Skip to content

Instantly share code, notes, and snippets.

@m4nu56

m4nu56/ApiService.java

Last active May 29, 2020
Embed
What would you like to do?
Using Generic Types in Java to create a method that will handle any API call
package com.dev1.api;
import com.dev1.api.exception.ApiException;
import com.dev1.api.exception.ApiExceptionNetwork;
import com.dev1.api.exception.ApiExceptionUncaught;
import com.dev1.api.exception.mapper.ErrorMessage;
import com.google.common.collect.ImmutableList;
import org.apache.http.HttpHeaders;
import org.apache.log4j.Logger;
import javax.ws.rs.client.Client;
import javax.ws.rs.client.ClientBuilder;
import javax.ws.rs.client.Entity;
import javax.ws.rs.client.WebTarget;
import javax.ws.rs.core.GenericType;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;
import java.util.List;
import java.util.Map;
import static com.dev1.Constants.AUTHENTICATION_SCHEME;
public class ApiService<T> {
private static final Logger logger = Logger.getLogger(ApiService.class);
private final GenericType<T> returnType;
public ApiService(GenericType<T> returnType) {
this.returnType = returnType;
}
public T makePost(String apiPath, String apiMethodPath, String token, Object entity) throws ApiException {
Response response;
try {
Client client = ClientBuilder.newClient();
response = client
.target(apiPath)
.path(apiMethodPath)
.request()
.header(HttpHeaders.AUTHORIZATION, AUTHENTICATION_SCHEME + " " + token)
.post(Entity.entity(entity, MediaType.APPLICATION_JSON_TYPE));
} catch (Exception t) {
ApiExceptionNetwork apiException = new ApiExceptionNetwork(t, apiPath + "/" + apiMethodPath);
logger.error(apiException);
throw apiException;
}
String jsonReceived = null;
try {
response.bufferEntity();
List<Integer> successStatuses = ImmutableList.of(Response.Status.OK.getStatusCode(), Response.Status.ACCEPTED.getStatusCode());
if (successStatuses.contains(response.getStatus())) {
return response.readEntity(returnType);
} else {
logApiError(apiPath, apiMethodPath, response);
ErrorMessage errorMessage = response.readEntity(ErrorMessage.class);
jsonReceived = response.readEntity(String.class);
throw new ApiException(errorMessage);
}
} catch (ApiException e) {
throw e;
} catch (Exception t) {
ApiException apiException = new ApiExceptionUncaught(t, response.getStatus(), apiPath + "/" + apiMethodPath, jsonReceived);
logger.error("API returned : " + response.getStatus() + " with URL " + apiPath + "/" + apiMethodPath, apiException);
throw apiException;
}
}
/**
* On log toute erreur qui ne serait pas du type 401 (comportement normal si erreur d'authentification)
*/
private void logApiError(String apiPath, String apiMethodPath, Response response) {
List<Integer> badAuthenthStatuses = ImmutableList.of(Response.Status.FORBIDDEN.getStatusCode(), Response.Status.UNAUTHORIZED.getStatusCode());
if (badAuthenthStatuses.contains(response.getStatus())) {
logger.error("API returned : " + response.getStatus() + " with URL " + apiPath + "/" + apiMethodPath);
}
}
public T makeGet(String apiPath, String apiMethodPath, String token) throws ApiException {
return makeGet(apiPath, apiMethodPath, token, null);
}
public T makeGet(String apiPath, String apiMethodPath, String token, Map<String, Object> queryParams) throws ApiException {
Response response;
try {
Client client = ClientBuilder.newClient();
WebTarget webTarget = client
.target(apiPath)
.path(apiMethodPath);
if (queryParams != null) {
for (Map.Entry<String, Object> entry : queryParams.entrySet()) {
webTarget = webTarget.queryParam(entry.getKey(), entry.getValue()); // webtarget is immutable
}
}
response = webTarget
.request()
.header(HttpHeaders.AUTHORIZATION, AUTHENTICATION_SCHEME + " " + token)
.get();
} catch (Exception t) {
ApiExceptionNetwork apiException = new ApiExceptionNetwork(t, apiPath + "/" + apiMethodPath);
logger.error(apiException);
throw apiException;
}
String jsonReceived = null;
try {
response.bufferEntity();
List<Integer> successStatuses = ImmutableList.of(Response.Status.OK.getStatusCode(), Response.Status.ACCEPTED.getStatusCode());
if (successStatuses.contains(response.getStatus())) {
return response.readEntity(returnType);
} else {
logApiError(apiPath, apiMethodPath, response);
ErrorMessage errorMessage = response.readEntity(ErrorMessage.class);
jsonReceived = response.readEntity(String.class);
throw new ApiException(errorMessage);
}
} catch (ApiException e) {
throw e;
} catch (Exception t) {
ApiException apiException = new ApiExceptionUncaught(t, response.getStatus(), apiPath + "/" + apiMethodPath, jsonReceived);
logger.error(apiException);
throw apiException;
}
}
}
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
You can’t perform that action at this time.