借了网上一位仁兄的例子，改了改。
直接上代码：
package reflect; public class PlainJavaClass { public int a = 2; public int b = 3; public PlainJavaClass() { } public PlainJavaClass(int a, int b) { this.a = a; this.b = b; } public int add() { return a + b; } public int plus(int[] a, int b) { return a[0] - b; } }
package reflect; import java.lang.reflect.*; public class ReflectJavaClass { public void invokePlain() { Class Plain = null; Method add = null; Method plus = null; Class[] plusPara = { int[].class, int.class }; int[] in = { 30, 50 }; Object[] transPlusPara = { in, 20 }; Object addReturnObj = null; Object plusReturnObj = null; try { Plain = Class.forName("reflect.PlainJavaClass"); } catch (ClassNotFoundException e) { e.printStackTrace(); return; } try { add = Plain.getDeclaredMethod("add", null); plus = Plain.getDeclaredMethod("plus", plusPara); } catch (SecurityException e) { e.printStackTrace(); return; } catch (NoSuchMethodException e) { e.printStackTrace(); return; } try { addReturnObj = add.invoke(new PlainJavaClass(5, 2), null); plusReturnObj = plus.invoke(new PlainJavaClass(), transPlusPara); } catch (IllegalArgumentException e) { e.printStackTrace(); return; } catch (IllegalAccessException e) { e.printStackTrace(); return; } catch (InvocationTargetException e) { e.printStackTrace(); return; } Integer addReturnValue = (Integer) addReturnObj; Integer plusReturnValue = (Integer) plusReturnObj; System.out.println("return value :" + addReturnValue); System.out.println("return value :" + plusReturnValue); } public static void main(String[] args) { new ReflectJavaClass().invokePlain(); } }