### Question:
LoadTypedBytes implements Tool { public int run(String[] args) throws Exception { if (args.length == 0) { System.err.println("Too few arguments!"); printUsage(); return 1; } Path path = new Path(args[0]); FileSystem fs = path.getFileSystem(getConf()); if (fs.exists(path)) { System.err.println("given path exists already!"); return -1; } TypedBytesInput tbinput = new TypedBytesInput(new DataInputStream(System.in)); SequenceFile.Writer writer = SequenceFile.createWriter(fs, conf, path, TypedBytesWritable.class, TypedBytesWritable.class); try { TypedBytesWritable key = new TypedBytesWritable(); TypedBytesWritable value = new TypedBytesWritable(); byte[] rawKey = tbinput.readRaw(); while (rawKey != null) { byte[] rawValue = tbinput.readRaw(); key.set(rawKey, 0, rawKey.length); value.set(rawValue, 0, rawValue.length); writer.append(key, value); rawKey = tbinput.readRaw(); } } finally { writer.close(); } return 0; } LoadTypedBytes(Configuration conf);  LoadTypedBytes(); Configuration getConf(); void setConf(Configuration conf); int run(String[] args); static void main(String[] args);  }### Answer:
@Test public void testLoading() throws Exception { Configuration conf = new Configuration(); MiniDFSCluster cluster = new MiniDFSCluster(conf, 2, true, null); FileSystem fs = cluster.getFileSystem(); ByteArrayOutputStream out = new ByteArrayOutputStream(); TypedBytesOutput tboutput = new TypedBytesOutput(new DataOutputStream(out)); for (int i = 0; i < 100; i++) { tboutput.write(new Long(i)); tboutput.write("" + (10 * i)); } InputStream isBackup = System.in; ByteArrayInputStream in = new ByteArrayInputStream(out.toByteArray()); System.setIn(in); LoadTypedBytes loadtb = new LoadTypedBytes(conf); try { Path root = new Path("/typedbytestest"); assertTrue(fs.mkdirs(root)); assertTrue(fs.exists(root)); String[] args = new String[1]; args[0] = "/typedbytestest/test.seq"; int ret = loadtb.run(args); assertEquals("Return value != 0.", 0, ret); Path file = new Path(root, "test.seq"); assertTrue(fs.exists(file)); SequenceFile.Reader reader = new SequenceFile.Reader(fs, file, conf); int counter = 0; TypedBytesWritable key = new TypedBytesWritable(); TypedBytesWritable value = new TypedBytesWritable(); while (reader.next(key, value)) { assertEquals(Long.class, key.getValue().getClass()); assertEquals(String.class, value.getValue().getClass()); assertTrue("Invalid record.", Integer.parseInt(value.toString()) % 10 == 0); counter++; } assertEquals("Wrong number of records.", 100, counter); } finally { try { fs.close(); } catch (Exception e) { } System.setIn(isBackup); cluster.shutdown(); } }