我试图从js获取JSON数据并在操作类中接收null [英] Im trying to get JSON data from js and receiving null in action class

问题描述

我从客户端获取JSON.我想通过ajax发送它.但是，我的动作类内部为空.

I'm getting JSON from client side. I want to send it through ajax. However, i'm getting null inside my action class.

我的JSON字符串

{"data":[{"id":"","col":1,"row":1,"size_x":1,"size_y":1},
         {"id":"","col":1,"row":2,"size_x":1,"size_y":1},
         {"id":"","col":1,"row":3,"size_x":1,"size_y":1},
         {"id":"","col":1,"row":4,"size_x":1,"size_y":1},
         {"id":"","col":1,"row":6,"size_x":1,"size_y":1},
         {"id":"","col":1,"row":5,"size_x":1,"size_y":1}
        ]
}

AJAX

var seats = {"data" : positions};

    var seatPosition = JSON.stringify(seats);

    console.log(seatPosition);  

    $.ajax({
        url: 'retrieve-seat',
        data: seatPosition,
        dataType: 'json',
        contentType: 'application/json',
        type: 'POST',
        async: true,
        success: function (data) {
        alert("success");

struts.xml

struts.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"
"http://struts.apache.org/dtds/struts-2.3.dtd">

<struts>

<constant name="struts.devMode" value="true" />
<constant name="struts.action.extension" value="," />
<constant name="struts.enable.SlashesInActionNames" value="true" />
<constant name="struts.custom.i18n.resources" value="global" />

<package name="default" namespace="/"
    extends="json-default,struts-default">

    <action name="retrieve-seat" class="com.pointwest.apex.actions.ReadPositionAction">
        <result name="SUCCESS" type="json"/>
    </action>

</package>

</struts>

Action.class

Action.class

public class ReadPositionAction extends ActionSupport {

private List<Seat> data;


public List<Seat> getData() {
     System.out.println("Getter Call");
    return data;
}

public void setData(List<Seat> data) {
     System.out.println("Setter Call");
    this.data = data;
}

@Override
public String execute() {
    System.out.println("action");
    try {
        System.out.println(data);


        System.out.println("Execute Method");
    } catch (Exception e) {
        e.printStackTrace();
    }
    return "SUCCESS";
}

}

控制台日志似乎显示了JSON的正确格式.有人请帮我谢谢！

The console log seems to display a correct format for JSON. Someone pls help me out thanks!

推荐答案

如果您需要产生 JSON(操作-> JSP)，则 json结果为足够的.

If you need to produce JSON (Action -> JSP), the json result is enough.

如果您需要使用 JSON(JSP->操作)，则需要将 Json拦截器添加到堆栈中.

If you need to consume JSON (JSP -> Action), you need to add the Json Interceptor to your stack.

来自文档:

接受JSON

如果您的操作位于程序包中，则可以接受传入的JSON 使用json拦截器或通过添加对它的引用，如下所示:

Your actions can accept incoming JSON if they are in package which uses json interceptor or by adding reference to it as follow:

@InterceptorRef(value="json")

还请注意，json-default包在内部扩展了struts-default，因此无需扩展它们两个.

Also note that the json-default package internally extends the struts-default, hence there is no need to extend both of them.

应该是:

<package name="default" namespace="/" extends="json-default">

    <interceptor-stack name="jsonFromJspStack">
        <interceptor-ref name="defaultStack"/>
        <interceptor-ref name="json" />
    </interceptor-stack>


    <action name="retrieve-seat" class="com.pointwest.apex.actions.ReadPositionAction">
        <interceptor-ref name="jsonFromJspStack"/>
        <result name="SUCCESS" type="json"/>
    </action>

</package>

这篇关于我试图从js获取JSON数据并在操作类中接收null的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！