j2me function java.lang.nullpointerexception - what is wrong in this?

StackOverflow https://stackoverflow.com/questions/7954967

  •  17-02-2021
  •  | 
  •  

Question

Yesterday Night, i wrote this function to fetch all the tags from string containing xml data but something is not correct in this... Pls help... this function is returning java.lang.NullPointerException

  public void parseWebXML(String xd){
      int i, j, k = 0;
      String tagn, check = "";
      int spos, epos;
      byte[] len = xd.getBytes();
      tags = new String[len.length*3/4];
      int nextpos = 0;
      for(i=0;i<len.length*3/4;i++){
        spos = xd.indexOf("<", nextpos);
        epos = xd.indexOf(">", spos);
        tagn = xd.substring(spos, epos);
        if(i == 0 || i == 1 || i == 2){
            if(tagn.indexOf("/") == -1){
                tags[k] = "<"+tagn+">";
                k +=1;
            }else{
                continue;
            }
        }else{
            if(tagn.indexOf("/") == -1){
                for(j=0;j<tags.length;j++){
                    if(tags[i].equals(tags[j])){
                        check = "found";
                    }else{
                        check = "notfound";
                    }
                }
                if(check.equals("notfound")){
                    tags[i] = "<"+tagn+">";
                    k+=1;
                }else{
                    continue;
                }
            }else{
                continue;
            }
        }
        nextpos = epos + 1;
      }
  }

error that i saw while executing in debugger mode

TRACE: <at java.lang.NullPointerException:   0>, Exception caught in Display class
java.lang.NullPointerException:   0
 - httpcon.parseWebXML(), bci=170
Was it helpful?

Solution

You initialized tags[], but not each of its cells, so tags[i].equals(tags[j]) probably caused the NPE (tags[i] is null).

OTHER TIPS

tags[] has only 3 items.

if(i == 0 || i == 1 || i == 2){
            if(tagn.indexOf("/") == -1){
                tags[k] = "<"+tagn+">";
                k +=1;

if i > 3 than tags[i] return null. And tags[i].equals throw NPE

Licensed under: CC-BY-SA with attribution
Not affiliated with StackOverflow
scroll top