Time Limit Exceed in Prime Generator (PRIME1)

Why am I getting a time limit exceeded error every time, here is my code?

import java.util.;
import java.lang.;
import java.util.Scanner;
class Main
{
public static void main (String[] args) throws java.lang.Exception
{
Scanner scan = new Scanner(System.in1);
int number, input1, input2, i, counter, j;
double number2 = 0;
boolean isPrime;
counter = 0;
number = scan.nextInt();
if(( number < 1) || (number > 10)) {
System.exit(0);
}
for( i = 0; i <number; i++) {
input1 = scan.nextInt();
input2 = scan.nextInt();

	if( (input1 < 1) || (input2 < 1) || (input1 > 1000000000) || (input2 > 1000000000) || (input2 < input1) || ((input2-input1) > 100000) ) {
		System.exit(0);
	}
	
	for (j = input1; j<=input2; j++) {
		
		isPrime = isPrime(j);
		
		if(isPrime == true) {
			System.out.println(j);
		}
		else {
			continue;
		}
}
	System.out.println("");

}
}
static boolean isPrime(int j) {
boolean flag = false;
for(int i = 2; i <= j/2; i++) {
if(j % i == 0)
{
flag = true;
break;
}
}

if (!flag)
		return true;
else {
		return false;
}

}
}