处理json的工具类（{本类为处理json的工具类}）

<jackson.version>2.2.3</jackson.version>

<!-- json -->
<dependency>
    <groupId>net.sf.json-lib</groupId>
    <artifactId>json-lib</artifactId>
    <version>2.3</version>
    <classifier>jdk15</classifier>
    <scope>compile</scope>
</dependency>
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>1.1.41</version>
</dependency>
<!-- jackson json -->
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-core</artifactId>
    <version>${jackson.version}</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>${jackson.version}</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-annotations</artifactId>
    <version>${jackson.version}</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.module</groupId>
    <artifactId>jackson-module-jaxb-annotations</artifactId>
    <version>${jackson.version}</version>
</dependency>

package com.dsj.gdbd.utils.jsonUtil;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URL;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.apache.commons.collections.map.ListOrderedMap;
import org.apache.commons.lang.ObjectUtils;
import org.apache.commons.lang3.StringUtils;
import org.apache.log4j.Logger;

import net.sf.json.JSONArray;
import net.sf.json.JSONObject;

/**
 *
 * 处理json的工具类. <br>
 * 本类为处理json的工具类
 *
 * @author slj
 */
public class JsonTools {
    private static Logger log = Logger.getLogger(JsonTools.class);
    /**
     *
     * json转换list. <br>
     * 详细说明
     *
     * @param jsonStr
     *            json字符串
     * @return
     * @return List<Map<String,Object>> list
     * @throws @author
     *             slj
     * @date 2013年12月24日 下午1:08:03
     */
    public static List<Map<String, Object>> parseJSON2List(String jsonStr) {
        JSONArray jsonArr = JSONArray.fromObject(jsonStr);
        List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();
        Iterator<JSONObject> it = jsonArr.iterator();
        while (it.hasNext()) {
            JSONObject json2 = it.next();
            list.add(parseJSON2Map(json2.toString()));
        }
        return list;
    }

    /**
     *
     * json转换map. <br>
     * 详细说明
     *
     * @param jsonStr
     *            json字符串
     * @return
     * @return Map<String,Object> 集合
     * @throws @author
     *             slj
     */
    public static Map<String, Object> parseJSON2Map(String jsonStr) {
        ListOrderedMap map = new ListOrderedMap();
        // 最外层解析
        JSONObject json = JSONObject.fromObject(jsonStr);
        for (Object k : json.keySet()) {
            Object v = json.get(k);
            // 如果内层还是数组的话，继续解析
            if (v instanceof JSONArray) {
                List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();
                Iterator<JSONObject> it = ((JSONArray) v).iterator();
                while (it.hasNext()) {
                    JSONObject json2 = it.next();
                    list.add(parseJSON2Map(json2.toString()));
                }
                map.put(k.toString(), list);
            } else {
                map.put(k.toString(), v);
            }
        }
        return map;
    }

    /**
     *
     * 通过HTTP获取JSON数据. <br>
     * 通过HTTP获取JSON数据返回list
     *
     * @param url
     *            链接
     * @return
     * @return List<Map<String,Object>> list
     * @throws @author
     *             slj
     */
    public static List<Map<String, Object>> getListByUrl(String url) {
        try {
            // 通过HTTP获取JSON数据
            InputStream in = new URL(url).openStream();
            BufferedReader reader = new BufferedReader(new InputStreamReader(in));
            StringBuilder sb = new StringBuilder();
            String line;
            while ((line = reader.readLine()) != null) {
                sb.append(line);
            }
            return parseJSON2List(sb.toString());
        } catch (Exception e) {
            log.error("Exception", e);
        }
        return null;
    }

    /**
     *
     * 通过HTTP获取JSON数据. <br>
     * 通过HTTP获取JSON数据返回map
     *
     * @param url
     *            链接
     * @return
     * @return Map<String,Object> 集合
     * @throws @author
     *             slj
     */
    public static Map<String, Object> getMapByUrl(String url) {
        try {
            // 通过HTTP获取JSON数据
            InputStream in = new URL(url).openStream();
            BufferedReader reader = new BufferedReader(new InputStreamReader(in));
            StringBuilder sb = new StringBuilder();
            String line;
            while ((line = reader.readLine()) != null) {
                sb.append(line);
            }
            return parseJSON2Map(sb.toString());
        } catch (Exception e) {
            log.error("Exception", e);
        }
        return null;
    }

    /**
     *
     * map转换json. <br>
     * 详细说明
     *
     * @param map
     *            集合
     * @return
     * @return String json字符串
     * @throws @author
     *             slj
     */
    public static String mapToJson(Map<String, Object> map) {
        Set<String> keys = map.keySet();
        String key="";
        StringBuffer jsonBuffer = new StringBuffer();
        jsonBuffer.append("{");
        for (Iterator<String> it = keys.iterator(); it.hasNext();) {
            key = (String) it.next();
            String value = ObjectUtils.toString(map.get(key), "");
            jsonBuffer.append(key + ":" + "\"" + value + "\"");
            if (it.hasNext()) {
                jsonBuffer.append(",");
            }
        }
        jsonBuffer.append("}");
        return jsonBuffer.toString();
    }

    /**
     *
     * map转换json. <br>
     * 详细说明
     *
     * @param map
     *            集合
     * @return
     * @return String json字符串
     * @throws @author
     *             slj
     */
    public static String mapToKvJson(Map<String, Object> map) {
        Set<String> keys = map.keySet();
           JSONArray jsonArray=new    JSONArray();
            String key = "";
        for (Iterator<String> it = keys.iterator(); it.hasNext();) {
            JSONObject object = new JSONObject();
            key = (String) it.next();
            String value = ObjectUtils.toString(map.get(key), "");
              object.put("key", key);
              object.put("value", value);
              jsonArray.add(object);
        }
        return jsonArray.toString();
    }

     /**
     * key     value转map
        [{"name":"sEcho","value":1},{"name":"iColumns","value":3}]转map
     * @param jsonStr
     * @return
     */
    public static Map<String, Object> parsePageMap(String jsonStr){
        Map<String, Object> map = new HashMap<String, Object>();
        //最外层解析
        if(StringUtils.isNotBlank(jsonStr)){
            jsonStr=jsonStr.replace("&quot;", "\"");
        }
        JSONArray jsonArray = JSONArray.fromObject(jsonStr);
        for (int i = 0; i < jsonArray.size(); i++) {
            JSONObject json = (JSONObject) jsonArray.get(i);
            map.put(json.getString("name"), json.getString("value"));

        }

        return map;
    } 

    // test
    public static void main(String[] args) {
        Map<String, Object> map=new HashMap<String, Object>();
        map.put("2", "1");
        map.put("3", "1");
        System.out.println(mapToKvJson(map));
    }
}

原文地址：https://www.cnblogs.com/mlq2017/p/10260187.html