Java实现map转换成json的方法详解_Java教程

Java实现map转换成json的方法详解

2022-12-27 20:22web18296061989 Java教程

这篇文章主要为大家详细介绍了Java语言实现map转换成json的几种方法，文中的示例代码讲解详细，对我们学习Java有一定帮助，需要的可以参考一下

1.alibaba falstjson

1.Map转JSON

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									Map<String, Object> map = new HashMap<String, Object>();

									      map.put("a", "a");

									      map.put("b", "123");

									      JSONObject json = new JSONObject(map);

2.map转string

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									Map<String, Object> map = new HashMap<>();

									      map.put("a", "b");

									      String s = JSONObject.toJSONString(map);

3.JSON转String

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									JSONObject json = new JSONObject();

									      json.put("c", "v");

									      json.put("z", "123n);

									      json.toJSONString();

4.JSON转Map

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									JSONObject json = new JSONObject();

									        json.put("ccc", "321");

									        json.put("bbb", "123");

									        Map<String, Object> map = (Map<String, Object>)json;

5.String转JSON

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									String str = "{"username":"dsad","qwewqe":"123"}";

									JSONObject json = JSONObject.parseObject(str);

2.google

maven坐标

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									<!-- https://mvnrepository.com/artifact/com.google.code.gson/gson -->

									<dependency>

									    <groupId>com.google.code.gson</groupId>

									    <artifactId>gson</artifactId>

									    <version>2.3.1</version>

									</dependency>

Map转换成JSON

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									Map<String,String> map = new HashMap<String,String>(); 

									map.put("a","aaa"); 

									map.put("b","bbb"); 

									map.put("c","ccc"); 

									String json=JSON.toJSONString(map); 

									System.out.println(json);//输出{"a":"aaa","b":"bbb","c":"ccc"}

JSON转换成Map

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									Map map1 = JSON.parseObject(json);

									System.out.println(map1.get("a"));

									for (Object mapData : map.entrySet()) {

									Map.Entry<String,String> entry = (Map.Entry<String,String>)mapData;

									System.out.println(entry.getKey()+"--->"+entry.getValue());

									}

									/*输出

									b--->bbb

									c--->ccc

									a--->aaa

									*/

map中含有对象Map -> JSON

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									//Map -> JSON

									Map<String,Bar> map = new HashMap<String, Bar>(); 

									map.put("a",new Bar()); 

									map.put("b",new Bar()); 

									map.put("c",new Bar()); 

									String json = JSON.toJSONString(map,true); 

									System.out.println(json); 

									/*

									输出{

									    "a":{

									        "barAge":383687382,

									        "barDate":1494945882018,

									        "barName":"name_1689176802"

									    },

									    "b":{

									        "barAge":-100528778,

									        "barDate":1494945882018,

									        "barName":"name_-878176366"

									    },

									    "c":{

									        "barAge":-344075192,

									        "barDate":1494945882018,

									        "barName":"name_-1710740534"

									    }

									}

									*/

JSON -> Map

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									Map<String,Bar> map1 = (Map<String,Bar>)JSON.parse(json); 

									for (String key : map1.keySet()) { 

									System.out.println(key+":"+map1.get(key)); 

									} 

									/*输出

									b:{"barAge":-100528778,"barDate":1494945882018,"barName":"name_-878176366"}

									c:{"barAge":-344075192,"barDate":1494945882018,"barName":"name_-1710740534"}

									a:{"barAge":383687382,"barDate":1494945882018,"barName":"name_1689176802"}

									*/

附–MAP的ASCII排序

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									StringBuilder sb = new StringBuilder();

									    List<String> keys = new ArrayList<String>(map.keySet());

									    Collections.sort(keys);//排序。

									    for(String k : keys){

									        String v = params.get(k);

									        if(StringUtils.isNotEmpty(v)){

									            sb.append(v);

									        }

									    }

									    //return MD5.toMD5(sb+key, "UTF-8");这个就不用看了~~~