[JavaEE] EL expression to get data, javaeeel

[JavaEE] EL expression to get data, javaeeel

Jsp Tag:

<Jsp: include>

<Jsp: forward> implement request forwarding

<Jsp: param> Add the Parameter

 

EL expression:

 

1. Get variable data

<%

String name = "Tao shihan ";

PageContext. setAttribute ("name", name );

%>

Hello, $ {name}

 

2. Get array data

<%

String [] names = {"Tao shihan", "Zhang San "};

PageContext. setAttribute ("names", names );

%>

Hello, $ {names [0]}

 

3. Get collection data

<%

List <String> names = new ArrayList <String> ();

Names. add ("Tao shihan ");

Names. add ("James ");

PageContext. setAttribute ("names", names );

%>

Hello, $ {names [1]}

 

<%

Map <String, String> names = new HashMap <String, String> ();

Names. put ("name", "Tao shihan ");

PageContext. setAttribute ("names", names );

%>

Hello, $ {names ['name'] }$ {names. name}

 

4. Obtain the javabean data

Note that you need to export the package, and the expression automatically calls the get method.

<%

Person person = new Person ();

Person. setName ("taoshihan ");

PageContext. setAttribute ("person", person );

%>

Hello, $ {person. name}

Path: $ {pageContext. request. contextPath }=<%= request. getContextPath () %>

 

 

 

 

5. Execute operations

Obtain common development objects

Call the java method

 

 

JSTL:

 

Custom Tag: