Java解析json字符串和json对象

傷城~ 2023-02-25 07:04 144阅读 0赞

### **一、引入jar包** ###

json常用的解析jar包有三种：Google、Alibaba、json官方

本篇介绍的是json官方的 org.json下的 json-20200518.jar包

<dependency>
          <groupId>org.json</groupId>
          <artifactId>json</artifactId>
          <version>20200518</version>
        </dependency>
        
        <dependency>
          <groupId>com.google.code.gson</groupId>
          <artifactId>gson</artifactId>
          <version>2.8.6</version>
        </dependency>
        
        <dependency>
          <groupId>com.alibaba</groupId>
          <artifactId>fastjson</artifactId>
          <version>1.2.72</version>
        </dependency>

### **二、API使用** ###

**（1）待解析的json字符串**

json在线解析：[https://www.sojson.com/][https_www.sojson.com]

String source = "{\"tSpeakUrl\":\"http://openapi.youdao.com/ttsapi?q=Brofjorden&langType=zh-CHS&sign=BDB192C3B71100805BE44500E1B9C8B1&salt=1594364869753&voice=4&format=mp3&appKey=2fddf5eb3360f6c6\",\"RequestId\":\"d596183f-ceb9-460d-864d-f8c41f7d950e\",\"web\":[{\"value\":[\"布罗夫约尔丹\",\"布罗福德港\",\"布罗弗约登\",\"港口名\"],\"key\":\"Brofjorden\"}],\"query\":\"Brofjorden\",\"translation\":[\"Brofjorden\"],\"errorCode\":\"0\",\"dict\":{\"url\":\"yddict://m.youdao.com/dict?le=eng&q=Brofjorden\"},\"webdict\":{\"url\":\"http://m.youdao.com/dict?le=eng&q=Brofjorden\"},\"l\":\"en2zh-CHS\",\"isWord\":false,\"speakUrl\":\"http://openapi.youdao.com/ttsapi?q=Brofjorden&langType=en&sign=BDB192C3B71100805BE44500E1B9C8B1&salt=1594364869753&voice=4&format=mp3&appKey=2fddf5eb3360f6c6\"}\n";

**（2）创建 JSONObject 对象**

JSONObject jsonObject = new JSONObject(source);

**（3）JSONObject 转 Map<String, Object>**

Map<String, Object> jsonMap = jsonObject.toMap();

**（4）遍历Map<String, Object>**

public static void foreachJsonMap(Map<String, Object> jsonMap) {
            // 遍历jsonMap
            Set<Map.Entry<String, Object>> set = jsonMap.entrySet();
            set.forEach( entry -> {
                String key = entry.getKey();
                Object valueObj = entry.getValue();
                System.out.println(key + "\t\t" + valueObj);
            });
        }

**（5）解析json字符串对象**

public static Map<String, Object> jsonObjectToMap(Object object) {
            String source = object.toString().substring(1,object.toString().length()-1).replace("=",":");
            JSONObject jsonObject = new JSONObject(source);
            Map<String, Object> objectMap = jsonObject.toMap();
            objectMap.forEach((key,value) -> System.out.println(key + "\t" + value));
            return objectMap;
        }

### **三、测试代码** ###

import org.json.JSONObject;
    
    import java.util.Map;
    import java.util.Set;
    
    public class JsonUtil {
    
        public static void main(String[] args) {
            String source = "{\"tSpeakUrl\":\"http://openapi.youdao.com/ttsapi?q=Brofjorden&langType=zh-CHS&sign=BDB192C3B71100805BE44500E1B9C8B1&salt=1594364869753&voice=4&format=mp3&appKey=2fddf5eb3360f6c6\",\"RequestId\":\"d596183f-ceb9-460d-864d-f8c41f7d950e\",\"web\":[{\"value\":[\"布罗夫约尔丹\",\"布罗福德港\",\"布罗弗约登\",\"港口名\"],\"key\":\"Brofjorden\"}],\"query\":\"Brofjorden\",\"translation\":[\"Brofjorden\"],\"errorCode\":\"0\",\"dict\":{\"url\":\"yddict://m.youdao.com/dict?le=eng&q=Brofjorden\"},\"webdict\":{\"url\":\"http://m.youdao.com/dict?le=eng&q=Brofjorden\"},\"l\":\"en2zh-CHS\",\"isWord\":false,\"speakUrl\":\"http://openapi.youdao.com/ttsapi?q=Brofjorden&langType=en&sign=BDB192C3B71100805BE44500E1B9C8B1&salt=1594364869753&voice=4&format=mp3&appKey=2fddf5eb3360f6c6\"}\n";
            System.out.println(source);
    
            // 创建json对象
            JSONObject jsonObject = new JSONObject(source);
            // json对象转map
            Map<String, Object> jsonMap = jsonObject.toMap();
    
            // 根据key返回value值
            Object web = jsonMap.get("web");
            System.out.println(web);
    
            // 遍历json
            System.out.println("\n=======================================================================================================================================\n");
            foreachJsonMap(jsonMap);
        }
    
        public static void foreachJsonMap(Map<String, Object> jsonMap) {
            // 遍历jsonMap
            Set<Map.Entry<String, Object>> set = jsonMap.entrySet();
            set.forEach( entry -> {
                String key = entry.getKey();
                Object valueObj = entry.getValue();
                System.out.println(key + "\t\t" + valueObj);
                if(key.equals("web")){
    //                jsonObjectToMap(valueObj);
                }
            });
        }
    
        /**
         * 解析json字符串里的对象，放回 Map<String, Object>
         * @param object
         * @return Map<String, Object>
         */
        public static Map<String, Object> jsonObjectToMap(Object object) {
            String source = object.toString().substring(1,object.toString().length()-1).replace("=",":");
            JSONObject jsonObject = new JSONObject(source);
            Map<String, Object> objectMap = jsonObject.toMap();
            objectMap.forEach((key,value) -> System.out.println(key + "\t" + value));
            return objectMap;
        }
    
    }

### **四、运行效果** ###

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxMjYyNTkzNDIx_size_16_color_FFFFFF_t_70][]

[https_www.sojson.com]: https://www.sojson.com/
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