java 无法解决匹配的构造函数。 Spring 依赖注入的歧义问题
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Could not resolve matching constructor.Ambiguity issue with Spring dependency injection
提问by Kriz
I am getting the error "Could not resolve matching constructor (hint: specify index/type/name arguments for simple parameters to avoid type ambiguities)" while executing my spring program. I am new to Spring core and trying to learn the framework. Below is the code:
我Could not resolve matching constructor (hint: specify index/type/name arguments for simple parameters to avoid type ambiguities)在执行我的 spring 程序时收到错误“ ”。我是 Spring 核心的新手，正在尝试学习该框架。下面是代码：
Student.java
学生.java
package com.inject.test;
public class Student {
private String name;
private String className;
private Address address;
public Address getAddress() {
return address;
}
public void setAddress(Address address) {
this.address = address;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getClassName() {
return className;
}
public void setClassName(String className) {
this.className = className;
}
}
Address.java
地址.java
package com.inject.test;
public class Address {
private String city;
private String state;
public String getCity() {
return city;
}
public void setCity(String city) {
this.city = city;
}
public String getState() {
return state;
}
public void setState(String state) {
this.state = state;
}
}
Test.java
测试.java
package com.inject.test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class Test {
public static void main(String[] args) {
@SuppressWarnings("resource")
ApplicationContext context = new ClassPathXmlApplicationContext("file:com/applicationContext.xml");
Student student = (Student) context.getBean("student");
System.out.println("Name: " + student.getName());
System.out.println("Class: " + student.getClassName());
Address studentAddress = student.getAddress();
System.out.println("Student Address: ");
System.out.println("City: " + studentAddress.getCity());
System.out.println("State: " + studentAddress.getState());
}
}
applicationContext.xml
应用上下文.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="student" class="com.inject.test.Student">
<property name="name" value="Jai"/>
<property name="className" value="MCA"/>
<constructor-arg ref="address" type="java.lang.String"/>
</bean>
<bean id="address" class="com.inject.test.Address">
<property name="city" value="Hyderabad"/>
<property name="state" value="Telangana"/>
</bean>
</beans>
What change should be made to resolve the constructor issue, please suggest.
应该进行哪些更改来解决构造函数问题，请提出建议。
回答by Jason
Your xml configuration specifies a constructor argument containing the address, but your Student class does not have a constructor that takes any arguments.
您的 xml 配置指定了一个包含地址的构造函数参数，但您的 Student 类没有接受任何参数的构造函数。
Either add the appropriate constructor, or change the constructor-arg to a property in the xml configuration.
添加适当的构造函数，或将构造函数参数更改为 xml 配置中的属性。
