本文整理汇总了Java中org.apache.hadoop.io.Text.Comparator方法的典型用法代码示例。如果您正苦于以下问题：Java Text.Comparator方法的具体用法？Java Text.Comparator怎么用？Java Text.Comparator使用的例子？那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类org.apache.hadoop.io.Text的用法示例。
在下文中一共展示了Text.Comparator方法的1个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的Java代码示例。
示例1: deleteNonexisting
import org.apache.hadoop.io.Text; //导入方法依赖的package包/类
/**
* Delete the dst files/dirs which do not exist in src
*
* @return total count of files and directories deleted from destination
* @throws IOException
*/
static private long deleteNonexisting(
FileSystem dstfs, FileStatus dstroot, Path dstsorted,
FileSystem jobfs, Path jobdir, JobConf jobconf, Configuration conf
) throws IOException {
if (dstroot.isFile()) {
throw new IOException("dst must be a directory when option "
+ Options.DELETE.cmd + " is set, but dst (= " + dstroot.getPath()
+ ") is not a directory.");
}
//write dst lsr results
final Path dstlsr = new Path(jobdir, "_distcp_dst_lsr");
try (final SequenceFile.Writer writer = SequenceFile.createWriter(jobconf,
Writer.file(dstlsr), Writer.keyClass(Text.class),
Writer.valueClass(NullWritable.class), Writer.compression(
SequenceFile.CompressionType.NONE))) {
//do lsr to get all file statuses in dstroot
final Stack<FileStatus> lsrstack = new Stack<FileStatus>();
for(lsrstack.push(dstroot); !lsrstack.isEmpty(); ) {
final FileStatus status = lsrstack.pop();
if (status.isDirectory()) {
for(FileStatus child : dstfs.listStatus(status.getPath())) {
String relative = makeRelative(dstroot.getPath(), child.getPath());
writer.append(new Text(relative), NullWritable.get());
lsrstack.push(child);
}
}
}
}
//sort lsr results
final Path sortedlsr = new Path(jobdir, "_distcp_dst_lsr_sorted");
SequenceFile.Sorter sorter = new SequenceFile.Sorter(jobfs,
new Text.Comparator(), Text.class, NullWritable.class, jobconf);
sorter.sort(dstlsr, sortedlsr);
//compare lsr list and dst list
long deletedPathsCount = 0;
try (SequenceFile.Reader lsrin =
new SequenceFile.Reader(jobconf, Reader.file(sortedlsr));
SequenceFile.Reader dstin =
new SequenceFile.Reader(jobconf, Reader.file(dstsorted))) {
//compare sorted lsr list and sorted dst list
final Text lsrpath = new Text();
final Text dstpath = new Text();
final Text dstfrom = new Text();
final Trash trash = new Trash(dstfs, conf);
Path lastpath = null;
boolean hasnext = dstin.next(dstpath, dstfrom);
while (lsrin.next(lsrpath, NullWritable.get())) {
int dst_cmp_lsr = dstpath.compareTo(lsrpath);
while (hasnext && dst_cmp_lsr < 0) {
hasnext = dstin.next(dstpath, dstfrom);
dst_cmp_lsr = dstpath.compareTo(lsrpath);
}
if (dst_cmp_lsr == 0) {
//lsrpath exists in dst, skip it
hasnext = dstin.next(dstpath, dstfrom);
} else {
//lsrpath does not exist, delete it
final Path rmpath = new Path(dstroot.getPath(), lsrpath.toString());
++deletedPathsCount;
if ((lastpath == null || !isAncestorPath(lastpath, rmpath))) {
if (!(trash.moveToTrash(rmpath) || dstfs.delete(rmpath, true))) {
throw new IOException("Failed to delete " + rmpath);
}
lastpath = rmpath;
}
}
}
}
return deletedPathsCount;
}