spring04 spel注入

public class Student {   //学生实体类

    private  String   name;  //姓名

    private  Integer  age;  //年龄

    private  Grade   grade;  //年级

    @Override

    public String toString() {

        return "Student [name=" + name + ", age=" + age + ", grade=" + grade

                + "]";

    }

    public Student() {

        super();

    }

    public Student(String name, Integer age, Grade grade) {

        super();

        this.name = name;

        this.age = age;

        this.grade = grade;

    }

    public String getName() {

        return name;

    }

    public void setName(String name) {

        this.name = name;

    }

    public Integer getAge() {

        return age;

    }

    public void setAge(Integer age) {

        this.age = age;

    }

    public Grade getGrade() {

        return grade;

    }

    public void setGrade(Grade grade) {

        this.grade = grade;

    }

  //根据年龄的不同返回age不同的值

    public  Integer   changeAge(){

        return (this.age>25)?20:this.age;

    }

}

public class Grade {   //年级实体类

    private String  name;  //年级名称

    @Override

    public String toString() {

        return "Grade [name=" + name + "]";

    }

    public Grade() {

        super();

    }

    public Grade(String name) {

        super();

        this.name = name;

    }

    public String getName() {

        return name;

    }

    public void setName(String name) {

        this.name = name;

    }

}

<?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"

    xmlns:c="http://www.springframework.org/schema/c"

    xsi:schemaLocation="

        http://www.springframework.org/schema/beans

         http://www.springframework.org/schema/beans/spring-beans.xsd">

  <!--  spel 注入    spring el表达式   需要实体类中 有对应的get（）

                       第一个学生 -->

     <bean id="student1" class="cn.bdqn.bean.Student">

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

     <property name="age" value="#{T(java.lang.Math).random()*50}"/>

     </bean>

    <!-- 第二个学生  name属性值 是 第一个学生的   age值  是方法中获取的  -->

     <bean id="student2" class="cn.bdqn.bean.Student">

     <property name="name" value="#{student1.name}"/>

    <!--  <property name="age" value="#{student1.age>30?25:student1.age}"/> -->

       <!--直接把年龄的判断写在类中 并且得到返回值  -->

     <property name="age" value="#{student1.changeAge()}"/>

     </bean>

    <!--匿名内部bean  年级只属于指定的Student  -->

   <!--   <bean id="student" class="cn.bdqn.bean.Student">

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

     <property name="age" value="50"/>

     <property name="grade">

      其他的bean中 无法访问

       <bean id="grade" class="cn.bdqn.bean.Grade" p:name="1年级"/>

     </property>

     </bean> -->

</beans>

public class StudentTest {

    //使用spel注入

    @Test

    public  void  test01(){

        ApplicationContext context=

                new ClassPathXmlApplicationContext("applicationContext.xml");

        Student student1=(Student) context.getBean("student1");

         Student student2=(Student) context.getBean("student2");

        System.out.println("student1信息："+student1);

        System.out.println("student2信息："+student2);

    }

    //匿名内部bean

    @Test

    public  void  test02(){

        ApplicationContext context=

                new ClassPathXmlApplicationContext("applicationContext.xml");

        Student student=(Student) context.getBean("student");

        System.out.println("student信息："+student);

    }

}