<span style="white-space:pre"> </span>private static final String HDFS_PATH = "hdfs://localhost:8020";
private Configuration conf = null;
private FileSystem fs = null;
@Before
public void beforeClass() throws IOException {
conf = new Configuration();
fs = FileSystem.get(URI.create(HDFS_PATH), conf);
}
@After
public void AfterClass() throws IOException {
fs.close();
}@Test
public void testCopyLocalFileToHDFS() throws IOException {
String[] args = { "/test.txt1",
"hdfs://localhost:8020/user/root/test.txt" };
if (args.length != 2) {
System.err.println("Usage: filecopy <source> <target>");
System.exit(2);
}
InputStream in = new BufferedInputStream(new FileInputStream(args[0]));
FileSystem fs = FileSystem.get(URI.create(args[1]), conf);
OutputStream out = fs.create(new Path(args[1]));
IOUtils.copyBytes(in, out, conf);
// fs.copyFromLocalFile(new
// Path("/eclipse-jee-luna-R-linux-gtk-x86_64.tar.gz"), new
// Path(HDFS_PATH+"/user/root/"));
fs.copyToLocalFile(
new Path(
"hdfs://localhost:8020/user/root/eclipse-jee-luna-R-linux-gtk-x86_64.tar.gz"),
new Path("/user/"));
}@Test
public void deleteFile() throws IOException {
fs.delete(new Path("hdfs://localhost:8020/user/root/out1"), true);
}
@Test
public void readFile() {
InputStream in = null;
try {
in = fs.open(new Path(HDFS_PATH + "/user/root/test.txt"));
IOUtils.copyBytes(in, System.out, conf);
} catch (IOException e) {
e.printStackTrace();
} finally {
IOUtils.closeStream(in);
}
}@Test
public void getFileInfo() throws IllegalArgumentException, IOException {
FileStatus fSta = fs.getFileStatus(new Path(HDFS_PATH
+ "/user/root/test.txt"));
System.out.println(fSta.getAccessTime());
System.out.println(fSta.getBlockSize());
System.out.println(fSta.getModificationTime());
System.out.println(fSta.getOwner());
System.out.println(fSta.getGroup());
System.out.println(fSta.getLen());
System.out.println(fSta.getPath());
System.out.println(fSta.isSymlink());
}@Test
public void listFile() throws FileNotFoundException,
IllegalArgumentException, IOException {
RemoteIterator<LocatedFileStatus> iterator = fs.listFiles(new Path(
HDFS_PATH + "/user/root/"), true);
while (iterator.hasNext()) {
System.out.println(iterator.next());
}
FileStatus[] fss = fs.listStatus(new Path(HDFS_PATH + "/"));
Path[] ps = FileUtil.stat2Paths(fss);
for (Path p : ps) {
System.out.println(p);
}
FileStatus sta = fs
.getFileStatus(new Path(
"hdfs://localhost:8020/user/root/eclipse-jee-luna-R-linux-gtk-x86_64.tar.gz"));
BlockLocation[] bls = fs.getFileBlockLocations(sta, 0, sta.getLen());
for (BlockLocation b : bls) {
for (String s : b.getTopologyPaths())
System.out.println(s);
for (String s : b.getHosts())
System.out.println(s);
}<property>
<name>dfs.support.append</name>
<value>true</value>
</property>代码实现是：@Test
public void appendFile() {
String hdfs_path = "hdfs://localhost:8020/user/root/input/test.txt";// 文件路径
// conf.setBoolean("dfs.support.append", true);
String inpath = "/test.txt1";
try {
// 要追加的文件流，inpath为文件
InputStream in = new BufferedInputStream(
new FileInputStream(inpath));
OutputStream out = fs.append(new Path(hdfs_path));
IOUtils.copyBytes(in, out, 4096, true);
} catch (IOException e) {
e.printStackTrace();
}
}原文地址：http://blog.csdn.net/dafeng_blog/article/details/38866715
