這個錯誤主要時型別出現錯誤： 

 m.invoke(t, va); 造成的錯誤 

va 為String型別的數值 

如果有一個方法需要的引數是Double就會出現該錯誤

private <T> T parseRequest(HttpServletRequest request, Class<T> cls) throws InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException {
		// 獲取物件
		T t = cls.newInstance();
		List<Method> setMethods = getAllSetMethods(cls);
		Map<String, String[]> map = request.getParameterMap();
		for (Map.Entry<String, String[]> entry : map.entrySet()) {
			String key = entry.getKey();
			String[] value = entry.getValue();

			String setKey = "set" + key;
			String va = "";
			if (value.length > 0 && value != null) {
				va = value[0];
			}

			if (va == "") {
				continue;
			}
			for (Method m : setMethods) {
				//如果鍵相同 則給該方法賦值
				if (m.getName().equalsIgnoreCase(setKey)) {
                              m.invoke(t, va);
				}

			}

		}

		return t;
	}

	private List<Method> getAllSetMethods(Class cls) {
		List<Method> setMethods = new ArrayList<>();
		Method methods[] = cls.getDeclaredMethods();
		for (Method m : methods) {
			if (m.getName().startsWith("set")) {
				setMethods.add(m);
			}
		}
		return setMethods;
	}
 

進行改良

先判斷型別再進行賦值

private <T> T parseRequest(HttpServletRequest request, Class<T> cls) throws InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException {
		// 獲取物件
		T t = cls.newInstance();
		List<Method> setMethods = getAllSetMethods(cls);
		Map<String, String[]> map = request.getParameterMap();
		for (Map.Entry<String, String[]> entry : map.entrySet()) {
			String key = entry.getKey();
			String[] value = entry.getValue();


			String setKey = "set" + key;
			String va = "";
			if (value.length > 0 && value != null) {
				va = value[0];
			}


			if (va == "") {
				continue;
			}
			for (Method m : setMethods) {
				//如果鍵相同 則給該方法賦值
				if (m.getName().equalsIgnoreCase(setKey)) {
					String parameterName=m.getParameterTypes()[0].getName();
					if("int".equals(parameterName)&&"java.lang.Integer".equals(parameterName) ){
						int v = Integer.parseInt(va);
						m.invoke(t, v);
					}else if("float".equals(parameterName)||"java.lang.Float".equals(parameterName)){
						float v = Float.parseFloat(va);
						m.invoke(t, v);
					}else if("double".equals(parameterName)||"java.lang.Double".equals(parameterName)){
						Double v = Double.parseDouble(va);
						m.invoke(t, v);
					}else{
						  m.invoke(t, va);
					}
				}


			}


		}


		return t;
	}


	private List<Method> getAllSetMethods(Class cls) {
		List<Method> setMethods = new ArrayList<>();
		Method methods[] = cls.getDeclaredMethods();
		for (Method m : methods) {
			if (m.getName().startsWith("set")) {
				setMethods.add(m);
			}
		}
		return setMethods;
	}