How to remove � from a String?

Question

What is that char ? and how to remove it from a String? I got it from a BufferedReader and i got it because i read the contents in a char array and this array has to be assigned to a particular size.So, i got the String like that "aaaaaaa " , and I tried trim and subString but didn't change anything:

 String a = "aaaaaaa����";
//subString
    int i = a.lastIndexOf("a");
    a = a.substring(0, i+1);
//trim
    a = a.trim();

And this is my way to read the input:

BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
char[] a = new char[1000];
int line;
String responseLine, server_response = "";
while((line = in.read(a)) != -1) {
      responseLine = String.valueOf(a);
      server_response = server_response + responseLine;
     }
in.close();
return server_response;

Answer 1

Try with unicode

Unicode corresponding to is \�

String str0 = "aaaaaaa����";
System.out.println(str0.replaceAll("\ufffd", ""));

Answer 2

This is very likely to be an encoding problem; you do not specify the encoding on your InputStreamReader , as such the system default is used.

Try and use:

new InputStreamReader(socket.getInputStream(), StandardCharsets.UTF_8)

instead.

If you are still stuck with JDK 6, replace StandardCharsets.UTF_8 with Charset.forName("UTF-8") .

If you are unsure what encoding is used at the other end, you should not use a Reader but read the contents into a byte array. Then you can use a CharsetDecoder to try and map the bytes read into one or more encodings.

Example:

StandardCharsets.ASCII.newDecoder()

Answer 3

finally i found a way to solve that, it's not a professional one but efficient enough. all i had to do is filling the char array with white spaces just before starting the while loop and then after receiving the whole response i have just to trim it before returning it :

BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
char[] a = new char[1000];
int line;
String responseLine, server_response = "";
for(int i = 0; i < a.length; i++){ //
      a[i] = ' ';                  // this is the for loop i added
    }                              //
while((line = in.read(a)) != -1) {
      responseLine = String.valueOf(a);
      server_response = server_response + responseLine;
      for(int i = 0; i < a.length; i++){ //
          a[i] = ' ';                    // this is the for loop i added
        }                                //
     }
in.close();
return server_response.trim();     // this is where i return the response trimmed 

Answer 4

you could handle it like this:

System.out.println("aaaaaaa����".replace("�", ""));

remaining string will be aaaaaaa .

I recommend to investigate the input source though and figure out why you get those chars there. Probably there is somewhere an issue with the encoding.

Answer 5

如果您唯一期望的数字和字符，您可以在字节数组上运行for循环，并在每个字符上运行Char.isLetterOrDigit，替换那些不是“”的字符