可以直接使用org.apache.hadoop.yarn.client.cli.LogsCLI（yarn logs -applicationId）中的main方法逻辑，如
public static void main(String[] args)
throws Exception
{
Configuration conf = new YarnConfiguration();
conf.addResource(new Path("/etc/hadoop/conf.cloudera.yarn/core-site.xml"));
conf.addResource(new Path("/etc/hadoop/conf.cloudera.yarn/yarn-site.xml"));
conf.addResource(new Path("/etc/hadoop/conf.cloudera.yarn/hdfs-site.xml"));
LogsCLI logDumper = new LogsCLI();
logDumper.setConf(conf);
int exitCode = logDumper.run(args);
System.exit(exitCode);
}
也可以仿照他的逻辑自己实现如下：
Configuration conf = new YarnConfiguration();
conf.addResource(new Path("/etc/hadoop/conf.cloudera.yarn/core-site.xml"));
conf.addResource(new Path("/etc/hadoop/conf.cloudera.yarn/yarn-site.xml"));
conf.addResource(new Path("/etc/hadoop/conf.cloudera.yarn/hdfs-site.xml"));
String appIdStr="application_1529377575914_8380";
PrintStream out=new PrintStream(appIdStr);
ApplicationId appId = null;
appId = ConverterUtils.toApplicationId(appIdStr);
Path remoteRootLogDir = new Path(conf.get("yarn.nodemanager.remote-app-log-dir", "/tmp/logs"));
String user = UserGroupInformation.getCurrentUser().getShortUserName();;
String logDirSuffix = LogAggregationUtils.getRemoteNodeLogDirSuffix(conf);
Path remoteAppLogDir = LogAggregationUtils.getRemoteAppLogDir(remoteRootLogDir, appId, user, logDirSuffix);
RemoteIterator<FileStatus> nodeFiles;
try
{
Path qualifiedLogDir = FileContext.getFileContext(conf).makeQualified(remoteAppLogDir);
nodeFiles = FileContext.getFileContext(qualifiedLogDir.toUri(), conf).listStatus(remoteAppLogDir);
}
catch (FileNotFoundException fnf)
{
logDirNotExist(remoteAppLogDir.toString());
return -1;
}
boolean foundAnyLogs = false;
while (nodeFiles.hasNext())
{
FileStatus thisNodeFile = (FileStatus)nodeFiles.next();
if (!thisNodeFile.getPath().getName().endsWith(".tmp"))
{
AggregatedLogFormat.LogReader reader = new AggregatedLogFormat.LogReader(conf, thisNodeFile.getPath());
try
{
//System.out.println(thisNodeFile.getPath().getName());
AggregatedLogFormat.LogKey key = new AggregatedLogFormat.LogKey();
DataInputStream valueStream = reader.next(key);
for (;;)
{
if (valueStream != null)
{
String containerString = "\n\nContainer: " + key + " on " + thisNodeFile.getPath().getName();
out.println(containerString);
out.println(StringUtils.repeat("=", containerString.length()));
try
{
for (;;)
{
AggregatedLogFormat.LogReader.readAContainerLogsForALogType(valueStream, out, thisNodeFile.getModificationTime());
foundAnyLogs = true;
}
}
catch (EOFException eof)
{
key = new AggregatedLogFormat.LogKey();
valueStream = reader.next(key);
}
}else{
break;
}
}
}
finally
{
reader.close();
}
}
}
if (!foundAnyLogs)
{
emptyLogDir(remoteAppLogDir.toString());
return -1;
}
return 0;
}