Hadoop HDFS编程 API入门系列之合并小文件到HDFS（三）

　　不多说，直接上代码。

 代码版本1

package zhouls.bigdata.myWholeHadoop.HDFS.hdfs7;

import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;
import org.apache.hadoop.conf.Configuration;
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.FileUtil;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.PathFilter;
import org.apache.hadoop.io.IOUtils;
/**
 * function 合并小文件至 HDFS 
 * 
 *
 */
public class MergeSmallFilesToHDFS 
{
    private static FileSystem fs = null;  //定义文件系统对象，是HDFS上的
    private static FileSystem local = null; //定义文件系统对象，是本地上的
    
    /**
     * @function main 
     * @param args
     * @throws IOException
     * @throws URISyntaxException
     */
    
    public static void main(String[] args) throws IOException,URISyntaxException{
    
        list();
    }

    /**
     * 
     * @throws IOException
     * @throws URISyntaxException
     */
    public static void list() throws IOException, URISyntaxException{
        // 读取hadoop配置文件
        Configuration conf = new Configuration();
        // 文件系统访问接口和创建FileSystem对象，在本地上运行模式
        URI uri = new URI("hdfs://HadoopMaster:9000");
        fs = FileSystem.get(uri, conf);
        // 获得本地文件系统
        local = FileSystem.getLocal(conf);
        // 过滤目录下的 svn 文件
        FileStatus[] dirstatus = local.globStatus(new Path("./data/mergeSmallFilesToHDFS/73/*"),new RegexExcludePathFilter("^.*svn$"));
//    FileStatus[] dirstatus = local.globStatus(new Path("D://data/73/*"),new RegexExcludePathFilter("^.*svn$"));
        //获取D:Data	vdata目录下的所有文件路径
        Path[] dirs = FileUtil.stat2Paths(dirstatus);
        FSDataOutputStream out = null;
        FSDataInputStream in = null;
        for (Path dir : dirs) 
        {//比如拿2012-09-17为例
            //将文件夹名称2012-09-17的-去掉，直接，得到20120901文件夹名称
            String fileName = dir.getName().replace("-", "");//文件名称
            //只接受20120917日期目录下的.txt文件
            FileStatus[] localStatus = local.globStatus(new Path(dir+"/*"),new RegexAcceptPathFilter("^.*txt$"));
            // 获得20120917日期目录下的所有文件
            Path[] listedPaths = FileUtil.stat2Paths(localStatus);
            // 输出路径
            Path block = new Path("hdfs://HadoopMaster:9000/middle/tv/"+ fileName + ".txt");
            System.out.println("合并后的文件名称："+fileName+".txt");
            // 打开输出流
            out = fs.create(block);    
            //循环20120917日期目录下的所有文件
            for (Path p : listedPaths){//这是星型for循环，即listedPaths的值传给Path p
                in = local.open(p);// 打开输入流
                IOUtils.copyBytes(in, out, 4096, false); // 复制数据
                // 关闭输入流
                in.close();
            }
            if (out != null){
                // 关闭输出流
                out.close();
            }
            //当循环完20120917日期目录下的所有文件之后，接着依次20120918,20120919,,,
        }
    }

    /**
     * 
     * @function 过滤 regex 格式的文件
     *
     */
    public static class RegexExcludePathFilter implements PathFilter{
        private final String regex;

        public RegexExcludePathFilter(String regex){
            this.regex = regex;
        }

        
        public boolean accept(Path path){
            // TODO Auto-generated method stub
            boolean flag = path.toString().matches(regex);
            return !flag;
        }

    }

    /**
     * 
     * @function 接受 regex 格式的文件
     *
     */
    public static class RegexAcceptPathFilter implements PathFilter{
        private final String regex;

        public RegexAcceptPathFilter(String regex){
            this.regex = regex;
        }

    
        public boolean accept(Path path){
            // TODO Auto-generated method stub
            boolean flag = path.toString().matches(regex);
            return flag;
        }

    }
}

代码版本2

package com.dajiangtai.Hadoop.HDFS;

import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;
import org.apache.hadoop.conf.Configuration;
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.FileUtil;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.PathFilter;
import org.apache.hadoop.hdfs.DistributedFileSystem;
import org.apache.hadoop.io.IOUtils;
/**
 * function 合并小文件至 HDFS     ，  文件与块大小（比如128M）来比，小的话，称为小文件。是一个相对概念！相对于数据块而言的！
 * @author 小讲
 *  我们利用通配符和PathFilter 对象，将本地多种格式的文件上传至 HDFS文件系统，并过滤掉 txt文本格式以外的文件。
 */
public class MergeSmallFilesToHDFS {
    private static FileSystem fs = null;
    private static FileSystem local = null;
    /**
     * @function main 
     * @param args
     * @throws IOException
     * @throws URISyntaxException
     */
    public static void main(String[] args) throws IOException,
            URISyntaxException {
        list();
    }

    /**
     * 
     * @throws IOException
     * @throws URISyntaxException
     */
    public static void list() throws IOException, URISyntaxException {
        // 读取hadoop文件系统的配置
        Configuration conf = new Configuration();
//        conf=Configuration
//        conf是Configuration: core-default.xml, core-site.xml, mapred-default.xml, mapred-site.xml, yarn-default.xml, yarn-site.xml, hdfs-default.xml, hdfs-site.xml
        
        //文件系统访问接口
        URI uri = new URI("hdfs://djt002:9000");
//        uri=URI
//        uri是hdfs://djt002:9000
        
//        URL、URI与Path三者的区别
//        Hadoop文件系统中通过Hadoop Path对象来代表一个文件    
//        URL（相当于绝对路径）    ->   （文件） ->    URI（相当于相对路径，即代表URL前面的那一部分）
//        URI：如hdfs://dajiangtai:9000
//        如，URL.openStream
        
        
        
        //获得FileSystem实例，即HDFS
        fs = FileSystem.get(uri, conf);
//        fs=DistributedFileSystem
//        fs是DFS[DFSClient[clientName=DFSClient_NONMAPREDUCE_1814566850_1, ugi=Administrator (auth:SIMPLE)]]
        
        //获得FileSystem实例，即Local
        local = FileSystem.getLocal(conf);
//        local=LocalFileSystem
//        local是org.apache.hadoop.fs.LocalFileSystem@3ce1b8c5
//            为什么要获取到Local呢，因为，我们要把本地D盘下data/73目录下的文件要合并后，上传到HDFS里，所以，我们需先获取到Local，再来做合并工作啦！
        
        
//        18、列出文件或目录内容(主要是存放文件或目录的元数据，即大小，权限，副本，，，)
//        public FileStatus[] listStatus(Path f) throws IOException
//        public FileStatus[] listStatus(Path f,PathFilter filter) throws IOException
//                PathFilter是路径过滤器
//        public FileStatus[] listStatus(Path[] files) throws IOException
//        public FileStatus[] listStatus(Path[] files,PathFilter filter)
//                传送Path数组和路径过滤器
//                
//                
//        19、FileUtil中的stat2Paths()，将一个FileStatus元数据对象数组转换为一个Path对象数组
//
//        20、(1)使用通配符来匹配多个目录下的多个文件，也是列出文件或目录内容(主要是存放文件或目录的元数据，即大小，权限，副本，，，)
//        public FileStatus[] globStatus(Path pathPattern) throws IOException
//        public FileStatus[] globStatus(Path pathPattern,PathFilter filter) throws IOException
//                    
//          (2)PathFilter对象
//        public interface PathFilter{
//            boolean accpet(Path path);
//        }        
        
        
        
        //过滤目录下的 svn 文件，globStatus从第一个参数通配符合到文件，剔除满足第二个参数到结果，因为PathFilter中accept是return!  
        FileStatus[] dirstatus = local.globStatus(new Path("D://data/73/*"),new RegexExcludePathFilter("^.*svn$"));//一般这是隐藏文件，所以得排除
        //dirstatus=FileStatus[7]
//        dirstatus是[DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-17; isDirectory=true; modification_time=1427791478002; access_time=0; owner=; group=; permission=rwxrwxrwx; isSymlink=false}
//        , DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-18; isDirectory=true; modification_time=1427791505373; access_time=0; owner=; group=; permission=rwxrwxrwx; isSymlink=false}
//        , DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-19; isDirectory=true; modification_time=1427791532277; access_time=0; owner=; group=; permission=rwxrwxrwx; isSymlink=false}
//        , DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-20; isDirectory=true; modification_time=1427791553035; access_time=0; owner=; group=; permission=rwxrwxrwx; isSymlink=false}
//        , DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-21; isDirectory=true; modification_time=1427791577709; access_time=0; owner=; group=; permission=rwxrwxrwx; isSymlink=false}
//        , DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-22; isDirectory=true; modification_time=1427791602770; access_time=0; owner=; group=; permission=rwxrwxrwx; isSymlink=false}
//        , DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-23; isDirectory=true; modification_time=1427791647177; access_time=0; owner=; group=; permission=rwxrwxrwx; isSymlink=false}]
        
                        
                        //        ^表示匹配我们字符串开始的位置               *代表0到多个字符                        $代表字符串结束的位置
//        RegexExcludePathFilter来只排除我们不需要的，即svn格式
//        RegexExcludePathFilter这个方法我们自己写
        
//        但是我们，最终是要处理文件里的东西，最终是要转成Path类型，因为Path对象f,它对应着一个文件。
        
        //获取73目录下的所有文件路径，注意FIleUtil中stat2Paths()的使用，它将一个FileStatus对象数组转换为Path对象数组。
        Path[] dirs = FileUtil.stat2Paths(dirstatus);//dirstatus是FileStatus数组类型
//        dirs=Path[7]
//        dirs是    [file:/D:/data/73/2012-09-17
//                 , file:/D:/data/73/2012-09-18
//                 , file:/D:/data/73/2012-09-19
//                 , file:/D:/data/73/2012-09-20
//                 , file:/D:/data/73/2012-09-21
//                 , file:/D:/data/73/2012-09-22
//                 , file:/D:/data/73/2012-09-23]        
                
        
        FSDataOutputStream out = null;//输出流
//        out=HdfsDaDataOutputStream
//        out是org.apache.hadoop.hdfs.client.HdfsDataOutputStream@2b11624e
        
        FSDataInputStream in = null;//输入流
//        in=ChecksumFileSystem&FSDataBoundedInputStream
//        in是org.apache.hadoop.fs.ChecksumFileSystem$FSDataBoundedInputStream@526d542f
        
//        很多人搞不清输入流和输出流，！！！！
//        其实啊，输入流、输出流都是针对内存的
//        往内存里写，是输入流。
//        内存往文件里写，是输出Luis。
//        
//        比如一个文件A复制到另一文件B，那么，先写到内存里，再写到文件B。
//           =>   则文件A写到内存里，叫输入流。
//           =>    则内存里写到文件B，叫输出流    
        
        
        for (Path dir : dirs) {//for星型循环，即将dirs是Path对象数组，一一传给Path dir
//            dirs=Path[7]
//            dirs是[file:/D:/data/73/2012-09-17
//                  , file:/D:/data/73/2012-09-18
//                  , file:/D:/data/73/2012-09-19
//                  , file:/D:/data/73/2012-09-20
//                  , file:/D:/data/73/2012-09-21
//                  , file:/D:/data/73/2012-09-22
//                  , file:/D:/data/73/2012-09-23]    
            
//        dir= Path    
//        先传，dir是file:/D:/data/73/2012-09-17
//        再传，file:/D:/data/73/2012-09-18           
//        再传，file:/D:/data/73/2012-09-19     
//        再传，file:/D:/data/73/2012-09-20       
//        再传，file:/D:/data/73/2012-09-21       
//        再传，file:/D:/data/73/2012-09-22       
//        再传，file:/D:/data/73/2012-09-23       
            
            String fileName = dir.getName().replace("-", "");//文件名称
//                        先获取到如2012-09-17，然后经过replace("-", "")，得到20120917
//                                                                再获取，20120918
//                                                                再获取，20120919
//                                                                再获取，20120920
//                                                                再获取，20120921
//                                                                再获取，20120922
//                                                                再获取，20120923            
            
            //只接受日期目录下的.txt文件，^匹配输入字符串的开始位置,$匹配输入字符串的结束位置,*匹配0个或多个字符。
            FileStatus[] localStatus = local.globStatus(new Path(dir+"/*"),new RegexAcceptPathFilter("^.*txt$"));
//            先获取到，localStatus=FileStatus[23]
//                   localStatus是[DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-17/ars10767@20120917000000.txt; isDirectory=false; length=1111961; replication=1; blocksize=33554432; modification_time=1398669214000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-17/ars10767@20120917001500.txt; isDirectory=false; length=782533; replication=1; blocksize=33554432; modification_time=1398669214000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-17/ars10767@20120917003000.txt; isDirectory=false; length=593507; replication=1; blocksize=33554432; modification_time=1398669214000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-17/ars10767@20120917004500.txt; isDirectory=false; length=839019; replication=1; blocksize=33554432; modification_time=1398669214000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-17/ars10767@20120917010000.txt; isDirectory=false; length=866393; replication=1; blocksize=33554432; modification_time=1398669214000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-17/ars10767@20120917011500.txt; isDirectory=false; length=678491; replication=1; blocksize=33554432; modification_time=1398669214000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-17/ars10767@20120917013000.txt; isDirectory=false; length=593292; replication=1; blocksize=33554432; modification_time=1398669214000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-17/ars10767@20120917014500.txt; isDirectory=false; length=688620; replication=1; blocksize=33554432; modification_time=1398669214000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-17/ars10767@20120917020000.txt; isDirectory=false; length=674864; replication=1; blocksize=33554432; modification_time=1398669214000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-17/ars10767@20120917021500.txt; isDirectory=false; length=635052; replication=1; blocksize=33554432; modification_time=1398669214000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-17/ars10767@20120917023000.txt; isDirectory=false; length=547324; replication=1; blocksize=33554432; modification_time=1398669214000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-17/ars10767@20120917024500.txt; isDirectory=false; length=598814; replication=1; blocksize=33554432; modification_time=1398669214000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-17/ars10767@20120917030000.txt; isDirectory=false; length=542600; replication=1; blocksize=33554432; modification_time=1398669214000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-17/ars10767@20120917031500.txt; isDirectory=false; length=535446; replication=1; blocksize=33554432; modification_time=1398669214000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-17/ars10767@20120917033000.txt; isDirectory=false; length=592780; replication=1; blocksize=33554432; modification_time=1398669214000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-17/ars10767@20120917034500.txt; isDirectory=false; length=619410; replication=1; blocksize=33554432; modification_time=1398669216000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-17/ars10767@20120917040000.txt; isDirectory=false; length=590326; replication=1; blocksize=33554432; modification_time=1398669214000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-17/ars10767@20120917041500.txt; isDirectory=false; length=428487; replication=1; blocksize=33554432; modification_time=1398669214000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-17/ars10767@20120917043000.txt; isDirectory=false; length=598048; replication=1; blocksize=33554432; modification_time=1398669214000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-17/ars10767@20120917044500.txt; isDirectory=false; length=598792; replication=1; blocksize=33554432; modification_time=1398669216000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-17/ars10767@20120917050000.txt; isDirectory=false; length=575613; replication=1; blocksize=33554432; modification_time=1398669214000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-17/ars10767@20120917051500.txt; isDirectory=false; length=619080; replication=1; blocksize=33554432; modification_time=1398669214000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-17/ars10767@20120917053000.txt; isDirectory=false; length=587763; replication=1; blocksize=33554432; modification_time=1398669214000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}]
//                   再获取到，localStatus=FileStatus[23]
//            localStatus是[DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-18/ars10767@20120918131500.txt; isDirectory=false; length=1722797; replication=1; blocksize=33554432; modification_time=1398669244000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-18/ars10767@20120918133000.txt; isDirectory=false; length=1922955; replication=1; blocksize=33554432; modification_time=1398669244000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-18/ars10767@20120918134500.txt; isDirectory=false; length=1388036; replication=1; blocksize=33554432; modification_time=1398669244000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-18/ars10767@20120918140000.txt; isDirectory=false; length=1888871; replication=1; blocksize=33554432; modification_time=1398669244000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-18/ars10767@20120918141500.txt; isDirectory=false; length=1685719; replication=1; blocksize=33554432; modification_time=1398669244000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-18/ars10767@20120918143000.txt; isDirectory=false; length=1541381; replication=1; blocksize=33554432; modification_time=1398669244000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-18/ars10767@20120918144500.txt; isDirectory=false; length=1723638; replication=1; blocksize=33554432; modification_time=1398669244000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-18/ars10767@20120918150000.txt; isDirectory=false; length=1629322; replication=1; blocksize=33554432; modification_time=1398669244000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-18/ars10767@20120918151500.txt; isDirectory=false; length=1658684; replication=1; blocksize=33554432; modification_time=1398669244000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-18/ars10767@20120918153000.txt; isDirectory=false; length=1548216; replication=1; blocksize=33554432; modification_time=1398669244000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-18/ars10767@20120918154500.txt; isDirectory=false; length=1510965; replication=1; blocksize=33554432; modification_time=1398669244000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-18/ars10767@20120918160000.txt; isDirectory=false; length=1559078; replication=1; blocksize=33554432; modification_time=1398669244000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-18/ars10767@20120918161500.txt; isDirectory=false; length=1752005; replication=1; blocksize=33554432; modification_time=1398669244000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-18/ars10767@20120918163000.txt; isDirectory=false; length=1901994; replication=1; blocksize=33554432; modification_time=1398669244000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-18/ars10767@20120918164500.txt; isDirectory=false; length=2234304; replication=1; blocksize=33554432; modification_time=1398669244000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-18/ars10767@20120918170000.txt; isDirectory=false; length=1912051; replication=1; blocksize=33554432; modification_time=1398669244000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-18/ars10767@20120918171500.txt; isDirectory=false; length=1711317; replication=1; blocksize=33554432; modification_time=1398669244000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-18/ars10767@20120918173000.txt; isDirectory=false; length=1799747; replication=1; blocksize=33554432; modification_time=1398669244000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-18/ars10767@20120918174500.txt; isDirectory=false; length=2038653; replication=1; blocksize=33554432; modification_time=1398669244000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-18/ars10767@20120918180000.txt; isDirectory=false; length=2341515; replication=1; blocksize=33554432; modification_time=1398669244000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-18/ars10767@20120918181500.txt; isDirectory=false; length=2396977; replication=1; blocksize=33554432; modification_time=1398669244000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-18/ars10767@20120918183000.txt; isDirectory=false; length=2382769; replication=1; blocksize=33554432; modification_time=1398669244000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}, DeprecatedRawLocalFileStatus{path=file:/D:/data/73/2012-09-18/ars10767@20120918184500.txt; isDirectory=false; length=2709048; replication=1; blocksize=33554432; modification_time=1398669244000; access_time=0; owner=; group=; permission=rw-rw-rw-; isSymlink=false}]
//            再获取到,,,,不多赘述。
            
            
//            FileStatus[] localStatus = local.listStatus(new Path(dir+"/*"),new RegexAcceptPathFilter("^.*txt$"));//试试，看有什么区别？

//            如果不设置过滤器，FileInputFormat 会使用一个默认的过滤器来排除隐藏文件。 
//            如果通过调用 setInputPathFilter()设置了过滤器，它会在默认过滤器的基础上进行过滤。换句话说，自定义的过滤器只能看到非隐藏文件。
            
            
                    //RegexAcceptPathFilter这个方法，我们自己写
//            RegexAcceptPathFilter来只接收我们需要，即txt格式
//            这里，我们还可以只接收别的格式，自己去改，一定要锻炼学会改别人的代码
            
            
            // 获得如2012-09-17日期目录下的所有文件
            Path[] listedPaths = FileUtil.stat2Paths(localStatus);
//            同样，但是我们，最终是要处理文件里的东西，最终是要转成Path类型，因为Path对象f,它对应着一个文件。
            
//            先获取，listedPaths=Path[23]
//            先获取2012-09-17下的所有，这个不多赘述啦！
            
//            再获取，listedPaths=Path[23]
//            listedPaths是[file:/D:/data/73/2012-09-18/ars10767@20120918131500.txt
//                         , file:/D:/data/73/2012-09-18/ars10767@20120918133000.txt
//                         , file:/D:/data/73/2012-09-18/ars10767@20120918134500.txt
//                         , file:/D:/data/73/2012-09-18/ars10767@20120918140000.txt
//                         , file:/D:/data/73/2012-09-18/ars10767@20120918141500.txt
//                         , file:/D:/data/73/2012-09-18/ars10767@20120918143000.txt
//                         , file:/D:/data/73/2012-09-18/ars10767@20120918144500.txt
//                         , file:/D:/data/73/2012-09-18/ars10767@20120918150000.txt
//                         , file:/D:/data/73/2012-09-18/ars10767@20120918151500.txt
//                         , file:/D:/data/73/2012-09-18/ars10767@20120918153000.txt
//                         , file:/D:/data/73/2012-09-18/ars10767@20120918154500.txt
//                         , file:/D:/data/73/2012-09-18/ars10767@20120918160000.txt
//                         , file:/D:/data/73/2012-09-18/ars10767@20120918161500.txt
//                         , file:/D:/data/73/2012-09-18/ars10767@20120918163000.txt
//                         , file:/D:/data/73/2012-09-18/ars10767@20120918164500.txt
//                         , file:/D:/data/73/2012-09-18/ars10767@20120918170000.txt
//                         , file:/D:/data/73/2012-09-18/ars10767@20120918171500.txt
//                         , file:/D:/data/73/2012-09-18/ars10767@20120918173000.txt
//                         , file:/D:/data/73/2012-09-18/ars10767@20120918174500.txt
//                         , file:/D:/data/73/2012-09-18/ars10767@20120918180000.txt
//                         , file:/D:/data/73/2012-09-18/ars10767@20120918181500.txt
//                         , file:/D:/data/73/2012-09-18/ars10767@20120918183000.txt
//                         , file:/D:/data/73/2012-09-18/ars10767@20120918184500.txt]
            
            //输出路径
            Path block = new Path("hdfs://djt002:9000/outData/MergeSmallFilesToHDFS/"+ fileName + ".txt");
            //fileName是"fileName"
//            block=Path
//            block是hdfs://djt002:9000/outData/MergeSmallFilesToHDFS/20120918.txt
            
            // 打开输出流
            out = fs.create(block);//因为，合并小文件之后，比如这是，合并2012-09-17日期目录下的所有小文件，之后，要上传到HDFS里。
//                类似于，文件A写到内存里，再内存里写到文件B。而这行代码out = fs.create(block);是相当于是，内存里写到文件B。所以是输出流，即是从内存里输出的，所以叫输出流。
//                            这里，文件A是Local                文件B是HDFS

//                                        文件与块大小（比如128M）来比，小的话，称为小文件。是一个相对概念！相对于数据块而言的！
            
//            很多人搞不清输入流和输出流，！！！！
//            其实啊，输入流、输出流都是针对内存的
//            往内存里写，是输入流。
//            内存往文件里写，是输出Luis。
//            
//            比如一个文件A复制到另一文件B，那么，先写到内存里，再写到文件B。
//               =>   则文件A写到内存里，叫输入流。
//               =>    则内存里写到文件B，叫输出流    
            
            
            for (Path p : listedPaths) {//for星型循环，即将listedPaths的值一一传给Path p
            //先获取2012-09-17下的所有，这个不多赘述啦！
            //现在，获取到2012-09-18下了
//            p=Path
//            p是file:/D:/data/73/2012-09-18/ars10767@20120918134500.txt
//            得一个一个来，这才叫做一一传给Path p
                
                in = local.open(p);// 打开输入流in
//                类似于，文件A写到内存里，再内存里写到文件B。而这行代码in = local.open(p);是相当于是，文件A写到内存里。所以是输如流，即是写到内存里的，所以叫输入流。
//                    这里，文件A是Local                文件B是HDFS
                
                IOUtils.copyBytes(in, out, 4096, false); // 复制数据，IOUtils.copyBytes可以方便地将数据写入到文件，不需要自己去控制缓冲区，也不用自己去循环读取输入源。false表示不自动关闭数据流，那么就手动关闭。
//                IOUtils.copyBytes这个方法很重要
                                //是否自动关闭输入流和输出流，若是false，就要单独去关闭。则不在这个方法体里关闭输入和输出流了。
//                                                     若是true，则在这个方法里关闭输入和输出流。不需单独去关闭了
                
                
//                明白，IOUtils类的copyBytes将hdfs数据流拷贝到标准输出流System.out中，
//                copyBytes前两个参数好理解，一个输入，一个输出，第三个是缓存大小，第四个指定拷贝完毕后是否关闭流。
//                要设置为false，标准输出流不关闭，我们要手动关闭输入流。即，设置为false表示关闭输入流
                
//                主要是把最后的这个参数定义好， 就可以了。 定义为true还是false，则决定着是否在这个方法体里关闭
//                若定义为true,则在这个方法体里直接关闭输入流、输出流。不需单独去关闭了
//                若定义为false,则不在这个方法体里直接关闭输入流、输出流。需单独去关闭了
                
                
                // 关闭输入流
                in.close();//若定义为false,则不在这个方法体里直接关闭输入流、输出流。需单独去关闭了。这就是单独在关闭输入流！！！懂了吗
            }
            if (out != null) {//这里为什么不为空，空指针，则说明里面还有资源。
                // 关闭输出流
                out.close();//若定义为false,则不在这个方法体里直接关闭输入流、输出流。需单独去关闭了。这就是单独在关闭输出流！！！懂了吗
            }
        }
        
    }

    /**
     * 
     * @function 过滤 regex 格式的文件
     *
     */
    public static class RegexExcludePathFilter implements PathFilter {
        private final String regex;//变量

        public RegexExcludePathFilter(String regex) {//这个是上面的那个，正在表达式
            this.regex = regex;//将String regex的值，赋给RegexExcludePathFilter类里的private final String regex的值
        }

        public boolean accept(Path path) {//主要是实现accept方法
            // TODO Auto-generated method stub
            boolean flag = path.toString().matches(regex);//匹配正则表达式，这里是^.*svn$
            return !flag;
        }

    }

    /**
     * 
     * @function 接受 regex 格式的文件
     *
     */
    public static class RegexAcceptPathFilter implements PathFilter {
        private final String regex;//变量

        public RegexAcceptPathFilter(String regex) {//这个是上面的那个，正在表达式
            this.regex = regex;//将String regex的值，赋给RegexAcceptPathFilter类里的private final String regex的值
        }

        public boolean accept(Path path) {//主要是实现accept方法
            // TODO Auto-generated method stub
            boolean flag = path.toString().matches(regex);//匹配正则表达式,这里是^.*txt$
            return flag;
        }

    }
}