---恢復內容開始---

 

用@AutoWired和@Resource自動裝配Bean

1.@AutoWired和@Resource介紹

　　Spring的主配置文件如下

　　

<?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: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-4.1.xsd">


　　
    <context:component-scan base-package="liusheng.springboot.Spring"/>
　　
　　<!-- 學生-->
    <bean name="student" class="ls.entity.Student">
        <property name="student_ID" value="1"></property>
        <property name="name" value="張三"></property>
        <property name="age" value="19"></property>
    </bean>

　<!-- 用戶-->

    <bean name="user" class="ls.entity.User">
        <property name="age" value="10"></property>
        <property name="name" value="李四"></property>
    </bean>
</beans>

 

    @AutoWired

　　@AutoWired只有一個屬性：required boolean 類型 該值默認是true ，

　　 它會從你的配置文件中尋找類型一致或者類型存在繼承，實現的關系的bean  

　　如果required=true，找不到就報異常 ，required=false 找不到就不注入了

　　@AutoWired 的定義

從定義上看這個注解可以作用在構造函數上，字段上，方法上，注解上（注解上我不知道怎么用）

實體類Student

package ls.entity;
/**
 * 學生類
 * @author liusheng
 */
public class Student {
    /**
     * 學號
     */
    private String Student_ID;
    /**
     * 名字
     */
    private String name;
    /**
     * 年齡
     */
    private  int age;
    public String getStudent_ID() {
        return Student_ID;
    }
    public void setStudent_ID(String student_ID) {
        Student_ID = student_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 String toString() {
        return "Student [Student_ID=" + Student_ID + ", name=" + name + ", age=" + age + "]";
    }
}

　實體類 User

package ls.entity;
/**
 * User class
 * @author liusheng
 */
public class User {
    /**
     * name
     */
        private String name;
        /**
         * age
         */
        private Integer age;
        public String getName() {
            return name;
        }
        public void setName(String name) {
            this.name = name;
        }
        public Integer getAge() {
            return age;
        }
        public void setAge(Integer age) {
            this.age = age;
        }
        public String toString() {
            return "User [name=" + name + ", age=" + age + "]";
        }
}

字段上

package liusheng.springboot.Spring;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import ls.entity.Student;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class AotuWiredTest  {
        @Autowired
        Student student;
        @Test
        public void test1() throws Exception {
            System.out.println(student);
        }
}

因為在字段上，所以不需要set方法，通過反射對屬性直接賦值

通過方法賦值（注意：這個方法不一定是setStudent(Student student) ,還可以是setaa(Student student);）

package liusheng.springboot.Spring;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import ls.entity.Student;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class AotuWiredTest  {
        Student student;
        @Test
        
        public void test1() throws Exception {
            System.out.println(student);
        }
        @Autowired
        public void setStudent(Student student) {
            this.student = student;
        }
}

通過構造方法賦值（注意：要保留無參構造函數）

package liusheng.springboot.Spring;

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

import ls.entity.Student;

@Component
public class ConstuctorWired {
        private Student student;

        public Student getStudent() {
            return student;
        }
        
        public ConstuctorWired() {
        }
        @Autowired
        public ConstuctorWired(Student student) {
            this.student = student;
        }

        public String toString() {
            return "constuctorWired [student=" + student + "]";
        }

        public void setStudent(Student student) {
            this.student = student;
        }
        
}

package liusheng.springboot.Spring;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import ls.entity.Student;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class AotuWiredTest  {
        @Autowired
        ConstuctorWired c;
        
        @Test
        public void test1() throws Exception {
            System.out.println(c);
        }
        
        public AotuWiredTest() {
        }
        
}

@Resource

該注解可以用在方法上和字段上

如果不寫name屬性那么按照類型注入，如果指定的name 屬性那么就按name注入

 

package liusheng.springboot.Spring;

import javax.annotation.Resource;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import ls.entity.User;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class ResourceAutoWired {
        @Resource()
        private User user;
        
        private User user1;
        @Resource(name="user")
        private User user2;
        @Resource(name="user")
        public void setUser1(User user1) {
            this.user1 = user1;
        }

        @Test
        public void test() throws Exception {
            System.out.println("有name屬性在方法上"+user1);
            System.out.println("有name屬性在字段上"+user2);
            System.out.println("沒有name屬性"+user);
        }
}

console輸出：

總結：這兩個注解很常用，要多理解理解。我是初學者，今天是總結的，博客可能很爛，有錯誤的地方請大牛指點迷津。。。