javascript
java解析json_JAVA解析JSON数据
在使用第三方api的使用，有時候會從網絡中獲得json數據，所以說我們將如何解析json數據？
下面小編將通過以下幾點來進行json的講解
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 theJavaScript 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數據類型
2-1.json對象
2-2.json數組
ps：JSONObject與JSONArray的區別
(JSON數組)
(JSON數組)
3.解析JSON數據(小編使用的GSON進行json數據的解析)
3-1 【JSONObject的解析】
下面是一個json文件：
{
"resultcode": "200",
"reason": "successed!",
"result": {
"sk": {
"temp": "24",
"wind_direction": "西南風",
"wind_strength": "2級",
"humidity": "51%",
"time": "10:11"
},
"today": {
"temperature": "16℃~27℃",
"weather": "陰轉多云",
"weather_id": {
"fa": "02",
"fb": "01"
},
"wind": "西南風3-4 級",
"week": "星期四",
"city": "濱州",
"date_y": "2015年06月04日",
"dressing_index": "舒適",
"dressing_advice": "建議著長袖T恤、襯衫加單褲等服裝。年老體弱者宜著針織長袖襯衫、馬甲和長褲。",
"uv_index": "最弱",
"comfort_index": "",
"wash_index": "較適宜",
"travel_index": "",
"exercise_index": "較適宜",
"drying_index": ""
},
"future": [
{
"temperature": "16℃~27℃",
"weather": "陰轉多云",
"weather_id": {
"fa": "02",
"fb": "01"
},
"wind": "西南風3-4 級",
"week": "星期四",
"date": "20150604"
},
{
"temperature": "20℃~32℃",
"weather": "多云轉晴",
"weather_id": {
"fa": "01",
"fb": "00"
},
"wind": "西風3-4 級",
"week": "星期五",
"date": "20150605"
},
{
"temperature": "23℃~35℃",
"weather": "多云轉陰",
"weather_id": {
"fa": "01",
"fb": "02"
},
"wind": "西南風3-4 級",
"week": "星期六",
"date": "20150606"
},
{
"temperature": "20℃~33℃",
"weather": "多云",
"weather_id": {
"fa": "01",
"fb": "01"
},
"wind": "北風微風",
"week": "星期日",
"date": "20150607"
},
{
"temperature": "22℃~34℃",
"weather": "多云",
"weather_id": {
"fa": "01",
"fb": "01"
},
"wind": "西南風3-4 級",
"week": "星期一",
"date": "20150608"
},
{
"temperature": "22℃~33℃",
"weather": "陰",
"weather_id": {
"fa": "02",
"fb": "02"
},
"wind": "西南風3-4 級",
"week": "星期二",
"date": "20150609"
},
{
"temperature": "22℃~33℃",
"weather": "多云",
"weather_id": {
"fa": "01",
"fb": "01"
},
"wind": "南風3-4 級",
"week": "星期三",
"date": "20150610"
}
]
},
"error_code": 0
}
我們進行解析(解析一部分)：
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(); //創建json解析器
try {
JsonObject json=(JsonObject) parse.parse(new FileReader("weather.json")); //創建jsonObject對象
System.out.println("resultcode:"+json.get("resultcode").getAsInt()); //將json數據轉為為int型的數據
System.out.println("reason:"+json.get("reason").getAsString()); //將json數據轉為為String型的數據
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();
}
}
}
輸出結果：
3-2 【JSONArray的解析】
下面是一個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}
我們進行解析：
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(); //創建JSON解析器
JsonObject object=(JsonObject) parser.parse(new FileReader("test.json")); //創建JsonObject對象
System.out.println("cat="+object.get("cat").getAsString()); //將json數據轉為為String型的數據
System.out.println("pop="+object.get("pop").getAsBoolean()); //將json數據轉為為boolean型的數據
JsonArray array=object.get("language").getAsJsonArray(); //得到為json的數組
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();
}
}
}
輸出結果：
3-3 【分析】
我們通過Gson進行解析，所以在使用前需要導入Gson.jar
解析json數據時，
1.需要進行創建Gson解析器
2.創建JSONObject對象
3.將json數據轉為為相應的數據
4.源代碼下載：
總結
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