Fix checkstyle errors and various warnings.

stratosphere-java/src/main/java/eu/stratosphere/api/java/operators/Keys.java

@@ -187,6 +187,7 @@ public abstract class Keys<T> {
 
 		private final TypeInformation<?>[] types;
 
+		@SuppressWarnings("unused")
 		private PojoTypeInfo<?> type;
 
 		public ExpressionKeys(String[] expressions, TypeInformation<T> type) {

stratosphere-java/src/main/java/eu/stratosphere/api/java/typeutils/runtime/PojoPairComparator.java

@@ -28,6 +28,7 @@ public class PojoPairComparator<T1, T2> extends TypePairComparator<T1, T2> imple
 
 	private static final long serialVersionUID = 1L;
 
+	@SuppressWarnings("unused")
 	private final int[] keyPositions1, keyPositions2;
 	private transient Field[] keyFields1, keyFields2;
 	private final TypeComparator<Object>[] comparators1;

stratosphere-java/src/test/java/eu/stratosphere/api/java/operator/CoGroupOperatorTest.java

@@ -18,8 +18,6 @@ import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.List;
 
-import eu.stratosphere.api.java.typeutils.TypeExtractor;
-import eu.stratosphere.types.TypeInformation;
 import junit.framework.Assert;
 
 import org.junit.BeforeClass;

stratosphere-java/src/test/java/eu/stratosphere/api/java/operator/GroupingTest.java

@@ -18,8 +18,6 @@ import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.List;
 
-import eu.stratosphere.api.java.typeutils.TypeExtractor;
-import eu.stratosphere.types.TypeInformation;
 import junit.framework.Assert;
 
 import org.junit.Test;

stratosphere-java/src/test/java/eu/stratosphere/api/java/operator/JoinOperatorTest.java

@@ -14,13 +14,10 @@
  **********************************************************************************************************************/
 package eu.stratosphere.api.java.operator;
 
-import java.beans.Expression;
 import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.List;
 
-import eu.stratosphere.api.java.typeutils.TypeExtractor;
-import eu.stratosphere.types.TypeInformation;
 import junit.framework.Assert;
 
 import org.junit.BeforeClass;

stratosphere-java/src/test/java/eu/stratosphere/api/java/type/extractor/PojoTypeInformationTest.java

@@ -13,17 +13,15 @@
 
 package eu.stratosphere.api.java.type.extractor;
 
-import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 
 import org.junit.Test;
 
 import eu.stratosphere.api.java.typeutils.PojoTypeInfo;
 import eu.stratosphere.api.java.typeutils.TypeExtractor;
-import eu.stratosphere.types.Record;
-import eu.stratosphere.types.StringValue;
 import eu.stratosphere.types.TypeInformation;
 
+@SuppressWarnings("unused")
 public class PojoTypeInformationTest {
 
 	static class SimplePojo {

stratosphere-java/src/test/java/eu/stratosphere/api/java/typeutils/runtime/PojoSerializerTest.java

@@ -17,8 +17,6 @@ package eu.stratosphere.api.java.typeutils.runtime;
 import java.util.Random;
 
 import com.google.common.base.Objects;
-import com.google.common.hash.HashFunction;
-import com.google.common.hash.Hashing;
 
 import eu.stratosphere.api.common.typeutils.SerializerTestBase;
 import eu.stratosphere.api.common.typeutils.TypeSerializer;

stratosphere-runtime/src/main/java/eu/stratosphere/nephele/instance/HardwareDescriptionFactory.java

@@ -23,8 +23,6 @@ import java.util.regex.Pattern;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
-import eu.stratosphere.configuration.ConfigConstants;
-import eu.stratosphere.configuration.GlobalConfiguration;
 import eu.stratosphere.util.OperatingSystem;
 
 /**

stratosphere-tests/src/test/java/eu/stratosphere/test/javaApiOperators/DistinctITCase.java

@@ -14,7 +14,6 @@
  **********************************************************************************************************************/
 package eu.stratosphere.test.javaApiOperators;
 
-import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.util.Collection;
 import java.util.LinkedList;