Disable duplication of numbers in an array - if-statement

Question

I managed to make the program works but the problem is the between Row 3 Column 2 and Row 3 Column 3. Whenever i input two duplicate numbers in row 3 column 2 and row 3 column 3, it accepts those two.
If i input 1 there, it loops back. My only problem is the number 8. Why's that?
Here's my code:
Scanner input = new Scanner(System.in);
int magic_square[][]=new int[3][3];
int counter = 0;
int valid = 0;
int duplicate = 0;
int sum_row[] = new int[3];
int sum_col[] = new int[3];
int rowcolcheck =0;
int rowcheck=0;
System.out.println("Enter the Magic Number: ");
for(int i=0;i<3;i++){
for(int j=0;j<3;j++){
valid = 0;
do{
duplicate = 0;
System.out.print("Row "+(i+1)+" Column "+(j+1)+": ");
magic_square[i][j] = input.nextInt();
if(magic_square[i][j]<0||magic_square[i][j]>9){
System.out.println("Invalid input range! Please try again!");
valid = 1;
continue;
}
valid = 0;
for(int a=0;a<3;a++){
for(int b=0;b<3;b++){
if(a==i&&b==j)
{
continue;
}
if(magic_square[i][j]==magic_square[a][b]){
duplicate = 1;
System.out.println("Duplicate Number! Please try again!");
continue;
}
if(duplicate==1){
valid = 1;
}
}
}
}while(valid!=0);
}
}

Answer 1

I fixed it!
valid = 0;
for(int a=0;a<3;a++){
for(int b=0;b<3;b++){
if(a==i&&b==j)
{
continue;
}
if(magic_square[i][j]==magic_square[a][b]){
valid = 1; // i change this. it was duplicate = 1.
//now it's valid = 1.
System.out.println("Duplicate Number! Please try again!");
continue;
}
//i removed this conditon and the integer duplicate =
// 0 and it works like a charm!
//if(duplicate==1){
// valid = 1;
//}
}
}