Java tutorial
/* * Copyright 2015 VMware, Inc. All Rights Reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); you may not * use this file except in compliance with the License. You may obtain a copy of * the License at http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software distributed * under the License is distributed on an "AS IS" BASIS, without warranties or * conditions of any kind, EITHER EXPRESS OR IMPLIED. See the License for the * specific language governing permissions and limitations under the License. */ package com.vmware.photon.controller.api.client.resource; import com.vmware.photon.controller.api.client.RestClient; import com.vmware.photon.controller.api.model.Task; import com.fasterxml.jackson.core.JsonProcessingException; import com.fasterxml.jackson.core.type.TypeReference; import com.fasterxml.jackson.databind.ObjectMapper; import com.google.common.util.concurrent.FutureCallback; import org.apache.http.HttpEntity; import org.apache.http.HttpResponse; import org.apache.http.HttpStatus; import org.apache.http.entity.ContentType; import org.apache.http.entity.StringEntity; import java.io.IOException; import java.io.UnsupportedEncodingException; import java.net.URLEncoder; import java.util.Map; import java.util.Map.Entry; import java.util.logging.Level; import java.util.logging.Logger; /** * Base class for Apis. */ public abstract class ApiBase { protected static ObjectMapper objectMapper = new ObjectMapper(); protected final RestClient restClient; public ApiBase(RestClient restClient) { this.restClient = restClient; } public abstract String getBasePath(); public static StringEntity serializeObjectAsJson(Object o) throws JsonProcessingException { String payload = objectMapper.writeValueAsString(o); return new StringEntity(payload, ContentType.APPLICATION_JSON); } public static <T> T deserializeObjectFromJson(String jsonString, TypeReference<T> typeReference) throws IOException { return objectMapper.readValue(jsonString, typeReference); } public final Task parseTaskFromHttpResponse(HttpResponse httpResponse) throws IOException { return this.restClient.parseHttpResponse(httpResponse, new TypeReference<Task>() { }); } /** * Creates an object as async. * * @param path * @param responseCallback * @throws IOException */ public final void createObjectAsync(final String path, final HttpEntity payload, final FutureCallback<Task> responseCallback) throws IOException { this.restClient.performAsync(RestClient.Method.POST, path, payload, new org.apache.http.concurrent.FutureCallback<HttpResponse>() { @Override public void completed(HttpResponse result) { Task task = null; try { restClient.checkResponse(result, HttpStatus.SC_CREATED); task = restClient.parseHttpResponse(result, new TypeReference<Task>() { }); } catch (Throwable e) { responseCallback.onFailure(e); } if (task != null) { Logger.getAnonymousLogger().log(Level.INFO, String .format("createObjectAsync returned task [%s] %s", this.toString(), path)); responseCallback.onSuccess(task); } else { Logger.getAnonymousLogger().log(Level.INFO, String.format("createObjectAsync failed [%s] %s", this.toString(), path)); } } @Override public void failed(Exception ex) { Logger.getAnonymousLogger().log(Level.INFO, "{}", ex); responseCallback.onFailure(ex); } @Override public void cancelled() { responseCallback.onFailure( new RuntimeException(String.format("createAsync %s was cancelled", path))); } }); } /** * Deletes an object as async. * * @param id * @param responseCallback * @throws IOException */ public final void deleteObjectAsync(final String id, final FutureCallback<Task> responseCallback) throws IOException { final String path = String.format("%s/%s", getBasePath(), id); this.restClient.performAsync(RestClient.Method.DELETE, path, null, new org.apache.http.concurrent.FutureCallback<HttpResponse>() { @Override public void completed(HttpResponse result) { Task task = null; try { restClient.checkResponse(result, HttpStatus.SC_CREATED); task = restClient.parseHttpResponse(result, new TypeReference<Task>() { }); } catch (Throwable e) { responseCallback.onFailure(e); } if (task != null) { Logger.getAnonymousLogger().log(Level.INFO, String .format("deleteObjectAsync returned task [%s] %s", this.toString(), path)); responseCallback.onSuccess(task); } else { Logger.getAnonymousLogger().log(Level.INFO, String.format("deleteObjectAsync failed [%s] %s", this.toString(), path)); } } @Override public void failed(Exception ex) { Logger.getAnonymousLogger().log(Level.INFO, "{}", ex); responseCallback.onFailure(ex); } @Override public void cancelled() { responseCallback.onFailure( new RuntimeException(String.format("deleteAsync %s was cancelled", path))); } }); } public final <T> void getObjectByPathAsync(final String path, final FutureCallback<T> responseCallback, final TypeReference<T> tr) throws IOException { getObjectByPathAsync(path, HttpStatus.SC_OK, responseCallback, tr); } public final <T> void getObjectByPathAsync(final String path, final int expectedStatus, final FutureCallback<T> responseCallback, final TypeReference<T> tr) throws IOException { this.restClient.performAsync(RestClient.Method.GET, path, null, new org.apache.http.concurrent.FutureCallback<HttpResponse>() { @Override public void completed(HttpResponse result) { T response = null; try { restClient.checkResponse(result, expectedStatus); response = restClient.parseHttpResponse(result, tr); } catch (Throwable e) { responseCallback.onFailure(e); } if (response != null) { Logger.getAnonymousLogger().log(Level.INFO, String .format("getObjectByPathAsync returned task [%s] %s", this.toString(), path)); responseCallback.onSuccess(response); } else { Logger.getAnonymousLogger().log(Level.INFO, String.format("getObjectByPathAsync failed [%s] %s", this.toString(), path)); } } @Override public void failed(Exception ex) { Logger.getAnonymousLogger().log(Level.INFO, "{}", ex); responseCallback.onFailure(ex); } @Override public void cancelled() { responseCallback.onFailure( new RuntimeException(String.format("getObjectByPathAsync %s was cancelled", path))); } }); } /** * Generates query string from query params. * * @param queryParams * @return * @throws UnsupportedEncodingException */ public String generateQueryString(Map<String, String> queryParams) throws UnsupportedEncodingException { StringBuilder query = new StringBuilder(); if (queryParams == null) { return query.toString(); } if (queryParams != null && queryParams.size() > 0) { query.append("?"); } for (Entry<String, String> param : queryParams.entrySet()) { query.append(String.format("%s=%s&", URLEncoder.encode(param.getKey(), "UTF-8"), URLEncoder.encode(param.getValue(), "UTF-8"))); } return query.deleteCharAt(query.length() - 1).toString(); } }