十三、根据HDFS提供的API，实现文件上传、下载、删除、重命名、移动

一、

根据HDFS提供的API，实现以下功能：
针对文件： 上传、下载、删除、重命名、移动

package HdfsApi;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.FileStatus;import org.apache.hadoop.fs.FileSystem;import org.apache.hadoop.fs.Path;import org.apache.hadoop.io.IOUtils;public class HdfsApi {    //获取FSpublic static FileSystem getFs() throws IOException{//获取配置文件Configuration conf = new  Configuration();//获取文件系统FileSystem fs = FileSystem.get(conf);return fs;}//读取文件public static void readFile(String src) throws IOException{// 获取 FileSystemFileSystem fs = getFs();//读的路径Path readPath = new Path(src);FSDataInputStream inStream = null;try {//打开输入流inStream = fs.open(readPath);IOUtils.copyBytes(inStream, System.out, 4096, false);} catch (Exception e) {e.printStackTrace();}finally{IOUtils.closeStream(inStream);}}public static void putFlie() throws IOException{  //获取filesystemFileSystem fs=getFs();//上传到路径File readpath=new File("/opt/app/hadoop/wc.input");//本地路径Path putpath=new Path("/data/put-wc.input");FileInputStream in=new FileInputStream(readpath);FSDataOutputStream out =fs.create(putpath);try {IOUtils.copyBytes(in, out, 4096, false);} catch (Exception e) {e.printStackTrace();}finally{IOUtils.closeStream(in);IOUtils.closeStream(out);}}//上传文件 public static void writeFile(String src,String dst) throws IOException{//获取filesystemFileSystem fs = getFs();//本地路径File inFile = new File(src);//目标路径Path outFile = new Path(dst);FileInputStream inStream = null;FSDataOutputStream outStream = null;try {//打开输入流inStream = new FileInputStream(inFile);//打开输出流outStream = fs.create(outFile);IOUtils.copyBytes(inStream, outStream,4096, false);} catch (Exception e) {// TODO: handle exception}finally{IOUtils.closeStream(inStream);IOUtils.closeStream(outStream);}}//下载文件 public static void downLoad(String src,String dst) throws IOException{FileSystem fs = getFs();//设置下载地址和目标地址fs.copyToLocalFile(new Path(src), new Path(dst));fs.close();}//重命名和移动public static void renameMV(String src,String dst) throws IOException{FileSystem fs = getFs();fs.rename(new Path(src), new Path(dst));fs.close();}//删除文件public static void delete(String fileName) throws IOException{FileSystem fs = getFs(); fs.deleteOnExit(new Path(fileName));}//获取文件列表public static void listFile(String dirName) throws IOException{FileSystem fs = getFs();FileStatus[]  fileStatuses = fs.listStatus(new Path(dirName));for(FileStatus fileName:fileStatuses){System.out.println(fileName.getPath().getName());}}//创建目录public static void mkdir() throws  IOException {FileSystem fs = getFs(); fs.mkdirs(new Path("/data/bb"));fs.close();}//创建目录public static void deletedir() throws  IOException {FileSystem fs = getFs();     fs.delete(new Path("/data/bb"), true);fs.close();}         public static void main(String[] args) throws IOException {}}

二、实现把本地某个目录下面所有小文件合并上传到HDFS文件系统

package HdfsApi;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;import org.apache.hadoop.conf.Configuration;import org.apache.hadoop.fs.FSDataInputStream;import org.apache.hadoop.fs.FileStatus;import org.apache.hadoop.fs.FileSystem;import org.apache.hadoop.fs.LocalFileSystem;import org.apache.hadoop.fs.Path;import org.apache.hadoop.io.IOUtils;public class PutMerge {public static void main(String[] args) throws IOException {//step 1 ：  获取  FileSystemConfiguration conf = new Configuration();LocalFileSystem localFs = FileSystem.getLocal(conf);FileSystem dfs = FileSystem.get(conf);//step 2  : 设置输入输出 in/out PathPath inPath = new Path("/opt/app/hadoop-2.5.0/etc/hadoop");Path outPath = new Path("/data2/putmerge.xml");FileStatus[] fileStatuses = localFs.listStatus(inPath);OutputStream outStream = null;InputStream inStream = null;try {//step 4 : 打开输出流outStream = dfs.create(outPath);for(FileStatus fileName:fileStatuses){//step 3 :  打开输入流inStream = localFs.open(fileName.getPath());IOUtils.copyBytes(inStream, outStream, 4096, false);IOUtils.closeStream(inStream);System.out.println(fileName.getPath());}} catch (Exception e) {e.printStackTrace();}finally{IOUtils.closeStream(outStream);System.out.println("PutMerge Success");}}}