我正在试着运行我的MapReduce程序。在我尝试运行它之后，输出如下(我只显示输出的最后一部分）

File System Counters
    FILE: Number of bytes read=3052
    FILE: Number of bytes written=224295
    FILE: Number of read operations=0
    FILE: Number of large read operations=0
    FILE: Number of write operations=0
    HDFS: Number of bytes read=0
    HDFS: Number of bytes written=0
    HDFS: Number of read operations=5
    HDFS: Number of large read operations=0
    HDFS: Number of write operations=1
Map-Reduce Framework
    Map input records=4
    Map output records=4
    Map output bytes=120
    Map output materialized bytes=0
    Input split bytes=97
    Combine input records=0
    Combine output records=0
    Spilled Records=0
    Failed Shuffles=0
    Merged Map outputs=0
    GC time elapsed (ms)=40
    CPU time spent (ms)=0
    Physical memory (bytes) snapshot=0
    Virtual memory (bytes) snapshot=0
    Total committed heap usage (bytes)=117927936
File Input Format Counters 
    Bytes Read=272
Exception in thread "main" java.io.IOException: Job failed!
at org.apache.hadoop.mapred.JobClient.runJob(JobClient.java:836)
at mapreduceprogram.main(mapreduceprog.java:68)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at org.apache.hadoop.util.RunJar.main(RunJar.java:212)

我不知道哪里出错了，有什么帮助吗？
我的主要方法内容：

public static void main(String[] args) throws Exception {
     JobConf conf = new JobConf(mapreduceprog.class);
     conf.setJobName("mapreduceprog");

     conf.setOutputKeyClass(Text.class);
     conf.setOutputValueClass(IntWritable.class);

         conf.setMapOutputKeyClass(Text.class);
         conf.setMapOutputValueClass(Text.class);

     conf.setMapperClass(Map.class);
     conf.setCombinerClass(Reduce.class);
     conf.setReducerClass(Reduce.class);

     conf.setInputFormat(TextInputFormat.class);
     conf.setOutputFormat(TextOutputFormat.class);

     FileInputFormat.setInputPaths(conf, new Path(args[0]));
     FileOutputFormat.setOutputPath(conf, new Path(args[1]));

     JobClient.runJob(conf);

我的68号线是

JobClient.runJob(conf);