Test Performance for MethodInvoker, Reflect

TestSimple.java

package demo.invoke;

import java.lang.invoke.*;
import java.lang.reflect.Method;

@SuppressWarnings("unused")
public class TestSimple {
	
	public static final int LOOPS = 100000000;

	public static void main(String[] args) throws Throwable {
		
		testDirect();
		
		testInvoker();
		
		testReflect();
	}
	
	static void testReflect() throws Throwable {
		String test = "Hello World";
		
		long start = System.currentTimeMillis();
		
		Method method = String.class.getMethod("replace", char.class, char.class);
		
		for(int i = 0; i<LOOPS; i++){
			
//			test.replace('o', 'O');
//			System.out.println("Invoke " + i);
			String res = (String) method.invoke(test, 'o', 'O');
			
		}
		
		long end = System.currentTimeMillis();
		
		System.out.println("TestReflect Total time is " + (end-start));
		
	}
	
	static void testInvoker() throws Throwable{
		String test = "Hello World";
		
		MethodHandles.Lookup lookup = MethodHandles.lookup();
		MethodType methodType = MethodType.methodType(String.class, char.class, char.class);
		
		MethodHandle mh = lookup.findVirtual(String.class, "replace", methodType);
		
		long start = System.currentTimeMillis();
		
		for(int i = 0; i<LOOPS; i++){
			
//			test.replace('o', 'O');
//			System.out.println("Invoke " + i);
			String res = (String) mh.invoke(test, 'o', 'O');
			
		}
		
		long end = System.currentTimeMillis();
		
		System.out.println("TestInvoke Total time is " + (end-start));
		
	}
	
	static void testDirect(){
		String test = "Hello World";
		
		long start = System.currentTimeMillis();
		
		for(int i = 0; i<LOOPS; i++){
			
			String str = test.replace('o', 'O');
			
		}
		
		long end = System.currentTimeMillis();
		
		System.out.println("TestDirect Total time is " + (end-start));

	}
	
}