配置：hdfs-site.xml

    	    
     
      dfs.support.append
     	    
     
      true
     
    

追加一个文件

package com.wyp;	 	import org.apache.hadoop.conf.Configuration;	import org.apache.hadoop.fs.FileSystem;	import org.apache.hadoop.fs.Path;	import org.apache.hadoop.io.IOUtils;	 	import java.io.*;	import java.net.URI;	 	/**	 * blog: http://www.iteblog.com/	 * Date: 14-1-2	 * Time: 下午6:09	 */	public class AppendContent {	    public static void main(String[] args) {	        String hdfs_path = "hdfs://mycluster/home/wyp/wyp.txt";//文件路径	        Configuration conf = new Configuration();	        conf.setBoolean("dfs.support.append", true);	 	        String inpath = "/home/wyp/append.txt";	        FileSystem fs = null;	        try {	            fs = FileSystem.get(URI.create(hdfs_path), conf);	            //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();	        }	    }	}

追加一行内容

/**      * 以append方式将内容添加到HDFS上文件的末尾;注意：文件更新，需要在hdfs-site.xml中添
    
     
      dfs.      * append.support
     
     
      true
     
          */      private static void appendToHdfs() throws FileNotFoundException,              IOException {          String dst = "hdfs://192.168.1.11:9000/usr/yujing/test.txt";          Configuration conf = new Configuration();          FileSystem fs = FileSystem.get(URI.create(dst), conf);          FSDataOutputStream out = fs.append(new Path(dst));            int readLen = "zhangzk add by hdfs java api".getBytes().length;            while (-1 != readLen) {              out.write("zhangzk add by hdfs java api".getBytes(), 0, readLen);          }          out.close();          fs.close();      }

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