Question

我是spring的新手，所以我只是想在spring中实现继承。

Customer.java

public class Customer {

    String name;

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

Country.java

public class Country {

    String cname;
    String city;
    public String getCname() {
        return cname;
    }
    public void setCname(String cname) {
        this.cname = cname;
    }
    public String getCity() {
        return city;
    }
    public void setCity(String city) {
        this.city = city;
    }
}

Main.java

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Main {

    public static void main(String args[]){

        ApplicationContext context = new ClassPathXmlApplicationContext("Bean1.xml");
        Customer cus = (Customer) context.getBean("customer");
        System.out.println(cus.getName());
        Country con = (Country) context.getBean("country");
        System.out.println(con.getCname());

    }
}

Bean1.xml

<?xml version = "1.0" encoding = "UTF-8"?>
<beans xmlns = "http://www.springframework.org/schema/beans"
       xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation = "http://www.springframework.org/schema/beans
                    http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">

    <bean id = "customer" class = "Customer">
        <property name = "name" value = "Garima"/>    
    </bean>

    <bean id ="country" class="Country" parent="customer">
        <property name = "cname" value = "India"/>
        <property name = "city" value = "Delhi"/>
    </bean>
</beans>

每次我在Bean1.xml中都没有父母的情况下运行此程序时，运行良好。一旦添加parent，就会收到以下错误。错误：Bean类[name]的无效属性Country：Bean属性name是不可写的或具有无效的setter方法。您是说cname吗？我还通过许多其他示例注意到了这种情况。有人可以帮我吗？

Answer 1

这是因为您的bean定义表明Customer 是 Country的父级，但是您的课程Country 不是 < strong>扩展 Customer

<bean id ="country" class="Country" parent="customer">

所以您有两个选择

任一从您的bean定义中删除parent="customer"
OR 将国家/地区类别的客户扩展为 public class Country extends Customer{...

Answer 2

在您的bean中，class属性应具有与该类对应的包名称。喜欢

<bean id = "customer" class = "com.test.entity.Customer">
  <property name = "name" value = "Garima"/>
</bean>

<bean id ="country" class="com.test.entity.Country" parent="customer">
  <property name = "cname" value = "India"/>
  <property name = "city" value = "Delhi"/>
</bean>

Bean类[Country]的无效属性“名称”：Bean属性“名称”不可写，或者具有无效的setter方法。您是说'cname'吗？

2 个答案: