Bean两种传值方式

两种方式：

①属性传值
②构造方法传值
name ref：引用类型

举例：Student类和Phone类

Ⅰ、Class Student 属性：封装name、age、phone 其中phone属于应用类型，所以之后的bean中使用ref，
自动生成constructor， getter/setter,覆写tostring()方法
如下：

public class Student {
private String name;
private int age;
private Phone phone;

public Student(String name, int age, Phone phone) {
    this.name = name;
    this.age = age;
    this.phone = phone;
}

public Student(){

}

public String getName() {
    return name;
}

public int getAge() {
    return age;
}

public void setName(String name) {
    this.name = name;
}

public void setAge(int age) {
    this.age = age;
}

public Phone getPhone() {
    return phone;
}

public void setPhone(Phone phone) {
    this.phone = phone;
}

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

Ⅱ、Class Phone属性:封装brand、price 自动生成constructor， getter/setter,覆写tostring()方法
如下:

public class Phone {
private double price;
private double size;

public Phone(double price, double size) {
    this.price = price;
    this.size = size;
}
public Phone(){

}

public double getPrice() {
    return price;
}

public double getSize() {
    return size;
}

public void setPrice(double price) {
    this.price = price;
}

public void setSize(double size) {
    this.size = size;
}

@Override
public String toString() {
    return "Phone{" +
            "price=" + price +
            ", size=" + size +
            '}';
}
}

Ⅲ、在beans.xml中对Phone类和Student类配置bean，分别用到属性传值和构造器传值

注意此处用到 ref
代码如下：

 <!--属性传值-->
 <bean id="phone" class="com.soft1721.spring.hello.Phone">
      <property name="size" value="8.0"/>
      <property name="price" value="10000"/>
 </bean>
 <!--构造器传值-->
 <bean id="student" class="com.soft1721.spring.hello.Student">
      <constructor-arg name="age" value="21"/>
      <constructor-arg name="name" value="tom"/>
      <constructor-arg name="phone" ref="phone"/>
 </bean>

Ⅳ、编写主类进行测试
如下：

public class StudentApp {
public static void main(String[] args) {
    ApplicationContext context=new
            ClassPathXmlApplicationContext("beans.xml");
    Student student=(Student) context.getBean("student");
    System.out.println(student);
}
}

效果图：

效果图