第五讲：5.2 Spring方法注入

一，spring默认是单例模式
1，spring 默认管理的bean是单例，修改beans.xml ，
xml version="1.0" encoding="UTF-8"?>
<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.xsd">

<bean id="dog" class="com.cruise.entity.Dog">
    <property name="name" value="Tom">property>
bean>

beans>
2，修改测试代码，运行-测试
package com.cruise.test;

import org.junit.Before;
import org.junit.Test;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class T {

    private ClassPathXmlApplicationContext CPXAC=null;
    @Before
    public void setUp() throws Exception {
       CPXAC= new ClassPathXmlApplicationContext("beans.xml");
    }

    @Test
    public void test1() {
    System.out.println(CPXAC.getBean("dog")==CPXAC.getBean("dog"));
    }
}
3. Dog类代码如下：
package com.cruise.entity;

public class Dog {

    private String name;

    public String getName() {
       return name;
    }

    public void setName(String name) {
       this.name = name;
    }
}

3，测试结果分析：返回为true，说明spring默认是单例模式。
二，spring修改为多例模式
1，修改beans.xml文件，
xml version="1.0" encoding="UTF-8"?>
<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.xsd">

<bean id="dog" class="com.cruise.entity.Dog" scope="prototype">
    <property name="name" value="Tom">property>
bean>

beans>
2，测试结果分析：为false，说明每次获取的不一样。
三，，
1，修改beans.xml,将dog注入到People的bean中
xml version="1.0" encoding="UTF-8"?>
<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.xsd">

<bean id="dog1" class="com.cruise.entity.Dog" scope="prototype">
    <property name="name" value="Tom">property>
bean>

<bean id="people1" class="com.cruise.entity.People">
    <property name="id" value="1">property>
    <property name="name" value="张三">property>
    <property name="age" value="11">property>
    <property name="dog" ref="dog1">property>
bean>

beans>
2,修改测试代码：
package com.cruise.test;

import org.junit.Before;
import org.junit.Test;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.cruise.entity.People;

public class T {

    private ClassPathXmlApplicationContext CPXAC=null;
    @Before
    public void setUp() throws Exception {
       CPXAC= new ClassPathXmlApplicationContext("beans.xml");
    }

    @Test
    public void test1() {
       
       People  people1 = (People) CPXAC.getBean("people1");
       People  people2 = (People) CPXAC.getBean("people1");
       
        System.out.println(people1.getDog()==people2.getDog());
    }
}
3，测试结果分析，为true， 说明是单例，说明Dog在输入的时候已经固定死了，
四，lookup 方法注入
1. 修改People类为抽象类，修改getDog()改成抽象方法，
package com.cruise.entity;

public abstract class People {

    private int id;
    private String name;
    private int age;
    private Dog dog;
    public int getId() {
       return id;
    }
    public void setId(int id) {
       this.id = id;
    }
    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 abstract Dog getDog();
    public void setDog(Dog dog) {
       this.dog = dog;
    }
    @Override
    public String toString() {
       return "People [id=" + id + ", name=" + name + ", age=" + age + ", dog=" + dog.getName() + "]";
    }
    public People(Dog dog) {
       super();
       this.dog = dog;
    }
    public People() {
       super();
    }
}
2. 修改beans.xml类-lookup-method标签，
<?xml version="1.0" encoding="UTF-8"?>
<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.xsd">

<bean id="dog1" class="com.cruise.entity.Dog" scope="prototype">
    <property name="name" value="Tom"></property>
</bean>

<bean id="people1" class="com.cruise.entity.People">
    <property name="id" value="1"></property>
    <property name="name" value="张三"></property>
    <property name="age" value="11"></property>
    <lookup-method name="getDog" bean="dog1"/>
</bean>

</beans>
3，T类中写测试方法，
package com.cruise.test;

import org.junit.Before;
import org.junit.Test;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.cruise.entity.Dog;
import com.cruise.entity.People;

public class T {

    private ClassPathXmlApplicationContext CPXAC=null;
    @Before
    public void setUp() throws Exception {
       CPXAC= new ClassPathXmlApplicationContext("beans.xml");
    }

    @Test
    public void test1() {
       
       People  people1 = (People) CPXAC.getBean("people1");
       People  people2 = (People) CPXAC.getBean("people1");
        System.out.println(people1.getDog()==people2.getDog());
       
       Dog  dog1 = (Dog) CPXAC.getBean("dog1");
       Dog  dog2 = (Dog) CPXAC.getBean("dog1");
       System.out.println(dog1==dog2);
    }
}
4，测试结果分析：两个输出结果都为false，说明通过修改，获取到的bean不是同一个。