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
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】
下面是一段json数据：
{ "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", }, "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" }, ] }, "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();
}
}
}
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 }
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<array.size();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();
}
}
}
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
4.源代码下载：
https://github.com/monsterLin/TestReadJSON
5.转载：
https://www.cnblogs.com/boy1025/p/4551593.html
