11、spring的bean基础（3）

11、spring的bean基础（3）

在本文中，主要介绍的知识点有以下三个

1. ListFactoryBean
2. SetFactoryBean
3. MapFactoryBean

现项目中存在一个实体类，将用于以下三个例子的演示
HelloWorld.java

public class HelloWorld{
    private List list;
    private Set set;
    private Map map;

    //.....
}

---

ListFactoryBean示例
在spring bean配置文件中

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">

    <bean id="HelloWorld" class="com.main.HelloWorld">
        <property name="list">
            <bean class="org.springframework.beans.factory.config.ListFactoryBean">
                <property name="targetListClass">
                    <value>java.util.ArrayList</value>
                </property>
                <property name="sourceList">
                    <list>
                        <value>hello</value>
                        <value>1</value>
                        <value>three</value>
                    </list>
                </property>
            </bean>
        </property>
    </bean>

</beans>

还可以使用下方式:

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xmlns:util="http://www.springframework.org/schema/util"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
    http://www.springframework.org/schema/util
    http://www.springframework.org/schema/util/spring-util-2.5.xsd">

    <bean id="CustomerBean" class="com.yiibai.common.Customer">
        <property name="list">
            <util:list list-class="java.util.ArrayList">
                <value>Hello</value>
                <value>1</value>
                <value>three</value>
            </util:list>
        </property>
    </bean>

</beans>

如果你不把util：list模式包含进配置文件中：或许会出现以下错误：

Caused by: org.xml.sax.SAXParseException: 
    The prefix "util" for element "util:list" is not bound.

---

SetFactoryBean实例

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">

    <bean id="HelloWorld" class="com.main.HelloWorld">
        <property name="set">
            <bean class="org.springframework.beans.factory.config.SetFactoryBean">
                <property name="targetSetClass">
                    <value>java.util.HashSet</value>
                </property>
                <property name="sourceSet">
                    <list>
                        <value>one</value>
                        <value>2</value>
                        <value>three</value>
                    </list>
                </property>
            </bean>
        </property>
    </bean>
</beans>

也可以使用以下模式：

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">

    <bean id="HelloWorld" class="com.main.HelloWorld">
        <property name="set">
            <util:set set-class="java.util.HashSet">
                <value>one</value>
                <value>2</value>
                <value>three</value>
            </util:set>
        </property>
    </bean>
</beans>

---

MapFactoryBean实例

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">

    <bean id="HelloWorld" class="com.main.HelloWorld">
        <property name="map">
            <bean class="org.springframework.beans.factory.config.MapFactoryBean">
                <property name="targetMapClass">
                    <value>java.util.HashMap</value>
                </property>
                <property name="sourceMap">
                    <map>
                        <entry key="Key1" value="one" />
                        <entry key="Key2" value="two" />
                        <entry key="Key3" value="three" />
                    </map>
                </property>
            </bean>
        </property>
    </bean>
</beans>

也可以使用以下方式：

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">

    <bean id="HelloWorld" class="com.main.HelloWorld">
        <property name="map">
            <util:map map-class="java.util.HashMap">
                <entry key="Key1" value="1" />
                <entry key="Key2" value="2" />
                <entry key="Key3" value="3" />
            </util:map>
        </property>
    </bean>
</beans>