[FLINK-6688] Activate strict checkstyle for flink-test-utils

This closes apache#3983.

flink-test-utils-parent/flink-test-utils-junit/src/main/java/org/apache/flink/core/testutils/CheckedThread.java

@@ -31,7 +31,7 @@
  */
 public abstract class CheckedThread extends Thread {
 
-	/** The error thrown from the main work method */
+	/** The error thrown from the main work method. */
 	private volatile Throwable error;
 
 	// ------------------------------------------------------------------------

flink-test-utils-parent/flink-test-utils-junit/src/main/java/org/apache/flink/core/testutils/CommonTestUtils.java

@@ -46,7 +46,7 @@ public class CommonTestUtils {
 
 	/**
 	 * Reads the path to the directory for temporary files from the configuration and returns it.
-	 * 
+	 *
 	 * @return the path to the directory for temporary files
 	 */
 	public static String getTempDir() {
@@ -85,9 +85,9 @@ public static <T extends java.io.Serializable> T createCopySerializable(T origin
 	/**
 	 * Creates a temporary file that contains the given string.
 	 * The file is written with the platform's default encoding.
-	 * 
+	 *
 	 * <p>The temp file is automatically deleted on JVM exit.
-	 * 
+	 *
 	 * @param contents The contents to be written to the file.
 	 * @return The temp file URI.
 	 */
@@ -267,7 +267,7 @@ public static Class<? extends Serializable> createClassNotInClassPath(ClassLoade
 				29, 0, 0, 0, 1, 0, 39, 0, 40, 0, 1, 0, 25, 0, 0, 0, 70, 0, 3, 0, 1, 0, 0, 0, 28, -69, 0, 8,
 				89, -73, 0, 9, 18, 10, -74, 0, 11, 42, -76, 0, 5, -74, 0, 12, 16, 125, -74, 0, 13, -74, 0, 14,
 				-80, 0, 0, 0, 2, 0, 26, 0, 0, 0, 6, 0, 1, 0, 0, 0, 51, 0, 27, 0, 0, 0, 12, 0, 1, 0, 0, 0, 28,
-				0, 28, 0, 29, 0, 0, 0, 1, 0, 41, 0, 0, 0, 2, 0, 42,};
+				0, 28, 0, 29, 0, 0, 0, 1, 0, 41, 0, 0, 0, 2, 0, 42};
 
 		try {
 			// define a class into the classloader

flink-test-utils-parent/flink-test-utils-junit/src/main/java/org/apache/flink/core/testutils/ManuallyTriggeredDirectExecutor.java

@@ -19,13 +19,14 @@
 package org.apache.flink.core.testutils;
 
 import javax.annotation.Nonnull;
+
 import java.util.ArrayDeque;
 import java.util.concurrent.Executor;
 
 /**
  * An executor that does not immediately execute a Runnable, but only executes it
  * upon an explicit trigger.
- * 
+ *
  * <p>This executor can be used in concurrent tests to control when certain asynchronous
  * actions should happen.
  */

flink-test-utils-parent/flink-test-utils-junit/src/main/java/org/apache/flink/core/testutils/OneShotLatch.java

@@ -47,7 +47,7 @@ public void trigger() {
 	/**
 	 * Waits until {@link OneShotLatch#trigger()} is called. Once {@code trigger()} has been called this
 	 * call will always return immediately.
-	 * 
+	 *
 	 * @throws InterruptedException Thrown if the thread is interrupted while waiting.
 	 */
 	public void await() throws InterruptedException {
@@ -61,15 +61,15 @@ public void await() throws InterruptedException {
 	/**
 	 * Waits until {@link OneShotLatch#trigger()} is called. Once {@code #trigger()} has been called this
 	 * call will always return immediately.
-	 * 
+	 *
 	 * <p>If the latch is not triggered within the given timeout, a {@code TimeoutException}
 	 * will be thrown after the timeout.
-	 * 
+	 *
 	 * <p>A timeout value of zero means infinite timeout and make this equivalent to {@link #await()}.
-	 * 
+	 *
 	 * @param timeout   The value of the timeout, a value of zero indicating infinite timeout.
 	 * @param timeUnit  The unit of the timeout
-	 * 
+	 *
 	 * @throws InterruptedException Thrown if the thread is interrupted while waiting.
 	 * @throws TimeoutException Thrown, if the latch is not triggered within the timeout time.
 	 */
@@ -101,15 +101,15 @@ public void await(long timeout, TimeUnit timeUnit) throws InterruptedException,
 
 	/**
 	 * Checks if the latch was triggered.
-	 * 
+	 *
 	 * @return True, if the latch was triggered, false if not.
 	 */
 	public boolean isTriggered() {
 		return triggered;
 	}
 
 	/**
-	 * resets the latch to triggered = false
+	 * Resets the latch so that {@link #isTriggered()} returns false.
 	 */
 	public void reset() {
 		synchronized (lock) {

flink-test-utils-parent/flink-test-utils-junit/src/main/java/org/apache/flink/testutils/junit/RetryOnException.java

@@ -40,7 +40,7 @@
  *         // This will be retried 1 time (total runs 2) before failing the test.
  *         throw new IOException("Failing test");
  *     }
- *     
+ *
  *     {@literal @}Test
  *     {@literal @}RetryOnException(times=1, exception=IOException.class)
  *     public void yourTest() throws Exception {
@@ -55,6 +55,6 @@
 public @interface RetryOnException {
 
 	int times();
-	
+
 	Class<? extends Throwable> exception();
 }

flink-test-utils-parent/flink-test-utils-junit/src/main/java/org/apache/flink/testutils/junit/RetryRule.java

@@ -22,7 +22,6 @@
 import org.junit.rules.TestRule;
 import org.junit.runner.Description;
 import org.junit.runners.model.Statement;
-
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -48,7 +47,7 @@
  */
 public class RetryRule implements TestRule {
 
-	public final static Logger LOG = LoggerFactory.getLogger(RetryRule.class);
+	public static final Logger LOG = LoggerFactory.getLogger(RetryRule.class);
 
 	@Override
 	public Statement apply(Statement statement, Description description) {
@@ -69,7 +68,7 @@ public Statement apply(Statement statement, Description description) {
 			throw new IllegalArgumentException(
 					"You cannot combine the RetryOnFailure and RetryOnException annotations.");
 		}
-		
+
 		if (retryOnFailure != null) {
 			return new RetryOnFailureStatement(retryOnFailure.times(), statement);
 		}
@@ -133,7 +132,7 @@ private static class RetryOnExceptionStatement extends Statement {
 		private final Class<? extends Throwable> exceptionClass;
 		private final int timesOnFailure;
 		private final Statement statement;
-		
+
 		private int currentRun;
 
 		private RetryOnExceptionStatement(int timesOnFailure, Class<? extends Throwable> exceptionClass, Statement statement) {
@@ -150,7 +149,7 @@ private RetryOnExceptionStatement(int timesOnFailure, Class<? extends Throwable>
 		}
 
 		/**
-		 * Retry a test in case of a failure with a specific exception
+		 * Retry a test in case of a failure with a specific exception.
 		 *
 		 * @throws Throwable
 		 */

flink-test-utils-parent/flink-test-utils-junit/src/main/java/org/apache/flink/util/TestLogger.java

@@ -22,7 +22,6 @@
 import org.junit.rules.TestRule;
 import org.junit.rules.TestWatcher;
 import org.junit.runner.Description;
-
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -63,7 +62,7 @@ public void failed(Throwable e, Description description) {
 					, description, exceptionToString(e));
 		}
 	};
-	
+
 	private static String exceptionToString(Throwable t) {
 		if (t == null) {
 			return "(null)";

flink-test-utils-parent/flink-test-utils-junit/src/test/java/org/apache/flink/core/testutils/OneShotLatchTest.java

@@ -27,6 +27,9 @@
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
+/**
+ * Tests for the OneShotLatch.
+ */
 public class OneShotLatchTest {
 
 	@Test

flink-test-utils-parent/flink-test-utils-junit/src/test/java/org/apache/flink/testutils/junit/RetryOnExceptionTest.java

@@ -24,22 +24,24 @@
 
 import static org.junit.Assert.assertEquals;
 
+/**
+ * Tests for the RetryOnException annotation.
+ */
 public class RetryOnExceptionTest {
 
 	@Rule
 	public RetryRule retryRule = new RetryRule();
 
 	private static final int NUMBER_OF_RUNS = 3;
-	
+
 	private static int runsForSuccessfulTest = 0;
 
 	private static int runsForTestWithMatchingException = 0;
 
 	private static int runsForTestWithSubclassException = 0;
-	
+
 	private static int runsForPassAfterOneFailure = 0;
 
-
 	@AfterClass
 	public static void verify() {
 		assertEquals(NUMBER_OF_RUNS + 1, runsForTestWithMatchingException);

flink-test-utils-parent/flink-test-utils-junit/src/test/java/org/apache/flink/testutils/junit/RetryOnFailureTest.java

@@ -24,6 +24,9 @@
 
 import static org.junit.Assert.assertEquals;
 
+/**
+ * Tests for the RetryOnFailure annotation.
+ */
 public class RetryOnFailureTest {
 
 	@Rule

flink-test-utils-parent/flink-test-utils/src/main/java/org/apache/flink/streaming/util/StreamingMultipleProgramsTestBase.java

@@ -34,7 +34,7 @@
  * shutdown of the Flink clusters (including actor systems, etc) usually dominates
  * the execution of the actual tests.
  *
- * To write a unit test against this test base, simply extend it and add
+ * <p>To write a unit test against this test base, simply extend it and add
  * one or more regular test methods and retrieve the StreamExecutionEnvironment from
  * the context:
  *

flink-test-utils-parent/flink-test-utils/src/main/java/org/apache/flink/streaming/util/StreamingProgramTestBase.java

@@ -25,28 +25,30 @@
 
 import static org.junit.Assert.fail;
 
+/**
+ * Base class for unit tests that run a single test.
+ *
+ * <p>To write a unit test against this test base, simply extend it and implement the {@link #testProgram()} method.
+ */
 public abstract class StreamingProgramTestBase extends AbstractTestBase {
 
 	protected static final int DEFAULT_PARALLELISM = 4;
 
 	private int parallelism;
-
-
+
 	public StreamingProgramTestBase() {
 		super(new Configuration());
 		setParallelism(DEFAULT_PARALLELISM);
 	}
 
-
 	public void setParallelism(int parallelism) {
 		this.parallelism = parallelism;
 		setTaskManagerNumSlots(parallelism);
 	}
-	
+
 	public int getParallelism() {
 		return parallelism;
 	}
-
 
 	// --------------------------------------------------------------------------------------------
 	//  Methods to create the test program and for pre- and post- test work
@@ -55,9 +57,9 @@ public int getParallelism() {
 	protected abstract void testProgram() throws Exception;
 
 	protected void preSubmit() throws Exception {}
-	
+
 	protected void postSubmit() throws Exception {}
-	
+
 	// --------------------------------------------------------------------------------------------
 	//  Test entry point
 	// --------------------------------------------------------------------------------------------

flink-test-utils-parent/flink-test-utils/src/main/java/org/apache/flink/streaming/util/TestStreamEnvironment.java

@@ -36,8 +36,8 @@
  * A {@link StreamExecutionEnvironment} that executes its jobs on {@link LocalFlinkMiniCluster}.
  */
 public class TestStreamEnvironment extends StreamExecutionEnvironment {
-	
-	/** The mini cluster in which this environment executes its jobs */
+
+	/** The mini cluster in which this environment executes its jobs. */
 	private final LocalFlinkMiniCluster miniCluster;
 
 	private final Collection<Path> jarFiles;
@@ -63,7 +63,6 @@ public TestStreamEnvironment(
 		this(miniCluster, parallelism, Collections.<Path>emptyList(), Collections.<URL>emptyList());
 	}
 
-
 	@Override
 	public JobExecutionResult execute(String jobName) throws Exception {
 		final StreamGraph streamGraph = getStreamGraph();
@@ -114,7 +113,7 @@ public StreamExecutionEnvironment createExecutionEnvironment() {
 	/**
 	 * Sets the streaming context environment to a TestStreamEnvironment that runs its programs on
 	 * the given cluster with the given default parallelism.
-	 * 
+	 *
 	 * @param cluster The test cluster to run the test program on.
 	 * @param parallelism The default parallelism for the test programs.
 	 */
@@ -131,5 +130,5 @@ public static void setAsContext(final LocalFlinkMiniCluster cluster, final int p
 	 */
 	public static void unsetAsContext() {
 		resetContextEnvironment();
-	} 
+	}
 }

flink-test-utils-parent/flink-test-utils/src/main/java/org/apache/flink/test/testdata/ConnectedComponentsData.java

@@ -18,16 +18,19 @@
 
 package org.apache.flink.test.testdata;
 
+import org.apache.flink.api.java.tuple.Tuple2;
+
+import org.junit.Assert;
+
 import java.io.BufferedReader;
 import java.io.IOException;
 import java.util.List;
 import java.util.Random;
 import java.util.regex.Pattern;
 
-import org.apache.flink.api.java.tuple.Tuple2;
-import org.junit.Assert;
-
-
+/**
+ * Test data for ConnectedComponents programs.
+ */
 public class ConnectedComponentsData {
 
 	public static final String getEnumeratingVertices(int num) {
@@ -107,7 +110,7 @@ public static void checkOddEvenResult(BufferedReader result) throws IOException
 			}
 		}
 	}
-	
+
 	public static void checkOddEvenResult(List<Tuple2<Long, Long>> lines) throws IOException {
 		for (Tuple2<Long, Long> line : lines) {
 			try {

flink-test-utils-parent/flink-test-utils/src/main/java/org/apache/flink/test/testdata/EnumTriangleData.java

@@ -18,9 +18,12 @@
 
 package org.apache.flink.test.testdata;
 
+/**
+ * Test data for EnumTriangle programs.
+ */
 public class EnumTriangleData {
 
-	public static final String EDGES = 
+	public static final String EDGES =
 			"1 2\n" +
 			"1 3\n" +
 			"1 4\n" +
@@ -33,13 +36,13 @@ public class EnumTriangleData {
 			"3 8\n" +
 			"7 8\n";
 
-	public static final String TRIANGLES_BY_ID = 
+	public static final String TRIANGLES_BY_ID =
 			"1,2,3\n" +
 			"1,3,4\n" +
 			"1,2,5\n" +
-			"3,7,8\n"; 
-	
-	public static final String TRIANGLES_BY_DEGREE = 
+			"3,7,8\n";
+
+	public static final String TRIANGLES_BY_DEGREE =
 			"2,1,3\n" +
 			"4,1,3\n" +
 			"2,1,5\n" +