我不知道我的代码有什么问题。它卡在Map100%的输入：

expression, number
1+2+3, 0.4

输出应为：

count   expression    number
1 1+2+3 0.4
2 3*4   0.8

这就是 map 方法：

public void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
    inputs = value.toString();  
    tokens = inputs.split(",");
    expr = new Text (tokens[0]);
    fit = new DoubleWritable(Double.parseDouble(tokens[1]));
    EF.setExpr(tokens[0]);
    EF.setFit(Double.parseDouble(tokens[1]));
    count++;
    context.write(new IntWritable(count),EF );    
}

和阶级 Reduce :

public static class Reduce extends Reducer<IntWritable,exprfit,IntWritable,exprfit> {
  private exprfit EF = new exprfit();
  private int count;

  public void reduce(IntWritable key, Iterable<exprfit> values, Context context) throws IOException, InterruptedException {
    EF.setExpr(values.iterator().next().getExpr());
    EF.setFit(values.iterator().next().getFit());
    context.write(key, EF); 
  }
}

班级 exprfit :

public static class exprfit implements Writable {
  private String expr;
  private Double fit;// type of output value

  public String getExpr() {
    return expr;
  }

  public void setExpr(String expr) {
    this.expr = expr;
  }

  public double getFit() {
    return fit;
  }

  public void setFit(Double fit) {
    this.fit = fit;
  }

  @Override
  public void write(DataOutput out) throws IOException {
    out.writeChars(expr);
    out.writeDouble(fit);
  }

  @Override
  public String toString() {
    // TODO Auto-generated method stub
    return super.toString();
  }

  public void readFields(DataInput in) throws IOException {
    expr =in.readLine();
    fit = in.readDouble();  
  }
}