char (int) 和 int 之间的区别

Question

I have a piece of code, that receives values from a sensor (Via serialport using rxtx) and displays it. Strangely, the following code

int value = in.read();
System.out.print((char) value);

Outputs the desired value as:

RXTX Warning:  Removing stale lock file. /var/lock/LK.005.018.009
20
27
29
26
21

But when I change the above code as following:

int value = in.read();
System.out.print("The value is"+(char) value);

The output becomes:

RXTX Warning:  Removing stale lock file. /var/lock/LK.005.018.009
The value is2The value is6The value is
The value is2The value is2The value is

As it can be seen, the integer splits. For quite a while, I am unable to figure it out?

Is there a way where I can save the console value into an integer, as I would be using this value in the future.

Answer 1

As it can be seen, the integer splits. For quite a while, I am unable to figure it out?

You are not reading integers, you are reading bytes which have characters encoded as ?ASCII?

Is there a way where I can save the console value into an integer, as I would be using this value in the future?

The simplest way is to use a Scanner

Scanner scanner = new Scanner(in);
while (scanner.hasNextInt()) {
   // read bytes up the next whitespace, parse as a int
   int n = scanner.nextInt();

Answer 2

Don't cast it to char. Just print

System.out.print("The value is " + value);

Answer 3

在第二个示例中，您将 int 转换为 char，但是当您将它连接到 string 时，您什么也看不到，因为这些是不可打印的字符。

Answer 4

Your code converted the value number into a character, using Java's UCS2 representation. You may need it only if you want to treat the value as a character data (eg String).

If you need it only as an integer value (eg for printing), you don't need to convert.

Answer 5

please check this snippet by adopting to your code

BufferedReader br = new BufferedReader(new InputStreamReader(System.in));   
   String  line = br.readLine();
   String[] words = line.split("[ ]",0); //white space delimiter
   for(int i = 0; i < words.length; i++) {
   System.out.print("The value is " +words[i]);
   System.out.print("\n");