所需jar包路径:
hadoop-2.8.5/share/hadoop/common hadoop-2.8.5/share/hadoop/common/bin hadoop-2.8.5/share/hadoop/hdfs hadoop-2.8.5/share/hadoop/hdfs/bin
java代码实例
import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.fs.FileSystem; import org.apache.hadoop.fs.Path; import org.apache.hadoop.io.IOUtils; import java.io.*; import java.net.URI; import java.net.URISyntaxException; /** * HDFS操作,需要导入common和hdsf文件夹下的jar */ public class HDSFDemo { private FileSystem fs = null; HDSFDemo() throws IOException, URISyntaxException, InterruptedException { Configuration conf = new Configuration(); fs = FileSystem.get(new URI("hdfs://master:9000"), conf, "root"); } /** * 下载文件 * * @throws IOException */ public void download() throws IOException { InputStream in = fs.open(new Path("/java")); OutputStream out = new FileOutputStream("/Users/Desktop"); IOUtils.copyBytes(in, out, 4096, true); } /** * 上传文件 * * @throws IOException */ public void upload() throws IOException { System.out.println("开始上传..."); InputStream in = new FileInputStream("/Users/Desktop/compare.py"); OutputStream out = this.fs.create(new Path("/compare.py")); IOUtils.copyBytes(in, out, 4096, true); } /** * 删除文件 * * @throws IOException */ public void delete() throws IOException { boolean ret = this.fs.delete(new Path("/java"), true); System.out.println("文件删除结果:" + ret); } /** * 创建文件夹 * * @throws IOException */ public void mkdir() throws IOException { boolean ret = this.fs.mkdirs(new Path("/temp")); System.out.println("文件创建成功:" + ret); } public static void main(String[] args) throws URISyntaxException, IOException, InterruptedException { HDSFDemo hdfs = new HDSFDemo(); hdfs.upload(); } }
备注:
URI的端口号一定要和配置文件中的端口号一致
问题:
log4j:WARN Please initialize the log4j system properly
可参考:log4j:WARN Please initialize the log4j system properly 问题解决