HBASE-27210 Clean up error-prone findings in hbase-endpoint (#4646)

Signed-off-by: Duo Zhang <zhangduo@apache.org>

Conflicts:
	hbase-endpoint/src/test/java/org/apache/hadoop/hbase/client/TestRpcControllerFactory.java
	hbase-endpoint/src/test/java/org/apache/hadoop/hbase/coprocessor/TestSecureExport.java

hbase-endpoint/src/main/java/org/apache/hadoop/hbase/client/coprocessor/AggregationClient.java

@@ -692,10 +692,9 @@ public <R, S, P extends Message, Q extends Message, T extends Message> double st
   public <R, S, P extends Message, Q extends Message, T extends Message> double
     std(final Table table, ColumnInterpreter<R, S, P, Q, T> ci, Scan scan) throws Throwable {
     Pair<List<S>, Long> p = getStdArgs(table, ci, scan);
-    double res = 0d;
     double avg = ci.divideForAvg(p.getFirst().get(0), p.getSecond());
     double avgOfSumSq = ci.divideForAvg(p.getFirst().get(1), p.getSecond());
-    res = avgOfSumSq - (avg) * (avg); // variance
+    double res = avgOfSumSq - avg * avg; // variance
     res = Math.pow(res, 0.5);
     return res;
   }
@@ -868,14 +867,6 @@ public <R, S, P extends Message, Q extends Message, T extends Message> R median(
   }
 
   byte[] getBytesFromResponse(ByteString response) {
-    ByteBuffer bb = response.asReadOnlyByteBuffer();
-    bb.rewind();
-    byte[] bytes;
-    if (bb.hasArray()) {
-      bytes = bb.array();
-    } else {
-      bytes = response.toByteArray();
-    }
-    return bytes;
+    return response.toByteArray();
   }
 }

hbase-endpoint/src/main/java/org/apache/hadoop/hbase/client/coprocessor/AggregationHelper.java

@@ -84,7 +84,7 @@ private static void validateParameters(Scan scan, boolean canFamilyBeAbsent) thr
    * @return the instance
    * @throws IOException Either we couldn't instantiate the method object, or "parseFrom" failed.
    */
-  @SuppressWarnings("unchecked")
+  @SuppressWarnings({ "unchecked", "TypeParameterUnusedInFormals" })
   // Used server-side too by Aggregation Coprocesor Endpoint. Undo this interdependence. TODO.
   public static <T extends Message> T getParsedGenericInstance(Class<?> runtimeClass, int position,
     ByteString b) throws IOException {

hbase-endpoint/src/main/java/org/apache/hadoop/hbase/coprocessor/AggregateImplementation.java

@@ -31,6 +31,7 @@
 import java.util.Collections;
 import java.util.List;
 import java.util.NavigableSet;
+import org.apache.commons.io.IOUtils;
 import org.apache.hadoop.hbase.Cell;
 import org.apache.hadoop.hbase.CoprocessorEnvironment;
 import org.apache.hadoop.hbase.client.Scan;
@@ -50,12 +51,12 @@
  * aggregate function at a region level. {@link ColumnInterpreter} is used to interpret column
  * value. This class is parameterized with the following (these are the types with which the
  * {@link ColumnInterpreter} is parameterized, and for more description on these, refer to
- * {@link ColumnInterpreter}):
- * @param <T> Cell value data type
- * @param <S> Promoted data type
- * @param <P> PB message that is used to transport initializer specific bytes
- * @param <Q> PB message that is used to transport Cell (&lt;T&gt;) instance
- * @param <R> PB message that is used to transport Promoted (&lt;S&gt;) instance
+ * {@link ColumnInterpreter}):<br>
+ * &lt;T&gt; Cell value data type<br>
+ * &lt;S&gt; Promoted data type<br>
+ * &lt;P&gt; PB message that is used to transport initializer specific bytes<br>
+ * &lt;Q&gt; PB message that is used to transport Cell (&lt;T&gt;) instance<br>
+ * &lt;R&gt; PB message that is used to transport Promoted (&lt;S&gt;) instance<br>
  */
 @InterfaceAudience.Private
 public class AggregateImplementation<T, S, P extends Message, Q extends Message, R extends Message>
@@ -107,10 +108,7 @@ public void getMax(RpcController controller, AggregateRequest request,
       CoprocessorRpcUtils.setControllerException(controller, e);
     } finally {
       if (scanner != null) {
-        try {
-          scanner.close();
-        } catch (IOException ignored) {
-        }
+        IOUtils.closeQuietly(scanner);
       }
     }
     log.info("Maximum from this region is "
@@ -160,10 +158,7 @@ public void getMin(RpcController controller, AggregateRequest request,
       CoprocessorRpcUtils.setControllerException(controller, e);
     } finally {
       if (scanner != null) {
-        try {
-          scanner.close();
-        } catch (IOException ignored) {
-        }
+        IOUtils.closeQuietly(scanner);
       }
     }
     log.info("Minimum from this region is "
@@ -216,10 +211,7 @@ public void getSum(RpcController controller, AggregateRequest request,
       CoprocessorRpcUtils.setControllerException(controller, e);
     } finally {
       if (scanner != null) {
-        try {
-          scanner.close();
-        } catch (IOException ignored) {
-        }
+        IOUtils.closeQuietly(scanner);
       }
     }
     log.debug("Sum from this region is " + env.getRegion().getRegionInfo().getRegionNameAsString()
@@ -267,10 +259,7 @@ public void getRowNum(RpcController controller, AggregateRequest request,
       CoprocessorRpcUtils.setControllerException(controller, e);
     } finally {
       if (scanner != null) {
-        try {
-          scanner.close();
-        } catch (IOException ignored) {
-        }
+        IOUtils.closeQuietly(scanner);
       }
     }
     log.info("Row counter from this region is "
@@ -331,10 +320,7 @@ public void getAvg(RpcController controller, AggregateRequest request,
       CoprocessorRpcUtils.setControllerException(controller, e);
     } finally {
       if (scanner != null) {
-        try {
-          scanner.close();
-        } catch (IOException ignored) {
-        }
+        IOUtils.closeQuietly(scanner);
       }
     }
     done.run(response);
@@ -397,10 +383,7 @@ public void getStd(RpcController controller, AggregateRequest request,
       CoprocessorRpcUtils.setControllerException(controller, e);
     } finally {
       if (scanner != null) {
-        try {
-          scanner.close();
-        } catch (IOException ignored) {
-        }
+        IOUtils.closeQuietly(scanner);
       }
     }
     done.run(response);
@@ -462,10 +445,7 @@ public void getMedian(RpcController controller, AggregateRequest request,
       CoprocessorRpcUtils.setControllerException(controller, e);
     } finally {
       if (scanner != null) {
-        try {
-          scanner.close();
-        } catch (IOException ignored) {
-        }
+        IOUtils.closeQuietly(scanner);
       }
     }
     done.run(response);

hbase-endpoint/src/main/java/org/apache/hadoop/hbase/coprocessor/Export.java

@@ -25,7 +25,6 @@
 import java.security.PrivilegedExceptionAction;
 import java.util.ArrayList;
 import java.util.Collections;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.TreeMap;
@@ -109,6 +108,7 @@ static Map<byte[], Response> run(final Configuration conf, final String[] args)
     return run(conf, arguments.getFirst(), arguments.getSecond(), arguments.getThird());
   }
 
+  @SuppressWarnings("ModifiedButNotUsed")
   public static Map<byte[], Response> run(final Configuration conf, TableName tableName, Scan scan,
     Path dir) throws Throwable {
     FileSystem fs = dir.getFileSystem(conf);
@@ -125,7 +125,6 @@ public static Map<byte[], Response> run(final Configuration conf, TableName tabl
         table.coprocessorService(ExportProtos.ExportService.class, scan.getStartRow(),
           scan.getStopRow(), (ExportProtos.ExportService service) -> {
             ServerRpcController controller = new ServerRpcController();
-            Map<byte[], ExportProtos.ExportResponse> rval = new TreeMap<>(Bytes.BYTES_COMPARATOR);
             CoprocessorRpcUtils.BlockingRpcCallback<ExportProtos.ExportResponse> rpcCallback =
               new CoprocessorRpcUtils.BlockingRpcCallback<>();
             service.export(controller, request, rpcCallback);
@@ -190,7 +189,7 @@ private static SequenceFile.Writer.Option getOutputPath(final Configuration conf
 
   private static List<SequenceFile.Writer.Option> getWriterOptions(final Configuration conf,
     final RegionInfo info, final ExportProtos.ExportRequest request) throws IOException {
-    List<SequenceFile.Writer.Option> rval = new LinkedList<>();
+    List<SequenceFile.Writer.Option> rval = new ArrayList<>(5);
     rval.add(SequenceFile.Writer.keyClass(ImmutableBytesWritable.class));
     rval.add(SequenceFile.Writer.valueClass(Result.class));
     rval.add(getOutputPath(conf, info, request));

hbase-endpoint/src/test/java/org/apache/hadoop/hbase/client/TestAsyncAggregationClient.java

@@ -56,7 +56,7 @@ public class TestAsyncAggregationClient {
 
   private static byte[] CQ2 = Bytes.toBytes("CQ2");
 
-  private static int COUNT = 1000;
+  private static long COUNT = 1000;
 
   private static AsyncConnection CONN;
 
@@ -141,7 +141,7 @@ public void testMedian() throws InterruptedException, ExecutionException {
     long halfSum = COUNT * (COUNT - 1) / 4;
     long median = 0L;
     long sum = 0L;
-    for (int i = 0; i < COUNT; i++) {
+    for (long i = 0; i < COUNT; i++) {
       sum += i;
       if (sum > halfSum) {
         median = i - 1;
@@ -158,7 +158,7 @@ public void testMedianWithWeight() throws InterruptedException, ExecutionExcepti
       LongStream.range(0, COUNT).map(l -> l * l).reduce((l1, l2) -> l1 + l2).getAsLong() / 2;
     long median = 0L;
     long sum = 0L;
-    for (int i = 0; i < COUNT; i++) {
+    for (long i = 0; i < COUNT; i++) {
       sum += i * i;
       if (sum > halfSum) {
         median = i - 1;

hbase-endpoint/src/test/java/org/apache/hadoop/hbase/client/TestRpcControllerFactory.java

@@ -155,71 +155,70 @@ public void testCountController() throws Exception {
     // change one of the connection properties so we get a new Connection with our configuration
     conf.setInt(HConstants.HBASE_RPC_TIMEOUT_KEY, HConstants.DEFAULT_HBASE_RPC_TIMEOUT + 1);
 
-    Connection connection = ConnectionFactory.createConnection(conf);
-    Table table = connection.getTable(tableName);
-    byte[] row = Bytes.toBytes("row");
-    Put p = new Put(row);
-    p.addColumn(fam1, fam1, Bytes.toBytes("val0"));
-    table.put(p);
-
-    Integer counter = 1;
-    counter = verifyCount(counter);
-
-    Delete d = new Delete(row);
-    d.addColumn(fam1, fam1);
-    table.delete(d);
-    counter = verifyCount(counter);
-
-    Put p2 = new Put(row);
-    p2.addColumn(fam1, Bytes.toBytes("qual"), Bytes.toBytes("val1"));
-    table.batch(Lists.newArrayList(p, p2), null);
-    // this only goes to a single server, so we don't need to change the count here
-    counter = verifyCount(counter);
-
-    Append append = new Append(row);
-    append.addColumn(fam1, fam1, Bytes.toBytes("val2"));
-    table.append(append);
-    counter = verifyCount(counter);
-
-    // and check the major lookup calls as well
-    Get g = new Get(row);
-    table.get(g);
-    counter = verifyCount(counter);
-
-    ResultScanner scan = table.getScanner(fam1);
-    scan.next();
-    scan.close();
-    counter = verifyCount(counter + 1);
-
-    Get g2 = new Get(row);
-    table.get(Lists.newArrayList(g, g2));
-    // same server, so same as above for not changing count
-    counter = verifyCount(counter);
-
-    // make sure all the scanner types are covered
-    Scan scanInfo = new Scan(row);
-    // regular small
-    scanInfo.setSmall(true);
-    counter = doScan(table, scanInfo, counter);
-
-    // reversed, small
-    scanInfo.setReversed(true);
-    counter = doScan(table, scanInfo, counter);
-
-    // reversed, regular
-    scanInfo.setSmall(false);
-    counter = doScan(table, scanInfo, counter + 1);
-
-    // make sure we have no priority count
-    verifyPriorityGroupCount(HConstants.ADMIN_QOS, 0);
-    // lets set a custom priority on a get
-    Get get = new Get(row);
-    get.setPriority(HConstants.ADMIN_QOS);
-    table.get(get);
-    verifyPriorityGroupCount(HConstants.ADMIN_QOS, 1);
-
-    table.close();
-    connection.close();
+    try (Connection connection = ConnectionFactory.createConnection(conf)) {
+      try (Table table = connection.getTable(tableName)) {
+        byte[] row = Bytes.toBytes("row");
+        Put p = new Put(row);
+        p.addColumn(fam1, fam1, Bytes.toBytes("val0"));
+        table.put(p);
+
+        Integer counter = 1;
+        counter = verifyCount(counter);
+
+        Delete d = new Delete(row);
+        d.addColumn(fam1, fam1);
+        table.delete(d);
+        counter = verifyCount(counter);
+
+        Put p2 = new Put(row);
+        p2.addColumn(fam1, Bytes.toBytes("qual"), Bytes.toBytes("val1"));
+        table.batch(Lists.newArrayList(p, p2), null);
+        // this only goes to a single server, so we don't need to change the count here
+        counter = verifyCount(counter);
+
+        Append append = new Append(row);
+        append.addColumn(fam1, fam1, Bytes.toBytes("val2"));
+        table.append(append);
+        counter = verifyCount(counter);
+
+        // and check the major lookup calls as well
+        Get g = new Get(row);
+        table.get(g);
+        counter = verifyCount(counter);
+
+        ResultScanner scan = table.getScanner(fam1);
+        scan.next();
+        scan.close();
+        counter = verifyCount(counter + 1);
+
+        Get g2 = new Get(row);
+        table.get(Lists.newArrayList(g, g2));
+        // same server, so same as above for not changing count
+        counter = verifyCount(counter);
+
+        // make sure all the scanner types are covered
+        Scan scanInfo = new Scan(row);
+        // regular small
+        scanInfo.setSmall(true);
+        counter = doScan(table, scanInfo, counter);
+
+        // reversed, small
+        scanInfo.setReversed(true);
+        counter = doScan(table, scanInfo, counter);
+
+        // reversed, regular
+        scanInfo.setSmall(false);
+        doScan(table, scanInfo, counter + 1);
+
+        // make sure we have no priority count
+        verifyPriorityGroupCount(HConstants.ADMIN_QOS, 0);
+        // lets set a custom priority on a get
+        Get get = new Get(row);
+        get.setPriority(HConstants.ADMIN_QOS);
+        table.get(get);
+        verifyPriorityGroupCount(HConstants.ADMIN_QOS, 1);
+      }
+    }
   }
 
   int doScan(Table table, Scan scan, int expectedCount) throws IOException {

hbase-endpoint/src/test/java/org/apache/hadoop/hbase/client/coprocessor/TestAggregationClient.java

@@ -83,8 +83,7 @@ public void itCreatesConnectionless() throws Throwable {
     try {
       client.rowCount(TABLE_NAME, new LongColumnInterpreter(), new Scan());
       fail("Expected IOException");
-    } catch (Throwable e) {
-      assertTrue(e instanceof IOException);
+    } catch (IOException e) {
       assertTrue(e.getMessage().contains("Connection not initialized"));
     }