如何使用Json.simple解析Java中的JSONArray？

Question

我尝试读取这样的JSON文件:

{
  "presentationName" : "Here some text",
  "presentationAutor" : "Here some text",
  "presentationSlides" : [
  {
    "title" : "Here some text.",
    "paragraphs" : [
    {
        "value" : "Here some text."
    },
    {
        "value" : "Here some text."
    }
    ]
  },
  {
    "title" : "Here some text.",
    "paragraphs" : [
    {
        "value" : "Here some text.",
        "image" : "Here some text."
    },
    {
        "value" : "Here some text."
    },
    {
        "value" : "Here some text."
    }
    ]
  }
  ]
}

这是一个学校练习,我选择尝试使用JSON.simple(来自GoogleCode),但我对另一个JSON库开放.我听说过Jackson和Gson:他们比JSON.simple好吗？

这是我目前的Java代码:

        Object obj = parser.parse(new FileReader( "file.json" ));

        JSONObject jsonObject = (JSONObject) obj;

        // First I take the global data
        String name = (String) jsonObject.get("presentationName");
        String autor = (String) jsonObject.get("presentationAutor");
        System.out.println("Name: "+name);
        System.out.println("Autor: "+autor);

        // Now we try to take the data from "presentationSlides" array
        JSONArray slideContent = (JSONArray) jsonObject.get("presentationSlides");
        Iterator i = slideContent.iterator();

        while (i.hasNext()) {
            System.out.println(i.next());
            // Here I try to take the title element from my slide but it doesn't work!
            String title = (String) jsonObject.get("title");
            System.out.println(title);
        }

我查了很多例子(有些在Stack!)但是我从未找到问题的解决方案.

也许我们不能用JSON.simple做到这一点？您有什么推荐的吗？

Answer 1

您永远不会为其分配新值jsonObject,因此在循环内它仍然指向完整的数据对象.我想你想要的东西:

JSONObject slide = i.next();
String title = (String)slide.get("title");

Answer 2

它的工作原理!Thx Russell.我将完成我的练习,并尝试GSON看看差异.

新代码在这里:

        JSONArray slideContent = (JSONArray) jsonObject.get("presentationSlides");
        Iterator i = slideContent.iterator();

        while (i.hasNext()) {
            JSONObject slide = (JSONObject) i.next();
            String title = (String)slide.get("title");
            System.out.println(title);
        }