Spring给对象属性赋值的三种注入方式

bean类

package com.zxh.model;

public class Student {
    private String username;
    private String password;
    private Integer id;

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public Student() {
    }

    public Student(String username, Integer id) {
        this.username = username;
        this.id = id;
    }

    public Student(String username, String password) {
        this.username = username;
        this.password = password;
    }

    @Override
    public String toString() {
        return "Student{" +
                "username='" + username + '\'' +
                ", password='" + password + '\'' +
                ", id=" + id +
                '}';
    }
}

<?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:p="http://www.springframework.org/schema/p"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd">
    <!--构造方法注入属性值-->
    <bean id="student1" class="com.zxh.model.Student">
        <constructor-arg name="username" value="zxh"></constructor-arg>
        <constructor-arg name="password" value="123456"></constructor-arg>
    </bean>
    <!--构造方法通过索引注入属性值-->
    <bean id="student2" class="com.zxh.model.Student">
        <constructor-arg index="0" value="zxh" type="java.lang.String"></constructor-arg>
        <constructor-arg index="1" value="123456" type="java.lang.String"></constructor-arg>
    </bean>
    <!--set方法注入属性值-->
    <bean id="student3" class="com.zxh.model.Student">
        <property name="username" value="zxh"></property>
        <property name="password" value="123456"></property>
        <property name="id" value="12"></property>
    </bean>
    <!--p标签注入属性值-->
    <bean id="student4" class="com.zxh.model.Student" p:id="10" p:username="zxh" p:password="123456"></bean>

</beans>

测试类

package com.zxh.test;

import com.zxh.model.Student;
import com.zxh.model.User;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class lesson06 {
    @Test
    public void test() throws Exception {

        /**
         * 给对象属性赋值的方式
         */
       ApplicationContext ac = new ClassPathXmlApplicationContext("beans6.xml");
       Student student = (Student) ac.getBean("student4");
       System.out.println(student);
    }
}