```
public class Solution {
public int[] findErrorNums(int[] nums) {
Arrays.sort(nums);
int sum = 0;
int sum1 = nums[0];
int[] res = new int[2];
for(int i = 1; i<nums.length; i++){
if(nums[i] == nums[i-1]){
res[0] = nums[i];
}
sum1 = sum1 + nums[i];
}
sum = (nums.length*(nums.length + 1))/2;
res[1] = (sum - sum1) + res[0];
return res;
}
}
```