simpler strings

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/conf/TestCommonConfigurationFields.java

@@ -60,7 +60,7 @@ public class TestCommonConfigurationFields extends TestConfigurationFieldsBase {
   @SuppressWarnings("deprecation")
   @Override
   public void initializeMemberVariables() {
-    xmlFilename = new String("core-default.xml");
+    xmlFilename = "core-default.xml";
     configurationClasses = new Class[] {
         CommonConfigurationKeys.class,
         CommonConfigurationKeysPublic.class,

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/offlineImageViewer/ImageLoaderCurrent.java

@@ -19,6 +19,7 @@
 
 import java.io.DataInputStream;
 import java.io.IOException;
+import java.nio.charset.StandardCharsets;
 import java.text.DateFormat;
 import java.text.SimpleDateFormat;
 import java.util.Date;
@@ -320,7 +321,7 @@ private void processINodesUC(DataInputStream in, ImageVisitor v,
     for(int i = 0; i < numINUC; i++) {
       v.visitEnclosingElement(ImageElement.INODE_UNDER_CONSTRUCTION);
       byte [] name = FSImageSerialization.readBytes(in);
-      String n = new String(name, "UTF8");
+      String n = new String(name, StandardCharsets.UTF_8);
       v.visit(ImageElement.INODE_PATH, n);
 
       if (NameNodeLayoutVersion.supports(Feature.ADD_INODE_ID, imageVersion)) {

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/DFSTestUtil.java

@@ -1438,7 +1438,7 @@ public static void runOperations(MiniDFSCluster cluster,
     Short permission = 0777;
     filesystem.setPermission(pathFileCreate, new FsPermission(permission));
     // OP_SET_OWNER 8
-    filesystem.setOwner(pathFileCreate, new String("newOwner"), null);
+    filesystem.setOwner(pathFileCreate, "newOwner", null);
     // OP_CLOSE 9 see above
     // OP_SET_GENSTAMP 10 see above
     // OP_SET_NS_QUOTA 11 obsolete

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDatanodeReport.java

@@ -160,7 +160,7 @@ public void testDatanodeReportMissingBlock() throws Exception {
       cluster.waitActive();
       DistributedFileSystem fs = cluster.getFileSystem();
       Path p = new Path("/testDatanodeReportMissingBlock");
-      DFSTestUtil.writeFile(fs, p, new String("testdata"));
+      DFSTestUtil.writeFile(fs, p, "testdata");
       LocatedBlock lb = fs.getClient().getLocatedBlocks(p.toString(), 0).get(0);
       assertEquals(3, lb.getLocations().length);
       ExtendedBlock b = lb.getBlock();

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestDataNodeMetrics.java

@@ -553,7 +553,7 @@ public void testDNShouldNotDeleteBlockONTooManyOpenFiles()
       cluster.waitActive();
       DistributedFileSystem fs = cluster.getFileSystem();
       Path p = new Path("/testShouldThrowTMP");
-      DFSTestUtil.writeFile(fs, p, new String("testdata"));
+      DFSTestUtil.writeFile(fs, p, "testdata");
       //Before DN throws too many open files
       verifyBlockLocations(fs, p, 1);
       Mockito.doThrow(new FileNotFoundException("Too many open files")).

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestFavoredNodesEndToEnd.java

@@ -60,7 +60,7 @@ public class TestFavoredNodesEndToEnd {
   private static Configuration conf;
   private final static int NUM_DATA_NODES = 10;
   private final static int NUM_FILES = 10;
-  private final static byte[] SOME_BYTES = new String("foo").getBytes();
+  private final static byte[] SOME_BYTES = "foo".getBytes();
   private static DistributedFileSystem dfs;
   private static ArrayList<DataNode> datanodes;
 

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestFsck.java

@@ -919,7 +919,7 @@ public void testFsckReplicaDetails() throws Exception {
     dfs = cluster.getFileSystem();
 
     // create files
-    final String testFile = new String("/testfile");
+    final String testFile = "/testfile";
     final Path path = new Path(testFile);
     DFSTestUtil.createFile(dfs, path, fileSize, replFactor, 1000L);
     DFSTestUtil.waitReplication(dfs, path, replFactor);
@@ -1202,7 +1202,7 @@ public void testFsckMissingReplicas() throws IOException {
     assertNotNull("Failed to get FileSystem", dfs);
 
     // Create a file that will be intentionally under-replicated
-    final String pathString = new String("/testfile");
+    final String pathString = "/testfile";
     final Path path = new Path(pathString);
     long fileLen = blockSize * numBlocks;
     DFSTestUtil.createFile(dfs, path, fileLen, replFactor, 1);
@@ -1263,7 +1263,7 @@ public void testFsckMisPlacedReplicas() throws IOException {
     assertNotNull("Failed to get FileSystem", dfs);
 
     // Create a file that will be intentionally under-replicated
-    final String pathString = new String("/testfile");
+    final String pathString = "/testfile";
     final Path path = new Path(pathString);
     long fileLen = blockSize * numBlocks;
     DFSTestUtil.createFile(dfs, path, fileLen, replFactor, 1);
@@ -1436,7 +1436,7 @@ public void testBlockIdCK() throws Exception {
     DFSTestUtil util = new DFSTestUtil.Builder().
         setName(getClass().getSimpleName()).setNumFiles(1).build();
     //create files
-    final String pathString = new String("/testfile");
+    final String pathString = "/testfile";
     final Path path = new Path(pathString);
     util.createFile(dfs, path, 1024, replFactor, 1000L);
     util.waitReplication(dfs, path, replFactor);
@@ -1490,7 +1490,7 @@ public void testBlockIdCKDecommission() throws Exception {
     DFSTestUtil util = new DFSTestUtil.Builder().
         setName(getClass().getSimpleName()).setNumFiles(1).build();
     //create files
-    final String pathString = new String("/testfile");
+    final String pathString = "/testfile";
     final Path path = new Path(pathString);
     util.createFile(dfs, path, 1024, replFactor, 1000L);
     util.waitReplication(dfs, path, replFactor);
@@ -1577,7 +1577,7 @@ public void testBlockIdCKMaintenance() throws Exception {
     DFSTestUtil util = new DFSTestUtil.Builder().
         setName(getClass().getSimpleName()).setNumFiles(1).build();
     //create files
-    final String pathString = new String("/testfile");
+    final String pathString = "/testfile";
     final Path path = new Path(pathString);
     util.createFile(dfs, path, 1024, replFactor, 1000L);
     util.waitReplication(dfs, path, replFactor);
@@ -1694,7 +1694,7 @@ public void testBlockIdCKStaleness() throws Exception {
           setName(getClass().getSimpleName()).setNumFiles(1).build();
 
       // Create one file.
-      final String pathString = new String("/testfile");
+      final String pathString = "/testfile";
       final Path path = new Path(pathString);
       util.createFile(fs, path, 1024L, replFactor, 1024L);
       util.waitReplication(fs, path, replFactor);
@@ -1780,7 +1780,7 @@ public void testBlockIdCKCorruption() throws Exception {
     DFSTestUtil util = new DFSTestUtil.Builder().
         setName(getClass().getSimpleName()).setNumFiles(1).build();
     //create files
-    final String pathString = new String("/testfile");
+    final String pathString = "/testfile";
     final Path path = new Path(pathString);
     util.createFile(dfs, path, 1024, repFactor, 1000L);
     util.waitReplication(dfs, path, repFactor);
@@ -1937,7 +1937,7 @@ public void testFsckWithDecommissionedReplicas() throws Exception {
         setName(getClass().getSimpleName()).setNumFiles(1).build();
 
     //create files
-    final String testFile = new String("/testfile");
+    final String testFile = "/testfile";
     final Path path = new Path(testFile);
     util.createFile(dfs, path, fileSize, replFactor, 1000L);
     util.waitReplication(dfs, path, replFactor);
@@ -2020,7 +2020,7 @@ public void testFsckWithMaintenanceReplicas() throws Exception {
     DFSTestUtil util = new DFSTestUtil.Builder().
         setName(getClass().getSimpleName()).setNumFiles(1).build();
     //create files
-    final String testFile = new String("/testfile");
+    final String testFile = "/testfile";
     final Path path = new Path(testFile);
     util.createFile(dfs, path, 1024, replFactor, 1000L);
     util.waitReplication(dfs, path, replFactor);
@@ -2394,7 +2394,7 @@ private void testUpgradeDomain(boolean defineUpgradeDomain,
     }
 
     // create files
-    final String testFile = new String("/testfile");
+    final String testFile = "/testfile";
     final Path path = new Path(testFile);
     DFSTestUtil.createFile(dfs, path, fileSize, replFactor, 1000L);
     DFSTestUtil.waitReplication(dfs, path, replFactor);

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestINodeFile.java

@@ -1163,7 +1163,7 @@ public void testFilesInGetListingOps() throws Exception {
           HdfsFileStatus.EMPTY_NAME, false);
       assertTrue(dl.getPartialListing().length == 3);
 
-      String f2 = new String("f2");
+      String f2 = "f2";
       dl = cluster.getNameNodeRpc().getListing("/tmp", f2.getBytes(), false);
       assertTrue(dl.getPartialListing().length == 1);
 

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/web/TestWebHdfsFileSystemContract.java

@@ -27,6 +27,7 @@
 import java.io.InputStreamReader;
 import java.net.HttpURLConnection;
 import java.net.URL;
+import java.nio.charset.StandardCharsets;
 import java.text.MessageFormat;
 import java.util.Arrays;
 import java.util.Map;
@@ -341,7 +342,7 @@ public void testLengthParamLongerThanFile() throws IOException {
       byte[] respBody = new byte[content.length()];
       is = conn.getInputStream();
       IOUtils.readFully(is, respBody, 0, content.length());
-      assertEquals(content, new String(respBody, "US-ASCII"));
+      assertEquals(content, new String(respBody, StandardCharsets.US_ASCII));
     } finally {
       IOUtils.closeStream(is);
       if (conn != null) {
@@ -392,7 +393,7 @@ public void testOffsetPlusLengthParamsLongerThanFile() throws IOException {
       byte[] respBody = new byte[content.length() - 1];
       is = conn.getInputStream();
       IOUtils.readFully(is, respBody, 0, content.length() - 1);
-      assertEquals(content.substring(1), new String(respBody, "US-ASCII"));
+      assertEquals(content.substring(1), new String(respBody, StandardCharsets.US_ASCII));
     } finally {
       IOUtils.closeStream(is);
       if (conn != null) {

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/tools/TestHdfsConfigFields.java

@@ -39,7 +39,7 @@ public class TestHdfsConfigFields extends TestConfigurationFieldsBase {
 
   @Override
   public void initializeMemberVariables() {
-    xmlFilename = new String("hdfs-default.xml");
+    xmlFilename = "hdfs-default.xml";
     configurationClasses = new Class[] { HdfsClientConfigKeys.class,
         HdfsClientConfigKeys.Failover.class,
         HdfsClientConfigKeys.StripedRead.class, DFSConfigKeys.class,

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-jobclient/src/test/java/org/apache/hadoop/mapred/TestFixedLengthInputFormat.java

@@ -97,7 +97,7 @@ public void testFormatCompressedIn() throws IOException {
   @Test (timeout=5000)
   public void testNoRecordLength() throws IOException {
     localFs.delete(workDir, true);
-    Path file = new Path(workDir, new String("testFormat.txt"));
+    Path file = new Path(workDir, "testFormat.txt");
     createFile(file, null, 10, 10);
     // Set the fixed length record length config property 
     JobConf job = new JobConf(defaultConf);
@@ -124,7 +124,7 @@ public void testNoRecordLength() throws IOException {
   @Test (timeout=5000)
   public void testZeroRecordLength() throws IOException {
     localFs.delete(workDir, true);
-    Path file = new Path(workDir, new String("testFormat.txt"));
+    Path file = new Path(workDir, "testFormat.txt");
     createFile(file, null, 10, 10);
     // Set the fixed length record length config property 
     JobConf job = new JobConf(defaultConf);
@@ -152,7 +152,7 @@ public void testZeroRecordLength() throws IOException {
   @Test (timeout=5000)
   public void testNegativeRecordLength() throws IOException {
     localFs.delete(workDir, true);
-    Path file = new Path(workDir, new String("testFormat.txt"));
+    Path file = new Path(workDir, "testFormat.txt");
     createFile(file, null, 10, 10);
     // Set the fixed length record length config property 
     JobConf job = new JobConf(defaultConf);

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-jobclient/src/test/java/org/apache/hadoop/mapreduce/lib/input/TestFixedLengthInputFormat.java

@@ -102,7 +102,7 @@ public void testFormatCompressedIn() throws Exception {
   @Test (timeout=5000)
   public void testNoRecordLength() throws Exception {
     localFs.delete(workDir, true);
-    Path file = new Path(workDir, new String("testFormat.txt"));
+    Path file = new Path(workDir, "testFormat.txt");
     createFile(file, null, 10, 10);
     // Create the job and do not set fixed record length
     Job job = Job.getInstance(defaultConf);
@@ -136,7 +136,7 @@ public void testNoRecordLength() throws Exception {
   @Test (timeout=5000)
   public void testZeroRecordLength() throws Exception {
     localFs.delete(workDir, true);
-    Path file = new Path(workDir, new String("testFormat.txt"));
+    Path file = new Path(workDir, "testFormat.txt");
     createFile(file, null, 10, 10);
     Job job = Job.getInstance(defaultConf);
     // Set the fixed length record length config property 
@@ -172,7 +172,7 @@ public void testZeroRecordLength() throws Exception {
   @Test (timeout=5000)
   public void testNegativeRecordLength() throws Exception {
     localFs.delete(workDir, true);
-    Path file = new Path(workDir, new String("testFormat.txt"));
+    Path file = new Path(workDir, "testFormat.txt");
     createFile(file, null, 10, 10);
     // Set the fixed length record length config property 
     Job job = Job.getInstance(defaultConf);

hadoop-tools/hadoop-kafka/src/test/java/org/apache/hadoop/metrics2/impl/TestKafkaMetrics.java

@@ -159,7 +159,7 @@ StringBuilder recordToJson(MetricsRecord record) {
     String date = dateFormat.format(currDate);
     SimpleDateFormat timeFormat = new SimpleDateFormat("HH:mm:ss");
     String time = timeFormat.format(currDate);
-    String hostname = new String("null");
+    String hostname = "null";
     try {
       hostname = InetAddress.getLocalHost().getHostName();
     } catch (Exception e) {

hadoop-tools/hadoop-streaming/src/test/java/org/apache/hadoop/streaming/mapreduce/TestStreamXmlRecordReader.java

@@ -24,6 +24,7 @@
 import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
+import java.nio.charset.StandardCharsets;
 import java.util.Arrays;
 import java.util.HashSet;
 import java.util.Set;
@@ -88,7 +89,7 @@ private String slurpHadoop(Path p, FileSystem fs) throws IOException {
     String contents = null;
     try {
       in.readFully(in.getPos(), buf);
-      contents = new String(buf, "UTF-8");
+      contents = new String(buf, StandardCharsets.UTF_8);
     } finally {
       in.close();
     }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-api/src/test/java/org/apache/hadoop/yarn/conf/TestYarnConfigurationFields.java

@@ -36,7 +36,7 @@ public class TestYarnConfigurationFields extends TestConfigurationFieldsBase {
   @SuppressWarnings({"deprecation", "methodlength"})
   @Override
   public void initializeMemberVariables() {
-    xmlFilename = new String("yarn-default.xml");
+    xmlFilename = "yarn-default.xml";
     configurationClasses = new Class[] { YarnConfiguration.class };
 
     // Allocate for usage