java读写HDFS简单demo

 
  package 
   test; 
 
  import 
   java.io.IOException; 
 
  import 
   java.net.URI; 
 
  import 
   org.apache.hadoop.conf.Configuration; 
 
  import 
   org.apache.hadoop.fs.FileSystem; 
 
  import 
   org.apache.hadoop.fs.Path;  
 
  import 
   org.apache.hadoop.fs.FSDataInputStream; 
 
  import 
   org.apache.hadoop.fs.FSDataOutputStream;; 
 
  public 
   class 
  Test { 
 
  public 
  void 
  WriteFile(String hdfs) 
  throws 
  IOException { 
 
  Configuration conf = 
  new 
  Configuration(); 
 
  FileSystem fs = FileSystem.get(URI.create(hdfs),conf); 
 
  FSDataOutputStream hdfsOutStream = fs.create( 
  new 
  Path(hdfs)); 
 
  hdfsOutStream.writeChars( 
  "hello" 
  ); 
 
  hdfsOutStream.close(); 
 
  fs.close();     
 
  } 
 
  public 
  void 
  ReadFile(String hdfs) 
  throws 
  IOException { 
 
  Configuration conf = 
  new 
  Configuration(); 
 
  FileSystem fs = FileSystem.get(URI.create(hdfs),conf); 
 
  FSDataInputStream hdfsInStream = fs.open( 
  new 
  Path(hdfs)); 
 
  byte 
  [] ioBuffer = 
  new 
  byte 
  [ 
  1024 
  ]; 
 
  int 
  readLen = hdfsInStream.read(ioBuffer); 
 
  while 
  (readLen!=- 
  1 
  ) 
 
  { 
 
  System.out.write(ioBuffer, 
  0 
  , readLen); 
 
  readLen = hdfsInStream.read(ioBuffer); 
 
  } 
 
  hdfsInStream.close(); 
 
  fs.close(); 
 
  } 
 
  public 
  static 
  void 
  main(String[] args)  
  throws 
  IOException {      
 
  String hdfs = 
  "hdfs://192.168.56.112:9000/test/hello.txt" 
  ; 
 
  Test t = 
  new 
  Test();        
 
  t.WriteFile(hdfs); 
 
  t.ReadFile(hdfs); 
 
  } 
 
  }
java读写HDFS简单demo

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