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Java: Hadoop檔案系統的讀寫操作

所需jar包路徑:

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程式碼例項

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,需要匯入common和hdsf資料夾下的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"); } /** * 下載檔案 * * @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); } /** * 上傳檔案 * * @throws IOException */ public void upload() throws IOException { System.out.println("開始上傳..."); InputStream in = new FileInputStream("/Users/Desktop/compare.py"); OutputStream out = this.fs.create(new Path("/compare.py")); IOUtils.copyBytes(in, out, 4096, true); } /** * 刪除檔案 * * @throws IOException */ public void delete() throws IOException { boolean ret = this.fs.delete(new Path("/java"), true); System.out.println("檔案刪除結果:" + ret); } /** * 建立資料夾 * * @throws IOException */ public void mkdir() throws IOException { boolean ret = this.fs.mkdirs(new Path("/temp")); System.out.println("檔案建立成功:" + ret); } public static void main(String[] args) throws URISyntaxException, IOException, InterruptedException { HDSFDemo hdfs = new HDSFDemo(); hdfs.upload(); } }

備註:
URI的埠號一定要和配置檔案中的埠號一致

問題:

log4j:WARN Please initialize the log4j system properly

可參考:log4j:WARN Please initialize the log4j system properly 問題解決