spring-依赖注入

1、构造器注入

 前面有提及过！！！

 

 

2、set方式注入

依赖注入：set注入

依赖：bean对象的创建依赖于容器

注入：bean对象的属性由容器注入

 

环境搭建：

配置文件beans:xml：

<?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:lang="http://www.springframework.org/schema/lang"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
      https://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/lang http://www.springframework.org/schema/lang/spring-lang.xsd">

    <bean id="address" class="com.haoqi.pojo.Address"/>
<bean id="student" class="com.haoqi.pojo.Student">
<!--    普通值注入 value-->
    <property name="name" value="搜索搜索"></property>
    <!--    地址注入 ref-->
    <property name="address" ref="address">
    </property>
<!--    数组-->
    <property name="books">
        <array>
            <value>你</value>
            <value>听说</value>
            <value>爱看书</value>
        </array>
    </property>

<!--    列表-->
    <property name="hobbys">
        <list>
            <value>萨顶顶</value>
            <value>使得</value>
            <value>vdv</value>
            <value>萨</value>
        </list>
    </property>

<!--    Map-->
    <property name="cards">
        <map>
            <entry key="id" value="445202200322214355"></entry>
            <entry key="bank_id" value="213214124"></entry>
        </map>
    </property>
<!--    Set-->
<property name="games">
    <set>
        <value>lol</value>
        <value>lpl</value>
        <value>lbl</value>
    </set>
</property>
<!--  设null值  -->
    <property name="wife">
        <null></null>
    </property>
    
<!--    properties-->
    <property name="info">
        <props>
            <prop key="学号">20205080</prop>
            <prop key="姓名">陈</prop>
            <prop key="性别">男</prop>
            <prop key="username">root</prop>
            <prop key="password">123456</prop>
        </props>
    </property>
</bean>


</beans>

实体类：

 

Student.java

package com.haoqi.pojo;

import java.util.*;

public class Student {
    private String name;
    private Address address;
    private String[] books;
    private List<String> hobbys;
    private Map<String,String> cards;
    private Set<String> games;
    private String wife;
    private Properties info;

    @Override
    public String toString() {
        return "Student{" +
                "name='" + name + '\'' +
                ", address=" + address +
                ", books=" + Arrays.toString(books) +
                ", hobbys=" + hobbys +
                ", cards=" + cards +
                ", games=" + games +
                ", wife='" + wife + '\'' +
                ", info=" + info +
                '}';
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Address getAddress() {
        return address;
    }

    public void setAddress(Address address) {
        this.address = address;
    }

    public String[] getBooks() {
        return books;
    }

    public void setBooks(String[] books) {
        this.books = books;
    }

    public List<String> getHobbys() {
        return hobbys;
    }

    public void setHobbys(List<String> hobbys) {
        this.hobbys = hobbys;
    }

    public Map<String, String> getCards() {
        return cards;
    }

    public void setCards(Map<String, String> cards) {
        this.cards = cards;
    }

    public Set<String> getGames() {
        return games;
    }

    public void setGames(Set<String> games) {
        this.games = games;
    }

    public String getWife() {
        return wife;
    }

    public void setWife(String wife) {
        this.wife = wife;
    }

    public Properties getInfo() {
        return info;
    }

    public void setInfo(Properties info) {
        this.info = info;
    }
}

测试类

Test.java

import com.haoqi.pojo.Student;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Test {
    public static void main(String[] args) {


        ApplicationContext context = new ClassPathXmlApplicationContext("beans.xml");
        Student student = (Student) context.getBean("student");
        System.out.println(student.toString());
    }
}

 

 

3、其他注入

 

配置文件xml：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:c="http://www.springframework.org/schema/c"
       xmlns:p="http://www.springframework.org/schema/p"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:lang="http://www.springframework.org/schema/lang"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        https://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/lang http://www.springframework.org/schema/lang/spring-lang.xsd">



    <bean id="user" class="com.haoqi.pojo.User" c:age="15" c:name="太子"></bean>
    <bean id="user1" class="com.haoqi.pojo.User" p:age="17" p:name="第三">

</bean>
</beans>