1：创建一个可以上传到hdfs文件系统的文件（wc.input）

2：编写java代码调用api完成附件的上传相当于执行-put命令

3：查看执行结果

全部代码

package com.lizh.hadoop.hdfs;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IOUtils;
public class HdfsApp {

    public static FileSystem getFileSystem() throws IOException{
        Configuration conf = new Configuration();
        FileSystem fs = FileSystem.get(conf);
        return fs;
    }
    
    public static void readFile(String path1) {
        try {
            FileSystem fs = getFileSystem();
            Path path = new Path(path1);
            FSDataInputStream in = fs.open(path);
            IOUtils.copyBytes(in, System.out, 4000, false);
        } catch (Exception e) {
            // TODO: handle exception
            e.printStackTrace();
        }
        
    }
    

    
    public static void main(String[] args) throws Exception{
        //String path ="/user/beifeng/mapreduce/wordcount/input/wc.input";
        //readFile(path);
        //把/opt/modules/hadoop-2.5.0/wc.input 内容写入到 /user/beifeng/put-wc.input
        //write file
        FileInputStream fisin =null;
        FSDataOutputStream fsoutstream =null;
        try {
            String filename="/user/beifeng/put-wc.input";//文件系统目录
            Path inputpath = new Path(filename);   
            FileSystem fs = getFileSystem();
            fsoutstream = fs.create(inputpath);
        
            fisin = new FileInputStream(new File("/opt/modules/hadoop-2.5.0/wc.input"));//本地系统目录文件
            IOUtils.copyBytes(fisin, fsoutstream, 4000, false);
        } catch (Exception e) {
            // TODO: handle exception
            e.printStackTrace();
        }finally{
            IOUtils.closeStream(fsoutstream);
            IOUtils.closeStream(fisin);
        }
    }
    
    
    
}

写文件流程图