Gson解析复杂的json数据
最近在给公司做一个直播APK的项目,主要就是通过解析网络服务器上的json数据,然后将频道地址下载下来再调用Android的播放器进行播放,原先本来打算使用普通的json解析方法即JsonObject和JsonArray的配合使用,这对于解析小数据的json数据还是比较实用,但是当解析json数据比较复杂的时候这种方法就显得比较吃力也比较麻烦了,如果大家感兴趣的话网上有大量的实例可以到网上去看看。
在这里我将介绍解析json数据的另外一种方法就是通过Gson解析,对于解析比较简单的json数据我就不介绍了来一个比较复杂一点的json数据,如下面我们要解析的一个json数据:
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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的配合起来使用也是可以解析的但是解析起来就比较麻烦了,如果使用Gson解析就比较简单了,首先我们需要定义一个序列化的Bean,这里采用内部类的形式,这样比较容易看得清晰些
首先我们需要定义一个序列化的Bean,这里采用内部类的形式,看起来会比较清晰一些:
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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;
}
}
很多时候大家都是不知道这个Bean是该怎么定义,这里面需要注意几点:
1、内部嵌套的类必须是static的,要不然解析会出错;
2、类里面的属性名必须跟Json字段里面的Key是一模一样的;
3、内部嵌套的用[]括起来的部分是一个List,所以定义为 public List<B> b,而只用{}嵌套的就定义为public C c,
具体的大家对照Json字符串看看就明白了,不明白的我们可以互相交流,本人也是开发新手!
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Gson gson = new Gson();
java.lang.reflect.Type type = newTypeToken<JsonBean>() {}.getType();
JsonBean jsonBean = gson.fromJson(json,type);</span>
然后想拿数据就很简单啦,直接在jsonBean里面取就可以了!
如果需要解析的Json嵌套了很多层,同样可以可以定义一个嵌套很多层内部类的Bean,需要细心的对照Json字段来定义哦。
下面我将以一个具体的列子来说明通过Gson方式解析复杂的json数据
1.将要解析的数据如下面的格式
{
"error": 0,
"status": "success",
"date": "2014-05-10",
"results": [
{
"currentCity": "南京",
"weather_data": [
{
"date": "周六(今天, 实时: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": "东南风5-6级",
"temperature":"18℃"
},
{
"date": "周日",
"dayPictureUrl":"http://api.map.baidu.com/images/weather/day/zhenyu.png",
"nightPictureUrl":"http://api.map.baidu.com/images/weather/night/duoyun.png",
"weather": "阵雨转多云",
"wind": "西北风4-5级",
"temperature":"21 ~ 14℃"
}
]
}
]
}
2.必须定义如下一些的javaBean数据
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
+"]";
}
然后具体的javabean定义好了就将解析数据了,下面就是我的解析数据类
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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是测试使用的json数据
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);
}
});
}
}