Code:
 <hdp:job id="news_result_sim_job"
	    input-path="${sim.output.path}/news/convert/" output-path="${sim.output.path}/news/result/" 
		mapper="com.xxx.wap.algorithm.mapred.sim.SimResultJob.MapClass"
		reducer="com.xxx.wap.algorithm.mapred.sim.SimResultJob.Reduce"	
		combiner="com.xxx.wap.algorithm.mapred.sim.SimResultJob.Combine"
		jar="file:/data/DATA/smc/whftest/newrecom/algorithmUtils/algorithmUtils-1.0-SNAPSHOT.jar"
		input-format="org.apache.hadoop.mapreduce.lib.input.SequenceFileInputFormat"
		output-format="org.apache.hadoop.mapreduce.lib.output.TextOutputFormat"	
		map-key="com.sohu.wap.algorithm.model.sim.SimKeyPair"
		map-value="org.apache.hadoop.io.DoubleWritable"
		key="com.xxx.wap.algorithm.model.sim.SimKeyPair"
		value="org.apache.hadoop.io.DoubleWritable"
		number-reducers="1"
		configuration-ref="hadoopConfiguration"
		>
	</hdp:job>
	
	<hdp:cache configuration-ref="hadoopConfiguration" file-system-ref="fs">
       <hdp:cache value="/tmp/wanghf/sim/output/news/length/part-r-00000.lzo_deflate" />
    </hdp:cache>
java code
Code:
private static Map<Integer, Double> loadCache(Configuration conf) {
		Map<Integer, Double> gidLength = new HashMap<Integer, Double>();
		try {
		    System.out.println("$$$$$$$$$$$$$$$$$$$$"+conf.get("mapred.cache.localFiles"));
			Path[] localFiles = DistributedCache.getLocalCacheFiles(conf);
why localFiles is null?why?why?why?,please,