Java string replacement sort instance

import java.util.LinkedList;
public class OJ {
 public OJ() {
  super();
 }
 
 public static int getSortNum(final String input, final StringBuilder output) {

  if(input.length()<=0 || input.length() > 1000){
   return -1;
  }

  String[] nums = input.split("5");
  int len = nums.length;
  LinkedList<Integer> sorted = new LinkedList<Integer>();
  int j = 0;
  for (int i = 0; i < len; i++) {
   int temp = 0;
   int k = j;
   if (!nums[i].equals("")) {
    try {
     temp = Integer.valueOf(nums[i]);
     if(temp > 100000000){
      return -1;
     }
     if (sorted.isEmpty()) {
      sorted.addFirst(temp);
      j++;
     } else {
      while (k > 0 && (temp > sorted.get(k - 1))) {
       k--;
      }
      sorted.add(k, temp);
      j++;
     }
    } catch (Exception ex) {
     return -1;
    }
   }
  }
  for (int i = 0; i < sorted.size() - 1; i++) {
   output.append(sorted.get(i) + " ");
  }
  output.append(sorted.getLast());
  output.trimToSize();
  return 0;
 }
}        

Test case:

import junit.framework.Assert;
import junit.framework.TestCase;

public class OJTest extends TestCase
{
    public void testCase01()
    {
        //Write the test case here
        final StringBuilder output = new StringBuilder();
        Assert.assertTrue(-1 == OJ.getSortNum("1234543 215555", output));
    }
    
    public void testCase02()
    {
        final StringBuilder output = new StringBuilder();
        Assert.assertTrue(0 == OJ.getSortNum("1234543215555", output) && "4321 1234".equals(output.toString()));
    }

    public void testCase03()
    {
        final StringBuilder output = new StringBuilder();
        Assert.assertTrue(0 == OJ.getSortNum("12345432155556436567", output) && "6436 4321 1234 67".equals(output.toString()));
    }
    public void testCase04()
    {
        final StringBuilder output = new StringBuilder();
        Assert.assertTrue(0 == OJ.getSortNum("123454321555000000000056436567", output) && "6436 4321 1234 67 0".equals(output.toString()));
    }

    public void testCase05()
    {
        final StringBuilder output = new StringBuilder();
        Assert.assertTrue(-1 == OJ.getSortNum("1234543215510000000000000001556436567", output));
    }
}