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.engine.logic.component.loader.impl.json.utils;
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;
}
}