Converting stream of int's to char's in java

This has probably been answered else where but how do you get the character value of an int value?

Specifically I'm reading a from a tcp stream and the readers .read() method returns an int.

How do I get a char from this?

Solution 1:

Maybe you are asking for:

Character.toChars(65) // returns ['A']

More info: Character.toChars(int codePoint)

Converts the specified character (Unicode code point) to its UTF-16 representation stored in a char array. If the specified code point is a BMP (Basic Multilingual Plane or Plane 0) value, the resulting char array has the same value as codePoint. If the specified code point is a supplementary code point, the resulting char array has the corresponding surrogate pair.

Solution 2:

It depends on what you mean by "convert an int to char".

If you simply want to cast the value in the int, you can cast it using Java's typecast notation:

int i = 97; // 97 is 'a' in ASCII
char c = (char) i; // c is now 'a'

If you mean transforming the integer 1 into the character '1', you can do it like this:

if (i >= 0 && i <= 9) {
char c = Character.forDigit(i, 10);
....
}

Solution 3:

If you're trying to convert a stream into text, you need to be aware of which encoding you want to use. You can then either pass an array of bytes into the String constructor and provide a Charset, or use InputStreamReader with the appropriate Charset instead.

Simply casting from int to char only works if you want ISO-8859-1, if you're reading bytes from a stream directly.

EDIT: If you are already using a Reader, then casting the return value of read() to char is the right way to go (after checking whether it's -1 or not)... but it's normally more efficient and convenient to call read(char[], int, int) to read a whole block of text at a time. Don't forget to check the return value though, to see how many characters have been read.