我正在使用来自外部API的一些REST端点,并且为此使用了Rest Template接口。当我从这些调用中收到某些HTTP状态代码时,我希望能够引发自定义应用程序异常。为了实现它,我实现了ResponseErrorHandler接口,如下所示:
public class MyCustomResponseErrorHandler implements ResponseErrorHandler { private ResponseErrorHandler myErrorHandler = new DefaultResponseErrorHandler(); public boolean hasError(ClientHttpResponse response) throws IOException { return myErrorHandler.hasError(response); } public void handleError(ClientHttpResponse response) throws IOException { String body = IOUtils.toString(response.getBody()); MyCustomException exception = new MyCustomException(response.getStatusCode(), body, body); throw exception; } } public class MyCustomException extends IOException { private HttpStatus statusCode; private String body; public MyCustomException(String msg) { super(msg); // TODO Auto-generated constructor stub } public MyCustomException(HttpStatus statusCode, String body, String msg) { super(msg); this.statusCode = statusCode; this.body = body; } public HttpStatus getStatusCode() { return statusCode; } public void setStatusCode(HttpStatus statusCode) { this.statusCode = statusCode; } public String getBody() { return body; } public void setBody(String body) { this.body = body; } }
最后,这是客户端代码(省略了无关的代码):
public LoginResponse doLogin(String email, String password) { HttpEntity<?> requestEntity = new HttpEntity<Object>(crateBasicAuthHeaders(email,password)); try{ ResponseEntity<LoginResponse> responseEntity = restTemplate.exchange(myBaseURL + "/user/account/" + email, HttpMethod.GET, requestEntity, LoginResponse.class); return responseEntity.getBody(); } catch (Exception e) { //Custom error handler in action, here we're supposed to receive a MyCustomException if (e instanceof MyCustomException){ MyCustomException exception = (MyCustomException) e; logger.info("An error occurred while calling api/user/account API endpoint: " + e.getMessage()); } else { logger.info("An error occurred while trying to parse Login Response JSON object"); } } return null; }
我的应用环境:
<?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:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:spring="http://camel.apache.org/schema/spring" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd"> <!-- Rest template (used in bridge communication) --> <bean id="restTemplate" class="org.springframework.web.client.RestTemplate"> <property name="errorHandler" ref="myCustomResponseErrorHandler"></property> </bean> <!-- Bridge service --> <bean id="myBridgeService" class="a.b.c.d.service.impl.MyBridgeServiceImpl"/> <!-- Bridge error handler --> <bean id="myCustomResponseErrorHandler" class="a.b.c.d.service.handlers.MyCustomResponseErrorHandler"/> </beans>
我怀疑我没有正确理解此自定义错误处理的行为。每个单独的rest模板方法都可能抛出RestClientException,该异常遵循异常层次结构,它是RuntimeException的子类,而不是IOException,它是在自定义响应错误处理程序中抛出的,即:我无法在rest模板方法中捕获我的自定义异常电话。
关于如何捕获这些异常的任何线索?Spring RestTemplate调用带有错误的Web服务并分析状态代码是高度相关的,但是从我的角度来看,尽管它是作为解决方案提出的,但我仍然遇到相同的问题。
[1]:
您已将自定义Exception扩展自IOException
Exception
IOException
public class MyCustomException extends IOException {
该ResponseErrorHandler#handleError()方法是从调用RestTemplate#handleResponseError(..)其通过调用RestTemplate#doExecute(..)。此根调用被包装在一个try- catch块中,该块被捕获IOException并重新包装在a中ResourceAccessException,即a RestClientException。
ResponseErrorHandler#handleError()
RestTemplate#handleResponseError(..)
RestTemplate#doExecute(..)
try- catch
ResourceAccessException
RestClientException
一种可能性是抓住RestClientException并获得成功cause。
cause
另一种可能性是使您的自定义Exception成为的子类型RuntimeException。
RuntimeException