ListLogs.java Source code

Introduction

Here is the source code for ListLogs.java

Source

/**
 * Copyright (c) 2015 Google Inc.
 *
 * 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.
 */
// [START imports]
import com.google.api.client.googleapis.auth.oauth2.GoogleCredential;
import com.google.api.client.http.HttpTransport;
import com.google.api.client.http.javanet.NetHttpTransport;
import com.google.api.client.json.JsonFactory;
import com.google.api.client.json.jackson2.JacksonFactory;
import com.google.api.client.util.Strings;
import com.google.api.services.logging.Logging;
import com.google.api.services.logging.LoggingScopes;
import com.google.api.services.logging.model.ListLogsResponse;
import com.google.api.services.logging.model.Log;

import java.io.IOException;
import java.net.URLDecoder;
import java.util.Collections;
import java.util.List;
// [END imports]

/**
 * Cloud Logging Java API sample that lists the logs available to a project.
 * Uses the v1beta3 Cloud Logging API, version 1.20.0 or later.
 * See https://cloud.google.com/logging/docs/api/libraries/.
 */
public class ListLogs {

    private static final List<String> LOGGING_SCOPES = Collections.singletonList(LoggingScopes.LOGGING_READ);

    private static final String APPLICATION_NAME = "ListLogs sample";

    /**
     * Returns an authorized Cloud Logging API service client that is usable
     * on Google App Engine, Google Compute Engine, workstations with the Google Cloud SDK,
     * and other computers if you install service account private credentials.
     * See https://cloud.google.com/logging/docs/api/tasks.
     */
    // [START auth]
    public static Logging getLoggingService() throws IOException {
        HttpTransport transport = new NetHttpTransport();
        JsonFactory jsonFactory = JacksonFactory.getDefaultInstance();
        GoogleCredential credential = GoogleCredential.getApplicationDefault(transport, jsonFactory);
        if (credential.createScopedRequired()) {
            credential = credential.createScoped(LOGGING_SCOPES);
        }
        Logging service = new Logging.Builder(transport, jsonFactory, credential)
                .setApplicationName(APPLICATION_NAME).build();
        return service;
    }
    // [END auth]

    /**
     * Lists the names of the logs visible to a project, which may require fetching multiple
     * pages of results from the Cloud Logging API. This method converts log resource names
     * ("/projects/PROJECTID/logs/SERVICENAME%2FLOGNAME") to simple log names ("SERVICENAME/LOGNAME").
     * 
     * @param service The logging service client returned by getLoggingService.
     * @param projectId The project whose logs are to be listed.
     * @throws IOException If the Cloud Logging API fails because, for example, the project ID
     *     doesn't exist or authorization fails.
     *     See https://cloud.google.com//logging/docs/api/tasks/#java_sample_code.
     */
    // [START listlogs]
    private static void listLogs(Logging service, String projectId) throws IOException {
        final int pageSize = 3;
        final int resourcePrefixLength = ("/projects/" + projectId + "/logs/").length();
        String nextPageToken = "";

        do {
            ListLogsResponse response = service.projects().logs().list(projectId).setPageToken(nextPageToken)
                    .setPageSize(pageSize).execute();
            if (response.isEmpty()) {
                break;
            }
            for (Log log : response.getLogs()) {
                System.out.println(URLDecoder.decode(log.getName().substring(resourcePrefixLength), "utf-8"));
            }
            nextPageToken = response.getNextPageToken();
        } while (!Strings.isNullOrEmpty(nextPageToken));
        System.out.println("Done.");
    }
    // [END listlogs]

    /**
     * Demonstrates the Cloud Logging API by listing the logs in a project.
     * @param args The project ID.
     * @throws IOException if a Cloud Logging API call fails because, say, the project ID is wrong
     *     or authorization fails.
     */
    public static void main(String[] args) throws IOException {
        if (args.length != 1) {
            System.err.println(String.format("Usage: %s <project-name>", ListLogs.class.getSimpleName()));
            return;
        }

        String projectId = args[0];
        Logging service = getLoggingService();
        listLogs(service, projectId);
    }
}
// [END all]