Struts2之Ognl用法
OgnlAction.java
package
com.kaishengit.web;
import
java.util.HashMap;
import
java.util.List;
import
java.util.Map;
import
com.kaishengit.dao.UserDao;
import
com.kaishengit.vo.User;
import
com.opensymphony.xwork2.ActionContext;
import
com.opensymphony.xwork2.ActionSupport;
public
class
OgnlAction
extends
ActionSupport {
private
int
id;
private
String address;
private
Map
<
String,User
>
userMap;
private
User user;
private
List
<
User
>
userList;
private
UserDao dao
=
new
UserDao();
private
static
final
long
serialVersionUID
=
5838762467757449050L
;
@SuppressWarnings(
"
unchecked
"
)
public
String execute()
throws
Exception{
user
=
dao.findById(
"
1
"
);
userList
=
dao.findAll();
id
=
12
;
address
=
"
China
"
;
userMap
=
new
HashMap
<
String,User
>
();
userMap.put(
"
tom
"
, user);
userMap.put(
"
jerry
"
, dao.findById(
"
2
"
));
Map
<
String,Object
>
session
=
ActionContext.getContext().getSession();
session.put(
"
sessionKey
"
,
"
sessionValue
"
);
Map
<
String,Object
>
application
=
ActionContext.getContext().getParameters();
application.put(
"
applicationKey
"
,
"
applicationValue
"
);
Map
<
String,Object
>
request
=
(Map
<
String, Object
>
) ActionContext.getContext().get(
"
request
"
);
request.put(
"
requestKey
"
,
"
requestValue
"
);
return
SUCCESS;
}
//
-------------------------------------
public
int
getId() {
return
id;
}
public
void
setId(
int
id) {
this
.id
=
id;
}
public
String getAddress() {
return
address;
}
public
void
setAddress(String address) {
this
.address
=
address;
}
public
User getUser() {
return
user;
}
public
void
setUser(User user) {
this
.user
=
user;
}
public
List
<
User
>
getUserList() {
return
userList;
}
public
void
setUserList(List
<
User
>
userList) {
this
.userList
=
userList;
}
public
Map
<
String, User
>
getUserMap() {
return
userMap;
}
public
void
setUserMap(Map
<
String, User
>
userMap) {
this
.userMap
=
userMap;
}
}
struts.xml
<
action
name
="ognl"
class
="com.kaishengit.web.OgnlAction"
>
<
result
>
ognl.jsp
</
result
>
</
action
>
ognl.jsp
<%
@ page language
=
"
java
"
import
=
"
java.util.*
"
pageEncoding
=
"
utf-8
"
%>
<%
@ taglib prefix
=
"
s
"
uri
=
"
/struts-tags
"
%>
<!
DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
>
<
html
>
<
head
>
<
title
></
title
>
<
meta
http-equiv
="pragma"
content
="no-cache"
>
<
meta
http-equiv
="cache-control"
content
="no-cache"
>
<
meta
http-equiv
="expires"
content
="0"
>
<
meta
http-equiv
="keywords"
content
="keyword1,keyword2,keyword3"
>
<
meta
http-equiv
="description"
content
="This is my page"
>
</
head
>
<
body
>
ognl.jsp.....................
<
br
>
编号:
<
s:property
value
="id"
/><
br
>
地址:
<
s:property
value
="address"
/><
br
>
User对象:
<
s:property
value
="user"
/><
br
>
userName:
<
s:property
value
="user.userName"
/><
br
>
userPwd:
<
s:property
value
="user.userPwd"
/><
br
>
userList集合:
<
s:property
value
="userList"
/><
br
>
list size:
<
s:property
value
="userList.size"
/><
br
>
第一个对象：
<
s:property
value
="userList[0]"
/><
br
>
投影
<
br
>
取得List中所有的姓名:
<
s:property
value
="userList.{userName}"
/><
br
>
取得List中第一个对象的姓名:
<
s:property
value
="userList.{userName}[0]"
/>
输出List中姓名为tom的所有用户对象:
<
br
>
<
s:property
value
="userList.{?#this.userName=='tom'}"
/><
br
>
输出List中姓名为tom的第一个用户对象:
<
br
>
<
s:property
value
="userList.{^#this.userName=='tom'}"
/><
br
>
输出List中姓名为tom的最后一个用户对象：
<
br
>
<
s:property
value
="userList.{$#this.userName=='tom'}"
/><
br
>
OGNL操作Map集合--------------------
<
br
>
输出Map中的key:
<
s:property
value
="userMap.keys"
/><
br
>
输出Map中的value:
<
s:property
value
="userMap.values"
/><
br
>
输出Map中的数量:
<
s:property
value
="userMap.size"
/><
br
>
输出key(tom)对应的value:
<
s:property
value
="userMap['tom'].{id}[0]"
/><
br
>
---
判断Map是否为empty:
<
s:property
value
="userMap.isEmpty"
/><
br
>
动态创建List和Map ---------------------------
<
br
>
动态创建List:
<
s:property
value
="{'aa','bb','cc'}"
/>
动态创建Map:
<
s:property
value
="#{'aa':'aa','bb':'bb'}"
/>
<
br
>
获取request session Application中的值--------------------------
<
br
>
获取Session中的值：
<
br
>
<
s:property
value
="#session.sessionKey"
/><
br
>
获取reuqst中的值:
<
br
>
<
s:property
value
="#request.requestKey"
/><
br
>
获取Application中的值:
<
br
>
<
s:property
value
="#application.applicationKey"
/>
</
body
>
</
html
>