用Java编写hdfs文件 [英] Write a file in hdfs with Java

问题描述

我想在HDFS中创建一个文件并在其中写入数据。我使用这段代码：

I want to create a file in HDFS and write data in that. I used this code:

Configuration config = new Configuration();     
FileSystem fs = FileSystem.get(config); 
Path filenamePath = new Path("input.txt");  
try {
    if (fs.exists(filenamePath)) {
        fs.delete(filenamePath, true);
    }

    FSDataOutputStream fin = fs.create(filenamePath);
    fin.writeUTF("hello");
    fin.close();
}

它创建文件，但不会写入任何内容。我搜查了很多，但
没有找到任何东西。我的问题是什么？我需要任何权限写入HDFS吗？

It creates the file, but it does't write anything in it. I searched a lot but didn't find anything. What is my problem? Do I need any permission to write in HDFS?

谢谢。

推荐答案

替代@ Tariq的asnwer，您可以在获取文件系统时传递URI

an alternative to @Tariq's asnwer you could pass the URI when getting the filesystem

Configuration configuration = new Configuration();
FileSystem hdfs = FileSystem.get( new URI( "hdfs://localhost:54310" ), configuration );
Path file = new Path("hdfs://localhost:54310/s2013/batch/table.html");
if ( hdfs.exists( file )) { hdfs.delete( file, true ); } 
OutputStream os = hdfs.create( file,
    new Progressable() {
        public void progress() {
            out.println("...bytes written: [ "+bytesWritten+" ]");
        } });
BufferedWriter br = new BufferedWriter( new OutputStreamWriter( os, "UTF-8" ) );
br.write("Hello World");
br.close();
hdfs.close();

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