Java中如何将json字符串转换成map/list
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这篇文章主要介绍了Java中如何将json字符串转换成map/list，具有很好的参考价值，希望对大家有所帮助。如有错误或未考虑完全的地方，望不吝赐教
将json字符串转换成map/list
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import org.codehaus.jettison.json.JSONArray;
import org.codehaus.jettison.json.JSONObject;
public class JsonStr2MapOrList {
/**
* 以"{"开头的jsonStr转map,map里面有list,list里面还装有map
*/
@SuppressWarnings("rawtypes")
public static Map<String, Object> jsonStr2Map(String jsonStr) throws Exception {
Map<String, Object> map = new HashMap<String, Object>();
if (!jsonStr.isEmpty()) {
JSONObject json = new JSONObject(jsonStr);
Iterator i = json.keys();
while (i.hasNext()) {
String key = (String) i.next();
String value = json.getString(key);
if (value.indexOf("{") == 0) {
map.put(key.trim(), jsonStr2Map(value));
} else if (value.indexOf("[") == 0) {
map.put(key.trim(), jsonStr2List(value));
} else {
map.put(key.trim(), value.trim());
}
}
}
return map;
}
/**
* 以"["开头的String转list,list里装有map
*/
public static List<Map<String, Object>> jsonStr2List(String jsonStr) throws Exception {
List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();
JSONArray ja = new JSONArray(jsonStr);
for (int j = 0; j < ja.length(); j++) {
String jm = ja.getString(j);
if (jm.indexOf("{") == 0) {
Map<String, Object> m = jsonStr2Map(jm);
list.add(m);
}
}
return list;
}
/**
* jsonStr和Map之间的转换, jsonStr和List之间的转换
*
* @param args
* @throws Exception
*/
public static void main(String[] args) throws Exception {
// 1.jsonStr和Map之间的转换
Map<String, Object> map = new HashMap<String, Object>();
map.put("key1", "val1");
map.put("key2", "val2");
List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();
Map<String, Object> map1 = new HashMap<String, Object>();
Map<String, Object> map2 = new HashMap<String, Object>();
map1.put("key11", "val11");
map1.put("key21", "val21");
map2.put("key111", "val111");
map2.put("key211", "val211");
list.add(map1);
list.add(map2);
map.put("keyList", list);
System.out.println("原始的map:" + map);
String map2JsonStr = map.toString();
System.out.println("map2JsonStr:" + map2JsonStr);
Map<String, Object> jsonStr2Map = jsonStr2Map(map2JsonStr);
System.out.println("jsonStr2Map:" + jsonStr2Map);
// 2.jsonStr和List之间的转换
List<Object> list_ = new ArrayList<Object>();
list_.add(map);
String list_Str = list_.toString();
System.out.println("list_Str:" + list_Str);
List<Map<String, Object>> listM = jsonStr2List(list_Str);
System.out.println("listM:" + listM);
}
}输出结果：
原始的map:{key2=val2, key1=val1, keyList=[{key11=val11, key21=val21}, {key211=val211, key111=val111}]}
map2JsonStr:{key2=val2, key1=val1, keyList=[{key11=val11, key21=val21}, {key211=val211, key111=val111}]}
jsonStr2Map:{key2=val2, key1=val1, keyList=[{key11=val11, key21=val21}, {key211=val211, key111=val111}]}
list_Str:[{key2=val2, key1=val1, keyList=[{key11=val11, key21=val21}, {key211=val211, key111=val111}]}]
listM:[{key2=val2, key1=val1, keyList=[{key11=val11, key21=val21}, {key211=val211, key111=val111}]}]
字符串,json,Map互相转换(各种转换都有)
前提：使用jar包为fastjson
import com.alibaba.fastjson.JSON; import com.alibaba.fastjson.JSONObject;
程序如下
Map map = new HashMap();
map.put("AAA", "1");
map.put("BBB", "2");
map.put("CCC", "3");
System.out.println("map=>"+map);
//1.map转string
String jsonString = JSON.toJSONString(map);
System.out.println("mapToString=>"+jsonString);
//2.map转jsonObject
JSONObject JSONObj = JSONObject.parseObject(JSON.toJSONString(map));
System.out.println("mapToJSON=>"+JSONObj);
//3.String转jsonObject
String jsonString2 = "{\"AAA\":\"1\",\"CCC\":\"3\",\"BBB\":\"2\"}";
JSONObject parseObject = JSONObject.parseObject(jsonString2);
System.out.println("StringToJson=>"+parseObject);
//4.String转map
Map stringToMap = JSONObject.parseObject(jsonString2);
System.out.println("StringToMap=>"+stringToMap);
String str = "{\"age\":\"24\",\"name\":\"summer\"}";
JSONObject jsonObject = JSONObject.parseObject(str);
//5.jsonObject转map
Map jsonToMap = JSONObject.parseObject(jsonObject.toJSONString());
System.out.println("jsonToMap=>"+jsonToMap);
//6.jsonObject转String
String jsonString3 = jsonObject.toJSONString();
System.out.println("jsonToString=>"+jsonString3);结果如下
map=>{AAA=1, CCC=3, BBB=2}
mapToString=>{"AAA":"1","CCC":"3","BBB":"2"}
mapToJSON=>{"AAA":"1","CCC":"3","BBB":"2"}
StringToJson=>{"AAA":"1","CCC":"3","BBB":"2"}
StringToMap=>{"AAA":"1","CCC":"3","BBB":"2"}
jsonToMap=>{"name":"summer","age":"24"}
jsonToString=>{"name":"summer","age":"24"}
以上为个人经验，希望能给大家一个参考，也希望大家多多支持脚本之家。