[RocksJava] Code-cleanup + Java7 warnings removed

java/org/rocksdb/BackupableDB.java

@@ -104,7 +104,7 @@ public class BackupableDB extends RocksDB {
     super();
   }
 
-  @Override protected void finalize() {
+  @Override protected void finalize() throws Throwable {
     close();
     super.finalize();
   }

java/org/rocksdb/MergeOperator.java

@@ -5,8 +5,6 @@
 
 package org.rocksdb;
 
-import java.util.*;
-
 /**
  * MergeOperator holds an operator to be applied when compacting
  * two merge operands held under the same key in order to obtain a single

java/org/rocksdb/NativeLibraryLoader.java

@@ -9,12 +9,12 @@ import org.rocksdb.util.Environment;
  */
 public class NativeLibraryLoader {
   private static String sharedLibraryName = Environment.getJniLibraryName("rocksdb");
-  private static String tempFilePrefix = "librocksdbjni";
   private static String tempFileSuffix = "." + Environment.getJniLibraryExtension();
 
   public static void loadLibraryFromJar(String tmpDir)
       throws IOException {
     File temp;
+    String tempFilePrefix = "librocksdbjni";
     if(tmpDir == null || tmpDir.equals(""))
       temp = File.createTempFile(tempFilePrefix, tempFileSuffix);
     else
@@ -43,9 +43,7 @@ public class NativeLibraryLoader {
     } finally {
       if(os != null)
         os.close();
-
-      if(is != null)
-        is.close();
+      is.close();
     }
 
     System.load(temp.getAbsolutePath());

java/org/rocksdb/PlainTableConfig.java

@@ -131,7 +131,7 @@ public class PlainTableConfig extends TableFormatConfig {
    *
    * <p>See linux doc Documentation/vm/hugetlbpage.txt</p>
    *
-   * @param hugePageTlbSize
+   * @param hugePageTlbSize huge page tlb size
    * @return the reference to the current config.
    */
   public PlainTableConfig setHugePageTlbSize(int hugePageTlbSize) {

java/org/rocksdb/RocksDB.java

@@ -734,7 +734,7 @@ public class RocksDB extends RocksObject {
     List<byte[]> values = multiGet(
         nativeHandle_, keys, keys.size());
 
-    Map<byte[], byte[]> keyValueMap = new HashMap<byte[], byte[]>();
+    Map<byte[], byte[]> keyValueMap = new HashMap<>();
     for(int i = 0; i < values.size(); i++) {
       if(values.get(i) == null) {
         continue;
@@ -774,7 +774,7 @@ public class RocksDB extends RocksObject {
     List<byte[]> values = multiGet(nativeHandle_, keys, keys.size(),
         columnFamilyHandleList);
 
-    Map<byte[], byte[]> keyValueMap = new HashMap<byte[], byte[]>();
+    Map<byte[], byte[]> keyValueMap = new HashMap<>();
     for(int i = 0; i < values.size(); i++) {
       if (values.get(i) == null) {
         continue;
@@ -801,7 +801,7 @@ public class RocksDB extends RocksObject {
     List<byte[]> values = multiGet(
         nativeHandle_, opt.nativeHandle_, keys, keys.size());
 
-    Map<byte[], byte[]> keyValueMap = new HashMap<byte[], byte[]>();
+    Map<byte[], byte[]> keyValueMap = new HashMap<>();
     for(int i = 0; i < values.size(); i++) {
       if(values.get(i) == null) {
         continue;
@@ -844,7 +844,7 @@ public class RocksDB extends RocksObject {
     List<byte[]> values = multiGet(nativeHandle_, opt.nativeHandle_,
         keys, keys.size(), columnFamilyHandleList);
 
-    Map<byte[], byte[]> keyValueMap = new HashMap<byte[], byte[]>();
+    Map<byte[], byte[]> keyValueMap = new HashMap<>();
     for(int i = 0; i < values.size(); i++) {
       if(values.get(i) == null) {
         continue;
@@ -1051,7 +1051,7 @@ public class RocksDB extends RocksObject {
   public List<RocksIterator> newIterators(
       List<ColumnFamilyHandle> columnFamilyHandleList) throws RocksDBException {
     List<RocksIterator> iterators =
-        new ArrayList<RocksIterator>(columnFamilyHandleList.size());
+        new ArrayList<>(columnFamilyHandleList.size());
 
     long[] iteratorRefs = iterators(nativeHandle_, columnFamilyHandleList);
     for (int i=0; i<columnFamilyHandleList.size(); i++){

java/org/rocksdb/RocksDBException.java

@@ -5,8 +5,6 @@
 
 package org.rocksdb;
 
-import java.util.*;
-
 /**
  * A RocksDBException encapsulates the error of an operation.  This exception
  * type is used to describe an internal error from the c++ rocksdb library.

java/org/rocksdb/RocksObject.java

@@ -107,8 +107,9 @@ public abstract class RocksObject {
    * Simply calls {@code dispose()} and release its c++ resource if it has not
    * yet released.
    */
-  @Override protected void finalize() {
+  @Override protected void finalize() throws Throwable {
     dispose();
+    super.finalize();
   }
 
   /**

java/org/rocksdb/Statistics.java

@@ -24,9 +24,8 @@ public class Statistics {
 
   public HistogramData geHistogramData(HistogramType histogramType) {
     assert(isInitialized());
-    HistogramData hist = geHistogramData0(
+    return geHistogramData0(
         histogramType.getValue(), statsHandle_);
-    return hist;
   }
 
   private boolean isInitialized() {

java/org/rocksdb/StatisticsCollector.java

@@ -6,11 +6,9 @@
 package org.rocksdb;
 
 import java.util.List;
-import java.util.concurrent.ArrayBlockingQueue;
 import java.util.concurrent.Executors;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.TimeUnit;
-import java.util.concurrent.atomic.AtomicBoolean;
 
 /**
  * <p>Helper class to collect DB statistics periodically at a period specified in

java/org/rocksdb/util/Environment.java

@@ -5,17 +5,17 @@ public class Environment {
   private static String ARCH = System.getProperty("os.arch").toLowerCase();
 
   public static boolean isWindows() {
-    return (OS.indexOf("win") >= 0);
+    return (OS.contains("win"));
   }
 
   public static boolean isMac() {
-    return (OS.indexOf("mac") >= 0);
+    return (OS.contains("mac"));
   }
 
   public static boolean isUnix() {
-    return (OS.indexOf("nix") >= 0 ||
-            OS.indexOf("nux") >= 0 ||
-            OS.indexOf("aix") >= 0);
+    return (OS.contains("nix") ||
+        OS.contains("nux") ||
+        OS.contains("aix"));
   }
 
   public static boolean is64Bit() {