流量统计之代码重构NullWritable（第五步）

1、Access.java

 　　@Override
    //为了后续使用方便，定义了一个toString
    //具体方式：右键-Generate-toString()
    public String toString() {
        return phone +
                "," + up +
                "," + down +
                "," + sum;

    }

2、AccessReducer.java

将AccessReducer类中的Text输出，修改为NullWritable

将context中的Text输出，修改为NullWritable.get()

public class AccessReducer extends Reducer<Text, Access, NullWritable, Access>

context.write(NullWritable.get(), new Access(key.toString(), ups, downs));

3、AccessLocalApp.java

将Access.class，修改为NullWritable.class

job.setOutputKeyClass(NullWritable.class);