/**

* 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]