查看文本文件SomeData.txt中的数据并分析其格式,用Java I0 api将其中的所有数据读出,计算出每一行的后4列数据的平均值,存放到新文件AvgSomeData.txt文件中,存放时每一行前面要加上行号(行号占3位,右对齐),平均值放到行末并左对齐。
import java.util.*;
import java.io.*;
public class FIleStream {
public static void main(String[] args) {
FileReader inReader;
FileWriter outWriter;
try{
inReader=new FileReader("D:\\Documents\\SomeData.txt");
outWriter=new FileWriter("D:\\Documents\\SomeData2.txt");
//inReader.
}
catch (IOException e)
{
System.out.println("File can't be found or File creates error.");
return;
}
BufferedReader in=new BufferedReader(inReader);//???????????????????????
BufferedWriter out=new BufferedWriter(outWriter);//????????????????????????
String str;
int lineNo=0;
//inStream.read
try{
while ((str=in.readLine())!=null)
{
System.out.print(str);
String[] splits=str.split("\t");
System.out.println(" "+(int)(Double.parseDouble(splits[3])+Double.parseDouble(splits[4])+Double.parseDouble(splits[5])+Double.parseDouble(splits[6]))/4);
out.write(String.format("%1$03d", lineNo++)+" "+str+"\t"+(int)(Double.parseDouble(splits[3])+Double.parseDouble(splits[4])+Double.parseDouble(splits[5])+Double.parseDouble(splits[6]))/4+"\r\n");
}
in.close();
out.close();
inReader.close();
outWriter.close();
}catch(IOException e)
{
System.out.println("\nIO Errors.");
return;
}
System.out.println("\n\n\nDone!");
}
}