如何将JSON字符串转换为GSON对象？

Question

我将开发一个web服务，它的输入应该用JSON描述，我希望在我的内部逻辑中用作GSON对象。 因此，无论谁使用Web服务，都会发送一些请求，其中包含以下信息：

{
"glossary": {
    "title": "example glossary",
    "GlossDiv": {
        "title": "S",
        "GlossList": {
            "GlossEntry": {
                "ID": "SGML",
                "SortAs": "SGML",
                "GlossTerm": "Standard Generalized Markup Language",
                "Acronym": "SGML",
                "Abbrev": "ISO 8879:1986",
                "GlossDef": {
                    "para": "A meta-markup language, used to create markup languages such as DocBook.",
                    "GlossSeeAlso": ["GML", "XML"]
                },
                "GlossSee": "markup"
            }
        }
    }
 }
}

我现在需要的是处理它的东西。 类似于以下内容:(这只是一个例子，我想象以下步骤让它运行;））

public class AnyClass{

    public AnyClass(String jsonString){
        GSONObject gobject = new GSONObject(jsonString);
        String title = gobject.getValueOf("title");
    }
}

谢谢你的每一个帮助:)

Answer 1

尝试这个

JSONParser parser = new JSONParser();
JSONObject json = (JSONObject) parser.parse(jsonString);

用gson

Gson gson = new Gson();
gson.fromJson(jsonString, YourBean.class);

Answer 2

您可以使用javax.json包来处理json数据。 有关详细信息，请参阅https://docs.oracle.com/javaee/7/tutorial/jsonp002.htm

Answer 3

将json字符串转换为Gson（反序列化）

使用gson.fromJson（）;

使用String类的示例

Gson gson = new Gson();
String str = gson.fromJson("\"abc\"", String.class);

使用用户定义的类的示例

BagOfPrimitives obj = new BagOfPrimitives();
Gson gson = new Gson();
BagOfPrimitives obj2 = gson.fromJson(json, BagOfPrimitives.class);

Gson的谷歌帮助页面有很好的解释。

https://sites.google.com/site/gson/gson-user-guide#TOC-Primitives-Examples

对象示例

class BagOfPrimitives {
  private int value1 = 1;
  private String value2 = "abc";
  private transient int value3 = 3;
  BagOfPrimitives() {
    // no-args constructor
  }
}

（串行化）

BagOfPrimitives obj = new BagOfPrimitives();
Gson gson = new Gson();
String json = gson.toJson(obj);  
==> json is {"value1":1,"value2":"abc"}

请注意，您无法使用循环引用序列化对象，因为这将导致无限递归。

（反序列化）

BagOfPrimitives obj2 = gson.fromJson(json, BagOfPrimitives.class);   
==> obj2 is just like obj

更精细的对象点

It is perfectly fine (and recommended) to use private fields 
There is no need to use any annotations to indicate a field is to be included for serialization and deserialization. All fields in the current class (and from all super classes) are included by default. 
If a field is marked transient, (by default) it is ignored and not included in the JSON serialization or deserialization.

This implementation handles nulls correctly

While serialization, a null field is skipped from the output

While deserialization, a missing entry in JSON results in setting the corresponding field in the object to null

If a field is synthetic, it is ignored and not included in JSON serialization or deserialization

Fields corresponding to the outer classes in  inner classes, anonymous classes, and local classes are ignored and not included in serialization or deserialization

如果您需要更多示例，请查看以下链接

http://www.mkyong.com/java/how-do-convert-java-object-to-from-json-format-gson-api/

http://filotechnologia.blogspot.it/2013/09/convert-java-object-from-json-gson-api.html