java reflection sample

reflection_samples.java

  public static void setPrivateField(Object targetObj, String fieldName, Object value)
            throws NoSuchFieldException, IllegalAccessException
    {
        Class c = targetObj.getClass();
        Field field = c.getDeclaredField(fieldName);
        field.setAccessible(true);
        field.set(targetObj, value);
    }

    public static Object invokePrivateMethod(Object targetObj, String methodName,
                                           Class[] argClasses, Object[] args)
            throws NoSuchMethodException, InvocationTargetException, IllegalAccessException
    {
        Class c = targetObj.getClass();
        Method method = c.getDeclaredMethod(methodName, argClasses);
        method.setAccessible(true);
        return method.invoke(targetObj, args);
    }
    
    public static String trimAllSpace(String str) {
        if (str == null || str.length() == 0) {
            return str;
        }
        int st = 0;
        int len = str.length();
        char[] val = str.toCharArray();
        while ((st < len) && ((val[st] <= '\u0020') || (val[st] == '\u00A0') || (val[st] == '\u3000'))) {
            st++;
        }
        while ((st < len) && ((val[len - 1] <= '\u0020') || (val[len - 1] == '\u00A0') || (val[len - 1] == '\u3000'))) {
            len--;
        }
        return ((st > 0) || (len < str.length())) ? str.substring(st, len) : str;
    }