Bean作用域的配置以及 Spring各种注入方式实例 list set map props

1.Bean有两种作用域属性，singleton 和 prototype ，默认为前者。对于singleton，当请求的 Bean 相同时，则不再重新生成新的实例化对象，通常应用程序中的组多组件都只需要一个实例就足够了。而 prototype ，用于每次返回 Bean 的一个新的实例，例如需要获取系统实时时间。

<bean id="mydate" class="com.lihui.MyDate" scope="prototype"></bean>

2.各种注入方式

所有的注入方式在Spring.xml 文件中配置如下：

<?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:p="http://www.springframework.org/schema/p"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">

    <!-- 注入基本类型 -->
    <bean id="person" class="com.lihui.Person">
        <property name="name" value="张三"></property>
        <property name="password" value="hello"></property>
        <property name="chock" value="true"></property>
    </bean>
    
    <!-- 注入list类型和数组类型-->
    <bean id="beansDemoClass" class="com.lihui.BeansDemoClass">
        <property name="fruit">
            <list>
                <value>荔枝</value>
                <value>桔子</value>
                <value>樱桃</value>
            </list>
        </property>
        <property name="num">
            <list>
                <value>20</value>
                <value>45</value>
                <value>12</value>
            </list>
        </property>
    </bean>
     
    <!-- 注入引用类型 -->
    <bean id="mydate" class="com.lihui.MyDate" scope="prototype">
        <property name="date" ref="refdate"></property>
    </bean>
    <bean id="refdate" class="java.util.Date" scope="prototype"></bean>
    
    <!-- 注入 set map props 类型 -->
    <bean id="gatherDemp" class="com.lihui.SetMapProps">
        <property name="scoreMap">
            <map>
                <!-- map 必须是 key-value 对应的 -->
                <entry key="Maths">
                    <value>98</value>
                </entry>
                <entry key="English">
                    <value>95</value>
                </entry>
            </map>
        </property>
        <property name="properties">
            <!-- 定义 properties 属性 -->
            <props>
                <!-- props 必须是 key-value 对应的 -->
                <prop key="path">C:/MyDocument/MyMusic</prop>
                <prop key="filename">lihui.txt</prop>
            </props>
        </property>
        <property name="settest">
            <set>
                <!-- set元素，使用value、bean、ref 等指定系列值 -->
                <value>set值</value>
            </set>
        </property>
    </bean>
</beans>

（1）基本注入方式

person.java

public class Person {
    public String name;
    public String password;
    public boolean islogin;
    
    public void setName(String name){
        this.name = name;
    }
    public void setPassword(String password){
        this.password = password;
    }
    public void setChock(boolean islogin){
        this.islogin = islogin;
    }
}

调用方法：

public static void main(String[] args) {
        XmlBeanFactory bFactory = new XmlBeanFactory(new ClassPathResource(
                "Spring.xml"));
        Person person = (Person) bFactory.getBean("person");
        System.out.println("姓名：" + person.name + "  密码：" + person.password
                + "  状态：" + person.islogin);        
    }

（2）注入引用类型

MyDate.java

public class MyDate {
    private Date date;
    public void setDate(Date date){
        this.date = date;
    }
    public void getDate(){
        System.out.println(date);
    }
}

应用举例：

public static void main(String[] args) {
        XmlBeanFactory bFactory = new XmlBeanFactory(new ClassPathResource("Spring.xml"));
        MyDate myDate = (MyDate)bFactory.getBean("mydate");
        myDate.getDate();
        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        ((MyDate)bFactory.getBean("mydate")).getDate();                
    }

（3）注入list类型和数组类型

BeansDemoClass.java

public class BeansDemoClass {
    public List<String> fruit;
    public int[] num;
    public void setFruit(List<String> fruit){
        this.fruit = fruit;
        for(String f : fruit){
            System.out.println(f);
        }
    }
    public void setNum(int[] num){
        this.num = num;
        for(int n : num){
            System.out.println(n);
        }
    }
}

应用举例：

public static void main(String[] args) {
        XmlBeanFactory bFactory = new XmlBeanFactory(new ClassPathResource("Spring.xml"));
        BeansDemoClass bDemoClass = (BeansDemoClass)bFactory.getBean("beansDemoClass");
        System.out.println(bDemoClass.fruit + "   " + bDemoClass.num);            
    }

（4）注入set、map 及 props 类型
SetMapProps.java

public class SetMapProps {
    public Map scoreMap = new HashMap<String, String>();
    public Properties properties = new Properties();
    public Set settest = new HashSet<String>();
    public void setScoreMap(Map scoreMap){
        this.scoreMap = scoreMap;
        System.out.println(this.scoreMap.get("English"));
    }
    public void setProperties(Properties properties){
        this.properties = properties;
        System.out.println(this.properties.get("path"));
        System.out.println(this.properties.get("filename"));
    }
    public void setSettest(Set settest){
        this.settest = settest;
        System.out.println(settest.toString());
    }
}

应用：

public static void main(String[] args) {
        XmlBeanFactory bFactory = new XmlBeanFactory(new ClassPathResource("Spring.xml"));
        SetMapProps beans = (SetMapProps) bFactory.getBean("gatherDemp");
                
    }