spring之注解

步骤1：修改applicationContext.xml

1 添加<context:annotation-config/>

表示告诉spring要用注解的方式进行配置

2 注入对象的21行注释掉，这个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:aop="http://www.springframework.org/schema/aop"    xmlns:tx="http://www.springframework.org/schema/tx" xmlns:context="http://www.springframework.org/schema/context"    xsi:schemaLocation="   http://www.springframework.org/schema/beans    http://www.springframework.org/schema/beans/spring-beans-3.0.xsd   http://www.springframework.org/schema/aop    http://www.springframework.org/schema/aop/spring-aop-3.0.xsd   http://www.springframework.org/schema/tx    http://www.springframework.org/schema/tx/spring-tx-3.0.xsd   http://www.springframework.org/schema/context         http://www.springframework.org/schema/context/spring-context-3.0.xsd">      <context:annotation-config/>    <bean name="c" class="com.how2java.pojo.Category">        <property name="name" value="category 1" />    </bean>    <bean name="p" class="com.how2java.pojo.Product">        <property name="name" value="product1" /><!--         <property name="category" ref="c" /> -->    </bean>  </beans>

步骤2：@Autowired

在Product.java的category属性前加上@Autowired注解

package com.how2java.pojo; import org.springframework.beans.factory.annotation.Autowired; public class Product {     private int id;    private String name;    @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;    }}

步骤3：运行测试

package com.how2java.test;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;import com.how2java.pojo.Product;public class TestSpring {public static void main(String[] args) {ApplicationContext context = new ClassPathXmlApplicationContext(new String[] { "applicationContext.xml" });Product p = (Product) context.getBean("p");System.out.println(p.getName());System.out.println(p.getCategory().getName());}}

步骤4：@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

package com.how2java.pojo; import org.springframework.beans.factory.annotation.Autowired; public class Product {     private int id;    private String name;         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;    }    @Autowired    public void setCategory(Category category) {        this.category = category;    }}