org.springframework.yarn.test.support.ContainerLogUtils.java Source code

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Here is the source code for org.springframework.yarn.test.support.ContainerLogUtils.java

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/*
 * Copyright 2014 the original author or authors.
 *
 * 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 org.springframework.yarn.test.support;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.yarn.api.records.ApplicationId;
import org.springframework.core.io.Resource;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.util.StringUtils;
import org.springframework.yarn.test.context.YarnCluster;

/**
 * Utilities for checking container logs.
 *
 * @author Janne Valkealahti
 *
 */
public abstract class ContainerLogUtils {

    static Log log = LogFactory.getLog(ContainerLogUtils.class);

    /**
     * Find container logs for running cluster and application.
     * <p>
     * Created pattern which is used with {@code PathMatchingResourcePatternResolver}
     * is resolved from {@code YarnCluster}, {@code ApplicationId} and fileName.
     * For example if fileName is given as <code>*.std*</code>, pattern will look like
     * <code>file:/path/to/project/target/yarn--1502101888/*logDir*&#47;application_1382082435804_0001&#47;**&#47;*.std*</code>
     *
     * @param yarnCluster the yarn cluster
     * @param applicationId the application id
     * @param fileName the part of a file name
     * @return the list of log file {@code Resource}s
     * @throws IOException Signals that an I/O exception has occurred.
     */
    public static List<Resource> queryContainerLogs(YarnCluster yarnCluster, ApplicationId applicationId,
            String fileName) throws IOException {
        String lastPart = StringUtils.hasText(fileName) ? fileName : "*";
        String pattern = "file:" + yarnCluster.getYarnWorkDir().getAbsolutePath() + "/*logDir*/"
                + applicationId.toString() + "/**/" + lastPart;
        PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
        ArrayList<Resource> ret = new ArrayList<Resource>();
        for (Resource r : resolver.getResources(pattern)) {
            if (r.getFile().isFile()) {
                ret.add(r);
            }
        }
        return ret;
    }

    /**
     * Find container logs for running cluster and application. <code>fileName</code>
     * will be <code>*</code>.
     *
     * @param yarnCluster the yarn cluster
     * @param applicationId the application id
     * @return the list of log file {@code Resource}s
     * @throws IOException Signals that an I/O exception has occurred.
     * @see #queryContainerLogs(YarnCluster, ApplicationId, String)
     */
    public static List<Resource> queryContainerLogs(YarnCluster yarnCluster, ApplicationId applicationId)
            throws IOException {
        return queryContainerLogs(yarnCluster, applicationId, null);
    }

    /**
     * Reads a file content and return it as String. Returns <code>NULL</code>
     * if file doesn't exist and empty String if file exists but is empty.
     * @param file the file
     * @return the file content
     * @throws Exception the exception if error occurred
     */
    public static String getFileContent(File file) throws Exception {
        Scanner scanner = null;
        String content = null;
        Exception reThrow = null;
        if (file != null && file.length() > 0) {
            try {
                scanner = new Scanner(file);
                content = scanner.useDelimiter("\\A").next();
            } catch (Exception e) {
                reThrow = e;
            } finally {
                if (scanner != null) {
                    try {
                        scanner.close();
                    } catch (Exception e) {
                    }
                }
            }
        } else if (file != null && file.length() == 0) {
            content = "";
        }
        if (reThrow != null) {
            throw reThrow;
        } else {
            return content;
        }
    }

}