Ajax很简单(jsp例子)

                        //req.open('POST', path+'/ajax.servlet');//servlet

                        //req.open('POST', path+'/ajax.action');//webwork


                          req.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
                          req.send("");//发送参数如果有参数req.send("username="+user_name);用request取得
      }
}
</script>

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

import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;