在使用第三方api的使用，有时候会从网络中获得json数据，所以说我们将如何解析json数据？
下面小编将通过以下几点来进行json的讲解
1.什么是JSON？ （http://www.json.org/）
JSON (JavaScript Object Notation) is a lightweight data-interchange format. It is easy for humans to read and write. It is easy for machines to parse and generate. It is based on a subset of the JavaScript Programming Language, Standard ECMA-262 3rd Edition - December 1999. JSON is a text format that is completely language independent but uses conventions that are familiar to programmers of the C-family of languages, including C, C++, C#, Java, JavaScript, Perl, Python, and many others. These properties make JSON an ideal data-interchange language.
2.Json数据类型
2-1.json对象
2-2.json数组
ps：JSONObject与JSONArray的区别
（JSON数组）
（JSON数组）
3.解析JSON数据（小编使用的GSON进行json数据的解析）
3-1 【JSONObject的解析】
下面是一个json文件：
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{
"resultcode"
:
"200"
,
"reason"
:
"successed!"
,
"result"
: {
"sk"
: {
"temp"
:
"24"
,
"wind_direction"
:
"西南风"
,
"wind_strength"
:
"2级"
,
"humidity"
:
"51%"
,
"time"
:
"10:11"
},
"today"
: {
"temperature"
:
"16℃~27℃"
,
"weather"
:
"阴转多云"
,
"weather_id"
: {
"fa"
:
"02"
,
"fb"
:
"01"
},
"wind"
:
"西南风3-4 级"
,
"week"
:
"星期四"
,
"city"
:
"滨州"
,
"date_y"
:
"2015年06月04日"
,
"dressing_index"
:
"舒适"
,
"dressing_advice"
:
"建议着长袖T恤、衬衫加单裤等服装。年老体弱者宜着针织长袖衬衫、马甲和长裤。"
,
"uv_index"
:
"最弱"
,
"comfort_index"
:
""
,
"wash_index"
:
"较适宜"
,
"travel_index"
:
""
,
"exercise_index"
:
"较适宜"
,
"drying_index"
:
""
},
"future"
: [
{
"temperature"
:
"16℃~27℃"
,
"weather"
:
"阴转多云"
,
"weather_id"
: {
"fa"
:
"02"
,
"fb"
:
"01"
},
"wind"
:
"西南风3-4 级"
,
"week"
:
"星期四"
,
"date"
:
"20150604"
},
{
"temperature"
:
"20℃~32℃"
,
"weather"
:
"多云转晴"
,
"weather_id"
: {
"fa"
:
"01"
,
"fb"
:
"00"
},
"wind"
:
"西风3-4 级"
,
"week"
:
"星期五"
,
"date"
:
"20150605"
},
{
"temperature"
:
"23℃~35℃"
,
"weather"
:
"多云转阴"
,
"weather_id"
: {
"fa"
:
"01"
,
"fb"
:
"02"
},
"wind"
:
"西南风3-4 级"
,
"week"
:
"星期六"
,
"date"
:
"20150606"
},
{
"temperature"
:
"20℃~33℃"
,
"weather"
:
"多云"
,
"weather_id"
: {
"fa"
:
"01"
,
"fb"
:
"01"
},
"wind"
:
"北风微风"
,
"week"
:
"星期日"
,
"date"
:
"20150607"
},
{
"temperature"
:
"22℃~34℃"
,
"weather"
:
"多云"
,
"weather_id"
: {
"fa"
:
"01"
,
"fb"
:
"01"
},
"wind"
:
"西南风3-4 级"
,
"week"
:
"星期一"
,
"date"
:
"20150608"
},
{
"temperature"
:
"22℃~33℃"
,
"weather"
:
"阴"
,
"weather_id"
: {
"fa"
:
"02"
,
"fb"
:
"02"
},
"wind"
:
"西南风3-4 级"
,
"week"
:
"星期二"
,
"date"
:
"20150609"
},
{
"temperature"
:
"22℃~33℃"
,
"weather"
:
"多云"
,
"weather_id"
: {
"fa"
:
"01"
,
"fb"
:
"01"
},
"wind"
:
"南风3-4 级"
,
"week"
:
"星期三"
,
"date"
:
"20150610"
}
]
},
"error_code"
:
0
}
|
我们进行解析（解析一部分）：
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package
cn.edu.bzu.json;
import
java.io.FileNotFoundException;
import
java.io.FileReader;
import
com.google.gson.JsonArray;
import
com.google.gson.JsonIOException;
import
com.google.gson.JsonObject;
import
com.google.gson.JsonParser;
import
com.google.gson.JsonSyntaxException;
public
class
Read {
public
static
void
main(String args[]){
JsonParser parse =
new
JsonParser();
//创建json解析器
try
{
JsonObject json=(JsonObject) parse.parse(
new
FileReader(
"weather.json"
));
//创建jsonObject对象
System.out.println(
"resultcode:"
+json.get(
"resultcode"
).getAsInt());
//将json数据转为为int型的数据
System.out.println(
"reason:"
+json.get(
"reason"
).getAsString());
//将json数据转为为String型的数据
JsonObject result=json.get(
"result"
).getAsJsonObject();
JsonObject today=result.get(
"today"
).getAsJsonObject();
System.out.println(
"temperature:"
+today.get(
"temperature"
).getAsString());
System.out.println(
"weather:"
+today.get(
"weather"
).getAsString());
}
catch
(JsonIOException e) {
e.printStackTrace();
}
catch
(JsonSyntaxException e) {
e.printStackTrace();
}
catch
(FileNotFoundException e) {
e.printStackTrace();
}
}
}
|
输出结果：
3-2 【JSONArray的解析】
下面是一个json文件
{
"cat":"it",
"language":[
{"id":1,"ide":"eclipse","name":Java},
{"id":2,"ide":"XCode","name":"Swift"},
{"id":3,"ide":"Visual Stdio","name":"C#"}
],
"pop":true
}
我们进行解析：
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package
cn.edu.bzu.json;
import
java.io.FileNotFoundException;
import
java.io.FileReader;
import
com.google.gson.JsonArray;
import
com.google.gson.JsonIOException;
import
com.google.gson.JsonObject;
import
com.google.gson.JsonParser;
import
com.google.gson.JsonSyntaxException;
public
class
ReadJSON {
public
static
void
main(String args[]){
try
{
JsonParser parser=
new
JsonParser();
//创建JSON解析器
JsonObject object=(JsonObject) parser.parse(
new
FileReader(
"test.json"
));
//创建JsonObject对象
System.out.println(
"cat="
+object.get(
"cat"
).getAsString());
//将json数据转为为String型的数据
System.out.println(
"pop="
+object.get(
"pop"
).getAsBoolean());
//将json数据转为为boolean型的数据
JsonArray array=object.get(
"language"
).getAsJsonArray();
//得到为json的数组
for
(
int
i=
0
;i
System.out.println(
"---------------"
);
JsonObject subObject=array.get(i).getAsJsonObject();
System.out.println(
"id="
+subObject.get(
"id"
).getAsInt());
System.out.println(
"name="
+subObject.get(
"name"
).getAsString());
System.out.println(
"ide="
+subObject.get(
"ide"
).getAsString());
}
}
catch
(JsonIOException e) {
e.printStackTrace();
}
catch
(JsonSyntaxException e) {
e.printStackTrace();
}
catch
(FileNotFoundException e) {
e.printStackTrace();
}
}
}
|
输出结果：
3-3 【分析】
我们通过Gson进行解析，所以在使用前需要导入Gson.jar
解析json数据时，
1.需要进行创建Gson解析器
2.创建JSONObject对象
3.将json数据转为为相应的数据