java上传文件到HDFS

拼搏现实的明天。 2022-07-15 08:26 231阅读 0赞

java上传本地文件到HDFS。  
1、pom依赖

<dependency>
        <groupId>org.apache.hadoop</groupId>
        <artifactId>hadoop-common</artifactId>
        <version>2.6.0-cdh5.5.1</version>
    </dependency>
    
    <dependency>
        <groupId>org.apache.hadoop</groupId>
        <artifactId>hadoop-hdfs</artifactId>
        <version>2.6.0-cdh5.5.1</version>
    </dependency>
    
    <dependency>
        <groupId>org.apache.hadoop</groupId>
        <artifactId>hadoop-maven-plugins</artifactId>
        <version>2.6.0-cdh5.5.1</version>
    </dependency>

2、java代码

/** * Created by xxx on 2016/11/9. */
    
    import java.io.*;
    import java.net.URI;
    import java.text.SimpleDateFormat;
    import java.util.Date;
    
    import org.apache.hadoop.conf.Configuration;
    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 HdfsTest { 
    
        static Configuration conf = new Configuration();
    
        static {
            conf.set("fs.defaultFS", "hdfs://nameservice1");
            conf.set("dfs.nameservices", "nameservice1");
            conf.set("dfs.ha.namenodes.nameservice1", "nn1,nn2");
            conf.set("dfs.namenode.rpc-address.nameservice1.nn1", "xxx:8020");
            conf.set("dfs.namenode.rpc-address.nameservice1.nn2", "xxx:8020");
            conf.set("dfs.client.failover.proxy.provider.nameservice1"
                    ,"org.apache.hadoop.hdfs.server.namenode.ha.ConfiguredFailoverProxyProvider");
    
    
    // conf.addResource("classpath:/hadoop/core-site.xml");
    // conf.addResource("classpath:/hadoop/hdfs-site.xml");
    // conf.addResource("classpath:/hadoop/mapred-site.xml");
        }
    
        //创建新文件
        public static void createFile(String dst , byte[] contents) throws IOException{
            FileSystem fs = FileSystem.get(conf);
            Path dstPath = new Path(dst); //目标路径
            //打开一个输出流
            FSDataOutputStream outputStream = fs.create(dstPath);
            outputStream.write(contents);
            outputStream.close();
            fs.close();
            System.out.println("文件创建成功！");
        }
    
        //上传本地文件
        public static void uploadFile(String src,String dst) throws IOException{
            //Configuration conf = new Configuration();
            FileSystem fs = FileSystem.get(conf);
            Path srcPath = new Path(src); //本地上传文件路径
            Path dstPath = new Path(dst); //hdfs目标路径
            //调用文件系统的文件复制函数,前面参数是指是否删除原文件，true为删除，默认为false
            fs.copyFromLocalFile(false, srcPath, dstPath);
    
            //打印文件路径
            System.out.println("Upload to "+conf.get("fs.default.name"));
            System.out.println("------------list files------------"+"\n");
            FileStatus [] fileStatus = fs.listStatus(dstPath);
            for (FileStatus file : fileStatus)
            {
                System.out.println(file.getPath());
            }
            fs.close();
        }
    
        //文件重命名
        public static void rename(String oldName,String newName) throws IOException{
            //Configuration conf = new Configuration();
            FileSystem fs = FileSystem.get(conf);
            Path oldPath = new Path(oldName);
            Path newPath = new Path(newName);
            boolean isok = fs.rename(oldPath, newPath);
            if(isok){
                System.out.println("rename ok!");
            }else{
                System.out.println("rename failure");
            }
            fs.close();
        }
        //删除文件
        public static void delete(String filePath) throws IOException{
            //Configuration conf = new Configuration();
            FileSystem fs = FileSystem.get(conf);
            Path path = new Path(filePath);
            boolean isok = fs.deleteOnExit(path);
            if(isok){
                System.out.println("delete ok!");
            }else{
                System.out.println("delete failure");
            }
            fs.close();
        }
    
        //创建目录
        public static void mkdir(String path) throws IOException{
            //Configuration conf = new Configuration();
            FileSystem fs = FileSystem.get(conf);
            Path srcPath = new Path(path);
            boolean isok = fs.mkdirs(srcPath);
            if(isok){
                System.out.println("create " + path + " dir ok!");
            }else{
                System.out.println("create " + path + " dir failure");
            }
            fs.close();
        }
    
        //读取文件的内容
        public static void readFile(String filePath) throws IOException{
            //Configuration conf = new Configuration();
            FileSystem fs = FileSystem.get(conf);
            Path srcPath = new Path(filePath);
            InputStream in = null;
            try {
                in = fs.open(srcPath);
                IOUtils.copyBytes(in, System.out, 4096, false); //复制到标准输出流
            } finally {
                IOUtils.closeStream(in);
            }
        }
    
        /** * 遍历指定目录(direPath)下的所有文件 */
        public static void  getDirectoryFromHdfs(String direPath){
            try {
                FileSystem fs = FileSystem.get(URI.create(direPath),conf);
                FileStatus[] filelist = fs.listStatus(new Path(direPath));
                for (int i = 0; i < filelist.length; i++) {
                    System.out.println("_________" + direPath + "目录下所有文件______________");
                    FileStatus fileStatus = filelist[i];
                    System.out.println("Name:"+fileStatus.getPath().getName());
                    System.out.println("Size:"+fileStatus.getLen());
                    System.out.println("Path:"+fileStatus.getPath());
                }
                fs.close();
            } catch (Exception e){
    
            }
        }
    
    
        public static void main(String[] args) throws IOException {
            String today = new SimpleDateFormat("yyyy-MM-dd").format(new Date());
    
            String localFilePath = "F:\\datafortag\\maimaimai\\quan-" + today;
            String hdfsFilePath = "/user/rec/maimaimai/upload_month=" + today.substring(0,7) + "/upload_date=" + today + "/";
            System.out.println(localFilePath);
            System.out.println(hdfsFilePath);
    
            //"/user/rec/maimaimai/upload_month=2016-11/upload_date=2016-11-09/"
            //1、遍历指定目录(direPath)下的所有文件
            //getDirectoryFromHdfs("/user/rec/maimaimai");
    
            //2、新建目录
            //mkdir(hdfsFilePath);
    
            //3、上传文件
            //uploadFile(localFilePath, hdfsFilePath);
            //getDirectoryFromHdfs(hdfsFilePath);
    
            //4、读取文件
            //readFile("/user/rec/maimaimai/quan-2016-11-09");
    
            //5、重命名
    // rename("/user/rec/maimaimai/2016-11/2016-11-09/quan-2016-11-09", "/user/rec/maimaimai/2016-11/2016-11-09/quan-2016-11-08.txt");
    // getDirectoryFromHdfs("/user/rec/maimaimai/2016-11/2016-11-09");
    
            //6、创建文件，并向文件写入内容
            //byte[] contents = "hello world 世界你好\n".getBytes();
            //createFile("/user/rec/maimaimai/2016-11/2016-11-09/test.txt",contents);
            //readFile("/user/rec/maimaimai/2016-11/2016-11-09/test.txt");
    
            //7、删除文件
            //delete("/user/rec/maimaimai/quan-2016-11-08.txt"); //使用相对路径
            //delete("test1"); //删除目录
        }
    
    }