6.依赖注入

构造器注入已经讲过

新建实体类

package com.dream.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 + ''' +
                '}';
    }
}

package com.dream.pojo;

import java.util.*;

public class Student {
    private String name;
    private Address address;
    private String[] books;
    private List hobbys;
    private Map card;
    private Set 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 getHobbys() {
        return hobbys;
    }

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

    public Map getCard() {
        return card;
    }

    public void setCard(Map card) {
        this.card = card;
    }

    public Set getGames() {
        return games;
    }

    public void setGames(Set 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.toString() +
                ", books=" + Arrays.toString(books) +
                ", hobbys=" + hobbys +
                ", card=" + card +
                ", games=" + games +
                ", wife='" + wife + ''' +
                ", info=" + info +
                '}';
    }
}

常量注入

bean注入

数组注入

    
        西游记
        红楼梦
        三国演义
        水浒传
    

List注入

            
                听歌
                跑步
                看电影
                敲代码
            
        

Map注入

Set注入

            
                英雄联盟
                星际争霸
                魔兽世界
            
        

Null注入

Properties注入

            
                2043784
                男
                root
                123456
            
        

测试

import com.dream.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());
    }
}

新建User类

package com.dream.pojo;

public class User {
    private String name;
    private int age;

    public User() {
    }

    public User(String name, int age) {
        this.name = name;
        this.age = age;
    }

    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;
    }

    @Override
    public String toString() {
        return "User{" +
                "name='" + name + ''' +
                ", age=" + age +
                '}';
    }
}

P命名空间注入和c命名空间注入都需要在头文件加入约束条件

测试

@Test
    public void test2(){
        ApplicationContext context = new ClassPathXmlApplicationContext("userbeans.xml");
        User user = (User) context.getBean("user");
        System.out.println(user);
        User user2 = (User) context.getBean("user2");
        System.out.println(user2);
    }

Singleton：在Spring Ioc容器中仅存在一个Bean实例，Bean以单例方式存在，默认值

Prototype：每次从容器中调用Bean时，都返回一个新的实例，即每次调用getBean()时，相当于执行new xxxBean()

Request：每次HTTP请求都会创建一个新的Bean，该作用域仅适用WebApplicationContext环境

Session：同一个HTTP Session共享一个Bean，不同Session使用不同Bean，仅适用于WebApplicationContext