我有一個簡單的java程序,名爲putmerge,我試圖執行。我一直在這裏工作了6個小時,在網上搜索了很多地方,但找不到解決方案。基本上,我嘗試用下面的命令所有類庫來構建JAR:Hadoop定製Java程序
javac -classpath *:lib/* -d playground/classes playground/src/PutMerge.java
然後我建立與下面的命令的罐子。
jar -cvf playground/putmerge.jar -C playground/classes/ .
然後我嘗試用下面的命令來執行它:
bin/hadoop jar playground/putmerge.jar org.scd.putmerge "..inputPath.." "..outPath"
..
Exception in thread "main" java.lang.ClassNotFoundException: com.scd.putmerge
at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:270)
at org.apache.hadoop.util.RunJar.main(RunJar.java:153)
我想盡排列/組合運行這個簡單的罐子,但是我總是得到如上所示的某種異常。
我的源代碼:
package org.scd.putmerge;
import java.io.IOException;
import java.util.Scanner;
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;
/**
*
* @author Anup V. Saumithri
*
*/
public class PutMerge
{
public static void main(String[] args) throws IOException
{
Configuration conf = new Configuration();
FileSystem hdfs = FileSystem.get(conf);
FileSystem local = FileSystem.getLocal(conf);
Path inputDir = new Path(args[0]);
Path hdfsFile = new Path(args[1]);
try
{
FileStatus[] inputFiles = local.listStatus(inputDir);
FSDataOutputStream out = hdfs.create(hdfsFile);
for(int i=0; i<inputFiles.length; i++)
{
System.out.println(inputFiles[i].getPath().getName());
FSDataInputStream in = local.open(inputFiles[i].getPath());
byte buffer[] = new byte[256];
int bytesRead = 0;
while((bytesRead = in.read(buffer)) > 0)
{
out.write(buffer, 0, bytesRead);
}
in.close();
}
out.close();
}
catch(IOException ex)
{
ex.printStackTrace();
}
}
}
太棒了!這解決了我的問題。萬分感謝。對於記錄來說,問題出在我的包規範在bin/hadoop jar命令中。如上所述,我將它更改爲org.scd.putmerge.PutMerge ......並開始工作.... – Ace