removing null chars from android string

Question

In my android project, i want to read a data structure from file. A field suppose 'name', which has maximum of 32 chars. Most of the time 'name' field contains less than maximum limit. Some unwanted chars (i think 'null') is filled with data. i used 'trim' method to remove, but nothing happened. I need only valid data for processing, how can i solve this problem ?

Answer 1

使用正则表达式替换不可打印的字符。

String string=line.replaceAll("[^\\p{Print}]","");

Answer 2

Check whether the ascii value of the character is greater than 0 to check whether the character is null

How to remove null from android String

String str = "abc def";
            StringBuffer sb = new StringBuffer();
            byte[] byteArray = str.getBytes();
            for(byte bytedata:byteArray){
                if(bytedata>0){
                    sb.append((char)bytedata);
                }
            }
            str = sb.toString();
            System.out.println("..."+str);

Answer 3

If the char 0 is appended at the end of the String, just find its first index in the String, and substring up to this index:

int nullCharIndex = s.indexOf((char) 0);
if (nullCharIndex >= 0) {
    s = s.substring(0, nullCharIndex);
}

Answer 4

If you have a name field that is completly null just check, whether the string == null.

If you want to parse one string, which contains for example spaces jsut use:

String string = "a b c d";
string.replaceAll(" ","");

This can be used for every other char. Be aware that you have to use RegEx for that.