对应的getter和setter方法；最后在execute方法获取这几个属性的信息，代码如下所示：

• private List<String> someList;
• private Set<String> someSet;
• private Map<String,Object> someMap;
• private Properties someProps;

package com.souvc.bean;import java.util.List;import java.util.Map;import java.util.Properties;import java.util.Set;public class MessageBean {    private String moduleName;    private int pageSize;    private String username;    private String password = "";         private List<String> someList;     private Set<String> someSet;     private Map<String,Object> someMap;     private Properties someProps;        public String getUsername() {        return username;    }    public void setUsername(String username) {        this.username = username;    }    public String getPassword() {        return password;    }    public void setPassword(String password) {        this.password = password;    }    public String getModuleName() {        return moduleName;    }    public void setModuleName(String moduleName) {        this.moduleName = moduleName;    }    public int getPageSize() {        return pageSize;    }    public void setPageSize(int pageSize) {        this.pageSize = pageSize;    }            public List<String> getSomeList() {        return someList;    }    public void setSomeList(List<String> someList) {        this.someList = someList;    }    public Set<String> getSomeSet() {        return someSet;    }    public void setSomeSet(Set<String> someSet) {        this.someSet = someSet;    }    public Map<String, Object> getSomeMap() {        return someMap;    }    public void setSomeMap(Map<String, Object> someMap) {        this.someMap = someMap;    }    public Properties getSomeProps() {        return someProps;    }    public void setSomeProps(Properties someProps) {        this.someProps = someProps;    }            public String execute() {        System.out.println("moduleName=" + moduleName);        System.out.println("pageSize=" + pageSize);        System.out.println("username=" + username);        System.out.println("password=" + password);        System.out.println("---List信息如下---");            for(String s : someList){            System.out.println(s);        }        System.out.println("---Set信息如下---");        for(String s : someSet){            System.out.println(s);        }        System.out.println("---Map信息如下---");        Set<String> keys = someMap.keySet();        for(String key : keys){            System.out.println(key+"="                    +someMap.get(key));        }        System.out.println("---Properties信息如下---");        Set<Object> keys1 = someProps.keySet();        for(Object key : keys1){            System.out.println(key+"="                    +someProps.getProperty(key.toString()));        }                        return "success";    }}

2. 修改applicationContext.xml文件，为MessageBean的四个属性注入集合参数值：

<?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:jpa="http://www.springframework.org/schema/data/jpa"    xmlns:util="http://www.springframework.org/schema/util"    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/util http://www.springframework.org/schema/util/spring-util-3.2.xsd">    <!-- 加载properties文件为bean        <util:properties id="jdbcProperties"        location="classpath:db.properties" /> -->    <bean id="messagebean" class="com.souvc.bean.MessageBean">        <property name="moduleName" value="测试基本属性的注入"></property>        <property name="pageSize" value="5"></property>        <!-- 表达式注入 -->        <property name="username" value="daliu_it"></property>        <property name="password" value="123456"></property>        <property name="someList">            <list>                <value>北京</value>                <value>上海</value>                <value>广州</value>            </list>        </property>        <property name="someSet">            <set>                <value>James Gosling</value>                <value>Martin fowler</value>                <value>Larry Ellision</value>            </set>        </property>        <property name="someMap">            <map>                <entry key="1001" value="Java语言基础"></entry>                <entry key="1002" value="Java Web基础"></entry>                <entry key="1003" value="Spring使用基础"></entry>            </map>        </property>        <property name="someProps">            <props>                <prop key="username">root</prop>                <prop key="password">1234</prop>            </props>        </property>    </bean>    <!-- 定义集合Bean         <util:list id="oneList">        <value>Tom</value>        <value>Andy</value>        </util:list>        <util:set id="oneSet">        <value>James Gosling</value>        <value>Martin fowler</value>        </util:set>        <util:map id="oneMap">        <entry key="1001" value="Java语言基础"></entry>        <entry key="1002" value="Java Web基础"></entry>        </util:map>        <util:properties id="oneProps">        <prop key="username">root</prop>        <prop key="password">1234</prop>        </util:properties>            -->    <!-- 引用方式注入集合属性         <bean id="messagebean2" class="com.souvc.bean.MessageBean">        <property name="moduleName" value="资费管理"></property>        <property name="pageSize" value="5"></property>        <property name="username" value="andy"></property>        <property name="password" value="123"></property>-->    <!-- 引用方式注入集合属性         <property name="someList" ref="oneList" />        <property name="someSet" ref="oneSet" />        <property name="someMap" ref="oneMap" />        <property name="someProps" ref="oneProps" />        </bean>--></beans>

3. 运行Test1类，控制台输出结果所示：

org.springframework.context.support.ClassPathXmlApplicationContext@42704baa: startup date [Wed Jun 17 11:30:43 CST 2015]; root of context hierarchycom.souvc.bean.MessageBean@25961581moduleName=测试基本属性的注入pageSize=5username=daliu_itpassword=123456---List信息如下---北京上海广州---Set信息如下---James GoslingMartin fowlerLarry Ellision---Map信息如下---1001=Java语言基础1002=Java Web基础1003=Spring使用基础---Properties信息如下---password=1234username=root

控制台输出的信息，说明只需要通过配置Spring就可以为Bean注入集合参数值。

步骤八：测试引用方式集合注入

1.为Spring配置文件applicationContext.xml增加如下配置, 采用引用方式注入集合对象, 代码参考如下:

<!-- 定义集合Bean -->    <util:list id="oneList">        <value>Tom</value>        <value>Andy</value>    </util:list>    <util:set id="oneSet">        <value>James Gosling</value>        <value>Martin fowler</value>    </util:set>    <util:map id="oneMap">        <entry key="1001" value="Java语言基础"></entry>        <entry key="1002" value="Java Web基础"></entry>    </util:map>    <util:properties id="oneProps">        <prop key="username">root</prop>        <prop key="password">1234</prop>    </util:properties>    <!-- 引用方式注入集合属性 -->    <bean id="messagebean2" class="com.souvc.bean.MessageBean">        <property name="moduleName" value="资费管理"></property>        <property name="pageSize" value="5"></property>        <property name="username" value="andy"></property>        <property name="password" value="123"></property>        <!-- 引用方式注入集合属性 -->        <property name="someList" ref="oneList" />        <property name="someSet" ref="oneSet" />        <property name="someMap" ref="oneMap" />        <property name="someProps" ref="oneProps" />    </bean>

2. 增加Test2类测试如上配置, Test2代码如下:

package com.souvc.test;import org.junit.Test;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;import com.souvc.bean.MessageBean;public class TestCase {    @Test    public void test1() {        String conf = "applicationContext.xml";        ApplicationContext ac = new ClassPathXmlApplicationContext(conf);        System.out.println(ac);        MessageBean messagebean = ac.getBean("messagebean", MessageBean.class);        System.out.println(messagebean.toString());        messagebean.execute();    }    @Test    public void test2() {        String conf = "applicationContext.xml";        ApplicationContext ac = new ClassPathXmlApplicationContext(conf);        MessageBean bean = ac.getBean("messagebean2", MessageBean.class);        bean.execute();    }}

3. 执行Test2 有如下结果所示:

moduleName=资费管理pageSize=5username=andypassword=123---List信息如下---TomAndy---Set信息如下---James GoslingMartin fowler---Map信息如下---1001=Java语言基础1002=Java Web基础---Properties信息如下---password=1234username=root

这个结果说明, 通过引用方式也可以为bean注入集合属性.

步骤九：利用 Spring表达式注入属性值

1.在工程的src下，新建属性文件db.properties，文件内容如下:

user=scott

2. 修改applicationContext.xml文件，注入Spring表达式值，代码所示：

<!-- 加载properties文件为bean --> <util:properties id="jdbcProperties" location="classpath:db.properties" />   <bean id="messagebean" class="org.tarena.bean.MessageBean">   <!-- ================================================================ -->   <property name="moduleName" value="资费管理"></property>  <property name="pageSize" value="5"></property>  <!-- 表达式注入 -->  <property name="username" value="#{jdbcProperties.user}"></property>   <property name="password">   <null />  </property>

3. 运行Test1类，控制台输出结果所示：

org.springframework.context.support.ClassPathXmlApplicationContext@68861f24: startup date [Wed Jun 17 11:41:35 CST 2015]; root of context hierarchycom.souvc.bean.MessageBean@209444d1moduleName=测试基本属性的注入pageSize=5username=daliu_itpassword=123456---List信息如下---北京上海广州---Set信息如下---James GoslingMartin fowlerLarry Ellision---Map信息如下---1001=Java语言基础1002=Java Web基础1003=Spring使用基础---Properties信息如下---password=1234username=root

控制台输出信息，说明获取到了注入的Spring表达式值。

步骤十：注入null值

1. 修改applicationContext.xml文件，将属性password注入null值，代码如图-11所示：

<?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:jpa="http://www.springframework.org/schema/data/jpa"    xmlns:util="http://www.springframework.org/schema/util"    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/util http://www.springframework.org/schema/util/spring-util-3.2.xsd">    <!-- 加载properties文件为bean-->    <util:properties id="jdbcProperties"        location="classpath:db.properties" />    <bean id="messagebean" class="com.souvc.bean.MessageBean">        <property name="moduleName" value="测试基本属性的注入"></property>        <property name="pageSize" value="5"></property>        <!-- 表达式注入             <property name="username" value="daliu_it"></property>-->        <property name="username" value="#{jdbcProperties.user}"></property>        <property name="password" >        <null/>        </property>        <property name="someList">            <list>                <value>北京</value>                <value>上海</value>                <value>广州</value>            </list>        </property>        <property name="someSet">            <set>                <value>James Gosling</value>                <value>Martin fowler</value>                <value>Larry Ellision</value>            </set>        </property>        <property name="someMap">            <map>                <entry key="1001" value="Java语言基础"></entry>                <entry key="1002" value="Java Web基础"></entry>                <entry key="1003" value="Spring使用基础"></entry>            </map>        </property>        <property name="someProps">            <props>                <prop key="username">root</prop>                <prop key="password">1234</prop>            </props>        </property>    </bean>    <!-- 定义集合Bean -->    <util:list id="oneList">        <value>Tom</value>        <value>Andy</value>    </util:list>    <util:set id="oneSet">        <value>James Gosling</value>        <value>Martin fowler</value>    </util:set>    <util:map id="oneMap">        <entry key="1001" value="Java语言基础"></entry>        <entry key="1002" value="Java Web基础"></entry>    </util:map>    <util:properties id="oneProps">        <prop key="username">root</prop>        <prop key="password">1234</prop>    </util:properties>    <!-- 引用方式注入集合属性 -->    <bean id="messagebean2" class="com.souvc.bean.MessageBean">        <property name="moduleName" value="资费管理"></property>        <property name="pageSize" value="5"></property>        <property name="username" value="andy"></property>        <property name="password" value="123"></property>        <!-- 引用方式注入集合属性 -->        <property name="someList" ref="oneList" />        <property name="someSet" ref="oneSet" />        <property name="someMap" ref="oneMap" />        <property name="someProps" ref="oneProps" />    </bean></beans>

2. 运行Test1类，控制台输出结果：

org.springframework.context.support.ClassPathXmlApplicationContext@2996c1b0: startup date [Wed Jun 17 11:42:47 CST 2015]; root of context hierarchycom.souvc.bean.MessageBean@195ed659moduleName=测试基本属性的注入pageSize=5username=daliu_itpassword=null---List信息如下---北京上海广州---Set信息如下---James GoslingMartin fowlerLarry Ellision---Map信息如下---1001=Java语言基础1002=Java Web基础1003=Spring使用基础---Properties信息如下---password=1234username=root

控制台输出所示的信息，说明获取到了注入的null值。

MessageBean类的完整代码如下所示：

package com.souvc.bean;import java.util.List;import java.util.Map;import java.util.Properties;import java.util.Set;public class MessageBean {    private String moduleName;    private int pageSize;    private String username;    private String password = "";    private List<String> someList;    private Set<String> someSet;    private Map<String, Object> someMap;    private Properties someProps;    public String getUsername() {        return username;    }    public void setUsername(String username) {        this.username = username;    }    public String getPassword() {        return password;    }    public void setPassword(String password) {        this.password = password;    }    public String getModuleName() {        return moduleName;    }    public void setModuleName(String moduleName) {        this.moduleName = moduleName;    }    public int getPageSize() {        return pageSize;    }    public void setPageSize(int pageSize) {        this.pageSize = pageSize;    }    public List<String> getSomeList() {        return someList;    }    public void setSomeList(List<String> someList) {        this.someList = someList;    }    public Set<String> getSomeSet() {        return someSet;    }    public void setSomeSet(Set<String> someSet) {        this.someSet = someSet;    }    public Map<String, Object> getSomeMap() {        return someMap;    }    public void setSomeMap(Map<String, Object> someMap) {        this.someMap = someMap;    }    public Properties getSomeProps() {        return someProps;    }    public void setSomeProps(Properties someProps) {        this.someProps = someProps;    }    public String execute() {        System.out.println("moduleName=" + moduleName);        System.out.println("pageSize=" + pageSize);        System.out.println("username=" + username);        System.out.println("password=" + password);        System.out.println("---List信息如下---");        for (String s : someList) {            System.out.println(s);        }        System.out.println("---Set信息如下---");        for (String s : someSet) {            System.out.println(s);        }        System.out.println("---Map信息如下---");        Set<String> keys = someMap.keySet();        for (String key : keys) {            System.out.println(key + "=" + someMap.get(key));        }        System.out.println("---Properties信息如下---");        Set<Object> keys1 = someProps.keySet();        for (Object key : keys1) {            System.out.println(key + "="                    + someProps.getProperty(key.toString()));        }        return "success";    }}

Test1，Test2的完整代码如下：

package com.souvc.test;import org.junit.Test;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;import com.souvc.bean.MessageBean;public class TestCase {    @Test    public void test1() {        String conf = "applicationContext.xml";        ApplicationContext ac = new ClassPathXmlApplicationContext(conf);        System.out.println(ac);        MessageBean messagebean = ac.getBean("messagebean", MessageBean.class);        System.out.println(messagebean.toString());        messagebean.execute();    }    @Test    public void test2() {        String conf = "applicationContext.xml";        ApplicationContext ac = new ClassPathXmlApplicationContext(conf);        MessageBean bean = ac.getBean("messagebean2", MessageBean.class);        bean.execute();    }}

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:jpa="http://www.springframework.org/schema/data/jpa"    xmlns:util="http://www.springframework.org/schema/util"    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/util http://www.springframework.org/schema/util/spring-util-3.2.xsd">    <!-- 加载properties文件为bean-->    <util:properties id="jdbcProperties"        location="classpath:db.properties" />    <bean id="messagebean" class="com.souvc.bean.MessageBean">        <property name="moduleName" value="测试基本属性的注入"></property>        <property name="pageSize" value="5"></property>        <!-- 表达式注入             <property name="username" value="daliu_it"></property>-->        <property name="username" value="#{jdbcProperties.user}"></property>        <property name="password" >        <null/>        </property>        <property name="someList">            <list>                <value>北京</value>                <value>上海</value>                <value>广州</value>            </list>        </property>        <property name="someSet">            <set>                <value>James Gosling</value>                <value>Martin fowler</value>                <value>Larry Ellision</value>            </set>        </property>        <property name="someMap">            <map>                <entry key="1001" value="Java语言基础"></entry>                <entry key="1002" value="Java Web基础"></entry>                <entry key="1003" value="Spring使用基础"></entry>            </map>        </property>        <property name="someProps">            <props>                <prop key="username">root</prop>                <prop key="password">1234</prop>            </props>        </property>    </bean>    <!-- 定义集合Bean -->    <util:list id="oneList">        <value>Tom</value>        <value>Andy</value>    </util:list>    <util:set id="oneSet">        <value>James Gosling</value>        <value>Martin fowler</value>    </util:set>    <util:map id="oneMap">        <entry key="1001" value="Java语言基础"></entry>        <entry key="1002" value="Java Web基础"></entry>    </util:map>    <util:properties id="oneProps">        <prop key="username">root</prop>        <prop key="password">1234</prop>    </util:properties>    <!-- 引用方式注入集合属性 -->    <bean id="messagebean2" class="com.souvc.bean.MessageBean">        <property name="moduleName" value="资费管理"></property>        <property name="pageSize" value="5"></property>        <property name="username" value="andy"></property>        <property name="password" value="123"></property>        <!-- 引用方式注入集合属性 -->        <property name="someList" ref="oneList" />        <property name="someSet" ref="oneSet" />        <property name="someMap" ref="oneMap" />        <property name="someProps" ref="oneProps" />    </bean></beans>

源码如下：http://yunpan.cn/cQVU3sLcMzXGC 访问密码 daf3

如何使用组件扫描的方式和"注解标记"配合获取容器中的ExampleBean对象。

使用组件扫描，首先需要在XML配置中指定扫描类路径，配置代码如下：

    <context:component-scan                   base-package="com.souvc"/> 

上述配置，容器实例化时会自动扫描com.souvc 包及其子包下所有组件类。

指定扫描类路径后，并不是该路径下所有组件类都扫描到Spring容器的，只有在组件类定义前面有以下注解标记时，才会扫描到Spring容器。

@Component  泛指组件，当组件不好归类的时候，我们可以使用这个注解进行标注。@Name 通用注解@Service  业务层组件注解， 用于标注业务层组件@Repository  持久层组件注解，用于标注数据访问组件，即DAO组件@Controller  控制层组件注解，用于标注控制层组件（如struts中的action）

步骤一：新建类ExampleBean

新建类ExampleBean，在该类前使用通用组件注解“@Component”，表明ExampleBean为可被扫描的组件，代码如下所示：

package com.souvc.bean;import org.springframework.stereotype.Component;@Componentpublic class ExampleBean {    public ExampleBean() {        System.out.println("实例化ExampleBean");    }    public void execute() {        System.out.println("执行ExampleBean处理");    }}

步骤二： 修改applicationContext.xml

修改applicationContext.xml，使容器实例化时自动扫描org.tarena包及其子包下所有组件类

<!-- 组件扫描 -->    <context:component-scan base-package="com.souvc" />

步骤三： 新建方法Test3

@Test    public void test3() {        String conf = "applicationContext.xml";        ApplicationContext ac = new ClassPathXmlApplicationContext(conf);        ExampleBean bean = ac.getBean("exampleBean", ExampleBean.class);        bean.execute();    }

运行Test3方法，控制台输出结果：

控制台输出上述结果，说明Spring会自动使用组件扫描的方式创建ExampleBean实例, 并且Test3中获取到了这个ExampleBean对象。

ExampleBean类的完整代码如下所示：

package com.souvc.bean;import org.springframework.stereotype.Component;@Componentpublic class ExampleBean {    public ExampleBean() {        System.out.println("实例化ExampleBean");    }    public void execute() {        System.out.println("执行ExampleBean处理");    }}

TestCase 类的完整代码如下所示：

package com.souvc.test;import org.junit.Test;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;import com.souvc.bean.ExampleBean;import com.souvc.bean.MessageBean;public class TestCase {    @Test    public void test1() {        String conf = "applicationContext.xml";        ApplicationContext ac = new ClassPathXmlApplicationContext(conf);        System.out.println(ac);        MessageBean messagebean = ac.getBean("messagebean", MessageBean.class);        System.out.println(messagebean.toString());        messagebean.execute();    }    @Test    public void test2() {        String c