Java - How to measure a time out -

i making ping program using java sockets. 1 bug in program not connect , sit there ever. trying add timeout (after twenty seconds) , ping fail. have no idea how to.

here part of ping program:

boolean result = false; long before1 = system.nanotime(); out.println(new byte[64]); system.out.println("(1) sent 64 bytes of data " + address                     + "..."); try {     if ((in.readline()) != null) {         int size = in.readline().tostring().getbytes().length;         long after = system.nanotime();         long s = ((after - before1) / 1000000l) / 1000;         system.out.println("(1) recieved reply " + address             + " (" + size + " bytes), time = " + s                 + " seconds...");         result = true;     } else if ((in.readline()) == null) {         long after = system.nanotime();         long s = ((after - before1) / 1000000l) / 1000;         system.out.println("(1) failed recieve reply "             + address + ", time = " + s + " seconds...");             result = false;     }  } catch (ioexception exc) {      long after = system.nanotime();     long s = ((after - before1) / 1000000l) / 1000;     system.err.println("(1) failed recieve reply "         + address + ", time = " + s + " seconds...\nreason: "                         + exc);     result = false;  } 

but measure time elapsed in code, instead of:

long time = system.nanotime(); 

if 1 part of code stuck doing time out after 20 seconds.
suggestions on how measure if twenty seconds has passed @ start of try/catch block or anywhere else in code doesn't stuck during ping?

as "jsn" , "jahory" said need threads. here's 2 useful links, can check them ;)

• how implement timeout using threads

• adding thread timeout methods in java