How to obtain parameters of JSP pages by using actions in struts2

Instance: Now, a parameter named username is passed to the action on the JSP page.

URL: http: // localhost: 8080/studentsystem/role_list.action? Username = qk12333.com

1. Get it through the Get Set Method

Define a variable with the same name in the corresponding action class and generate the set get method. Then, the parameter automatically obtains the value.

String username;

Public String GetUserName ()
{
Return username;
}

Public void setusername (string username)
{
This. Username = username;
}

System. Out. println (username); // The result is qk12333.com.

 

2. Use servletactioncontext to get // import org. Apache. struts2.servletactioncontext;

Httpservletrequest reqeust = servletactioncontext. getrequest ();

String username = reqeust. getparameter ("username"); // string

// URL: http: /localhost: 8080/studentsystem/role_list.action? Username = qk12333.com & username = qk12333.com

String [] username = reqeust. getparametervalues ("username"); // String Array

System. Out. println (username); // The result is qk12333.com.

System. Out. println (username [0]); // The result is qk12333.com.

 

3. Use actioncontext to get // import com. opensymphony. xwork2.actioncontext;

Actioncontext context = actioncontext. getcontext ();
Map Params = context. getparameters ();
String [] username = (string []) Params. Get ("username ");

// Actioncontext obtains an object such as object or string []

System. Out. println (username [0]); // The result is qk12333.com.