CharBuffer.put () does not work

Question

I am trying to put some lines in CharBuffer using the CharBuffer.put() function but the buffer remains empty.

my code is:

 CharBuffer charBuf = CharBuffer.allocate(1000); for (int i = 0; i < 10; i++) { String text = "testing" + i + "\n"; charBuf.put(text); } System.out.println(charBuf); 

I tried using with clear() or rewind() after allocate(1000) , but that did not change the result.

Answer 1

You have to rewind it after you put the objects, try this

 CharBuffer charBuf = CharBuffer.allocate(1000); for (int i = 0; i < 10; i++) { String text = "testing" + i + "\n"; charBuf.put(text); } charBuf.rewind(); System.out.println(charBuf); 

Answer 2

Add a rewind() call to the right after the loop.

Answer 3

Try the following:

 CharBuffer charBuf = CharBuffer.allocate(1000); for (int i = 0; i < 10; i++) { String text = "testing" + i + "\n"; charBuf.put(text); } charBuf.rewind(); System.out.println(charBuf); 

The detail that you are missing is that the record moves the current pointer to the end of the recorded data, so when you print it, it starts with the current pointer that did not write anything.

Answer 4

You will need to flip() buffer before you can read from the buffer. Before reading data from the buffer, you need to call the flip() method. When the flip() method is called the limit, the current position is set, and the position is 0. For example,

 CharBuffer charBuf = CharBuffer.allocate(1000); for (int i = 0; i < 10; i++) { String text = "testing" + i + "\n"; charBuf.put(text); } charBuf.flip(); System.out.println(charBuf); 

The above will only print characters in buffers, not in unwritten space in the buffer.