Program to read records from file "stud.dat" and calculate total and percentage
Here, we read the details of students from file and display the total marks and percentage of each student on console. The DataInputStream class is used in the context of DataOutputStream and can be used to read primitives. Following is the constructor to create an InputStream:
PROGRAM
DataInputStream in = DataInputStream (InputStream in);
PROGRAM
import java.io.DataInputStream;
import java.io.File;
import java.io.FileInputStream;
class ReadRecordFromFile {
public static void main(String[] args) {
try
{
File f=new File("stud.dat");
FileInputStream fos=new FileInputStream(f);
DataInputStream dos=new DataInputStream(fos);
int roll_no,m1,m2,tot;
float per;
String name;
System.out.println("Roll No Name M1 M2 Total Percent");
for(int i=1; i<=3; i++)
{
roll_no = dos.readInt();
name = dos.readUTF();
m1 = dos.readInt();
m2 = dos.readInt();
tot=m1+m2;
per=tot/2.0f;
System.out.printf(" %d %s %d %d %d %.2f\n",roll_no,name,m1,m2,tot,per);
}
dos.close();
}
catch(Exception ee){
System.out.println(ee);
}
}
}
OUTPUT
C:\>javac ReadRecordFromFile.java C:\>java ReadRecordFromFile Roll No Name M1 M2 Total Percent 4 Rohan 75 87 162 81.00 5 Darshan 65 70 135 67.50 8 Subhash 61 49 110 55.00