Bean方式

通过默认构造方法实例化Bean

• 类

public class Bean {
    public Bean()
    {
        System.out.println("Bean+++++++++++++++");
    }
}

• XML

<bean id="bean" class="cn.asdasd.java.ioc.Bean"></bean>

• 测试代码

import cn.asdasd.java.ioc.Bean;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class IocTest {
    @Test
    public void test(){
        ApplicationContext context = new ClassPathXmlApplicationContext("spring.xml");
        Bean bean = context.getBean("bean", Bean.class);
        System.out.println("bean === " +bean);
    }
}

通过静态工厂方法实例化Bean

• 类

public class Bean {
    public Bean()
    {
        System.out.println("Bean+++++++++++++++");
    }
}
public class Bean2 {
    public static Bean getBean2(){
        return new Bean();
    }
}

• XML

<bean id="bean2" class="cn.asdasd.java.ioc.Bean2" factory-method="getBean2" ></bean>

• 测试代码

import cn.asdasd.java.ioc.Bean;
import cn.asdasd.java.ioc.Bean2;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class IocTest {
    @Test
    public void test(){
        ApplicationContext context = new ClassPathXmlApplicationContext("spring.xml");
        Bean dd2 = Bean2.getBean2();
        System.out.println("bean =++++++++++++++++++++++++++ " + dd2);
    }
}

通过实例工厂方法实例化Bean

• 类

public class Bean {
    public Bean()
    {
        System.out.println("Bean+++++++++++++++");
    }
}
public class Bean3 {
    public Bean1 getBean3(){
        return new Bean1();
    }
}

• XML

    <bean id="bean1" class="cn.asdasd.java.ioc.Bean3"></bean>
    <bean id="bean3" class="cn.asdasd.java.ioc.Bean" factory-bean="bean1"
          factory-method="getBean3"></bean>

• 测试代码

import cn.asdasd.java.ioc.Bean;
import cn.asdasd.java.ioc.Bean2;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class IocTest {
    @Test
    public void test(){
        ApplicationContext context = new ClassPathXmlApplicationContext("spring.xml");
        Bean3 b3 = new Bean3();
        Bean bean =  b3.getBean3();
    }
}

Bean的别名

• XML

<bean id="bean" class="cn.asdasd.java.ioc.Bean" name="ddd"></bean>

• 测试代码

import cn.asdasd.java.ioc.Bean;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class IocTest {
    @Test
    public void test(){
        ApplicationContext context = new ClassPathXmlApplicationContext("spring.xml");
        Bean bean = context.getBean("ddd", Bean.class);
        System.out.println("bean === " +bean);
    }
}