Gson解析複雜的json數據
最近在給公司做一個直播APK的項目,主要就是通過解析網絡服務器上的json數據,然後將頻道地址下載下來再調用Android的播放器進行播放,原先本來打算使用普通的json解析方法即JsonObject和JsonArray的配合使用,這對於解析小數據的json數據還是比較實用,但是當解析json數據比較複雜的時候這種方法就顯得比較吃力也比較麻煩了,如果大家感興趣的話網上有大量的實例可以到網上去看看。
在這裏我將介紹解析json數據的另外一種方法就是通過Gson解析,對於解析比較簡單的json數據我就不介紹了來一個比較複雜一點的json數據,如下面我們要解析的一個json數據:
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String json ={"a":"100","b":[{"b1":"b_value1","b2":"b_value2"},{"b1":"b_value1","b2":"b_value2"}],"c":{"c1":"c_value1","c2":"c_value2"}}
如果使用JsonObject和JsonArray的配合起來使用也是可以解析的但是解析起來就比較麻煩了,如果使用Gson解析就比較簡單了,首先我們需要定義一個序列化的Bean,這裏採用內部類的形式,這樣比較容易看得清晰些
首先我們需要定義一個序列化的Bean,這裏採用內部類的形式,看起來會比較清晰一些:
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public class JsonBean {
public String a;
publicList<B> b;
public C c;
public static class B{
publicString b1;
public Stringb2;
}
public static class C{
public Stringc1;
public Stringc2;
}
}
很多時候大家都是不知道這個Bean是該怎麼定義,這裏面需要注意幾點:
1、內部嵌套的類必須是static的,要不然解析會出錯;
2、類裏面的屬性名必須跟Json字段裏面的Key是一模一樣的;
3、內部嵌套的用[]括起來的部分是一個List,所以定義爲 public List<B> b,而只用{}嵌套的就定義爲public C c,
具體的大家對照Json字符串看看就明白了,不明白的我們可以互相交流,本人也是開發新手!
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Gson gson = new Gson();
java.lang.reflect.Type type = newTypeToken<JsonBean>() {}.getType();
JsonBean jsonBean = gson.fromJson(json,type);</span>
然後想拿數據就很簡單啦,直接在jsonBean裏面取就可以了!
如果需要解析的Json嵌套了很多層,同樣可以可以定義一個嵌套很多層內部類的Bean,需要細心的對照Json字段來定義哦。
下面我將以一個具體的列子來說明通過Gson方式解析複雜的json數據
1.將要解析的數據如下面的格式
{
"error": 0,
"status": "success",
"date": "2014-05-10",
"results": [
{
"currentCity": "南京",
"weather_data": [
{
"date": "週六(今天, 實時:19℃)",
"dayPictureUrl":"http://api.map.baidu.com/images/weather/day/dayu.png",
"nightPictureUrl":"http://api.map.baidu.com/images/weather/night/dayu.png",
"weather": "大雨",
"wind": "東南風5-6級",
"temperature":"18℃"
},
{
"date": "週日",
"dayPictureUrl":"http://api.map.baidu.com/images/weather/day/zhenyu.png",
"nightPictureUrl":"http://api.map.baidu.com/images/weather/night/duoyun.png",
"weather": "陣雨轉多雲",
"wind": "西北風4-5級",
"temperature":"21 ~ 14℃"
}
]
}
]
}
2.必須定義如下一些的javaBean數據
Status.java
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public class Status
{
private String error;
private String status;
private String date;
private List<Results> results;
public String getError()
{
return error;
}
public void setError(String error)
{
this.error = error;
}
public String getStatus()
{
return status;
}
public void setStatus(String status)
{
this.status = status;
}
public String getDate()
{
return date;
}
public void setDate(String date)
{
this.date = date;
}
public List<Results> getResults()
{
return results;
}
public void setResults(List<Results> results)
{
this.results = results;
}
@Override
public String toString()
{
return "Status [error=" + error + ", status=" +status
+ ", date=" +date + ", results=" + results + "]";
}
</span>
Results.java
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public class Results
{
private String currentCity;
private List<Weather> weather_data;
public String getCurrentCity()
{
return currentCity;
}
public void setCurrentCity(String currentCity)
{
this.currentCity = currentCity;
}
public List<Weather> getWeather_data()
{
return weather_data;
}
public void setWeather_data(List<Weather> weather_data)
{
this.weather_data = weather_data;
}
@Override
public String toString()
{
return "Results [currentCity=" + currentCity + ",weather_data="
+ weather_data +"]";
}
Weather.java
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public class Weather {
private String date;
private StringdayPictureUrl;
private StringnightPictureUrl;
private String weather;
private String wind;
private Stringtemperature;
public String getDate() {
return date;
}
public void setDate(Stringdate) {
this.date = date;
}
public StringgetDayPictureUrl() {
return dayPictureUrl;
}
public voidsetDayPictureUrl(String dayPictureUrl) {
this.dayPictureUrl = dayPictureUrl;
}
public StringgetNightPictureUrl() {
returnnightPictureUrl;
}
public voidsetNightPictureUrl(String nightPictureUrl) {
this.nightPictureUrl =nightPictureUrl;
}
public String getWeather(){
return weather;
}
public void setWeather(Stringweather) {
this.weather =weather;
}
public String getWind() {
return wind;
}
public void setWind(Stringwind) {
this.wind = wind;
}
public StringgetTemperature() {
return temperature;
}
public voidsetTemperature(String temperature) {
this.temperature =temperature;
}
@Override
public String toString() {
return "Weather[date=" + date + ", dayPictureUrl="
+ dayPictureUrl +", nightPictureUrl="
+ nightPictureUrl +", weather=" + weather
+ ",wind=" + wind + ", temperature=" + temperature
+"]";
}
然後具體的javabean定義好了就將解析數據了,下面就是我的解析數據類
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public class MainActivity extendsActivity
{
private Button tojson;
RequestQueue mQueue;
StringRequest stringRequest;
Gson gson;
String str;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tojson = (Button)findViewById(R.id.tojson);
gson = new Gson();
mQueue = Volley.newRequestQueue(MainActivity.this);
//http://10.19.20.12/upgrade/test.txt是測試使用的json數據
stringRequest = newStringRequest("http://10.19.20.12/upgrade/test.txt",
newResponse.Listener<String>()
{
@Override
public voidonResponse(String response)
{
Log.d("TAG",response);
System.out.println("response="+response);
Status status =gson.fromJson(response, Status.class);
System.out.println("status="+status);
System.out.println("-------------------------------------");
List<Results>result = status.getResults();
System.out.println("result="+result);
}
},
newResponse.ErrorListener()
{
@Override
public voidonErrorResponse(VolleyError error)
{
Log.e("TAG",error.getMessage(), error);
}
});
tojson.setOnClickListener(new OnClickListener()
{
@Override
public void onClick(View v)
{
mQueue.add(stringRequest);
}
});
}
}