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);  
           }  
       });       
   }  
  
     
   
}