Spring基于xml文件配置Bean过程详解

  <bean id="helloWorld" class="com.gong.spring.beans.HelloWorld">
    <property name="name" value="jack"></property>
  </bean>

<bean id="student" class="com.gong.spring.beans.Student">    //第一种方式注入属性值
    <constructor-arg value="tom" index="0" type="java.lang.String"></constructor-arg>
    <constructor-arg value="12" index="1" type="int"></constructor-arg>    //第二种方式注入属性值
    <constructor-arg index="2" type="double">
      <value>99.00</value>
    </constructor-arg>
  </bean>

package com.gong.spring.beans;

public class Student {
  private String name;
  private int age;
  private double score;
  public Student(String name,int age,double score) {
    this.name = name;
    this.age = age;
    this.score = score;
  }
  @Override
  public String toString() {
    return "Student [name=" + name + ", age=" + age + ", score=" + score + "]";
  }
  
}

public static void main(String[] args) {
    //1.创建spring的IOC容器对象
    ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
    //2.从容器中获取Bean实例
    Student student = (Student) ctx.getBean("student"); 
    System.out.println(student.toString());
  }

    <constructor-arg index="0" type="java.lang.String">
      <value><![CDATA[<tom>]]></value>
    </constructor-arg>