| /** |
| * 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.ha; |
| |
| import java.io.BufferedReader; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.io.InputStreamReader; |
| |
| import org.apache.commons.logging.Log; |
| |
| /** |
| * Class responsible for pumping the streams of the subprocess |
| * out to log4j. stderr is pumped to WARN level and stdout is |
| * pumped to INFO level |
| */ |
| class StreamPumper { |
| enum StreamType { |
| STDOUT, STDERR; |
| } |
| |
| private final Log log; |
| |
| final Thread thread; |
| final String logPrefix; |
| final StreamPumper.StreamType type; |
| private final InputStream stream; |
| private boolean started = false; |
| |
| StreamPumper(final Log log, final String logPrefix, |
| final InputStream stream, final StreamType type) { |
| this.log = log; |
| this.logPrefix = logPrefix; |
| this.stream = stream; |
| this.type = type; |
| |
| thread = new Thread(new Runnable() { |
| @Override |
| public void run() { |
| try { |
| pump(); |
| } catch (Throwable t) { |
| ShellCommandFencer.LOG.warn(logPrefix + |
| ": Unable to pump output from " + type, |
| t); |
| } |
| } |
| }, logPrefix + ": StreamPumper for " + type); |
| thread.setDaemon(true); |
| } |
| |
| void join() throws InterruptedException { |
| assert started; |
| thread.join(); |
| } |
| |
| void start() { |
| assert !started; |
| thread.start(); |
| started = true; |
| } |
| |
| protected void pump() throws IOException { |
| InputStreamReader inputStreamReader = new InputStreamReader(stream); |
| BufferedReader br = new BufferedReader(inputStreamReader); |
| String line = null; |
| while ((line = br.readLine()) != null) { |
| if (type == StreamType.STDOUT) { |
| log.info(logPrefix + ": " + line); |
| } else { |
| log.warn(logPrefix + ": " + line); |
| } |
| } |
| } |
| } |