HDFS-4511. Cover package org.apache.hadoop.hdfs.tools with unit test (Andrey Klochkov via jeagles)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1533270 13f79535-47bb-0310-9956-ffa450edef68

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -326,6 +326,9 @@ Release 2.3.0 - UNRELEASED
 
     HDFS-5374. Remove deadcode in DFSOutputStream. (suresh)
 
+    HDFS-4511. Cover package org.apache.hadoop.hdfs.tools with unit test
+    (Andrey Klochkov via jeagles)
+
   OPTIMIZATIONS
 
     HDFS-5239.  Allow FSNamesystem lock fairness to be configurable (daryn)

hadoop-hdfs-project/hadoop-hdfs/dev-support/findbugsExcludeFile.xml

@@ -83,7 +83,7 @@
        <Class name="org.apache.hadoop.mapred.Task$TaskReporter" />
        <Method name="run" />
        <Bug pattern="DM_EXIT" />
-     </Match>
+     </Match>     
      <!--
        We need to cast objects between old and new api objects
      -->
@@ -325,6 +325,12 @@
        <Field name="modification" />
        <Bug pattern="VO_VOLATILE_INCREMENT" />
      </Match>
+      <!-- Replace System.exit() call with ExitUtil.terminate() -->
+     <Match>
+       <Class name="org.apache.hadoop.hdfs.tools.JMXGet"/>
+       <Method name="main" />
+       <Bug pattern="NP_NULL_ON_SOME_PATH" />
+     </Match>    
      <Match>
        <Class name="org.apache.hadoop.hdfs.server.datanode.ReplicaInfo" />
        <Method name="setDirInternal" />

hadoop-hdfs-project/hadoop-hdfs/pom.xml

@@ -176,6 +176,11 @@ http://maven.apache.org/xsd/maven-4.0.0.xsd">
       <artifactId>xmlenc</artifactId>
       <scope>compile</scope>
     </dependency>
+    <dependency>
+      <groupId>io.netty</groupId>
+      <artifactId>netty</artifactId>
+      <scope>test</scope>
+    </dependency>
   </dependencies>
 
   <build>

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/DelegationTokenFetcher.java

@@ -53,6 +53,7 @@ import org.apache.hadoop.security.Credentials;
 import org.apache.hadoop.security.SecurityUtil;
 import org.apache.hadoop.security.UserGroupInformation;
 import org.apache.hadoop.security.token.Token;
+import org.apache.hadoop.util.ExitUtil;
 import org.apache.hadoop.util.GenericOptionsParser;
 
 import com.google.common.base.Charsets;
@@ -86,7 +87,7 @@ public class DelegationTokenFetcher {
     err.println("  --print             Print the delegation token");
     err.println();
     GenericOptionsParser.printGenericCommandUsage(err);
-    System.exit(1);
+    ExitUtil.terminate(1);    
   }
 
   private static Collection<Token<?>> readTokens(Path file, Configuration conf)

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/JMXGet.java

@@ -43,6 +43,7 @@ import org.apache.commons.cli.Options;
 import org.apache.commons.cli.ParseException;
 
 import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.util.ExitUtil;
 
 /**
  * tool to get data from NameNode or DataNode using MBeans currently the
@@ -295,7 +296,7 @@ public class JMXGet {
       // invalid arguments
       err("Invalid args");
       printUsage(opts);
-      System.exit(-1);
+      ExitUtil.terminate(-1);      
     }
 
     JMXGet jm = new JMXGet();
@@ -317,7 +318,7 @@ public class JMXGet {
 
     if (commandLine.hasOption("help")) {
       printUsage(opts);
-      System.exit(0);
+      ExitUtil.terminate(0);
     }
 
     // rest of args
@@ -342,6 +343,6 @@ public class JMXGet {
       res = -1;
     }
 
-    System.exit(res);
+    ExitUtil.terminate(res);
   }
 }

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/tools/TestDelegationTokenRemoteFetcher.java

@@ -0,0 +1,358 @@
+/**
+ * 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.tools;
+
+import static org.jboss.netty.handler.codec.http.HttpMethod.GET;
+import static org.jboss.netty.handler.codec.http.HttpResponseStatus.OK;
+import static org.jboss.netty.handler.codec.http.HttpVersion.HTTP_1_1;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
+import java.io.IOException;
+import java.net.InetSocketAddress;
+import java.nio.charset.Charset;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.concurrent.Executors;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hdfs.HftpFileSystem;
+import org.apache.hadoop.hdfs.security.token.delegation.DelegationTokenIdentifier;
+import org.apache.hadoop.hdfs.tools.DelegationTokenFetcher;
+import org.apache.hadoop.io.DataOutputBuffer;
+import org.apache.hadoop.io.Text;
+import org.apache.hadoop.net.NetUtils;
+import org.apache.hadoop.security.Credentials;
+import org.apache.hadoop.security.token.Token;
+import org.apache.log4j.Logger;
+import org.jboss.netty.bootstrap.ServerBootstrap;
+import org.jboss.netty.buffer.ChannelBuffer;
+import org.jboss.netty.buffer.ChannelBuffers;
+import org.jboss.netty.channel.Channel;
+import org.jboss.netty.channel.ChannelFutureListener;
+import org.jboss.netty.channel.ChannelHandlerContext;
+import org.jboss.netty.channel.ChannelPipeline;
+import org.jboss.netty.channel.ChannelPipelineFactory;
+import org.jboss.netty.channel.Channels;
+import org.jboss.netty.channel.ExceptionEvent;
+import org.jboss.netty.channel.MessageEvent;
+import org.jboss.netty.channel.SimpleChannelUpstreamHandler;
+import org.jboss.netty.channel.socket.nio.NioServerSocketChannelFactory;
+import org.jboss.netty.handler.codec.http.DefaultHttpResponse;
+import org.jboss.netty.handler.codec.http.HttpChunkAggregator;
+import org.jboss.netty.handler.codec.http.HttpHeaders;
+import org.jboss.netty.handler.codec.http.HttpRequest;
+import org.jboss.netty.handler.codec.http.HttpRequestDecoder;
+import org.jboss.netty.handler.codec.http.HttpResponse;
+import org.jboss.netty.handler.codec.http.HttpResponseEncoder;
+import org.jboss.netty.handler.codec.http.HttpResponseStatus;
+import org.junit.After;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.UnmodifiableIterator;
+
+public class TestDelegationTokenRemoteFetcher {
+  private static final Logger LOG = Logger
+      .getLogger(TestDelegationTokenRemoteFetcher.class);
+
+  private static final String EXP_DATE = "124123512361236";
+  private static final String tokenFile = "http.file.dta";
+
+  private int httpPort;
+  private String serviceUrl;
+  private FileSystem fileSys;
+  private Configuration conf;
+  private ServerBootstrap bootstrap;
+  private Token<DelegationTokenIdentifier> testToken;
+  private volatile AssertionError assertionError;
+  
+  @Before
+  public void init() throws Exception {
+    conf = new Configuration();
+    fileSys = FileSystem.getLocal(conf);
+    httpPort = NetUtils.getFreeSocketPort();
+    serviceUrl = "http://localhost:" + httpPort;
+    testToken = createToken(serviceUrl);
+  }
+
+  @After
+  public void clean() throws IOException {
+    if (fileSys != null)
+      fileSys.delete(new Path(tokenFile), true);
+    if (bootstrap != null)
+      bootstrap.releaseExternalResources();
+  }
+
+  /**
+   * try to fetch token without http server with IOException
+   */
+  @Test
+  public void testTokenFetchFail() throws Exception {
+    try {
+      DelegationTokenFetcher.main(new String[] { "-webservice=" + serviceUrl,
+          tokenFile });
+      fail("Token fetcher shouldn't start in absense of NN");
+    } catch (IOException ex) {
+    }
+  }
+  
+  /**
+   * try to fetch token without http server with IOException
+   */
+  @Test
+  public void testTokenRenewFail() {
+    try {
+      DelegationTokenFetcher.renewDelegationToken(serviceUrl, testToken);
+      fail("Token fetcher shouldn't be able to renew tokens in absense of NN");
+    } catch (IOException ex) {
+    } 
+  }     
+  
+  /**
+   * try cancel token without http server with IOException
+   */
+  @Test
+  public void expectedTokenCancelFail() {
+    try {
+      DelegationTokenFetcher.cancelDelegationToken(serviceUrl, testToken);
+      fail("Token fetcher shouldn't be able to cancel tokens in absense of NN");
+    } catch (IOException ex) {
+    } 
+  }
+  
+  /**
+   * try fetch token and get http response with error
+   */
+  @Test  
+  public void expectedTokenRenewErrorHttpResponse() {
+    bootstrap = startHttpServer(httpPort, testToken, serviceUrl);
+    try {
+      DelegationTokenFetcher.renewDelegationToken(serviceUrl + "/exception", 
+          createToken(serviceUrl));
+      fail("Token fetcher shouldn't be able to renew tokens using an invalid"
+          + " NN URL");
+    } catch (IOException ex) {
+    } 
+    if (assertionError != null)
+      throw assertionError;
+  }
+  
+  /**
+   *   
+   *
+   */
+  @Test
+  public void testCancelTokenFromHttp() throws IOException {
+    bootstrap = startHttpServer(httpPort, testToken, serviceUrl);
+    DelegationTokenFetcher.cancelDelegationToken(serviceUrl, testToken);
+    if (assertionError != null)
+      throw assertionError;
+  }
+  
+  /**
+   * Call renew token using http server return new expiration time
+   */
+  @Test
+  public void testRenewTokenFromHttp() throws IOException {
+    bootstrap = startHttpServer(httpPort, testToken, serviceUrl);
+    assertTrue("testRenewTokenFromHttp error",
+        Long.valueOf(EXP_DATE) == DelegationTokenFetcher.renewDelegationToken(
+            serviceUrl, testToken));
+    if (assertionError != null)
+      throw assertionError;
+  }
+
+  /**
+   * Call fetch token using http server 
+   */
+  @Test
+  public void expectedTokenIsRetrievedFromHttp() throws Exception {
+    bootstrap = startHttpServer(httpPort, testToken, serviceUrl);
+    DelegationTokenFetcher.main(new String[] { "-webservice=" + serviceUrl,
+        tokenFile });
+    Path p = new Path(fileSys.getWorkingDirectory(), tokenFile);
+    Credentials creds = Credentials.readTokenStorageFile(p, conf);
+    Iterator<Token<?>> itr = creds.getAllTokens().iterator();
+    assertTrue("token not exist error", itr.hasNext());
+    Token<?> fetchedToken = itr.next();
+    Assert.assertArrayEquals("token wrong identifier error",
+        testToken.getIdentifier(), fetchedToken.getIdentifier());
+    Assert.assertArrayEquals("token wrong password error",
+        testToken.getPassword(), fetchedToken.getPassword());
+    if (assertionError != null)
+      throw assertionError;
+  }
+  
+  private static Token<DelegationTokenIdentifier> createToken(String serviceUri) {
+    byte[] pw = "hadoop".getBytes();
+    byte[] ident = new DelegationTokenIdentifier(new Text("owner"), new Text(
+        "renewer"), new Text("realuser")).getBytes();
+    Text service = new Text(serviceUri);
+    return new Token<DelegationTokenIdentifier>(ident, pw,
+        HftpFileSystem.TOKEN_KIND, service);
+  }
+
+  private interface Handler {
+    void handle(Channel channel, Token<DelegationTokenIdentifier> token,
+        String serviceUrl) throws IOException;
+  }
+
+  private class FetchHandler implements Handler {
+    
+    @Override
+    public void handle(Channel channel, Token<DelegationTokenIdentifier> token,
+        String serviceUrl) throws IOException {
+      Assert.assertEquals(testToken, token);
+
+      Credentials creds = new Credentials();
+      creds.addToken(new Text(serviceUrl), token);
+      DataOutputBuffer out = new DataOutputBuffer();
+      creds.write(out);
+      int fileLength = out.getData().length;
+      ChannelBuffer cbuffer = ChannelBuffers.buffer(fileLength);
+      cbuffer.writeBytes(out.getData());
+      HttpResponse response = new DefaultHttpResponse(HTTP_1_1, OK);
+      response.setHeader(HttpHeaders.Names.CONTENT_LENGTH,
+          String.valueOf(fileLength));
+      response.setContent(cbuffer);
+      channel.write(response).addListener(ChannelFutureListener.CLOSE);
+    }
+  }
+
+  private class RenewHandler implements Handler {
+    
+    @Override
+    public void handle(Channel channel, Token<DelegationTokenIdentifier> token,
+        String serviceUrl) throws IOException {
+      Assert.assertEquals(testToken, token);
+      byte[] bytes = EXP_DATE.getBytes();
+      ChannelBuffer cbuffer = ChannelBuffers.buffer(bytes.length);
+      cbuffer.writeBytes(bytes);
+      HttpResponse response = new DefaultHttpResponse(HTTP_1_1, OK);
+      response.setHeader(HttpHeaders.Names.CONTENT_LENGTH,
+          String.valueOf(bytes.length));
+      response.setContent(cbuffer);
+      channel.write(response).addListener(ChannelFutureListener.CLOSE);
+    }
+  }
+  
+  private class ExceptionHandler implements Handler {
+
+    @Override
+    public void handle(Channel channel, Token<DelegationTokenIdentifier> token,
+        String serviceUrl) throws IOException {
+      Assert.assertEquals(testToken, token);
+      HttpResponse response = new DefaultHttpResponse(HTTP_1_1, 
+          HttpResponseStatus.METHOD_NOT_ALLOWED);
+      channel.write(response).addListener(ChannelFutureListener.CLOSE);
+    }    
+  }
+  
+  private class CancelHandler implements Handler {
+
+    @Override
+    public void handle(Channel channel, Token<DelegationTokenIdentifier> token,
+        String serviceUrl) throws IOException {
+      Assert.assertEquals(testToken, token);
+      HttpResponse response = new DefaultHttpResponse(HTTP_1_1, OK);
+      channel.write(response).addListener(ChannelFutureListener.CLOSE);
+    }    
+  }
+  
+  private final class CredentialsLogicHandler extends
+      SimpleChannelUpstreamHandler {
+
+    private final Token<DelegationTokenIdentifier> token;
+    private final String serviceUrl;
+    private ImmutableMap<String, Handler> routes = ImmutableMap.of(
+        "/exception", new ExceptionHandler(),
+        "/cancelDelegationToken", new CancelHandler(),
+        "/getDelegationToken", new FetchHandler() , 
+        "/renewDelegationToken", new RenewHandler());
+
+    public CredentialsLogicHandler(Token<DelegationTokenIdentifier> token,
+        String serviceUrl) {
+      this.token = token;
+      this.serviceUrl = serviceUrl;
+    }
+
+    @Override
+    public void messageReceived(ChannelHandlerContext ctx, final MessageEvent e)
+        throws Exception {
+      HttpRequest request = (HttpRequest) e.getMessage();
+      if (request.getMethod() != GET) {
+        return;
+      }
+      UnmodifiableIterator<Map.Entry<String, Handler>> iter = routes.entrySet()
+          .iterator();
+      while (iter.hasNext()) {
+        Map.Entry<String, Handler> entry = iter.next();
+        if (request.getUri().contains(entry.getKey())) {
+          Handler handler = entry.getValue();
+          try {
+            handler.handle(e.getChannel(), token, serviceUrl);
+          } catch (AssertionError ee) {
+            TestDelegationTokenRemoteFetcher.this.assertionError = ee;
+            HttpResponse response = new DefaultHttpResponse(HTTP_1_1, 
+                HttpResponseStatus.BAD_REQUEST);
+            response.setContent(ChannelBuffers.copiedBuffer(ee.getMessage(), 
+                Charset.defaultCharset()));
+            e.getChannel().write(response).addListener(ChannelFutureListener.CLOSE);
+          }
+          return;
+        }
+      }
+    }
+
+    @Override
+    public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e)
+        throws Exception {
+      Channel ch = e.getChannel();
+      Throwable cause = e.getCause();
+
+      if (LOG.isDebugEnabled())
+        LOG.debug(cause.getMessage());
+      ch.close().addListener(ChannelFutureListener.CLOSE);
+    }
+  }
+
+  private ServerBootstrap startHttpServer(int port,
+      final Token<DelegationTokenIdentifier> token, final String url) {
+    ServerBootstrap bootstrap = new ServerBootstrap(
+        new NioServerSocketChannelFactory(Executors.newCachedThreadPool(),
+            Executors.newCachedThreadPool()));
+
+    bootstrap.setPipelineFactory(new ChannelPipelineFactory() {
+      @Override
+      public ChannelPipeline getPipeline() throws Exception {
+        return Channels.pipeline(new HttpRequestDecoder(),
+            new HttpChunkAggregator(65536), new HttpResponseEncoder(),
+            new CredentialsLogicHandler(token, url));
+      }
+    });
+    bootstrap.bind(new InetSocketAddress("localhost", port));
+    return bootstrap;
+  }
+  
+}

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/tools/TestJMXGet.java

@@ -21,9 +21,13 @@ package org.apache.hadoop.tools;
 import static org.apache.hadoop.test.MetricsAsserts.assertGauge;
 import static org.apache.hadoop.test.MetricsAsserts.getMetrics;
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
 
 import java.io.File;
 import java.io.IOException;
+import java.io.PipedInputStream;
+import java.io.PipedOutputStream;
+import java.io.PrintStream;
 import java.util.Random;
 
 import org.apache.hadoop.conf.Configuration;
@@ -92,6 +96,7 @@ public class TestJMXGet {
     //jmx.init();
     //jmx = new JMXGet();
     jmx.init(); // default lists namenode mbeans only
+    assertTrue("error printAllValues", checkPrintAllValues(jmx));
 
     //get some data from different source
     assertEquals(numDatanodes, Integer.parseInt(
@@ -103,7 +108,24 @@ public class TestJMXGet {
 
     cluster.shutdown();
   }
-
+  
+  private static boolean checkPrintAllValues(JMXGet jmx) throws Exception {
+    int size = 0; 
+    byte[] bytes = null;
+    String pattern = "List of all the available keys:";
+    PipedOutputStream pipeOut = new PipedOutputStream();
+    PipedInputStream pipeIn = new PipedInputStream(pipeOut);
+    System.setErr(new PrintStream(pipeOut));
+    jmx.printAllValues();
+    if ((size = pipeIn.available()) != 0) {
+      bytes = new byte[size];
+      pipeIn.read(bytes, 0, bytes.length);            
+    }
+    pipeOut.close();
+    pipeIn.close();
+    return bytes != null ? new String(bytes).contains(pattern) : false;
+  }
+  
   /**
    * test JMX connection to DataNode..
    * @throws Exception 

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/tools/TestTools.java

@@ -0,0 +1,160 @@
+package org.apache.hadoop.tools;
+
+/**
+ * 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.
+ */
+import static org.junit.Assert.*;
+
+import java.io.ByteArrayOutputStream;
+import java.io.PipedInputStream;
+import java.io.PipedOutputStream;
+import java.io.PrintStream;
+import org.apache.hadoop.hdfs.tools.DFSAdmin;
+import org.apache.hadoop.hdfs.tools.DelegationTokenFetcher;
+import org.apache.hadoop.hdfs.tools.JMXGet;
+import org.apache.hadoop.util.ExitUtil;
+import org.apache.hadoop.util.ToolRunner;
+import org.apache.hadoop.util.ExitUtil.ExitException;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.io.ByteStreams;
+
+public class TestTools {
+
+  private static final int PIPE_BUFFER_SIZE = 1024 * 5;
+  private final static String INVALID_OPTION = "-invalidOption";
+  private static final String[] OPTIONS = new String[2];
+
+  @BeforeClass
+  public static void before() {
+    ExitUtil.disableSystemExit();
+    OPTIONS[1] = INVALID_OPTION;
+  }
+
+  @Test  
+  public void testDelegationTokenFetcherPrintUsage() {
+    String pattern = "Options:";
+    checkOutput(new String[] { "-help" }, pattern, System.out,
+        DelegationTokenFetcher.class);
+  }
+
+  @Test  
+  public void testDelegationTokenFetcherErrorOption() {
+    String pattern = "ERROR: Only specify cancel, renew or print.";
+    checkOutput(new String[] { "-cancel", "-renew" }, pattern, System.err,
+        DelegationTokenFetcher.class);
+  }
+
+  @Test  
+  public void testJMXToolHelp() {
+    String pattern = "usage: jmxget options are:";
+    checkOutput(new String[] { "-help" }, pattern, System.out, JMXGet.class);
+  }
+
+  @Test  
+  public void testJMXToolAdditionParameter() {
+    String pattern = "key = -addition";
+    checkOutput(new String[] { "-service=NameNode", "-server=localhost",
+        "-addition" }, pattern, System.err, JMXGet.class);
+  }
+
+  @Test
+  public void testDFSAdminInvalidUsageHelp() {
+    ImmutableSet<String> args = ImmutableSet.of("-report", "-saveNamespace",
+        "-rollEdits", "-restoreFailedStorage", "-refreshNodes",
+        "-finalizeUpgrade", "-metasave", "-refreshUserToGroupsMappings",
+        "-printTopology", "-refreshNamenodes", "-deleteBlockPool",
+        "-setBalancerBandwidth", "-fetchImage");
+    try {
+      for (String arg : args)
+        assertTrue(ToolRunner.run(new DFSAdmin(), fillArgs(arg)) == -1);
+      
+      assertTrue(ToolRunner.run(new DFSAdmin(),
+          new String[] { "-help", "-some" }) == 0);
+    } catch (Exception e) {
+      fail("testDFSAdminHelp error" + e);
+    }
+
+    String pattern = "Usage: java DFSAdmin";
+    checkOutput(new String[] { "-cancel", "-renew" }, pattern, System.err,
+        DFSAdmin.class);
+  }
+
+  private static String[] fillArgs(String arg) {
+    OPTIONS[0] = arg;
+    return OPTIONS;
+  }
+
+  private void checkOutput(String[] args, String pattern, PrintStream out,
+      Class<?> clazz) {       
+    ByteArrayOutputStream outBytes = new ByteArrayOutputStream();
+    try {
+      PipedOutputStream pipeOut = new PipedOutputStream();
+      PipedInputStream pipeIn = new PipedInputStream(pipeOut, PIPE_BUFFER_SIZE);
+      if (out == System.out) {
+        System.setOut(new PrintStream(pipeOut));
+      } else if (out == System.err) {
+        System.setErr(new PrintStream(pipeOut));
+      }
+
+      if (clazz == DelegationTokenFetcher.class) {
+        expectDelegationTokenFetcherExit(args);
+      } else if (clazz == JMXGet.class) {
+        expectJMXGetExit(args);
+      } else if (clazz == DFSAdmin.class) {
+        expectDfsAdminPrint(args);
+      }
+      pipeOut.close();
+      ByteStreams.copy(pipeIn, outBytes);      
+      pipeIn.close();
+      assertTrue(new String(outBytes.toByteArray()).contains(pattern));            
+    } catch (Exception ex) {
+      fail("checkOutput error " + ex);
+    }
+  }
+
+  private void expectDfsAdminPrint(String[] args) {
+    try {
+      ToolRunner.run(new DFSAdmin(), args);
+    } catch (Exception ex) {
+      fail("expectDelegationTokenFetcherExit ex error " + ex);
+    }
+  }
+
+  private static void expectDelegationTokenFetcherExit(String[] args) {
+    try {
+      DelegationTokenFetcher.main(args);
+      fail("should call exit");
+    } catch (ExitException e) {
+      ExitUtil.resetFirstExitException();
+    } catch (Exception ex) {
+      fail("expectDelegationTokenFetcherExit ex error " + ex);
+    }
+  }
+
+  private static void expectJMXGetExit(String[] args) {
+    try {
+      JMXGet.main(args);
+      fail("should call exit");
+    } catch (ExitException e) {
+      ExitUtil.resetFirstExitException();
+    } catch (Exception ex) {
+      fail("expectJMXGetExit ex error " + ex);
+    }
+  }
+}