1.修改spring-config.xml文件
添加<context:annotation-config/>，表示告诉spring要用注解的方式进行配置
<context:annotation-config/>
- 注释掉<property name="category" ref="category" />，该行为在后面将使用注解来完成
<?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"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
<context:annotation-config/>
<bean id="category" class="com.jd.java.Category">
<property name="name" value="Spring"></property>
</bean>
<!--在创建Product的时候注入一个Category对象, 注意，这里要使用ref来注入另一个对象-->
<bean name="p" class="com.jd.java.Product">
<property name="name" value="product" />
<!--<property name="category" ref="category" />-->
</bean>
</beans>
3.@Autowired
在Product.java的category属性前加上@Autowired注解
4.测试运行
package com.jd.test;
import com.jd.java.Product;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class testSpring {
public static void main(String[] args){
ApplicationContext context = new ClassPathXmlApplicationContext("spring-config.xml");
Product p1 = (Product) context.getBean("p");
System.out.println(p1.getName());
System.out.println(p1.getCategory().getName());
}
}
- @Autowired的位置
除了前面的 在属性前加上@Autowired 这种方式外，也可以在setCategory方法前加上@Autowired，这样来达到相同的效果
- @Resource
除了@Autowired之外，@Resource也是常用的手段
@Resource(name = "category")
private Category category;
7.对Bean的注解
上述例子是对注入对象行为的注解，那么bean对象本身，比如Category,Product可不可以移出spring-config.xml配置文件，也通过注解进行呢？接下来是如何对Bean进行注解配置
8.修改spring-config.xml文件
新增<context:component-scan base-package="com.jd.java"/>，其作用是告诉Spring，bean都放在com.jd.java这个包下
<?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"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
<context:component-scan base-package="com.jd.java"/>
</beans>
9.@Component
为Product类加上@Component注解，即表明此类是bean
@Component("p")
public class Product {
为Category 类加上@Component注解，即表明此类是bean
@Component("category")
public class Category {
因为配置从spring-config.xml中移出来了，所以属性初始化放在属性声明上进行了。
private String name="product";
private String name="spring";
Product.java
package com.jd.java;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import javax.annotation.Resource;
@Component("p")
public class Product {
private int id;
private String name = "product";
@Autowired
private Category category;
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 Category getCategory() {
return category;
}
public void setCategory(Category category) {
this.category = category;
}
}
Category.java
package com.jd.java;
import org.springframework.stereotype.Component;
@Component("category")
public class Category {
private int id;
private String name = "spring";
public void setName(String name){
this.name = name;
}
public String getName(){
return name;
}
public void setId(int id){
this.id = id;
}
public int getId(){
return id;
}
}
10.测试运行
