adding list logs snippet (#830)

logging/cloud-client/src/main/java/com/example/logging/ListLogs.java

@@ -0,0 +1,52 @@
+/*
+  Copyright 2017 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.
+*/
+
+package com.example.logging;
+
+import com.google.api.gax.paging.Page;
+import com.google.cloud.logging.LogEntry;
+import com.google.cloud.logging.Logging;
+import com.google.cloud.logging.Logging.EntryListOption;
+import com.google.cloud.logging.LoggingOptions;
+
+/**
+ * List logs programmatically using the StackDriver Logging API.
+ */
+public class ListLogs {
+
+  /** Expects an existing Stackdriver log name as an argument. */
+  public static void main(String... args) throws Exception {
+    // [START listlogs]
+    // Instantiates a client
+    LoggingOptions options = LoggingOptions.getDefaultInstance();
+
+    String logName = args[0];
+
+    try (Logging logging = options.getService()) {
+
+      String logFilter = "logName=projects/" + options.getProjectId() + "/logs/" + logName;
+
+      // List log entries
+      Page<LogEntry> entries = logging.listLogEntries(
+          EntryListOption.filter(logFilter));
+      for (LogEntry logEntry : entries.iterateAll()) {
+        System.out.println(logEntry);
+      }
+      // Use entries.getNextPage() to paginate
+    }
+    // [END listlogs]
+  }
+}

logging/jul/src/main/resources/logging.properties

@@ -20,6 +20,9 @@ com.google.cloud.logging.LoggingHandler.level=FINE
 # default : ERROR
 com.google.cloud.logging.LoggingHandler.flushLevel=ERROR
 
+# default : auto-detected, fallback "global"
+com.google.cloud.logging.LoggingHandler.resourceType=container
+
 # custom formatter
 com.google.cloud.logging.LoggingHandler.formatter=java.util.logging.SimpleFormatter
 java.util.logging.SimpleFormatter.format=%3$s: %5$s%6$s

logging/logback/src/main/resources/logback.xml

@@ -21,6 +21,7 @@
       <level>INFO</level>
     </filter>
     <log>application.log</log> <!-- Optional : default java.log -->
+    <resourceType>gae_app</resourceType> <!-- Optional : default: auto-detected, fallback: global -->
     <enhancer>com.example.logging.logback.enhancers.ExampleEnhancer</enhancer> <!-- Optional -->
     <flushLevel>WARN</flushLevel> <!-- Optional : default ERROR -->
   </appender>