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我建立一個REST API，它收集來自其他API的數據，做一些邏輯與它併發送回客戶端：Vertx拋出IllegalStateException異常：響應已被寫入
我的主類：
public class Main {
public static void main(String[] args) {
Vertx.vertx().deployVerticle(RestVerticle.class.getName());
}
這是我RestVerticle：
public class RestVerticle extends AbstractVerticle {
public static final String API_V1 = "/api/v1";
private Map<String, JsonObject> products = new HashMap<>();
@Override
public void start() {
Router router = Router.router(vertx);
router.route().handler(BodyHandler.create());
router.get(API_V1 + "/business/all").handler(this::getAllBusinesses);
vertx.createHttpServer().requestHandler(router::accept).listen(8080);
}
private void getAllBusinesses(RoutingContext routingContext) {
vertx.deployVerticle(YelpClientVerticle.class.getName());
MessageConsumer<String> consumer = vertx.eventBus().consumer("api");
consumer.handler(message -> {
JsonObject m = new JsonObject((String) message.body());
System.out.println("Received message: " + message.body());
routingContext.response().putHeader("content-type", "application/json").end(m.encodePrettily());
});
}
}
這是我httpcl ient，這就要求對Yelp的API：
public class YelpClientVerticle extends AbstractVerticle {
private static final String API_HOST = "api.yelp.com";
private static final String DEFAULT_TERM = "dinner";
private static final String DEFAULT_LOCATION = "San Francisco, CA";
private static final int SEARCH_LIMIT = 20;
private static final String SEARCH_PATH = "/v2/search";
private static final String BUSINESS_PATH = "/v2/business";
/*
* Update OAuth credentials below from the Yelp Developers API site:
* http://www.yelp.com/developers/getting_started/api_access
*/
private static final String CONSUMER_KEY = "XXXXX";
private static final String CONSUMER_SECRET = "XXXXX";
private static final String TOKEN = "XXXXX";
private static final String TOKEN_SECRET = "XXXXX";
OAuthService service;
Token accessToken;
/**
* Setup the Yelp API OAuth credentials.
*
* @param consumerKey Consumer key
* @param consumerSecret Consumer secret
* @param token Token
* @param tokenSecret Token secret
*/
/**
* Creates and sends a request to the Search API by term and location.
* <p>
* See <a href="http://www.yelp.com/developers/documentation/v2/search_api">Yelp Search API V2</a>
* for more info.
*
* @param term <tt>String</tt> of the search term to be queried
* @param location <tt>String</tt> of the location
* @return <tt>String</tt> JSON Response
*/
public String searchForBusinessesByLocation(String term, String location) {
OAuthRequest request = createOAuthRequest(SEARCH_PATH);
request.addQuerystringParameter("term", term);
request.addQuerystringParameter("location", location);
request.addQuerystringParameter("limit", String.valueOf(SEARCH_LIMIT));
return sendRequestAndGetResponse(request);
}
/**
* Creates and sends a request to the Business API by business ID.
* <p>
* See <a href="http://www.yelp.com/developers/documentation/v2/business">Yelp Business API V2</a>
* for more info.
*
* @param businessID <tt>String</tt> business ID of the requested business
* @return <tt>String</tt> JSON Response
*/
public String searchByBusinessId(String businessID) {
OAuthRequest request = createOAuthRequest(BUSINESS_PATH + "/" + businessID);
return sendRequestAndGetResponse(request);
}
/**
* Creates and returns an {@link OAuthRequest} based on the API endpoint specified.
*
* @param path API endpoint to be queried
* @return <tt>OAuthRequest</tt>
*/
private OAuthRequest createOAuthRequest(String path) {
OAuthRequest request = new OAuthRequest(Verb.GET, "https://" + API_HOST + path);
return request;
}
/**
* Sends an {@link OAuthRequest} and returns the {@link Response} body.
*
* @param request {@link OAuthRequest} corresponding to the API request
* @return <tt>String</tt> body of API response
*/
private String sendRequestAndGetResponse(OAuthRequest request) {
System.out.println("Querying " + request.getCompleteUrl() + " ...");
this.service.signRequest(this.accessToken, request);
Response response = request.send();
return response.getBody();
}
/**
* Queries the Search API based on the command line arguments and takes the first result to query
* the Business API.
*
* @param yelpApiCli <tt>YelpAPICLI</tt> command line arguments
*/
private String queryAPI(YelpAPICLI yelpApiCli) {
String searchResponseJSON =
searchForBusinessesByLocation(yelpApiCli.term, yelpApiCli.location);
JSONParser parser = new JSONParser();
JSONObject response = null;
try {
response = (JSONObject) parser.parse(searchResponseJSON);
} catch (ParseException pe) {
System.out.println("Error: could not parse JSON response:");
System.out.println(searchResponseJSON);
System.exit(1);
}
JSONArray businesses = (JSONArray) response.get("businesses");
JSONObject firstBusiness = (JSONObject) businesses.get(0);
String firstBusinessID = firstBusiness.get("id").toString();
System.out.println(String.format(
"%s businesses found, querying business info for the top result \"%s\" ...",
businesses.size(), firstBusinessID));
// Select the first business and display business details
String businessResponseJSON = searchByBusinessId(firstBusinessID.toString());
System.out.println(String.format("Result for business \"%s\" found:", firstBusinessID));
System.out.println(businessResponseJSON);
return businessResponseJSON;
}
/**
* Command-line interface for the sample Yelp API runner.
*/
private static class YelpAPICLI {
@Parameter(names = {"-q", "--term"}, description = "Search Query Term")
public String term = DEFAULT_TERM;
@Parameter(names = {"-l", "--location"}, description = "Location to be Queried")
public String location = DEFAULT_LOCATION;
}
@Override
public void start() throws Exception {
// Note! in real-life you wouldn't often set trust all to true as it could leave you open to man in the middle attacks.
this.service =
new ServiceBuilder().provider(TwoStepOAuth.class).apiKey(CONSUMER_KEY)
.apiSecret(CONSUMER_SECRET).build();
this.accessToken = new Token(TOKEN, TOKEN_SECRET);
YelpAPICLI yelpApiCli = new YelpAPICLI();
new JCommander(yelpApiCli);
String response = queryAPI(yelpApiCli);
vertx.eventBus().send("api", response);
}
}
我2個問題運行英寸
的第一個問題是Yelp的客戶花費太長的時間來處理該請求，並且它阻止與此警告主線程：
Jan 04, 2016 1:34:30 AM io.vertx.core.impl.BlockedThreadChecker
WARNING: Thread Thread[vert.x-eventloop-thread-4,5,main] has been blocked for 3151 ms, time limit is 2000
的第二個問題是，後精加工過程的第一個請求，爲例如，我第一次去我的本地主機：8080/API/V1 /業務/所有的請求返回成功地，但再下一次擊中了URL，它拋出這樣一個異常：
Jan 04, 2016 1:34:30 AM io.vertx.core.eventbus.impl.HandlerRegistration
SEVERE: Failed to handleMessage
java.lang.IllegalStateException: Response has already been written
如何我可以解決這兩個問題嗎？