dwr+spring集成
DWR（Direct Web Remoting）是一个用于改善web页面与Java类交互的远程服务器端Ajax开源框架,可以帮助开发人员开发包含AJAX技术的网站.它可以允许在浏览器里的代码使用运行在WEB服务器上的JAVA函数,就像它就在浏览器里一样。
以下模拟一个简单的dwr入门案例，重点理解dwr是如何跟java后台服务器打交道的
模拟效果如下
该功能说明了dwr是怎么跟后台服务器打交道的
模拟从服务器加载下拉列表数据
模拟保存功能
模拟查询功能
接下来为dwr+spring集成步骤：
1、新建一个web工程，导入dwr+spring所需jar，如下图
目录结构图
修改web.xml
<?
xml version
=
"
1.0
"
encoding
=
"
UTF-8
"
?>
<
web
-
app version
=
"
2.4
"
xmlns
=
"
http://java.sun.com/xml/ns/j2ee
"
xmlns:xsi
=
"
http://www.w3.org/2001/XMLSchema-instance
"
xsi:schemaLocation
=
"
http://java.sun.com/xml/ns/j2ee
http:
//
java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
<!--
Spring上下文
-->
<
context
-
param
>
<
param
-
name
>
contextConfigLocation
</
param
-
name
>
<
param
-
value
>
classpath:resource
/
app
*
.xml
</
param
-
value
>
</
context
-
param
>
<
listener
>
<
listener
-
class
>
org.springframework.web.context.ContextLoaderListener
</
listener
-
class
>
</
listener
>
<!--
配置DWR前端控制器
-->
<
servlet
>
<
servlet
-
name
>
dwrServlet
</
servlet
-
name
>
<
servlet
-
class
>
org.directwebremoting.servlet.DwrServlet
</
servlet
-
class
>
<!--
指定配置文件
-->
<
init
-
param
>
<
param
-
name
>
config
</
param
-
name
>
<!--
如果有多个用
"
,
"
分开
-->
<
param
-
value
>
/
WEB
-
INF
/
classes
/
config
/
dwr.xml
</
param
-
value
>
</
init
-
param
>
<
init
-
param
>
<
param
-
name
>
debug
</
param
-
name
>
<
param
-
value
>
true
</
param
-
value
>
</
init
-
param
>
</
servlet
>
<
servlet
-
mapping
>
<
servlet
-
name
>
dwrServlet
</
servlet
-
name
>
<
url
-
pattern
>/
dwr
/*
</url-pattern>
</servlet-mapping>
</web-app>
新建实体类Dept
package
entity;
public
class
Dept {
private
Long id;
private
String name;
public
Dept() {
}
public
Dept(Long id, String name) {
this
.id
=
id;
this
.name
=
name;
}
public
Long getId() {
return
id;
}
public
void
setId(Long id) {
this
.id
=
id;
}
public
String getName() {
return
name;
}
public
void
setName(String name) {
this
.name
=
name;
}
}
新建业务逻辑类
DeptServices类
package
services;
import
java.util.ArrayList;
import
java.util.HashMap;
import
java.util.List;
import
java.util.Map;
import
entity.Dept;
@SuppressWarnings(
"
unchecked
"
)
public
class
DeptServices {
public
List findDept() {
throw
new
RuntimeException(
"
查找失败!
"
);
}
public
void
deleteDept(Long id) {
System.out.println(
"
Delete dept
"
+
id);
}
public
List getDeptsForPo() {
List depts
=
new
ArrayList();
depts.add(
new
Dept(
1l
,
"
教质部
"
));
depts.add(
new
Dept(
2l
,
"
学术部
"
));
depts.add(
new
Dept(
3l
,
"
就业部
"
));
depts.add(
new
Dept(
4l
,
"
咨询部
"
));
return
depts;
}
public
void
saveDept(List
<
Dept
>
depts) {
//
System.out.println(dept.getId() + ":" + dept.getName());
System.out.println(depts);
}
public
List getDepts() {
List depts
=
new
ArrayList();
Map map
=
new
HashMap();
map.put(
"
id
"
,
"
01
"
);
map.put(
"
name
"
,
"
教质部
"
);
depts.add(map);
map
=
new
HashMap();
map.put(
"
id
"
,
"
02
"
);
map.put(
"
name
"
,
"
学术部
"
);
depts.add(map);
map
=
new
HashMap();
map.put(
"
id
"
,
"
03
"
);
map.put(
"
name
"
,
"
就业部
"
);
depts.add(map);
map
=
new
HashMap();
map.put(
"
id
"
,
"
04
"
);
map.put(
"
name
"
,
"
咨询部
"
);
depts.add(map);
try
{
Thread.sleep(
1000
);
}
catch
(InterruptedException e) {
e.printStackTrace();
}
return
depts;
}
}
HelloServices类
package
services;
/**
*
@author
dlwu
*
*/
public
class
HelloServices {
public
String sayHello(String name){
System.out.println(
"
Hello now!
"
);
return
"
Hello
"
+
name
+
"
!
"
;
}
}
LoginService类
package
services;
import
org.directwebremoting.WebContext;
import
org.directwebremoting.WebContextFactory;
public
class
LoginService {
public
void
checkUserLogin(String userid, String pwd){
WebContext ctx
=
WebContextFactory.get();
ctx.getSession().setAttribute(
"
userid
"
, userid);
}
public
String getLoginUser(){
WebContext ctx
=
WebContextFactory.get();
return
(String)ctx.getSession().getAttribute(
"
userid
"
);
}
}
配置applicationContext.xml
<?
xml version
=
"
1.0
"
encoding
=
"
UTF-8
"
?>
<!--
配置系统基础环境
-->
<
beans
xmlns
=
"
http://www.springframework.org/schema/beans
"
xmlns:xsi
=
"
http://www.w3.org/2001/XMLSchema-instance
"
xsi:schemaLocation
=
"
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd
"
>
<
bean id
=
"
deptServices
"
class
=
"
services.DeptServices
"
></
bean
>
<
bean id
=
"
loginSrv
"
class
=
"
services.LoginService
"
></
bean
>
</
beans
>
配置dwr.xml,dwr.xml是前台js跟java服务器沟通的桥梁
<?
xml version
=
"
1.0
"
encoding
=
"
UTF-8
"
?>
<!
DOCTYPE dwr PUBLIC
"
-//GetAhead Limited//DTD Direct Web Remoting 2.0//EN
"
"
http://getahead.org/dwr/dwr20.dtd
"
>
<!--
通用dwr配置
-->
<
dwr
>
<
allow
>
<!--
建立JS对象，将目标对象的方法转换成JS对象的方法
-->
<
create javascript
=
"
helloSrv
"
creator
=
"
new
"
>
<
param name
=
"
class
"
value
=
"
services.HelloServices
"
></
param
>
</
create
>
<!--
从Spring中获取Java对象
-->
<
create javascript
=
"
deptSrv
"
creator
=
"
spring
"
>
<
param name
=
"
beanName
"
value
=
"
deptServices
"
></
param
>
<!--
禁止执行
-->
<
exclude method
=
"
deleteDept
"
/>
</
create
>
<
create javascript
=
"
loginSrv
"
creator
=
"
spring
"
>
<
param name
=
"
beanName
"
value
=
"
loginSrv
"
></
param
>
</
create
>
<!--
指定针对于特定对象的转换器
-->
<
convert match
=
"
entity.*
"
converter
=
"
bean
"
></
convert
>
<
convert match
=
"
java.lang.Throwable
"
converter
=
"
bean
"
>
<
param name
=
"
include
"
value
=
"
message
"
></
param
>
</
convert
>
</
allow
>
</
dwr
>
页面
hello.jsp页面
<%
@ page language
=
"
java
"
import
=
"
java.util.*
"
pageEncoding
=
"
UTF-8
"
%>
<%
String path
=
request.getContextPath();
String basePath
=
request.getScheme()
+
"
://
"
+
request.getServerName()
+
"
:
"
+
request.getServerPort()
+
path
+
"
/
"
;
%>
<!
DOCTYPE HTML PUBLIC
"
-//W3C//DTD HTML 4.01 Transitional//EN
"
>
<
html
>
<
head
>
<
base href
=
"
<%=basePath%>
"
>
<
title
>
My JSP
'
hello.jsp
'
starting page
</
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
>
<!--
记得引入js，测试地址： http:
//
localhost:8083/dwrweb/dwr/ -->
<
script type
=
"
text/javascript
"
src
=
"
dwr/engine.js
"
></
script
>
<
script type
=
"
text/javascript
"
src
=
"
dwr/interface/helloSrv.js
"
></
script
>
<
script type
=
"
text/javascript
"
src
=
"
dwr/util.js
"
></
script
>
<
script type
=
"
text/javascript
"
>
function hello(){
//
方法一
//
返回处理后的结果信息
/*
var fn = function(result){
$("msg").innerHTML = result;
}
helloSrv.sayHello($("name").value, fn);
*/
//
方法二
helloSrv.sayHello($(
"
name
"
).value, function(result){
$(
"
msg
"
).innerHTML
=
result;
});
//
方法三
//
使用如下的好处为：不用导入如上三个js
//
第一个参数: dwr访问路径，在web.xml中配置，如： <url-pattern>/dwr/*</url-pattern>
//
第二个参数: dwr与java服务器通信变量，在dwr.xml中声明
//
第三个参数: 服务器方法名
//
第四个参数: 页面请求参数，即服务器方法名得参数
//
第五个参数: 回调函数
//
dwr.engine._execute("dwr", 'helloSrv', 'sayHello', $("name").value, fn);
}
</
script
>
<
body
>
<
div id
=
"
msg
"
></
div
>
<
input type
=
"
text
"
id
=
"
name
"
/>
<
input type
=
"
button
"
value
=
"
Hello
"
onclick
=
"
hello();
"
/>
</
body
>
</
html
>
dept.jsp页面
<%
@ page language
=
"
java
"
import
=
"
java.util.*
"
pageEncoding
=
"
UTF-8
"
%>
<%
String path
=
request.getContextPath();
String basePath
=
request.getScheme()
+
"
://
"
+
request.getServerName()
+
"
:
"
+
request.getServerPort()
+
path
+
"
/
"
;
%>
<!
DOCTYPE HTML PUBLIC
"
-//W3C//DTD HTML 4.01 Transitional//EN
"
>
<
html
>
<
head
>
<
base href
=
"
<%=basePath%>
"
>
<
title
>
My JSP
'
hello.jsp
'
starting page
</
title
>
<
meta http
-
equiv
=
"
pragma
"
content
=
"
no-cache
"
>
<
meta http
-
equiv
=
"
cache-control
"
content
=
"
no-cache
"
>
<
meta http
-
equiv
=
"
expires
"
content
=
"
0
"
>
<
meta http
-
equiv
=
"
keywords
"
content
=
"
keyword1,keyword2,keyword3
"
>
<
meta http
-
equiv
=
"
description
"
content
=
"
This is my page
"
>
</
head
>
<!--
记得引入js，测试地址： http:
//
localhost:8083/dwrweb/dwr/ -->
<
script type
=
"
text/javascript
"
src
=
"
dwr/engine.js
"
></
script
>
<
script type
=
"
text/javascript
"
src
=
"
dwr/interface/helloSrv.js
"
></
script
>
<
script type
=
"
text/javascript
"
src
=
"
dwr/util.js
"
></
script
>
<
script type
=
"
text/javascript
"
>
function loadDept(){
//
说明已经加载，不必重新加载
if
($(
'
depts
'
).options.length
>
0
){
return
;
}
DWRUtil.addOptions(
'
depts
'
, [{id:
''
,name:
'
正在下载...
'
}],
'
id
'
,
'
name
'
);
dwr.engine._execute(
"
dwr
"
,
'
deptSrv
'
,
'
getDepts
'
, function(depts){
DWRUtil.removeAllOptions(
'
depts
'
);
DWRUtil.addOptions(
'
depts
'
, depts,
'
id
'
,
'
name
'
);
});
}
function loadDept2(){
if
($(
'
depts2
'
).options.length
>
0
){
return
;
}
DWRUtil.addOptions(
'
depts2
'
, [{id:
''
,name:
'
正在下载...
'
}],
'
id
'
,
'
name
'
);
dwr.engine._execute(
"
dwr
"
,
'
deptSrv
'
,
'
getDeptsForPo
'
, function(depts){
DWRUtil.removeAllOptions(
'
depts2
'
);
DWRUtil.addOptions(
'
depts2
'
, depts,
'
id
'
,
'
name
'
);
});
}
function saveDept(){
//
声明dept对象
var dept
=
{
id:$(
"
deptid
"
).value,
name:$(
"
deptname
"
).value
};
dwr.engine._execute(
"
dwr
"
,
'
deptSrv
'
,
'
saveDept
'
, [dept], function(){
alert(
'
保存成功!
'
);
});
}
function find(){
dwr.engine._execute(
"
dwr
"
,
'
deptSrv
'
,
'
findDept
'
, {
callback:function(results){
alert(
'
查询成功!
'
);
},
errorHandler:function(e){
alert(
"
查询失败:
"
+
e);
}
});
}
</
script
>
<
body
>
<
select id
=
"
depts
"
onclick
=
"
loadDept();
"
></
select
>
<
select id
=
"
depts2
"
onclick
=
"
loadDept2();
"
></
select
>
<
hr
/>
ID:
<
input id
=
"
deptid
"
type
=
"
text
"
size
=
"
8
"
/>
Name:
<
input id
=
"
deptname
"
type
=
"
text
"
size
=
"
8
"
/>
<
input value
=
"
保存部门
"
type
=
"
button
"
onclick
=
"
saveDept();
"
/>
<
input value
=
"
查找
"
type
=
"
button
"
onclick
=
"
find();
"
/>
</
body
>
</
html
>
访问路径：
测试路径：http://localhost:8083/dwrweb/dwr/