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();
    }
    
}