目前解析json有三种工具：org.json（Java常用的解析），fastjson（阿里巴巴工程师开发的），Gson（Google官网出的），解析速度最快的是Gson，下载地址：https://code.google.com/p/google-gson/
什么是JSON:
JSON即JavaScript Object Natation, 它是一种轻量级的数据交换格式, 与XML一样, 是广泛被采用的客户端和服务端交互的解决方案.
JSON对象:
JSON中对象(Object)以"{"开始, 以"}"结束. 对象中的每一个item都是一个key-value对, 表现为"key:value"的形式, key-value对之间使用逗号分隔. 如:{"name":"coolxing", "age"=24, "male":true, "address":{"street":"huiLongGuan", "city":"beijing", "country":"china"}}. JSON对象的key只能是string类型的, 而value可以是string, number, false, true, null, Object对象甚至是array数组, 也就是说可以存在嵌套的情况.
JSON数组:
JSON数组(array)以"["开始, 以"]"结束, 数组中的每一个元素可以是string, number, false, true, null, Object对象甚至是array数组, 数组间的元素使用逗号分隔. 如["coolxing", 24, {"street":"huiLongGuan", "city":"beijing", "country":"china"}].
Gson的基本使用方法：
通过获取JsonReader对象解析JSON数据：
1String jsonData = "[{\"username\":\"arthinking\",\"userId\":001},{\"username\":\"Jason\",\"userId\":002}]"; 2try{ 3 JsonReader reader = new JsonReader(new StringReader(jsonData)); 4 reader.beginArray(); 5 while(reader.hasNext()){ 6 reader.beginObject(); 7 while(reader.hasNext()){ 8 String tagName = reader.nextName(); 9 if(tagName.equals("username")){ 10 System.out.println(reader.nextString()); 11 } 12 else if(tagName.equals("userId")){ 13 System.out.println(reader.nextString()); 14 } 15 } 16 reader.endObject(); 17 } 18 reader.endArray(); 19} 20catch(Exception e){ 21 e.printStackTrace(); 22}
通过把JSON数据映射成一个对象，使用Gson对象的fromJson()方法获取一个对象数组进行操作：
创建JSON数据对应的一个POJO对象User.java：
1public class User { 2 private String username ; 3 private int userId ; 4 public String getUsername() { 5 return username; 6 } 7 public void setUsername(String username) { 8 this.username = username; 9 } 10 public int getUserId() { 11 return userId; 12 } 13 public void setUserId(int userId) { 14 this.userId = userId; 15 } 16}
使用Gson对象获取User对象数据进行相应的操作：
1Type listType = new TypeToken<LinkedList<User>>(){}.getType(); 2Gson gson = new Gson(); 3LinkedList<User> users = gson.fromJson(jsonData, listType); 4for (Iterator iterator = users.iterator(); iterator.hasNext();) { 5 User user = (User) iterator.next(); 6 System.out.println(user.getUsername()); 7 System.out.println(user.getUserId()); 8}
如果要处理的JSON字符串只包含一个JSON对象，则可以直接使用fromJson获取一个User对象：
1String jsonData = "{\"username\":\"arthinking\",\"userId\":001}"; 2Gson gson = new Gson(); 3User user = gson.fromJson(jsonData, User.class); 4System.out.println(user.getUsername()); 5System.out.println(user.getUserId());
解析复杂实例：
数据格式：
1{ 2 "data": { 3 "partnerteamlist": [ 4 { 5 "pteamId": 72825, 6 "ptitle": "随摄影/共6套服装/准爸准妈共拍/免费肚画/底片全送。", 7 "pteamprice": 288 8 }, 9 { 10 "pteamId": 72598, 11 "ptitle": "随摄影/拍摄200张/4本相册/品质拍摄/送全新婚纱。", 12 "pteamprice": 2888 13 }, 14 { 15 "pteamId": 72613, 16 "ptitle": "随摄影/送全新婚纱/多外景拍摄/服装不限数量/绝无二次消费！", 17 "pteamprice": 3699 18 }, 19 { 20 "pteamId": 72638, 21 "ptitle": "随摄影/服装不限数量/高品质拍摄260张/送全新婚纱。", 22 "pteamprice": 4299 23 }, 24 { 25 "pteamId": 72716, 26 "ptitle": "随摄影/3组服装造型/内外景拍摄/完全透明消费！", 27 "pteamprice": 388 28 } 29 ], 30 "liketeamlist": [ 31 { 32 "lteamId": 65886, 33 "ltitle": "爱丽尔婚纱摄影/2本相册/6套服装造型/拍摄不限最低拍摄150张。", 34 "limage": "http://img.pztuan.com/upfile/team/2013/0712/201307120257551465.jpg", 35 "lteamprice": 518, 36 "lmarketprice": 3999 37 }, 38 { 39 "lteamId": 57133, 40 "ltitle": "陶冶摄影/婚纱闺蜜/6组服装造型/拍摄不低于120张！", 41 "limage": "http://img.pztuan.com/upfile/team/2013/0628/201306281115249737.jpg", 42 "lteamprice": 580, 43 "lmarketprice": 3380 44 } 45 ], 46 "feedbacks": { 47 "feedbacklist": [ 48 { 49 "comment": "5分", 50 "createtime": "2014.07.08 13:38", 51 "score": 5, 52 "username": "l***2" 53 } 54 ], 55 "totalcount": 1, 56 "totalscore": 5 57 } 58 }, 59 "err": null, 60 "state": 1 61}
实体类（里面的成员变量和接口的返回值名称一 一对应才能保证解析正确）：
1package com.pztuan.entity; 2 3import java.util.List; 4 5public class OtherDetail { 6 7 private int state; 8 private List<err> err; 9 private OtherDetail2 data; 10 11 public int getState() { 12 return state; 13 } 14 15 public void setState(int state) { 16 this.state = state; 17 } 18 19 public List<err> getErr() { 20 return err; 21 } 22 23 public void setErr(List<err> err) { 24 this.err = err; 25 } 26 27 public OtherDetail2 getData() { 28 return data; 29 } 30 31 public void setData(OtherDetail2 data) { 32 this.data = data; 33 } 34 35 public class OtherDetail2 { 36 private List<partnerteamlist> partnerteamlist; 37 private List<liketeamlist> liketeamlist; 38 private List<feedbacks> feedbacks; 39 40 public List<liketeamlist> getLiketeamlist() { 41 return liketeamlist; 42 } 43 44 public void setLiketeamlist(List<liketeamlist> liketeamlist) { 45 this.liketeamlist = liketeamlist; 46 } 47 48 public List<feedbacks> getFeedbacks() { 49 return feedbacks; 50 } 51 52 public void setFeedbacks(List<feedbacks> feedbacks) { 53 this.feedbacks = feedbacks; 54 } 55 56 public class partnerteamlist { 57 private int pteamId; 58 private String ptitle; 59 private Double pteamprice; 60 61 public int getPteamId() { 62 return pteamId; 63 } 64 65 public void setPteamId(int pteamId) { 66 this.pteamId = pteamId; 67 } 68 69 public String getPtitle() { 70 return ptitle; 71 } 72 73 public void setPtitle(String ptitle) { 74 this.ptitle = ptitle; 75 } 76 77 public Double getPteamprice() { 78 return pteamprice; 79 } 80 81 public void setPteamprice(Double pteamprice) { 82 this.pteamprice = pteamprice; 83 } 84 85 } 86 87 public class liketeamlist { 88 private int lteamId; 89 private String ltitle; 90 private String limage; 91 private Double lteamprice; 92 private Double lmarketprice; 93 94 public int getLteamId() { 95 return lteamId; 96 } 97 98 public void setLteamId(int lteamId) { 99 this.lteamId = lteamId; 100 } 101 102 public String getLtitle() { 103 return ltitle; 104 } 105 106 public void setLtitle(String ltitle) { 107 this.ltitle = ltitle; 108 } 109 110 public String getLimage() { 111 return limage; 112 } 113 114 public void setLimage(String limage) { 115 this.limage = limage; 116 } 117 118 public Double getLteamprice() { 119 return lteamprice; 120 } 121 122 public void setLteamprice(Double lteamprice) { 123 this.lteamprice = lteamprice; 124 } 125 126 public Double getLmarketprice() { 127 return lmarketprice; 128 } 129 130 public void setLmarketprice(Double lmarketprice) { 131 this.lmarketprice = lmarketprice; 132 } 133 } 134 135 public class feedbacks { 136 private int totalcount; 137 private Double totalscore; 138 private List<feedbacklist> feedbacklist; 139 140 public int getTotalcount() { 141 return totalcount; 142 } 143 144 public void setTotalcount(int totalcount) { 145 this.totalcount = totalcount; 146 } 147 148 public Double getTotalscore() { 149 return totalscore; 150 } 151 152 public void setTotalscore(Double totalscore) { 153 this.totalscore = totalscore; 154 } 155 156 public List<feedbacklist> getFeedbacklist() { 157 return feedbacklist; 158 } 159 160 public void setFeedbacklist(List<feedbacklist> feedbacklist) { 161 this.feedbacklist = feedbacklist; 162 } 163 164 public class feedbacklist { 165 private String username; 166 private String comment; 167 private String createtime; 168 private Double score; 169 170 public String getUsername() { 171 return username; 172 } 173 174 public void setUsername(String username) { 175 this.username = username; 176 } 177 178 public String getComment() { 179 return comment; 180 } 181 182 public void setComment(String comment) { 183 this.comment = comment; 184 } 185 186 public String getCreatetime() { 187 return createtime; 188 } 189 190 public void setCreatetime(String createtime) { 191 this.createtime = createtime; 192 } 193 194 public Double getScore() { 195 return score; 196 } 197 198 public void setScore(Double score) { 199 this.score = score; 200 } 201 202 } 203 } 204 205 public List<partnerteamlist> getPartnerteamlist() { 206 return partnerteamlist; 207 } 208 209 public void setPartnerteamlist(List<partnerteamlist> partnerteamlist) { 210 this.partnerteamlist = partnerteamlist; 211 } 212 } 213 214 public class err { 215 private int code; 216 private String msg; 217 218 public int getCode() { 219 return code; 220 } 221 222 public void setCode(int code) { 223 this.code = code; 224 } 225 226 public String getMsg() { 227 return msg; 228 } 229 230 public void setMsg(String msg) { 231 this.msg = msg; 232 } 233 } 234}
注意上面内部类的运用。
解析：
1Gson gson = new Gson(); 2OtherDetail d = gson.fromJson(jsonString,Detail.class);//取值的时候就从父类一层一层调子类成员（重要）
若出现引用异常，请查看Java内部类设计原则。
如有问题请留言，转载注明出处。
参考：http://www.itzhai.com/android-to-parse-json-data-using-gson.html