1.Ajax 技术在现有开发中使用非常多，大多是做管理类型系统。在servlet中可以使用ajax。在struts2中共还可以使用servlet的方式来实现ajax。
2.案例：用户名检查
代码语言：javascript复制public String checkName() throws IOException{
HttpServletResponse resp = ServletActionContext.getResponse();
if("siggy".equals(name)){
resp.getWriter().print("true");
}else{
resp.getWriter().print("false");
}
//return Action.NONE;
return null;
}3.使用struts2提供的插件来完成 ajax步骤
a) 导入相关 jar 包
asm-3.3.jar asm-commons-3.3.jar asm-tree-3.3.jar commons-beanutils-1.8.0.jar commons-collections-3.1.jar commons-fileupload-1.2.2.jar commons-io-2.0.1.jar commons-lang-2.4.jar commons-lang3-3.1.jar commons-logging-1.1.1.jar ezmorph-1.0.6.jar freemarker-2.3.19.jar jackson-core-asl-1.9.2.jar jackson-mapper-asl-1.9.2.jar javassist-3.11.0.GA.jar json-lib-2.3-jdk15.jar jstl-1.2.jar log4j-1.2.17.jar ognl-3.0.5.jar struts2-core-2.3.4.jar struts2-json-plugin-2.3.4.jar xwork-core-2.3.4.jar
b) 编写Action
代码语言：javascript复制public class UserAction {
private String name;
private String result;
public String checkName() throws IOException{
HttpServletResponse resp = ServletActionContext.getResponse();
if("siggy".equals(name)){
resp.getWriter().print("true");
}else{
resp.getWriter().print("false");
}
//return Action.NONE;
return null;
}
public String list(){
System.out.println("list----------");
List<User> list = new ArrayList<User>();
list.add(new User("张三","男",33));
list.add(new User("李四","男",23));
list.add(new User("王五","男",13));
try {
result=JSONArray.fromObject(list).toString();
} catch (Exception e) {
e.printStackTrace();
}
System.out.println(result);
return Action.SUCCESS;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getResult() {
return result;
}
public void setResult(String result) {
this.result = result;
}
}c) 编写配置文件
代码语言：javascript复制<package name="default" extends="json-default" namespace="/">
<action name="checkName" class="cn.sxt.action.UserAction" method="checkName">
</action>
<action name="list" class="cn.sxt.action.UserAction" method="list">
<result type="json">
<param name="root">result</param>
</result>
</action>
</package>4.另一种获取 json 的方式：
代码语言：javascript复制public class ListAction {
private List<User> list;
public String list(){
list = new ArrayList<User>();
list.add(new User("张三","男",33));
list.add(new User("李四","男",23));
list.add(new User("王五","男",13));
return Action.SUCCESS;
}
public List<User> getList() {
return list;
}
public void setList(List<User> list) {
this.list = list;
}
}Struts.xml
代码语言：javascript复制<action name="listJson" class="cn.sxt.action.ListAction" method="list">
<result type="json">
<param name="root">list</param>
</result>
</action>Jsp
代码语言：javascript复制<script type="text/javascript">
$(function(){
$("#btn").click(function(){
$.post("listJson.action",function(data){
var html="";
for(var i=0;i<data.length;i ){
html ="<tr><td>" data[i].name
"</td><td>" data[i].sex
"</td><td>" data[i].age "</td></tr>";
}
$("#content").html(html);
});
});
});
</script>
</head>
<body>
<button id="btn">获取数据</button>
<table width="80%" align="center">
<tr>
<td>姓名</td>
<td>性别</td>
<td>年龄</td>
</tr>
<tbody id="content">
</tbody>
</table>
</body>
