nested exception is java.lang.IllegalStateException: PathVariable annotation was empty on param 0.

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错误显示：

使用SpringBoot进行开发时，使用feign组件进行远程调用，可能会产生了这样的异常信息：

Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'xxxxx': Injection of resource dependencies failed; 

nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'xxxx': Injection of resource dependencies failed;

nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'xxxxx': FactoryBean threw exception on object creation; 

nested exception is java.lang.IllegalStateException: PathVariable annotation was empty on param 0.

　　重点看这句话的异常信息

nested exception is java.lang.IllegalStateException: PathVariable annotation was empty on param 0.

原因：

从异常信息中看出，是因为PathVariable注解有问题！也就是@PathVariable注解的第0个值为空！

当时声明明Feign接口方法时候，使用@PathVariable注解的接口方法：

@GetMapping("/account/{clientId}")
public User get(@PathVariable String clientId);

path路径部分只有一个clientId变量，那么说在“was empty on param 0”，也就是说clientId值没有取到！

解决:

将@PathVariable修改为@PathVariable(value="clientId")的写法，明确带有value="clientId"！

@GetMapping("/account/{clientId}")
public User get(@PathVariable(value="clientId") String clientId);

重新编译即可！

一句话总结：

使用feign时，如果参数中带有@PathVariable则需要使用value显示指明参数名

本文为joshua317原创文章,转载请注明：转载自joshua317博客 https://www.joshua317.com/article/282