How to invoke a variable in another JSP page in one JSP page

In JSP learning, often need to call in a JSP page in another JSP page variables, the following days of learning, summed up.

There are several ways to invoke variable calls between JSP pages:

1, through the JSP built-in object-request object to obtain the parameter:

(1) to pass the reference through the hyperlink:

Example: The value of I in the a.jsp is passed to the b.jsp:

The core code in the A.jsp page is:

<a href= "B.jsp?i=1" > Parameter </a> (Note: You can also use JSP expressions when assigning to I, such as i=<% variable name%>)

The core code in the B.jsp page is:

<%string J=request.getparameter ("I"); %>

<%=j%>

(2) Through the table conveys parameters:

Example: Transfer the value of name from the form in the a.jsp to the b.jsp:

The core code in the A.jsp page is:

<form action= "b.jsp" method= "POST" >  
      
     <ul>  
      
           <li><input type= "text" name= "username" >  
      
           <li>w<input type= "Submit" name= "Submission" value= "submitted" >  
      
     <ul>  
      
</form>

The core code in the B.jsp page is;

<%string Getusername=request.getparameter ("username");>

<%=getusername%>

(3) pass through the hidden fields of the form:

Example: Transfer the variables defined in the a.jsp to the b.jsp;

The core code in A.JSP is:

<%!int a=4; %>  
<form action= "b.jsp" method= "POST" >  
      <input type= "Hide" name= "B" value=<%a%>>  
      
      <input type= "Submit" value= "submitted" >  
      
</form>

The core code in B.JSP is:

<%int c= (Integer) request.getattribute ("B"); %>

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(The previous code is either the <%string c=request.getattribute ("C"). ToString (); %> et cetera, type conversion pass Java)
<%=c%>

Run Result: The value of the variable a=4 through form hidden field B to C in b.jsp.

2, obtain form information through JavaBean:

Example: Use JavaBean to obtain user login form information:

The core code in LOGIN.JSP is:

<form action= "deal.jsp" method= "POST" >  
      
       <ul>  
      
            <li> user name: <input type= "text" name= "username ">  
      
            <li> Password: <input type=" password "name=" password ">  
      
            <li><input type=" Submit "Name=" Submit "value=" Login >  
      
       </ul>  
      
</form>

The core code in JavaBean is:

package com; public  
      
class userbean{  
      
       private String username;  
      
       private String password;  
      
       Public String GetUserName () {return  
      
              username;  
      
       }  
      
       public void Setusername (String username) {  
      
              this.username=username;   
      
       }  
      
       Public String GetPassword () {return  
      
              password;  
      
       }  
      
       public void SetPassword (String password) {  
      
              This.password=password  
      
       }}  
      
 

The core code in DEAL.JSP is:

<jsp:usebean id= "user" class= "com. UserBean ">  
      
<jsp:setproperty name=" user "property=" * ">  
      
<%string (); %>  
      
<%string Password=user.getpassword ();%>

The user named:<%=username%><br>

The password obtained is:<%=password%>

Where the asterisk in the <jsp:setproperty name= "user" property= "*" > in deal.jsp represents the assignment of all attributes with the same name, and, of course, can optionally assign values to properties: <jsp: SetProperty name= "user" property= "username" >, <jsp:setproperty name= "user" property= "password" > etc.

Of course, there must be better and more methods, look forward to master enlighten.