Gson+JsonPath+泛型 java json解析工具类

代码下载：点击打开链接

Json解析工具类完善一下，使用GSON+JsonPath+泛型来提高自己写JSON解析的效率 如下关于JsonPath

http://www.7mdm.com/1374.html

https://github.com/jayway/JsonPath

为json解析轻松加上Integer Double String  List<String> 以及 T   List<T>的泛型功能

比如这段json

{
    "store": {
        "book": [
            {
                "category": "reference",
                "author": "Nigel Rees",
                "title": "Sayings of the Century",
                "price": 8.95
            },
            {
                "category": "fiction",
                "author": "Evelyn Waugh",
                "title": "Sword of Honour",
                "price": 12.99,
                "isbn": "0-553-21311-3"
            }
        ],
        "bicycle": {
            "color": "red",
            "price": 19.95
        }
    }
}

Java获取所有作者  

List<String> list = JsonPathGeneric.getGenericList(json,"$.store.book[*].author", String.class)

输出=====> [Nigel Rees, Evelyn Waugh]

Double d = JsonPathGeneric.getGeneric(json,"$.store.bicycle.price",Double.class);

输出=====>19.95

如果单纯想要获得单本书

public class BeanBook implements Serializable {
	public String author;
	public Double price;
	public String category;
	public String title;
	@Override
	public String toString() {
		return "Book [author=" + author + ", price=" + price + ", category="
				+ category + ", title=" + title + "]";
	}

    
}

BeanBook bean=JsonPathGeneric.getGenericObject(json,"$.store.book[0]", BeanBook.class);

输出=====>Book [author=Evelyn Waugh, price=12.99, category=fiction, title=Sword of Honour]

除了静态的方法还有指定继承关系的json泛型强转

来一个开发的例子如下

json1

{
    "status": "success",
    "result": {
        "user_id": ​4,
        "nickname": "",
        "xiaoqu_id": ​1
    }
}

json2

{
    "status": "success",
    "result": [
        {
            "user_id": ​4,
            "nickname": "",
            "xiaoqu_id": ​1
        },
        {
            "user_id": 5,
            "nickname": "",
            "xiaoqu_id": ​3
        }
    ]
}

public class BeanUser {
	   public String xiaoqu_id  ;
	   public String user_id  ;
	   public String nickname  ;
}

java代码

	System.out.println(JsonPathGeneric.getGeneric(json1, "$.status", String.class));       
		{
			System.out.println(json1);
			String id = new Generic<BeanUser>(json1, "$.result") {
			}.getJsonBean().user_id;
			System.out.println("user_id=" + id);
		}
		{
			System.out.println(json2);
			List<BeanUser> list = new Generic<List<BeanUser>>(json2, "$.result") {
			}.getJsonBean();
			System.out.println("user_id=" + list.get(1).user_id);
		}

打印结果

success

user_id=​4

user_id=5

以下是工具类代码：

package org.utils.json;

import java.lang.reflect.Type;
import java.util.List;

import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;
import com.jayway.jsonpath.JsonPath;

public class JsonPathGeneric<T> {

	@SuppressWarnings("unchecked")
	public static <T> T getGeneric(String json, String jsonPath, Class<T> clazz) {
		
		return new JsonPathGeneric<T>(clazz, json, jsonPath).getObject();
	}

	@SuppressWarnings("unchecked")
	public static <T> T getGenericObject(String json, String jsonPath,
			Class<T> clazz) {
		String jsonResult =null;
		if(jsonPath==null||"".equals(jsonPath))
		{
			jsonResult=json;
		}else
		{
	        jsonResult = JsonPath.read(json, jsonPath).toString();
		}
		if (String.class.equals(clazz)) {
			return (T) jsonResult;
		}
		return (T) new Gson().fromJson(jsonResult, clazz);

	}

	@SuppressWarnings("unchecked")
	public static <T> List<T> getGenericList(String json, String jsonPath,
			Class<T> clazz) {
		String jsonResult =null;
		if(jsonPath==null||"".equals(jsonPath))
		{
			jsonResult=json;
		}else
		{
	        jsonResult = JsonPath.read(json, jsonPath).toString();
		}
	
		Type listtype = new TypeToken<List<T>>() {
		}.getType();
		return (List<T>) new Gson().fromJson(jsonResult, listtype);
	}

	public JsonPathGeneric() {
	}

	private String json;
	private String jsonPath;
	private String jsonResult;
	private Type type;
	private T object;

	/**继承关系时注意父类传值*/
	public JsonPathGeneric(Object obj, String json, String jsonPath) {
		if (obj instanceof Type) {
			parse((Type) obj, json, jsonPath);
		} else {
			parse(ReflectionUtil.getParameterizedTypes(obj)[0], json, jsonPath);
		}
	}

	public JsonPathGeneric(Type type, String json, String jsonPath) {
		parse(type, json, jsonPath);
	}

	public JsonPathGeneric(String json, String jsonPath) {
		Type[] parameterizedTypes = ReflectionUtil.getParameterizedTypes(this);
		type = parameterizedTypes[0];
		parse(type, json, jsonPath);
	}

	@SuppressWarnings("unchecked")
	public void parse(Type type, String json, String jsonPath) {
		this.json = json;
		this.jsonPath = jsonPath;
		this.type = type;
		if(jsonPath==null||"".equals(jsonPath))
		{
			jsonResult=json;
		}else{
			this.jsonResult = JsonPath.read(json, jsonPath).toString();
		}
		Class<T> clazz = null;
		try {
			clazz = (Class<T>) ReflectionUtil.getClass(type);
		} catch (ClassNotFoundException e) {
		}

		if (clazz != null) {
			if (String.class.equals(clazz)) {
				object = (T) jsonResult;
			} else {
				object = new Gson().fromJson(jsonResult, clazz);
			}
		} else {
			object = new Gson().fromJson(jsonResult, type);
		}
//		System.out.println("-------------------------------");
//		System.err.println(jsonResult);
//		System.err.println(object.getClass().getSimpleName());
//		System.err.println(object);
//		System.out.println("-------------------------------");
	}

	public String getJson() {
		return json;
	}

	public JsonPathGeneric<T> setJson(String json) {
		this.json = json;
		return this;
	}

	public String getJsonPath() {
		return jsonPath;
	}

	public JsonPathGeneric<T> setJsonPath(String jsonPath) {
		this.jsonPath = jsonPath;
		return this;
	}

	public String getJsonResult() {
		return jsonResult;
	}

	public Type getType() {
		return type;
	}

	public JsonPathGeneric<T> setType(Type type) {
		this.type = type;
		return this;
	}

	public T getObject() {
		return object;
	}

}

public class Generic<T> {

	public Generic(String json, String jsonPath) {
		// TODO Auto-generated constructor stub
		/**继承关系时注意父类传值this*/
		jsonBean = new JsonPathGeneric<T>(this, json, jsonPath).getObject();
	}

	public T jsonBean;

	public T getJsonBean() {
		return jsonBean;
	}

	public void setJsonBean(T jsonBean) {
		this.jsonBean = jsonBean;
	}

}

代码下载：点击打开链接