json字符串转成java的map与list复合对象的解决方法

开发时需要将json字符串转成java的map和list，找了半天竟然没有一个现成的的包支持这种功能！不可思议，苦苦在stackoverflow上求医问药，终于找到jackson的一个特性，可以生成json的节点树，这才终于解决了这个头疼的问题。

代码引用了jackson2.7.3的两个包：

        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>2.7.3</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.7.3</version>
        </dependency>

递归遍历每个节点然后判断节点的类型做转换，代码如下：

import com.fasterxml.jackson.core.JsonFactory;import com.fasterxml.jackson.databind.JsonNode;import com.fasterxml.jackson.databind.ObjectMapper;import java.io.IOException;import java.util.*;/** * Created by fineTu on 2016/09/27. */public class JsonUtil {    public static Map<String,Object> parse(String jsonStr) throws IOException {        Map<String,Object> resMap = new HashMap<String, Object>();        JsonFactory factory = new JsonFactory();        ObjectMapper mapper = new ObjectMapper(factory);        JsonNode rootNode = mapper.readTree(jsonStr);        resMap = parseNode2Obj(rootNode);        return resMap;    }    private static Map<String,Object> parseNode2Obj(JsonNode jsonNode){        Map<String,Object> resMap = new HashMap<String, Object>();        if(jsonNode.isValueNode()){            Object value = parseValue(jsonNode);            resMap.put("",value);            return resMap;        }else if(jsonNode.isArray()){            List<Object> list = new ArrayList<Object>();            Iterator<JsonNode> it = jsonNode.iterator();            while( it.hasNext()){                Map<String,Object> child = parseNode2Obj(it.next());                if (child.keySet().size() == 1 && child.keySet().contains("")){                    list.add(child.get(""));                }else{                    list.add(child);                }            }            resMap.put("",list);            return resMap;        }else {            Iterator<Map.Entry<String,JsonNode>> it = jsonNode.fields();            while( it.hasNext()){                Map.Entry<String,JsonNode> entry = it.next();                Map<String,Object> child = parseNode2Obj(entry.getValue());                if (child.keySet().size() == 1 && child.keySet().contains("")){                    resMap.put(entry.getKey(),child.get(""));                }else{                    resMap.put(entry.getKey(),child);                }            }            return resMap;        }    }    private static Object parseValue(JsonNode valueNode){        if(valueNode.isTextual()){            return valueNode.asText();        }else if(valueNode.isInt()){            return valueNode.asInt();        }else if(valueNode.isBigInteger() || valueNode.isLong()){            return valueNode.asLong();        }else if(valueNode.isFloat() || valueNode.isDouble()){            return valueNode.asDouble();        }else if(valueNode.isBoolean()){            return valueNode.asBoolean();        }        return valueNode.asText();    }    public static void main(String[] args){        String jsonStr = "{\"a\":12,\"b\":\"foobar\",\"c\":[\"tom\",\"peter\",\"joe\"],\"d\":{\"da\":\"1123\",\"db\":456,\"dc\":[{\"name\":\"super man\",\"id\":1},{\"name\":\"bat man\",\"id\":2}]}}";        try {            Map<String,Object> resMap = JsonUtil.parse(jsonStr);            System.out.println(resMap);        } catch (IOException e) {            e.printStackTrace();        }    }}

代码贡献出来，节省你的时间

转载请注明出处：http://blog.csdn.net/gklifg/article/details/52680854