Method triggerGc

vjmap/src/main/java/com/vip/vjtools/vjmap/VJMap.java:243–271

Trigger a remote gc using HotSpotVirtualMachine, inspired by jcmd's source code. @param pid

(Integer pid)

	 * @param pid
	 */
	private static void triggerGc(Integer pid) {
		VirtualMachine vm = null;
		try {
			vm = VirtualMachine.attach(String.valueOf(pid));
			HotSpotVirtualMachine hvm = (HotSpotVirtualMachine) vm;
			try (InputStream in = hvm.executeJCmd("GC.run");) {
				byte b[] = new byte[256];
				int n;
				do {
					n = in.read(b);
					if (n > 0) {
						String s = new String(b, 0, n, "UTF-8");
						tty.print(s);
					}
				} while (n > 0);
				tty.println();
			}
		} catch (Exception e) {
			tty.println(e.getMessage());
		} finally {
			if (vm != null) {
				try {
					vm.detach();
				} catch (IOException e) {
					tty.println(e.getMessage());
				}
			}
		}
	}

	private static void printHelp() {
		int leftLength = "-all:minsize=1024,byname".length();