Spring-注解方式獲取對象

一、修改ApplicationContext.xml配置文件

將<bean>內容注釋掉，增加一句如下代碼：

<context:component-scan base-package="com.yanyan.pojo"/>

 此時ApplicationContext.xml配置文件內容如下：

<?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: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:component-scan base-package="com.how2java.pojo"/>
  
      <!-- <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>

 

二、將pojo類加上注解，及屬性初始化

1.為類加上@Component(" ")注解

2.為部分屬性增加@Autowired注解

3.屬性初始化放到屬性聲明上進行了。

package com.yanyan.pojo;

import org.springframework.stereotype.Component;

@Component("c")
public class Category {

    private int id;
    private String name="category1";
    
    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;
    }
}

 

package com.yanyan.pojo;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

@Component("p")
public class Product {

    private int id;
    private String name="product1";
    @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;
    }
}

 

 

三、使用測試程序測試結果

package com.yanyan.test;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.how2java.pojo.Category;
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());
    }
}

運行結果為：

product1

category1