ArrayIndexOutOfBoundException在映射代碼

Question

輸入是1000:rohit:male:dev:2500

在這方面，我要計數的男性和女性的計數。當我使用分割，分配每個性別領域減速器節目ArrayIndexOutOfBounfException:2

public class DeptEmpcountMapper extends 
     Mapper<LongWritable, Text, Text, LongWritable> { 

    @Override 
    protected void map(LongWritable key, Text value, Context context) 

      throws IOException, InterruptedException { 

     String st = value.toString(); 

     String[] field = st.split(":"); 
     String st1 = field[2]; 

     context.write(new Text(st1), new LongWritable(1)); 
    } 

} 

Answer 1

你正在做危險的假設，即每輸入記錄的形式爲1000:rohit:male:dev:2500。從你的錯誤，很明顯，情況並非如此。壞數據總是需要考慮的事情。

考慮你輸入一些簡單的驗證事先：

String[] field = st.split(":"); 
if(ArrayUtils.getLength(field) == 5) { 
    String st1 = field[2]; 
    context.write(new Text(st1), new LongWritable(1)); 
} else { 
    //Consider printing "st" to see what the bad input looks like 
}