setRequestProperty throwing java.lang.IllegalStateException: Cannot set request property after connection is made

Question

I am getting java.lang.IllegalStateException:

java.lang.IllegalStateException: Cannot set request property after connection is made error w

Answer 1

not invoke setRequestProperty after write byte to OutputStream.

OutputStream os = connection.getOutputStream();
os.write("k=v".getBytes());
os.close();

you should invoke setRequestProperty above the code