[RocksJava] Incorporated review comments

java/Makefile

@@ -70,6 +70,12 @@ sample: java
 	@rm -rf /tmp/rocksdbjni
 	@rm -rf /tmp/rocksdbjni_not_found
 
+column_family_sample: java
+	javac -cp $(ROCKSDB_JAR) RocksDBColumnFamilySample.java
+	@rm -rf /tmp/rocksdbjni
+	java -ea -Djava.library.path=.:../ -cp ".:./*" -Xcheck:jni RocksDBColumnFamilySample /tmp/rocksdbjni
+	@rm -rf /tmp/rocksdbjni
+
 test: java
 	@rm -rf /tmp/rocksdbjni_*
 	javac org/rocksdb/test/*.java

java/RocksDBColumnFamilySample.java

@@ -0,0 +1,146 @@
+// Copyright (c) 2014, Facebook, Inc.  All rights reserved.
+// This source code is licensed under the BSD-style license found in the
+// LICENSE file in the root directory of this source tree. An additional grant
+// of patent rights can be found in the PATENTS file in the same directory.
+
+import org.rocksdb.*;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class RocksDBColumnFamilySample {
+  static {
+    RocksDB.loadLibrary();
+  }
+
+  public static void main(String[] args) throws RocksDBException {
+    if (args.length < 1) {
+      System.out.println(
+          "usage: RocksDBColumnFamilySample db_path");
+      return;
+    }
+    String db_path = args[0];
+
+    System.out.println("RocksDBColumnFamilySample");
+    RocksDB db = null;
+    DBOptions dbOptions = null;
+    List<RocksIterator> iterators = new ArrayList<>();
+    RocksIterator iterator = null;
+    ColumnFamilyHandle cfHandle = null;
+    WriteBatch wb = null;
+    try {
+      // Setup DBOptions
+      dbOptions = new DBOptions().
+          setCreateIfMissing(true).
+          setCreateMissingColumnFamilies(true);
+      // Setup ColumnFamily descriptors
+      List<ColumnFamilyDescriptor> cfNames =
+          new ArrayList<>();
+      // Default column family
+      cfNames.add(new ColumnFamilyDescriptor("default"));
+      // New column families
+      cfNames.add(new ColumnFamilyDescriptor("cf_green",
+          new ColumnFamilyOptions().setComparator(
+              BuiltinComparator.BYTEWISE_COMPARATOR)));
+      cfNames.add(new ColumnFamilyDescriptor("cf_blue",
+          new ColumnFamilyOptions().setComparator(
+              BuiltinComparator.REVERSE_BYTEWISE_COMPARATOR)));
+      cfNames.add(new ColumnFamilyDescriptor("cf_red",
+          new ColumnFamilyOptions().
+              setMergeOperator(new StringAppendOperator())));
+
+      List<ColumnFamilyHandle> cfHandles =
+          new ArrayList<>();
+      db = RocksDB.open(dbOptions,
+          db_path, cfNames, cfHandles);
+      // List column families in database
+      System.out.println("List existent column families:");
+      List<byte[]> cfListing = RocksDB.listColumnFamilies(
+          new Options(), db_path);
+      for (byte[] cf : cfListing) {
+        System.out.format(" - %s\n", new String(cf));
+      }
+      // Bootstrapping values
+      System.out.println("Writing values to database.");
+      for (int i=0; i < cfNames.size(); i++) {
+        for (int j=0; j < 10; j++) {
+          db.put(cfHandles.get(i),
+              String.valueOf(j).getBytes(),
+              String.valueOf(j).getBytes());
+        }
+      }
+      // Retrieve values using get
+      System.out.println("Retrieve values with get.");
+      for (int i=0; i < cfNames.size(); i++) {
+        for (int j=0; j < 10; j++) {
+          System.out.format(" %s", new String(
+              db.get(cfHandles.get(i),
+                  String.valueOf(j).getBytes())));
+        }
+        System.out.println("");
+      }
+      // Add a new column family to existing database
+      System.out.println("Add new column family");
+      cfHandle = db.createColumnFamily(new ColumnFamilyDescriptor(
+          "cf_temp", new ColumnFamilyOptions().
+          setMergeOperator(new StringAppendOperator())));
+      System.out.println("Write key/value into new column family.");
+      db.put(cfHandle, "key".getBytes(), "value".getBytes());
+      System.out.format("Lookup 'key' retrieved value: %s\n", new String(
+          db.get(cfHandle, "key".getBytes())));
+      // Delete key
+      System.out.println("Delete key/value in new column family.");
+      db.remove(cfHandle, "key".getBytes());
+      // WriteBatch with column family
+      wb = new WriteBatch();
+      wb.put(cfHandle, "key".getBytes(), "value".getBytes());
+      wb.put(cfHandle, "key2".getBytes(), "value2".getBytes());
+      wb.remove(cfHandle, "key2".getBytes());
+      wb.merge(cfHandle, "key".getBytes(), "morevalues".getBytes());
+      db.write(new WriteOptions(), wb);
+      // Retrieve a single iterator with a cf handle
+      System.out.println("Retrieve values using a iterator on" +
+          " a column family.");
+      iterator = db.newIterator(cfHandle);
+      iterator.seekToFirst();
+      while(iterator.isValid()) {
+        System.out.format(" %s", new String(
+            iterator.value()));
+        iterator.next();
+      }
+      System.out.println("");
+      // Delete column family
+      System.out.println("Delete column family.");
+      db.dropColumnFamily(cfHandle);
+      // Retrieve values from cf using iterator
+      System.out.println("Retrieve values with iterators");
+      iterators = db.newIterators(cfHandles);
+      assert(iterators.size() == 4);
+      for (RocksIterator iter : iterators) {
+        iter.seekToFirst();
+        while(iter.isValid()) {
+          System.out.format(" %s", new String(
+              iter.value()));
+          iter.next();
+        }
+        System.out.println("");
+      }
+    } finally {
+      if (db != null) {
+        db.close();
+      }
+      if (dbOptions != null) {
+        dbOptions.dispose();
+      }
+      if (iterator != null) {
+        iterator.dispose();
+      }
+      for (RocksIterator iter : iterators) {
+        iter.dispose();
+      }
+      if (wb != null) {
+        wb.dispose();
+      }
+    }
+  }
+}

java/org/rocksdb/test/ColumnFamilyTest.java

@@ -73,9 +73,9 @@ public class ColumnFamilyTest {
 
     // Test open database with column family names
     List<ColumnFamilyDescriptor> cfNames =
-        new ArrayList<ColumnFamilyDescriptor>();
+        new ArrayList<>();
     List<ColumnFamilyHandle> columnFamilyHandleList =
-        new ArrayList<ColumnFamilyHandle>();
+        new ArrayList<>();
     cfNames.add(new ColumnFamilyDescriptor("default"));
     cfNames.add(new ColumnFamilyDescriptor("new_cf"));
 
@@ -222,8 +222,6 @@ public class ColumnFamilyTest {
           .equals("value"));
     } catch (RocksDBException e) {
       assert(false);
-    } catch (IllegalArgumentException e) {
-      assert(false);
     }
 
     // Test multiget without correct number of column