Question

我是ajax的新手，想要从动作类获取数据到jsp。

文件： getRole.jsp

<head>
<script type="text/javascript">
var request;
function loaddata()
{
    var id = document.getElementById("newRole").value;
    alert("hi : "+ id);
    var xhttp;
      xhttp = new XMLHttpRequest();
      xhttp.onreadystatechange = function() {
        if (this.readyState == 4 && this.status == 200) {
          document.getElementById("display_info").innerHTML = this.responseText;
          }
      };
      xhttp.open("GET", "loadData?id="+id, true);
      xhttp.send();
}

</script>
</head>
<body>
<div class="container-fluid">
    <div class="col-sm-2"></div>
    <div class="col-sm-8">
        <label for="focusedInput" id="abc"><h4>Enter Id : </h4></label>
        <input type="text" class="form-control" name="newRole" id="newRole" onkeyup="loaddata();">
        <div id="display_info" ></div>
    </div>
    <div class="col-sm-2"></div>
 </div>
</body>

文件： loadData.java

public class loadData extends ActionSupport implements ServletRequestAware, ServletResponseAware{

private static final long serialVersionUID = 1L;
String url = "jdbc:mysql://localhost:3306/struts";
String user = "username";
String pass = "password";
HttpServletRequest request;
HttpServletResponse response;

@Override
public void setServletRequest(HttpServletRequest request) {
    // TODO Auto-generated method stub
    this.request = request;
}

public HttpServletRequest getServletRequest() {
    return request;
}

@Override
public void setServletResponse(HttpServletResponse response) {
    // TODO Auto-generated method stub
    this.response = response;
}

public HttpServletResponse getServletResponse()
{
    return response;
}

public String execute()
{
    try{
        String id = request.getParameter("id");
        String name = "null.";
        System.out.println("in servlet : " + id);

        Class.forName("com.mysql.jdbc.Driver");
        java.sql.Connection con =DriverManager.getConnection(url, user, pass);

        String s = "select * from tempemp where id="+id;
        Statement st = con.createStatement();
        ResultSet rs = st.executeQuery(s);

        while(rs.next())
        {
            name = rs.getString("role");
            System.out.println(name);
        }
        PrintWriter out = response.getWriter();
        out.println("Name: "+name);
        con.close();
    }
    catch(Exception e){
        e.printStackTrace();
    }
    return SUCCESS;
}
}

我想从用户那里获取Id，然后根据该ID打印角色。我只想使用ajax而不是json。所以请只回答我ajax代码。

Answer 1

您必须在操作中返回null而不是成功。返回null将不再进行进一步处理，它只会将当前响应发送给客户端。

返回SUCCESS将在struts.xml文件中搜索为该结果定义的特定jsp页面。

this.responseText您将获得name。更多参考https://struts.apache.org/docs/ajax.html

如何在struts2中使用ajax从动作类获取数据到jsp？

1 个答案: