Spring使用Setter完成依賴注入方式

更新時(shí)間：2021年09月28日 08:40:47 作者：想飛的魚Stitch

這篇文章主要介紹了Spring使用Setter完成依賴注入方式，具有很好的參考價(jià)值，希望對(duì)大家有所幫助。如有錯(cuò)誤或未考慮完全的地方，望不吝賜教

對(duì)依賴注入的理解

依賴：實(shí)體間的所有依賴由容器創(chuàng)建

注入：容器負(fù)責(zé)完成實(shí)體間依賴互相注入的任務(wù)

使用Setter完成不同類型屬性的注入

實(shí)體類Student

package indi.stitch.pojo;
import java.util.*;
public class Student {
    private String name;
    private Address address;
    private String[] books;
    private List<String> hobbys;
    private Set<String> games;
    private Map<String, String> card;
    private Properties info;
    private String wife;
    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 Set<String> getGames() {
        return games;
    }
    public void setGames(Set<String> games) {
        this.games = games;
    }
    public Map<String, String> getCard() {
        return card;
    }
    public void setCard(Map<String, String> card) {
        this.card = card;
    }
    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 + '\'' + "\n" +
                ", address=" + address.toString() + "\n" +
                ", books=" + Arrays.toString(books) + "\n" +
                ", hobbys=" + hobbys + "\n" +
                ", games=" + games + "\n" +
                ", card=" + card + "\n" +
                ", info=" + info + "\n" +
                ", wife='" + wife + '\'' +
                '}';
    }
}

實(shí)體類引用的復(fù)雜類型Address

package indi.stitch.pojo;
public class Address {
    private String address;
    public String getAddress() {
        return address;
    }
    public void setAddress(String address) {
        this.address = address;
    }
    @Override
    public String toString() {
        return "Address{" +
                "address='" + address + '\'' +
                '}';
    }
}

String字符串類型注入

<property name="name" value = "stitch" />

復(fù)雜VO類型注入

配置文件中增加復(fù)雜類型bean(Address)的依賴配置

<bean id = "address" class="indi.stitch.pojo.Address">
        <property name="address" value="北京" />
    </bean>
<bean id = "student" class = "indi.stitch.pojo.Student">

實(shí)體類Student的bean屬性依賴對(duì)其進(jìn)行引用

<property name="address" ref="address"/>

數(shù)組類型注入

<property name="books">
            <array>
                <value>西游記</value>
                <value>三國演義</value>
                <value>紅樓夢(mèng)</value>
                <value>水滸傳</value>
            </array>
</property>

List集合類型注入

<property name="hobbys">
            <list>
                <value>唱歌</value>
                <value>跳舞</value>
                <value>打籃球</value>
            </list>
</property>

Set集合類型注入

 <property name="games">
            <set>
                <value>英雄聯(lián)盟</value>
                <value>穿越火線</value>
                <value>刺激戰(zhàn)場(chǎng)</value>
            </set>
</property>

Map鍵值對(duì)類型注入

<property name="card">
            <map>
                <entry key="學(xué)生卡" value="123456"/>
                <entry key="身份證" value="111111222222223333" />
            </map>
</property>

Properties類型注入

<property name="info">
            <props>
                <prop key="sex">男</prop>
                <prop key="age">18</prop>
            </props>
</property>

null類型注入

<property name="wife">
            <null />
        </property>

整體配置文件

<?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">
    <bean id = "address" class="indi.stitch.pojo.Address">
        <property name="address" value="北京" />
    </bean>
    <bean id = "student" class = "indi.stitch.pojo.Student">
        <!-- String字符串類型注入-->
        <property name="name" value = "stitch" />
        <!--復(fù)雜VO類型注入-->
        <property name="address" ref="address"/>
        <!--數(shù)組類型注入-->
        <property name="books">
            <array>
                <value>西游記</value>
                <value>三國演義</value>
                <value>紅樓夢(mèng)</value>
                <value>水滸傳</value>
            </array>
        </property>
        <!--List集合類型注入-->
        <property name="hobbys">
            <list>
                <value>唱歌</value>
                <value>跳舞</value>
                <value>打籃球</value>
            </list>
        </property>
        <!--Set集合類型注入-->
        <property name="games">
            <set>
                <value>英雄聯(lián)盟</value>
                <value>穿越火線</value>
                <value>刺激戰(zhàn)場(chǎng)</value>
            </set>
        </property>
        <!--Map鍵值對(duì)類型注入-->
        <property name="card">
            <map>
                <entry key="學(xué)生卡" value="123456"/>
                <entry key="身份證" value="111111222222223333" />
            </map>
        </property>
        <!--Properties類型注入-->
        <property name="info">
            <props>
                <prop key="sex">男</prop>
                <prop key="age">18</prop>
            </props>
        </property>
        <!--null類型注入-->
        <property name="wife">
            <null />
        </property>
    </bean>
</beans>

測(cè)試類

import indi.stitch.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.toString());
    }
}

輸出結(jié)果：

在這里插入圖片描述