If one wants to create Java object from JSON and vice versa, use GSON or JACKSON third party jars etc. //from object to JSON Gson gson = new Gson(); gson.toJson(yourObject); // from JSON to object yourObject o = gson.fromJson(JSONString,yourObject.class); But if one just want to parse a JSON string and get some values, (OR create a JSON string from scratch to send over wire) just use JaveEE jar which contains JsonReader, JsonArray, JsonObject etc. You may want to download the implementation of that spec like javax.json. With these two jars I am able to parse the json and use the values. These APIs actually follow the DOM/SAX parsing model of XML. Response response = request.get(); // REST call JsonReader jsonReader = Json.createReader(new StringReader(response.readEntity(String.class))); JsonArray jsonArray = jsonReader.readArray(); ListIterator l = jsonArray.listIterator(); while ( l.hasNext() ) { JsonObject j = (JsonObject)l.next(); JsonObject ciAttr = j.getJsonObject("ciAttributes");

org。Json库易于使用。

只要记住(在强制转换或使用getJSONObject和getJSONArray等方法时)JSON表示法

[…]表示一个数组，因此库将把它解析为JSONArray {…}表示一个对象，因此库将把它解析为JSONObject

示例代码如下:

import org.json.*;

String jsonString = ... ; //assign your JSON String here
JSONObject obj = new JSONObject(jsonString);
String pageName = obj.getJSONObject("pageInfo").getString("pageName");

JSONArray arr = obj.getJSONArray("posts"); // notice that `"posts": [...]`
for (int i = 0; i < arr.length(); i++)
{
    String post_id = arr.getJSONObject(i).getString("post_id");
    ......
}

你可以从以下几个方面找到更多的例子

可下载的jar: http://mvnrepository.com/artifact/org.json/json

可以使用Apache @Model注释创建表示JSON文件结构的Java模型类，并使用它们访问JSON树中的各种元素。与其他解决方案不同，该解决方案完全没有反射，因此适用于不可能反射或开销很大的环境。

有一个示例Maven项目展示了这种用法。首先它定义了结构:

@Model(className="RepositoryInfo", properties = {
    @Property(name = "id", type = int.class),
    @Property(name = "name", type = String.class),
    @Property(name = "owner", type = Owner.class),
    @Property(name = "private", type = boolean.class),
})
final class RepositoryCntrl {
    @Model(className = "Owner", properties = {
        @Property(name = "login", type = String.class)
    })
    static final class OwnerCntrl {
    }
}

然后它使用生成的RepositoryInfo和Owner类来解析所提供的输入流，并在此过程中获取某些信息:

List<RepositoryInfo> repositories = new ArrayList<>();
try (InputStream is = initializeStream(args)) {
    Models.parse(CONTEXT, RepositoryInfo.class, is, repositories);
}

System.err.println("there is " + repositories.size() + " repositories");
repositories.stream().filter((repo) -> repo != null).forEach((repo) -> {
    System.err.println("repository " + repo.getName() + 
        " is owned by " + repo.getOwner().getLogin()
    );
})

就是这样!除此之外，这里还有一个生动的要点，展示了类似的例子以及异步网络通信。

您可以使用Gson库来解析JSON字符串。

Gson gson = new Gson();
JsonObject jsonObject = gson.fromJson(jsonAsString, JsonObject.class);

String pageName = jsonObject.getAsJsonObject("pageInfo").get("pageName").getAsString();
String pagePic = jsonObject.getAsJsonObject("pageInfo").get("pagePic").getAsString();
String postId = jsonObject.getAsJsonArray("posts").get(0).getAsJsonObject().get("post_id").getAsString();

你也可以循环"posts"数组，如下所示:

JsonArray posts = jsonObject.getAsJsonArray("posts");
for (JsonElement post : posts) {
  String postId = post.getAsJsonObject().get("post_id").getAsString();
  //do something
}

任何类型的json数组 解决问题的步骤。

将JSON对象转换为java对象。 你可以使用这个链接或任何在线工具。 保存为java类，如Myclass.java。 Myclass obj = new Gson().fromJson(JsonStr, Myclass.class); 使用obj，你可以得到你的值。

The below example shows how to read the text in the question, represented as the "jsonText" variable. This solution uses the Java EE7 javax.json API (which is mentioned in some of the other answers). The reason I've added it as a separate answer is that the following code shows how to actually access some of the values shown in the question. An implementation of the javax.json API would be required to make this code run. The full package for each of the classes required was included as I didn't want to declare "import" statements.

javax.json.JsonReader jr = 
    javax.json.Json.createReader(new StringReader(jsonText));
javax.json.JsonObject jo = jr.readObject();

//Read the page info.
javax.json.JsonObject pageInfo = jo.getJsonObject("pageInfo");
System.out.println(pageInfo.getString("pageName"));

//Read the posts.
javax.json.JsonArray posts = jo.getJsonArray("posts");
//Read the first post.
javax.json.JsonObject post = posts.getJsonObject(0);
//Read the post_id field.
String postId = post.getString("post_id");

现在，在大家对这个答案投反对票之前因为它没有使用GSON, org。json, Jackson或任何其他可用的第三方框架，它是每个问题解析所提供文本的“所需代码”的示例。我很清楚JDK 9没有考虑遵守当前标准JSR 353，因此JSR 353规范应该与任何其他第三方JSON处理实现一样对待。