DI依赖注入环境

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本文已参与「新人创作礼」活动，一起开启掘金创作之路。

小Tips:快捷键生成getter和setter:Alt+F12

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然后 按住Ctrl键，可以进行选择。

本次项目的项目结构：

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一.依赖注入环境（三种方式）

1.构造器注入（前面讲过）

2.set方式注入（重点！！！）

。依赖: bean对象的创建依赖于容器!

。注入: bean对象中的所有属性，由容器来注入!

【环境搭建】

1）复杂类型

package com.kuang.pojo;

public class Address {

    private String address;

    public String getAddress() {
        return address;
    }

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

2）真实测试对象

public class Student {

    private String name;
    private Address address;
    private String[] books;
    private List<String> hobbys;
    private Map<String,String> card;
    private Set<String> games;
    private String wife;
    private Properties info;

【步骤】

1.新建一个子项目模块spring-04-di；

2.在java文件夹下新建一个包：com.kuang.pojo；

3.在刚刚新建的包里，新建一个Student类；

4.然后再建一个新类Address,也就是引用对象;

package com.kuang.pojo;

public class Address {

    private String address;

    public String getAddress() {
        return address;
    }

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

Student类代码：

package com.kuang.pojo;

import java.util.*;

public class Student {

    private String name;
    private Address address;
    private String[] books;
    private List<String> hobbys;
    private Map<String,String> card;
    private Set<String> games;
    private String wife;
    private Properties 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> getCard() {
        return card;
    }

    public void setCard(Map<String, String> card) {
        this.card = card;
    }

    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;
    }

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

5.在resources文件夹里新建一个beans.xml文件；

下面这段代码是基本框架，以后直接copy过来即可；

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

    
</beans>

6.先写一个测试类进行测试一下；

7.在test文件夹里 的java文件夹里新建一个测试类Test;

beans.xml:

<bean id="student" class="com.kuang.pojo.Student">
        <!--第一种，普通值注入，利用value-->
        <property name="name" value="吴磊"/>
    </bean>

MyTest.java:

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

public class MyTest {

    public static void main(String[] args) {
        ApplicationContext context = new ClassPathXmlApplicationContext("beans.xml");
        Student student = (Student) context.getBean("student");
        System.out.println(student.getName());
    }
}

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 输出结果：

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3.拓展方式注入

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