Java tutorial
/** * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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 org.apache.hadoop.mapreduce.v2.app.webapp; import static org.apache.hadoop.yarn.util.StringHelper.join; import java.io.IOException; import java.net.URLDecoder; import javax.servlet.http.HttpServletResponse; import org.apache.commons.lang.StringUtils; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.mapreduce.JobACL; import org.apache.hadoop.mapreduce.v2.api.records.JobId; import org.apache.hadoop.mapreduce.v2.api.records.TaskId; import org.apache.hadoop.mapreduce.v2.app.job.Job; import org.apache.hadoop.mapreduce.v2.app.webapp.dao.AppInfo; import org.apache.hadoop.mapreduce.v2.util.MRApps; import org.apache.hadoop.mapreduce.v2.util.MRWebAppUtil; import org.apache.hadoop.security.UserGroupInformation; import org.apache.hadoop.yarn.util.StringHelper; import org.apache.hadoop.yarn.util.Times; import org.apache.hadoop.yarn.webapp.Controller; import org.apache.hadoop.yarn.webapp.View; import org.apache.hadoop.yarn.webapp.util.WebAppUtils; import com.google.common.base.Joiner; import com.google.inject.Inject; /** * This class renders the various pages that the web app supports. */ public class AppController extends Controller implements AMParams { private static final Log LOG = LogFactory.getLog(AppController.class); private static final Joiner JOINER = Joiner.on(""); protected final App app; protected AppController(App app, Configuration conf, RequestContext ctx, String title) { super(ctx); this.app = app; set(APP_ID, app.context.getApplicationID().toString()); set(RM_WEB, JOINER.join(MRWebAppUtil.getYARNWebappScheme(), WebAppUtils.getResolvedRemoteRMWebAppURLWithoutScheme(conf, MRWebAppUtil.getYARNHttpPolicy()))); } @Inject protected AppController(App app, Configuration conf, RequestContext ctx) { this(app, conf, ctx, "am"); } /** * Render the default(index.html) page for the Application Controller */ @Override public void index() { setTitle(join("MapReduce Application ", $(APP_ID))); } /** * Render the /info page with an overview of current application. */ public void info() { AppInfo info = new AppInfo(app, app.context); info("Application Master Overview")._("Application ID:", info.getId()) ._("Application Name:", info.getName())._("User:", info.getUser()) ._("Started on:", Times.format(info.getStartTime())) ._("Elasped: ", org.apache.hadoop.util.StringUtils.formatTime(info.getElapsedTime())); render(InfoPage.class); } /** * @return The class that will render the /job page */ protected Class<? extends View> jobPage() { return JobPage.class; } /** * Render the /job page */ public void job() { try { requireJob(); } catch (Exception e) { renderText(e.getMessage()); return; } render(jobPage()); } /** * @return the class that will render the /jobcounters page */ protected Class<? extends View> countersPage() { return CountersPage.class; } /** * Render the /jobcounters page */ public void jobCounters() { try { requireJob(); } catch (Exception e) { renderText(e.getMessage()); return; } if (app.getJob() != null) { setTitle(join("Counters for ", $(JOB_ID))); } render(countersPage()); } /** * Display a page showing a task's counters */ public void taskCounters() { try { requireTask(); } catch (Exception e) { renderText(e.getMessage()); return; } if (app.getTask() != null) { setTitle(StringHelper.join("Counters for ", $(TASK_ID))); } render(countersPage()); } /** * @return the class that will render the /singlejobcounter page */ protected Class<? extends View> singleCounterPage() { return SingleCounterPage.class; } /** * Render the /singlejobcounter page * @throws IOException on any error. */ public void singleJobCounter() throws IOException { try { requireJob(); } catch (Exception e) { renderText(e.getMessage()); return; } set(COUNTER_GROUP, URLDecoder.decode($(COUNTER_GROUP), "UTF-8")); set(COUNTER_NAME, URLDecoder.decode($(COUNTER_NAME), "UTF-8")); if (app.getJob() != null) { setTitle(StringHelper.join($(COUNTER_GROUP), " ", $(COUNTER_NAME), " for ", $(JOB_ID))); } render(singleCounterPage()); } /** * Render the /singletaskcounter page * @throws IOException on any error. */ public void singleTaskCounter() throws IOException { try { requireTask(); } catch (Exception e) { renderText(e.getMessage()); return; } set(COUNTER_GROUP, URLDecoder.decode($(COUNTER_GROUP), "UTF-8")); set(COUNTER_NAME, URLDecoder.decode($(COUNTER_NAME), "UTF-8")); if (app.getTask() != null) { setTitle(StringHelper.join($(COUNTER_GROUP), " ", $(COUNTER_NAME), " for ", $(TASK_ID))); } render(singleCounterPage()); } /** * @return the class that will render the /tasks page */ protected Class<? extends View> tasksPage() { return TasksPage.class; } /** * Render the /tasks page */ public void tasks() { try { requireJob(); } catch (Exception e) { renderText(e.getMessage()); return; } if (app.getJob() != null) { try { String tt = $(TASK_TYPE); tt = tt.isEmpty() ? "All" : StringUtils.capitalize( org.apache.hadoop.util.StringUtils.toLowerCase(MRApps.taskType(tt).toString())); setTitle(join(tt, " Tasks for ", $(JOB_ID))); } catch (Exception e) { LOG.error("Failed to render tasks page with task type : " + $(TASK_TYPE) + " for job id : " + $(JOB_ID), e); badRequest(e.getMessage()); } } render(tasksPage()); } /** * @return the class that will render the /task page */ protected Class<? extends View> taskPage() { return TaskPage.class; } /** * Render the /task page */ public void task() { try { requireTask(); } catch (Exception e) { renderText(e.getMessage()); return; } if (app.getTask() != null) { setTitle(join("Attempts for ", $(TASK_ID))); } render(taskPage()); } /** * @return the class that will render the /attempts page */ protected Class<? extends View> attemptsPage() { return AttemptsPage.class; } /** * Render the attempts page */ public void attempts() { try { requireJob(); } catch (Exception e) { renderText(e.getMessage()); return; } if (app.getJob() != null) { try { String taskType = $(TASK_TYPE); if (taskType.isEmpty()) { throw new RuntimeException("missing task-type."); } String attemptState = $(ATTEMPT_STATE); if (attemptState.isEmpty()) { throw new RuntimeException("missing attempt-state."); } setTitle(join(attemptState, " ", MRApps.taskType(taskType).toString(), " attempts in ", $(JOB_ID))); render(attemptsPage()); } catch (Exception e) { LOG.error("Failed to render attempts page with task type : " + $(TASK_TYPE) + " for job id : " + $(JOB_ID), e); badRequest(e.getMessage()); } } } /** * @return the page that will be used to render the /conf page */ protected Class<? extends View> confPage() { return JobConfPage.class; } /** * Render the /conf page */ public void conf() { try { requireJob(); } catch (Exception e) { renderText(e.getMessage()); return; } render(confPage()); } /** * Render a BAD_REQUEST error. * @param s the error message to include. */ void badRequest(String s) { setStatus(HttpServletResponse.SC_BAD_REQUEST); String title = "Bad request: "; setTitle((s != null) ? join(title, s) : title); } /** * Render a NOT_FOUND error. * @param s the error message to include. */ void notFound(String s) { setStatus(HttpServletResponse.SC_NOT_FOUND); setTitle(join("Not found: ", s)); } /** * Render a ACCESS_DENIED error. * @param s the error message to include. */ void accessDenied(String s) { setStatus(HttpServletResponse.SC_FORBIDDEN); setTitle(join("Access denied: ", s)); } /** * check for job access. * @param job the job that is being accessed * @return True if the requesting user has permission to view the job */ boolean checkAccess(Job job) { String remoteUser = request().getRemoteUser(); UserGroupInformation callerUGI = null; if (remoteUser != null) { callerUGI = UserGroupInformation.createRemoteUser(remoteUser); } if (callerUGI != null && !job.checkAccess(callerUGI, JobACL.VIEW_JOB)) { return false; } return true; } /** * Ensure that a JOB_ID was passed into the page. */ public void requireJob() { if ($(JOB_ID).isEmpty()) { badRequest("missing job ID"); throw new RuntimeException("Bad Request: Missing job ID"); } JobId jobID = MRApps.toJobID($(JOB_ID)); app.setJob(app.context.getJob(jobID)); if (app.getJob() == null) { notFound($(JOB_ID)); throw new RuntimeException("Not Found: " + $(JOB_ID)); } /* check for acl access */ Job job = app.context.getJob(jobID); if (!checkAccess(job)) { accessDenied("User " + request().getRemoteUser() + " does not have " + " permission to view job " + $(JOB_ID)); throw new RuntimeException("Access denied: User " + request().getRemoteUser() + " does not have permission to view job " + $(JOB_ID)); } } /** * Ensure that a TASK_ID was passed into the page. */ public void requireTask() { if ($(TASK_ID).isEmpty()) { badRequest("missing task ID"); throw new RuntimeException("missing task ID"); } TaskId taskID = MRApps.toTaskID($(TASK_ID)); Job job = app.context.getJob(taskID.getJobId()); app.setJob(job); if (app.getJob() == null) { notFound(MRApps.toString(taskID.getJobId())); throw new RuntimeException("Not Found: " + $(JOB_ID)); } else { app.setTask(app.getJob().getTask(taskID)); if (app.getTask() == null) { notFound($(TASK_ID)); throw new RuntimeException("Not Found: " + $(TASK_ID)); } } if (!checkAccess(job)) { accessDenied("User " + request().getRemoteUser() + " does not have " + " permission to view job " + $(JOB_ID)); throw new RuntimeException("Access denied: User " + request().getRemoteUser() + " does not have permission to view job " + $(JOB_ID)); } } }