问题描述

java 遍历hdfs文件夹报错！！急！！急

FileStatus[] srcFileStatus = hdfs.listStatus(new Path(srcPath));执行到这句话的时候会报如下错：

java.lang.NullPointerException
at org.apache.hadoop.fs.Path.(Path.java:104)
at org.apache.hadoop.fs.Path.makeQualified(Path.java:440)
at org.apache.hadoop.hdfs.protocol.HdfsFileStatus.makeQualified(HdfsFileStatus.java:263)
at org.apache.hadoop.hdfs.DistributedFileSystem.listStatusInternal(DistributedFileSystem.java:802)
at org.apache.hadoop.hdfs.DistributedFileSystem.access$700(DistributedFileSystem.java:106)
at org.apache.hadoop.hdfs.DistributedFileSystem$18.doCall(DistributedFileSystem.java:853)
at org.apache.hadoop.hdfs.DistributedFileSystem$18.doCall(DistributedFileSystem.java:849)
at org.apache.hadoop.fs.FileSystemLinkResolver.resolve(FileSystemLinkResolver.java:81)
at org.apache.hadoop.hdfs.DistributedFileSystem.listStatus(DistributedFileSystem.java:849)
at test.HdfsOperate.downloadFile(HdfsOperate.java:142)
at test.HdfsTest.main(HdfsTest.java:45)

代码：

public void downloadFile(String dstPath String srcPath) throws Exception
{
Path path = new Path(srcPath);

    Configuration conf = new Configuration();       FileSystem hdfs = path.getFileSystem(conf);    //hdfs = FileSystem.get(URI.create(srcPath) conf);    File rootfile = new File(dstPath);    if(!rootfile.exists()) rootfile.mkdirs();    hdfs.getFileStatus(path);    if (hdfs.isFile(path))    {        FSDataInputStream in = null;        FileOutputStream out = null;        try        {               in = hdfs.open(path);            File srcfile = new File(rootfile path.getName());            if(!srcfile.exists())srcfile.createNewFile();            out = new FileOutputStream(srcfile);            IOUtils.copyBytes(in out 4096 false);        }        finally        {            IOUtils.closeStream(in);            IOUtils.closeStream(out);        }    }    else    {        File dstDir = new File(dstPath);        if (!dstDir.exists())        {            dstDir.mkdirs();        }        FileStatus[] srcFileStatus = hdfs.listStatus(path);        Path[] srcFilePath = FileUtil.stat2Paths(srcFileStatus);        for (int i = 0; i < srcFilePath.length; i++)        {            String srcFile = srcFilePath[i].toString();            int fileNamePosi = srcFile.lastIndexOf(""/"");            String fileName = srcFile.substring(fileNamePosi + 1);            //String fileName = srcFilePath[i].getName();            downloadFile(dstPath  + fileName srcPath  + fileName +""/"");        }    }}

解决方案

就给这行代码，也是6。。。。

解决方案二：
就给这行代码，也是6。。。。

解决方案三：
srcPath为空了吧