學習測試，網上下的程式碼，測試通過，助於理解讀寫程式流程

package com.linbin.testmaven;

import java.net.URI;
import java.text.SimpleDateFormat;
import java.util.Date;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.LocatedFileStatus;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.RemoteIterator;
import org.apache.hadoop.fs.permission.FsPermission;
import org.apache.hadoop.hdfs.DistributedFileSystem;


/**
 * Hello world!
 *
 */
public class App 
{
    public static DistributedFileSystem dfs=new DistributedFileSystem();;
    public static String nameNodeUri="hdfs://centos7:8020";
    
    public static void main( String[] args ) throws Exception 
    {
    	System.out.println( "Hello World! how are you?" );
    	  App fot = new App();
        fot.initFileSystem();
        fot.testMkDir();
        fot.testFileList();
    }
    
    public void initFileSystem() throws Exception{
        System.out.println("初始化hadoop客戶端");
        //設定hadoop的登入使用者名稱
        System.setProperty("HADOOP_USER_NAME", "root");
        //dfs=new DistributedFileSystem();
        dfs.initialize(new URI(nameNodeUri), new Configuration());
        System.out.println("客戶端連線成功");
        Path workingDirectory = dfs.getWorkingDirectory();
        System.out.println("工作目錄："+workingDirectory);
    }
    
    /**
     * 建立資料夾
     * @throws Exception 
     */
    public void testMkDir() throws Exception{
        boolean res = dfs.mkdirs(new Path("/tmp/bbb"));
        System.out.println("目錄建立結果："+(res?"建立成功":"建立失敗"));
    }
    /**
     * 獲取指定目錄下所有檔案(忽略目錄)
     * @throws Exception 
     * @throws IllegalArgumentException 
     * @throws FileNotFoundException 
     */
    public void testFileList() throws Exception{
        RemoteIterator<LocatedFileStatus> listFiles = dfs.listFiles(new Path("/"), true);
        SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
        while (listFiles.hasNext()) {
            LocatedFileStatus fileStatus = (LocatedFileStatus) listFiles.next();
            FsPermission permission = fileStatus.getPermission();
            String owner = fileStatus.getOwner();
            String group = fileStatus.getGroup();
            long len = fileStatus.getLen();
            long modificationTime = fileStatus.getModificationTime();
            Path path = fileStatus.getPath();
            System.out.println("-------------------------------");
            System.out.println("path:"+path);
            System.out.println("permission:"+permission);
            System.out.println("owner:"+owner);
            System.out.println("group:"+group);
            System.out.println("len:"+len);
            System.out.println("modificationTime:"+sdf.format(new Date(modificationTime)));
        }
    }
}
 

測試結果，成功讀寫hadoop目錄資訊