JSon数据的解析

最近一个项目要对艺龙,携程等酒店预订网站进行价格信息采集.因为这两个网站都不是省油的灯啊,多次提交ajax表单,参数编码,获取特定的城市和酒店代码等等手段,可谓过五关斩六将,总算是把数据采集回来,但是又面临一个难题:采集回来的信息是json格式的,那就涉及到json数据转换成java对象了

首先要了解json数据的格式

[{"CityType":"hotel","TabList":[{"TabId":"1","Name":"\u70ED\u95E8","NameEn":"Hot","CityList":[{"ProvinceId":null,"CityId":"0101","CityCode":"0101","CityNameCn":"\u5317\u4EAC","CityNameEn":"Beijing","CityThreeSign":"","CityType":"hotel","OldEnglishName":"peking"},{"ProvinceId":null,"CityId":"0201","CityCode":"0201","CityNameCn":"\u4E0A\u6D77","CityNameEn":"Shanghai","CityThreeSign":"","CityType":"hotel","OldEnglishName":""},{"ProvinceId":null,"CityId":"2001","CityCode":"2001","CityNameCn":"\u5E7F\u5DDE","CityNameEn":"Guangzhou","CityThreeSign":"","CityType":"hotel","OldEnglishName":"canton"}]}]}];

jsonViewer是个好东西,不过HTTPAnalysis直接就集成了jsonViewer,不过还是前者比较轻巧:

json和java之间的互换可以使用json-lib, 基本的使用可以看文档就行.网上也有一些集成的类,我建议直接看它的源代码,了解他是如何通过反射和使用临时对象解析json数据,并封装成java对象.

这个json数据时list的嵌套,如果要对整个json文件解析,需要使用如下方法,需要构造跟json数据对应的Tab.class 和City.class,而且字段名称必须一致(骆驼首字母小写),提供默认构造方法,这样就可以将json数据作为一个完整的对象,想怎么干都行了.

 

HashMap<String,Class> map = new HashMap<String,Class>();
map.put("tabList", Tab.class);
map.put("cityList", City.class);

      
	    /**   
	     * 从一个JSON数组得到一个java对象集合，其中对象中包含有集合属性   
	     * @param object   
	     * @param clazz   
	     * @param map 集合属性的类型 (key : 集合属性名, value : 集合属性类型class) eg: ("beansList" : Bean.class)   
	     * @return   
	     */    
	    public static List getDTOList(String jsonString, Class clazz, Map map){     
	        setDataFormat2JAVA();     
	        JSONArray array = JSONArray.fromObject(jsonString);     
	        List list = new ArrayList();     
	        for(Iterator iter = array.iterator(); iter.hasNext();){     
	            JSONObject jsonObject = (JSONObject)iter.next();     
	            list.add(JSONObject.toBean(jsonObject, clazz, map));     
	        }     
	        return list;     
	    }     

由于我的需求只是需要重json数据中获取特定的信息对象,如上面的cityList,像tabList等对象我没必要去构造和获取,而且在实际使用过程中我发现

json数据中变量如果不是首字母小写,是无法转换成java对象的.这个确实很坑爹!!!!!

 

于是乎,我就写了个直接读取和解析一个片段json数据的类,有了这个类,加上对象映射,基本上没什么解析不了

package com.gxy.weixin.util;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

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

public class JSonStrUtils {

	/**
	 * json 数据括号自动补全
	 * **/
	public static String autoComplete(String targetJson) {
		LinkedList<Character> stack = new LinkedList<Character>();
		String returnStr = "";
		char[] charArray = targetJson.toCharArray();
		for (int i = 0; i < charArray.length; i++) {
			if (charArray[i] == '[' || charArray[i] == '{') {// 入栈
				stack.addFirst(charArray[i]);
			} else if (charArray[i] == ']') {
				// 判断是否闭合
				char last = stack.peekFirst();
				if (last != '[') {// 不闭合,补 }
					returnStr += '}';
				} else// 闭合
				{
					stack.pollFirst();
				}
			} else if (charArray[i] == '}') {
				// 判断是否闭合
				char last = stack.peekFirst();
				if (last != '{') {// 不闭合,补 }
					returnStr += ']';
				} else// 闭合
				{
					stack.pollFirst();
				}
			}
			returnStr += charArray[i];
		}
		for (char c : stack) {
			System.out.println("left in stack:" + c);
		}
		return returnStr;
	}

	/***
	 * 用于处理json数据中出现变量名非首字母小写的情况,利用正则匹配变量,然后把首字母变成小写
	 * */
	public static String dealWithFirstChar(String jsonInput) {
		String originalInput = jsonInput;
		StringBuilder inputStr = new StringBuilder(jsonInput);
		String regex = "\"(\\w+)\":";
		Pattern p = Pattern.compile(regex, Pattern.CASE_INSENSITIVE);
		Matcher m = p.matcher(inputStr);
		List<String> result = new ArrayList<String>();
		while (m.find()) {
			String valueName = m.group(1);
			String newValueName = null;
			char[] words = valueName.toCharArray();
			if (Character.isUpperCase(words[0])) {// 首字母大写,不符合变量命名规范

				words[0] = Character.toLowerCase(words[0]);
				newValueName = new String(words);
				// System.out.println("orignal value:"+valueName+" new value :"+
				// newValueName);
				// String regexWord = "\""+valueName+"\":";
				String regx1 = "\"" + valueName + "\":";
				String replace = "\"" + newValueName + "\":";
				originalInput = originalInput.replaceAll(regx1, replace);
			}
			result.add(valueName);
			inputStr.delete(0, m.end(0));
			m = p.matcher(inputStr);
		}
		return originalInput;

	}

	/***
	 * 用户将unicode编码转换成汉字
	 * */
	public static String UnicodeToString(String str) {
		Pattern pattern = Pattern.compile("(\\\\u(\\p{XDigit}{4}))");
		Matcher matcher = pattern.matcher(str);
		char ch;
		while (matcher.find()) {
			ch = (char) Integer.parseInt(matcher.group(2), 16);
			str = str.replace(matcher.group(1), ch + "");
		}
		return str;
	}

	/***
	 * 用户将汉字转换成unicode编码
	 * */
	public static String toUNICODE(String s) {
		StringBuilder sb = new StringBuilder();
		for (int i = 0; i < s.length(); i++) {
			if (s.charAt(i) <= 256) {
				sb.append("\\u00");
			} else {
				sb.append("\\u");
			}
			sb.append(Integer.toHexString(s.charAt(i)).toUpperCase());
		}
		return sb.toString();
	}

	/**
	 * 读取json文件,转换为字符串
	 * */
	public static String readJSonFile(String fileName) {
		InputStream in = null;
		String jsonStr = "";
		try {
			in = JSonStrUtils.class.getResourceAsStream(fileName);
			BufferedReader reader = new BufferedReader(
					new InputStreamReader(in));
			String temp = reader.readLine();
			while (temp != null) {
				jsonStr += temp;
				temp = reader.readLine();
			}
			in.close();
		} catch (IOException e) {
			e.printStackTrace();
			System.out.println("read json file failed :" + fileName);
		}
		return jsonStr;
	}

	/***
	 * 在指定的JSONObject 中寻找特定属性的第一个值
	 * */
	public static List<String> findTargetProperty(JSONObject object,
			String propertyName, boolean isRecursive) {
		List<String> values = new ArrayList<String>();
		for (Iterator entries = object.names().iterator(); entries.hasNext();) {
			String name = (String) entries.next();
			Object value = object.get(name);
			if (name.equals(propertyName)) {// 找到目标属性
				values.add(value.toString());
			} else if (isRecursive) {
				if (value instanceof JSONObject) {
					values.addAll(findTargetProperty((JSONObject) value,
							propertyName, isRecursive));
				} else if (value instanceof JSONArray) {
					JSONArray array = (JSONArray) value;
					for (Iterator iter = array.iterator(); iter.hasNext();) {
						JSONObject jsonObject = (JSONObject) iter.next();
						values.addAll(findTargetProperty(jsonObject,
								propertyName, isRecursive));
					}
				}
			}
		}
		return values;
	}

	/***
	 * 从指定的JSonArray中寻找指定名称的子json数组
	 * */
	public static List<JSONArray> findTargetJSonArray(JSONArray array,
			String targetName) {
		List<JSONArray> arrays = new ArrayList<JSONArray>();
		for (Iterator iter = array.iterator(); iter.hasNext();) {// 遍历数组中的JSONObject
			JSONObject jsonObject = (JSONObject) iter.next();
			if (jsonObject == null || jsonObject.isNullObject()) {
				continue;
			}
			for (Iterator entries = jsonObject.names().iterator(); entries
					.hasNext();) {
				String name = (String) entries.next();
				Object value = jsonObject.get(name);
				if (value instanceof JSONArray) {// 属性为数组
					// 先判断是否目标数组
					if (name.equals(targetName)) {
						arrays.add((JSONArray) value);
					}
					// 递归查找
					arrays.addAll(findTargetJSonArray((JSONArray) value,
							targetName));
				}
			}
		}
		return arrays;

	}
}

原文地址：http://xoknight.net/?cat=58