java处理json的工具类(list,map和json的之间的转换)

野性酷女 2022-08-01 12:25 150阅读 0赞

需要下载第三方的jar ：net.sf.json

import java.io.BufferedReader;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.net.URL;
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import org.apache.commons.collections.map.ListOrderedMap;
 import net.sf.json.JSONArray;
 import net.sf.json.JSONObject;
 /** * * 处理json的工具类. * 本类为处理json的工具类 * @author slj */
 public class JsonTools { 
 
 /** * * json转换list. * 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. * 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. * 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) {
 e.printStackTrace();
 }
 return null;
 }
 
 /** * * 通过HTTP获取JSON数据. * 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) {
 e.printStackTrace();
 }
 return null;
 }
 /** * * map转换json. * 详细说明 * @param map 集合 * @return * @return String json字符串 * @throws * @author slj */
 public static String mapToJson(Map<String, String> map) {
 Set<String> keys = map.keySet();
 String key = "";
 String value = "";
 StringBuffer jsonBuffer = new StringBuffer();
 jsonBuffer.append("{");
 for (Iterator<String> it = keys.iterator(); it.hasNext();) {
 key = (String) it.next();
 value = map.get(key);
 jsonBuffer.append(key + ":" +"\""+ value+"\"");
 if (it.hasNext()) {
 jsonBuffer.append(",");
 }
 }
 jsonBuffer.append("}");
 return jsonBuffer.toString();
 }
 
 //test
 public static void main(String[] args) {
 String url = "http://...";
 List<Map<String,Object>> list = getListByUrl(url);
 System.out.println(list);
 }
 }