HADOOP-13824. FsShell can suppress the real error if no error message is present. Contributed by John Zhuge.

(cherry picked from commit b606e025f1)

Conflicts:
   hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/TestFsShell.java

(cherry picked from commit 6c93c1870c)
This commit is contained in:
Wei-Chiu Chuang 2016-12-09 15:39:12 -08:00
parent e8b0ef0618
commit 983d487e98
3 changed files with 117 additions and 29 deletions

View File

@ -317,7 +317,12 @@ public class FsShell extends Configured implements Tool {
scope.close();
}
} catch (IllegalArgumentException e) {
displayError(cmd, e.getLocalizedMessage());
if (e.getMessage() == null) {
displayError(cmd, "Null exception message");
e.printStackTrace(System.err);
} else {
displayError(cmd, e.getLocalizedMessage());
}
printUsage(System.err);
if (instance != null) {
printInstanceUsage(System.err, instance);

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@ -17,18 +17,19 @@
*/
package org.apache.hadoop.fs;
import java.io.ByteArrayOutputStream;
import java.io.PrintStream;
import junit.framework.AssertionFailedError;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.io.IOUtils;
import org.apache.hadoop.fs.shell.Command;
import org.apache.hadoop.fs.shell.CommandFactory;
import org.apache.hadoop.test.GenericTestUtils;
import org.apache.hadoop.tracing.SetSpanReceiver;
import org.apache.hadoop.util.ToolRunner;
import org.apache.htrace.core.AlwaysSampler;
import org.apache.htrace.core.Tracer;
import org.hamcrest.core.StringContains;
import org.junit.Assert;
import org.junit.Test;
import org.mockito.Mockito;
public class TestFsShell {
@ -73,30 +74,42 @@ public class TestFsShell {
@Test
public void testDFSWithInvalidCommmand() throws Throwable {
Configuration conf = new Configuration();
FsShell shell = new FsShell(conf);
String[] args = new String[1];
args[0] = "dfs -mkdirs";
final ByteArrayOutputStream bytes = new ByteArrayOutputStream();
final PrintStream out = new PrintStream(bytes);
final PrintStream oldErr = System.err;
try {
System.setErr(out);
ToolRunner.run(shell, args);
String errorValue=new String(bytes.toString());
Assert
.assertTrue(
"FSShell dfs command did not print the error " +
"message when invalid command is passed",
errorValue.contains("-mkdirs: Unknown command"));
Assert
.assertTrue(
"FSShell dfs command did not print help " +
FsShell shell = new FsShell(new Configuration());
try (GenericTestUtils.SystemErrCapturer capture =
new GenericTestUtils.SystemErrCapturer()) {
ToolRunner.run(shell, new String[]{"dfs -mkdirs"});
Assert.assertThat("FSShell dfs command did not print the error " +
"message when invalid command is passed",
errorValue.contains("Usage: hadoop fs [generic options]"));
} finally {
IOUtils.closeStream(out);
System.setErr(oldErr);
capture.getOutput(), StringContains.containsString(
"-mkdirs: Unknown command"));
Assert.assertThat("FSShell dfs command did not print help " +
"message when invalid command is passed",
capture.getOutput(), StringContains.containsString(
"Usage: hadoop fs [generic options]"));
}
}
@Test
public void testExceptionNullMessage() throws Exception {
final String cmdName = "-cmdExNullMsg";
final Command cmd = Mockito.mock(Command.class);
Mockito.when(cmd.run(Mockito.<String>anyVararg())).thenThrow(
new IllegalArgumentException());
Mockito.when(cmd.getUsage()).thenReturn(cmdName);
final CommandFactory cmdFactory = Mockito.mock(CommandFactory.class);
final String[] names = {cmdName};
Mockito.when(cmdFactory.getNames()).thenReturn(names);
Mockito.when(cmdFactory.getInstance(cmdName)).thenReturn(cmd);
FsShell shell = new FsShell(new Configuration());
shell.commandFactory = cmdFactory;
try (GenericTestUtils.SystemErrCapturer capture =
new GenericTestUtils.SystemErrCapturer()) {
ToolRunner.run(shell, new String[]{cmdName});
Assert.assertThat(capture.getOutput(),
StringContains.containsString(cmdName
+ ": Null exception message"));
}
}
}

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@ -18,10 +18,13 @@
package org.apache.hadoop.test;
import java.io.BufferedReader;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintStream;
import java.io.StringWriter;
import java.lang.management.ManagementFactory;
import java.lang.management.ThreadInfo;
@ -272,7 +275,74 @@ public abstract class GenericTestUtils {
"Thread diagnostics:\n" +
TimedOutTestsListener.buildThreadDiagnosticString());
}
/**
* Prints output to one {@link PrintStream} while copying to the other.
* <p>
* Closing the main {@link PrintStream} will NOT close the other.
*/
public static class TeePrintStream extends PrintStream {
private final PrintStream other;
public TeePrintStream(OutputStream main, PrintStream other) {
super(main);
this.other = other;
}
@Override
public void flush() {
super.flush();
other.flush();
}
@Override
public void write(byte[] buf, int off, int len) {
super.write(buf, off, len);
other.write(buf, off, len);
}
}
/**
* Capture output printed to {@link System#err}.
* <p>
* Usage:
* <pre>
* try (SystemErrCapturer capture = new SystemErrCapturer()) {
* ...
* // Call capture.getOutput() to get the output string
* }
* </pre>
*
* TODO: Add lambda support once Java 8 is common.
* <pre>
* SystemErrCapturer.withCapture(capture -> {
* ...
* })
* </pre>
*/
public static class SystemErrCapturer implements AutoCloseable {
final private ByteArrayOutputStream bytes;
final private PrintStream bytesPrintStream;
final private PrintStream oldErr;
public SystemErrCapturer() {
bytes = new ByteArrayOutputStream();
bytesPrintStream = new PrintStream(bytes);
oldErr = System.err;
System.setErr(new TeePrintStream(oldErr, bytesPrintStream));
}
public String getOutput() {
return bytes.toString();
}
@Override
public void close() throws Exception {
IOUtils.closeQuietly(bytesPrintStream);
System.setErr(oldErr);
}
}
public static class LogCapturer {
private StringWriter sw = new StringWriter();
private WriterAppender appender;