在Java中检测HTTP中断
在Java中检测HTTP中断
提问于 2017-04-04 19:31:16
我正在从Java向外部系统发出REST调用。如果有任何连接中断，比如外部系统脱机，我需要一个侦听器来检测并执行相应的操作。如果我可以用Java实现这一点，请让我知道。最好是在Java 8中。
目前，如果我遇到这样的情况，我不会得到任何异常。我现在有以下代码
Client client = ClientBuilder.newClient();
WebTarget target = client.target(HOSTNAME);
Invocation.Builder requestBuilder;
requestBuilder = target.path(URL).request(MediaType.APPLICATION_JSON)
.header(HEADER_AUTHORIZATION, AUTH_TOKEN);
Response response = null;
if (HTTP_POST.equalsIgnoreCase(method)) {
try{
response = requestBuilder.post(Entity.entity(message, MediaType.APPLICATION_JSON_TYPE));
}catch(Exception ex ){
ex.printStackTrace();
}
} else if (HTTP_GET.equalsIgnoreCase(method)) {
response = requestBuilder.get();
}
String executeMessage = null;
if(response != null){
if (response.getStatus() == 200) {
executeMessage = response.readEntity(String.class);
return new JSONObject(executeMessage);
} else {
executeMessage = response.readEntity(String.class);
final JSONObject status = new JSONObject();
status.put(STATUS_CODE, response.getStatus());
status.put(STATUS_INFO, response.getStatusInfo());
status.put("response", executeMessage);
final JSONObject error = new JSONObject();
error.put(ERROR, status);
return error;
}
}回答 2
Stack Overflow用户
发布于 2017-06-18 04:45:15
如果使用Spring Boot，可以尝试名为Feign的声明式REST客户端
@FeignClient(url = "example.com", fallback = YourTestFeignClient.YourTestFeignClientFallback.class)
public interface YourTestFeignClient {
@RequestMapping(method = RequestMethod.POST, value = "/example/path/to/resource/{id}")
YourTestResponse requestExternalResource(@RequestParam("id") Long id, SomeRequestDTO requestDTO);
@Component
public static class YourTestFeignClientFallback implements YourTestFeignClient {
@Override
public YourTestResponse requestExternalResource(Long id, SomeRequestDTO requestDTO) {
YourTestResponse testResponse = new YourTestResponse();
testResponse.setMessage("Service unavailable");
return testResponse;
}
}
}在这里，您需要做的就是在代码中注入YourTestFeignClient并在其上调用requestExternalResource方法。这将使用从SomeRequestDTO获取的JSON body调用POST example.com/example/path/to/resource/34。如果请求失败，将调用YourTestFeignClientFallback内部的回退方法，然后返回一些默认数据。
Stack Overflow用户
发布于 2017-04-07 04:55:09
一旦Http响应/错误准备就绪，您就可以创建自己的侦听器，并使用传递回调用类的结果进行异步的HTTP调用。例如(有拼写错误)：
创建一个接口，您的主类将实现该接口，并且您的Http客户端将利用...
public interface MyHttpListener {
public httpComplete(MyHttpResults results);
}在你的主类中实现。
public MyClass implements MyHttpListener {
public void processHttpRequests(){
for(int i=0; i<10; i++){
// instantiate your Http Client class
HttpClient client = new HttpClient();
// register the listener
client.addHttpListener(this);
// execute whatever URL you want and you are notified later when complete
client.executeRequest("http://whatever");
}
}
public httpRequestComplete(MyHttpResults results) {
// do something with the results
results.getResponseCode();
results.getRawResponse();
results.whatever();
} }
将方法添加到HttpClient以接受侦听器
public class MyHttpClient {
List<MyHttpListener> httpListenerList = new ArrayList();
// register listeners
public void addHttpListener(MyHttpListener listener){
httpListenerList.add(listener);
}
// this is the method that processes the request
public void executeRequest(String url) {
// do whatever you were doing previously here
// optional POJO to wrap the results and/or exceptions
MyHttpResults results = new MyHttpResults();
results.withResponseCode(response.getResponseCode());
results.withResponse(responseAsString);
results.withException(ex);
results.withWhatever(whatever);
// notify listeners
notify(results);
}
public void notify(MyHttpResults results){
// notify listeners
for(MyHttpListener listener : httpListenerList){
listener.httpComplete(results);
}
}
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/43206012
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