1 使用阿里的FastJson

1.1 專案的pom.xml依賴

<dependency>
 <groupId>com.alibaba</groupId>
 <artifactId>fastjson</artifactId>
 <version>1.2.58</version>
</dependency>

1.2 Java示例程式碼

(1) 匯入的包:

com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.alibaba.fastjson.serializer.SerializerFeature;

(2) 測試程式碼:

其中JSON字串為:

{"_index":"book_shop","_type":"it_book","_id":"1","_score":1.0,"_source":{"name": "Java程式設計思想（第4版）","author": "[美] Bruce Eckel","category": "程式語言","price": 109.0,"publisher": "機械工業出版社","date": "2007-06-01","tags": [ "Java","程式語言" ]}}

public static void main(String[] args) {

 String jsonString = "{\"_index\":\"book_shop\",\"_type\":\"it_book\",\"_id\":\"1\",\"_score\":1.0," +
  "\"_source\":{\"name\": \"Java程式設計思想（第4版）\",\"author\": \"[美] Bruce Eckel\",\"category\": \"程式語言\"," +
  "\"price\": 109.0,\"publisher\": \"機械工業出版社\",\"date\": \"2007-06-01\",\"tags\": [ \"Java\",\"程式語言\" ]}}";

 JSONObject object = JSONObject.parseObject(jsonString);
 String pretty = JSON.toJSONString(object,SerializerFeature.PrettyFormat,SerializerFeature.WriteMapNullValue,SerializerFeature.WriteDateUseDateFormat);

 System.out.println(pretty);
}

(3) 格式化輸出後的結果:

說明: FastJson通過Tab鍵進行換行後的格式化.

{
 "_index":"book_shop","_source":{
 "date":"2007-06-01","author":"[美] Bruce Eckel","price":109.0,"name":"Java程式設計思想（第4版）","publisher":"機械工業出版社","category":"程式語言","tags":[
 "Java","程式語言"
 ]
 },"_score":1.0
}

2 使用谷歌的Gson

2.1 專案的pom.xml依賴

<dependency>
 <groupId>com.google.code.gson</groupId>
 <artifactId>gson</artifactId>
 <version>2.2.4</version>
</dependency>

2.2 Java示例程式碼

(1) 匯入的包:

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.JsonArray;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.gson.JsonParser;

(2) 測試程式碼:

JSON字串與上述測試程式碼相同.

public static void main(String[] args) {
 
 String jsonString = "{\"_index\":\"book_shop\",\"程式語言\" ]}}";
 
 String pretty = toPrettyFormat(jsonString) 
 System.out.println(pretty);
}

/**
 * 格式化輸出JSON字串
 * @return 格式化後的JSON字串
 */
private static String toPrettyFormat(String json) {
 JsonParser jsonParser = new JsonParser();
 JsonObject jsonObject = jsonParser.parse(json).getAsJsonObject();
 Gson gson = new GsonBuilder().setPrettyPrinting().create();
 return gson.toJson(jsonObject);
}

(3) 格式化輸出後的結果:

說明: Gson使用2個空格作為換行後的格式轉換.

{
 "_index": "book_shop","_type": "it_book","_id": "1","_score": 1.0,"_source": {
 "name": "Java程式設計思想（第4版）","tags": [
 "Java","程式語言"
 ]
 }
}

以上這篇Java 格式化輸出JSON字串的2種實現操作就是小編分享給大家的全部內容了，希望能給大家一個參考，也希望大家多多支援我們。