JAVA操作HDFS案例的简单实现

<dependency> 
 <groupId>org.apache.hadoop</groupId> 
 <artifactId>hadoop-common</artifactId> 
 <version>2.8.0</version> 
</dependency> 
<dependency> 
 <groupId>org.apache.hadoop</groupId> 
 <artifactId>hadoop-hdfs</artifactId> 
 <version>2.8.0</version> 
</dependency> 

/** 
 * 上传文件到hdfs上 
 */ 
@Test 
public void upload() throws IOException { 
  Configuration conf = new Configuration(); 
  conf.set("fs.defaultFS","hdfs://hzq:9000"); 
  FileSystem fs = FileSystem.get(conf); 
  fs.copyFromLocalFile(new Path("/home/hzq/jdk1.8.tar.gz"),new Path("/demo")); 
} 

/** 
 * 将hdfs上文件下载到本地 
 */ 
@Test 
public void download() throws IOException { 
  Configuration conf = new Configuration(); 
  conf.set("fs.defaultFS","hdfs://hzq:9000"); 
  FileSystem fs = FileSystem.newInstance(conf); 
  fs.copyToLocalFile(new Path("/java/jdk1.8.tar.gz"),new Path("/home/hzq/")); 
} 

/** 
 * 删除hdfs上的文件 
 * @throws IOException 
 */ 
@Test 
public void removeFile() throws IOException { 
  Configuration conf = new Configuration(); 
  conf.set("fs.defaultFS","hdfs://hzq:9000"); 
  FileSystem fs = FileSystem.newInstance(conf); 
  fs.delete(new Path("/demo/jdk1.8.tar.gz"),true); 
} 

/** 
 * 在hdfs更目录下面创建test1文件夹 
 * @throws IOException 
 */ 
@Test 
public void mkdir() throws IOException { 
  Configuration conf = new Configuration(); 
  conf.set("fs.defaultFS","hdfs://hzq:9000"); 
  FileSystem fs = FileSystem.newInstance(conf); 
  fs.mkdirs(new Path("/test1")); 
} 

@Test 
  public void listFiles() throws IOException { 
    Configuration conf = new Configuration(); 
    conf.set("fs.defaultFS","hdfs://hzq:9000"); 
    FileSystem fs = FileSystem.newInstance(conf); 
    // true 表示递归查找 false 不进行递归查找 
    RemoteIterator<LocatedFileStatus> iterator = fs.listFiles(new Path("/"), true); 
    while (iterator.hasNext()){ 
      LocatedFileStatus next = iterator.next(); 
      System.out.println(next.getPath()); 
    } 
    System.out.println("----------------------------------------------------------"); 
    FileStatus[] fileStatuses = fs.listStatus(new Path("/")); 
    for (int i = 0; i < fileStatuses.length; i++) { 
      FileStatus fileStatus = fileStatuses[i]; 
      System.out.println(fileStatus.getPath()); 
    } 
  }