package com.study.hdfs;

import org.apache.commons.io.IOUtils;

import org.apache.hadoop.conf.Configuration;

import org.apache.hadoop.fs.BlockLocation;

import org.apache.hadoop.fs.FSDataInputStream;

import org.apache.hadoop.fs.FSDataOutputStream;

import org.apache.hadoop.fs.FileStatus;

import org.apache.hadoop.fs.FileSystem;

import org.apache.hadoop.fs.LocatedFileStatus;

import org.apache.hadoop.fs.Path;

import org.apache.hadoop.fs.RemoteIterator;

import org.apache.hadoop.hdfs.DistributedFileSystem;

import org.apache.hadoop.hdfs.protocol.DatanodeInfo;

import org.junit.AfterClass;

import org.junit.BeforeClass;

import org.junit.Test;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.IOException;

import java.net.URI;

import java.net.URISyntaxException;

import java.util.Iterator;

import java.util.Map;

/**

 * @author wangxu

 * @date 2016/12/17

 */

public class HDFSTest {

    private static FileSystem fs;

    @BeforeClass

    public static void setup() throws URISyntaxException, IOException, InterruptedException {

        //方式1通过配置来获取fs

        /*Configuration conf = new Configuration();

        conf.set("fs.defaultFS", "hdfs://node1:9000");

        FileSystem fs = FileSystem.get(conf);

        System.setProperty("HADOOP_USER_NAME", "root");*/

        //方式2直接获取fs

        Configuration conf = new Configuration();

        conf.set("dfs.replication", "2");

        conf.set("dfs.block.size", "64m");

        fs = FileSystem.get(new URI("hdfs://node1:9000"), conf, "root");

    }

    @Test

    public void test01() throws IOException {

        fs.copyToLocalFile(new Path("/plans.txt"),new Path("C:/Users/wxisme/Desktop/bigdatatest/"));

    }

    @Test

    public void test02() throws IOException {

        FSDataOutputStream out = fs.create(new Path("/plans01.txt"));

        FileInputStream in = new FileInputStream("C:/Users/wxisme/Desktop/bigdatatest/plans.txt");

        IOUtils.copy(in, out);

    }

    @Test

    public void test03() throws IOException {

        DatanodeInfo[] dataNodeStats = ((DistributedFileSystem)fs).getDataNodeStats();

        for(DatanodeInfo dinfo: dataNodeStats){

            System.out.println(dinfo.getHostName());

        }

    }

    @Test

    public void test04() throws IOException {

//        fs.mkdirs(new Path("/wangxu/study"));

//        fs.rename(new Path("/wangxu/study"), new Path("/wangxu/play"));

        fs.delete(new Path("/wangxu/play"), true);

    }

    @Test

    public void test05() throws IOException {

        //返回迭代器，而不是List之类的容器,防止客户端内存溢出

        RemoteIterator<LocatedFileStatus> listFiles = fs.listFiles(new Path("/"), true);

        while (listFiles.hasNext()) {

            LocatedFileStatus fileStatus = listFiles.next();

            System.out.println(fileStatus.getPath().getName());

            System.out.println(fileStatus.getBlockSize());

            System.out.println(fileStatus.getPermission());

            System.out.println(fileStatus.getLen());

            BlockLocation[] blockLocations = fileStatus.getBlockLocations();

            for (BlockLocation bl : blockLocations) {

                System.out.println("block-length:" + bl.getLength() + "--" + "block-offset:" + bl.getOffset());

                String[] hosts = bl.getHosts();

                for (String host : hosts) {

                    System.out.println(host);

                }

            }

            System.out.println("--------------分割线--------------");

        }

    }

    @Test

    public void test06() throws IOException {

        FileStatus[] listStatus = fs.listStatus(new Path("/"));

        String flag = "";

        for (FileStatus fstatus : listStatus) {

            if (fstatus.isFile()) {

                flag = "f-- ";

            } else {

                flag = "d-- ";

            }

            System.out.println(flag + fstatus.getPath().getName());

            System.out.println(fstatus.getPermission());

        }

    }

    @Test

    public void test07() {

        Configuration conf = new Configuration();

        conf.addResource("test.xml");

        System.out.println(conf.get("xxx.uu"));

        Iterator<Map.Entry<String, String>> it = conf.iterator();

        while(it.hasNext()){

            System.out.println(it.next());

        }

    }

    @Test

    public void testDownLoadFileToLocal() throws IllegalArgumentException, IOException{

        //先获取一个文件的输入流----针对hdfs上的

        FSDataInputStream in = fs.open(new Path("/jdk-7u65-linux-i586.tar.gz"));

        //再构造一个文件的输出流----针对本地的

        FileOutputStream out = new FileOutputStream(new File("c:/jdk.tar.gz"));

        //再将输入流中数据传输到输出流

        org.apache.hadoop.io.IOUtils.copyBytes(in, out, 4096);

    }

    @Test

    public void testUploadByStream() throws Exception{

        //hdfs文件的输出流

        FSDataOutputStream fsout = fs.create(new Path("/aaa.txt"));

        //本地文件的输入流

        FileInputStream fsin = new FileInputStream("c:/111.txt");

        org.apache.hadoop.io.IOUtils.copyBytes(fsin, fsout,4096);

    }

    /**

     * hdfs支持随机定位进行文件读取，而且可以方便地读取指定长度

     * 用于上层分布式运算框架并发处理数据

     * @throws IllegalArgumentException

     * @throws IOException

     */

    @Test

    public void testRandomAccess() throws IllegalArgumentException, IOException{

        //先获取一个文件的输入流----针对hdfs上的

        FSDataInputStream in = fs.open(new Path("/iloveyou.txt"));

        //可以将流的起始偏移量进行自定义

        in.seek(22);

        //再构造一个文件的输出流----针对本地的

        FileOutputStream out = new FileOutputStream(new File("d:/iloveyou.line.2.txt"));

        org.apache.hadoop.io.IOUtils.copyBytes(in,out,19L,true);

    }

    /**

     * 读取指定的block

     * @throws IOException

     * @throws IllegalArgumentException

     */

    @Test

    public void testCat() throws IllegalArgumentException, IOException{

        FSDataInputStream in = fs.open(new Path("/weblog/input/access.log.10"));

        //拿到文件信息

        FileStatus[] listStatus = fs.listStatus(new Path("/weblog/input/access.log.10"));

        //获取这个文件的所有block的信息

        BlockLocation[] fileBlockLocations = fs.getFileBlockLocations(listStatus[0], 0L, listStatus[0].getLen());

        //第一个block的长度

        long length = fileBlockLocations[0].getLength();

        //第一个block的起始偏移量

        long offset = fileBlockLocations[0].getOffset();

        System.out.println(length);

        System.out.println(offset);

        //获取第一个block写入输出流

//        IOUtils.copyBytes(in, System.out, (int)length);

        byte[] b = new byte[4096];

        FileOutputStream os = new FileOutputStream(new File("d:/block0"));

        while(in.read(offset, b, 0, 4096)!=-1){

            os.write(b);

            offset += 4096;

            if(offset>length) return;

        };

        os.flush();

        os.close();

        in.close();

    }

    @AfterClass

    public static void shutdown() throws IOException {

        fs.close();

    }

}