首先是jsp页面和脚本，为了方便写在一个里面
这是一个很常见的检测用户名是否存在的功能
这里用的是struts
这个jsp页面并没有取得用户名，就是演示一下。还有<div>可以换span，具体作用问美工吧。
接受ajax请求的action。
import org.apache.struts.action.*;
import javax.servlet.http.*;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.PrintWriter;
/**
* <p>Title:AjaxAction </p>
*/
public class AjaxAction extends Action {
public ActionForward execute(ActionMapping mapping,
ActionForm form,
HttpServletRequest request,
HttpServletResponse response)
throws Exception {
PrintWriter out = response.getWriter();
out.print(1);//ajax取得都是字符的输出。如果数据量大的话，还可以用xml来发送和接受
return null;
}
}
struts-config.xml
<action type="test.whw.upload.AjaxAction" validate="false" scope="request" path="/ajax"/>
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如果是servlet
web.xml
<servlet>
<servlet-name>AjaxServlet </servlet-name>
<servlet-class>servlet.AjaxServlet </servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>AjaxServlet </servlet-name>
<url-pattern>/AjaxServlet .servlet</url-pattern>
</servlet-mapping>
AjaxServlet.java
public class AjaxServlet extends HttpServlet {
Logger log = Logger.getLogger(this.getClass());
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException,IOException {
response.setContentType("text/xml; charset=GBK");
PrintWriter out = response.getWriter();
out.print(2);
}
}
//Process the HTTP Post request
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
//Process the HTTP Put request
public void doPut(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
}
//Process the HTTP Delete request
public void doDelete(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
}
//Clean up resources
public void destroy() {
}
}
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如果是webwork
xwork.xml
<action name="ajax" class="com.whw.upload.action.webwork.AjaxAction" method="ajax"/>
AjaxAction.java
import java.io.PrintWriter;
public class AjexAlbumAction extends ActionSupport implements Action{
public void ajax()throws IOException {
PrintWriter pw = ServletActionContext.getResponse().getWriter();
ServletActionContext.getResponse().setContentType("text/html;charset=GBK");
pw.print(1);
pw.close();
}
}
本例子在winXPsp2、JB9、Eclipse3，j2sdk1.4.1 、Tomcat5、Tomcat4.1都能运行
