Java - removing strange characters from a String

Question

How do I remove strange and unwanted Unicode characters (such as a black diamond with question mark) from a String?

Updated:

Please tell me the Unicode chara

Answer 1

You can use a String.replaceAll("[my-list-of-strange-and-unwanted-chars]","")

There is no Character.isStrangeAndUnWanted(), you have to define what you want.

If you want to remove control characters you can do

String str = "\u0000\u001f hi \n";
str = str.replaceAll("[\u0000-\u001f]", "");

prints hi (keeps the space).

EDIT If you want to know the unicode of any 16-bit character you can do

int num = string.charAt(n);
System.out.println(num);

Answer 2

same happened with me when i was converting clob to string using getAsciiStream.

efficiently solved it using

public String getstringfromclob(Clob cl)
{
    StringWriter write = new StringWriter();
    try{
        Reader read  = cl.getCharacterStream();     
    int c = -1;
    while ((c = read.read()) != -1)
    {
        write.write(c);
    }
    write.flush();
    }catch(Exception ec)
    {
        ec.printStackTrace();
    }
    return write.toString();

}

Answer 3

You can't because strings are immutable.

It is possible, though, to make a new string that has the unwanted characters removed. Look up String#replaceAll().

Answer 4

I did the other way. I replace all letters that are not defined ((^)):

str.replaceAll("[^a-zA-Z0-9:;.?! ]","")

so for words like : "小米体验版 latin string 01234567890" we will get: "latin string 01234567890"

Answer 5

To delete non-Latin symbols from the string I use the following code:

String s = "小米体验版 latin string 01234567890";
s = s.replaceAll("[^\\x00-\\x7F]", "");

The output string will be: " latin string 01234567890"