Know the class name, method name, and parameters, how to call the function, string call

Know the class name, method name, and parameters, how to call the function, string call

There are three strings: Class Name, method name, method parameter, and string. You need to call this method as follows.

1) obtain the class first.

    Class cname=null;    try {        cname = Class.forName (classname);    } catch (ClassNotFoundException e) {    e.printStackTrace();    }    

Class. forName (classname); this method is used to obtain this Class object through reflection. For details about reflection, see http://www.cnblogs.com/xiufengd/p/4723426.html, or hundreds of degrees.

2) Obtain Methods

Method [] methodes = cname. getDeclaredMethods (); for (int I = 0; I <methodes. length; I ++) {method = methodes [I]; if (method. getName (). equals (methodName) {// other operations }}

The class object obtained after reflection has a method: getDeclaredMethods (), which is used to obtain all methods declared by the class or interface. Then, cyclically traverse the obtained Method data, use the getName Method to identify the same Method as the required Method, and then obtain the Method object.

3) Call Methods

Object result=null;if(arg.equals("")){    result = method.invoke(cname,null);}else if(arg.split(",").length==1){    result = method.invoke(cname, arg);}

 

The Method object has a method called the invoke Method. This method has two parameters: the first represents the class name and the second represents the parameter. The function of this Method is to call the method Method method of the cname class, the method parameter is arg.

Current problems:

Because the arg parameter is a string, all operations can only be divided into parameter arrays in a specific method, and then multiple parameters are called.