【第一篇】Volley的使用之json请求

最近项目写完，有开始新的学习了，volley很久以前就接触了，也看了源码，然而却没有通过文章去记录自己的学习成果。

首先讲下volley的特点：

 　　1，扩展性强。Volley 中大多是基于接口的设计，可配置性强。

　　 2，一定程度符合 Http 规范，包括返回 ResponseCode(2xx、3xx、4xx、5xx）的处理，请求头的处理，缓存机制的支持等。并支持重试及优先级定义。

 　　3，默认 Android2.3 及以上基于 HttpURLConnection，2.3 以下基于 HttpClient 实现，这两者的区别及优劣在4.2.1 Volley中具体介绍。

 　　4，提供简便的图片加载工具。

现在计划是：

1. 写volley相关demo
2. 分析volley源码
3. 扩展和完善volley,给volley添加一些更加方便开发的功能等。

在编写代码前首先导入volley的库或者引入jar包，这里不进行赘述，只讲使用。

demo1,json数据请求：

    首先请求的json数据格式：

1. {
      "weatherinfo" : {
         "Radar" : "JC_RADAR_AZ9200_JB",
         "SD" : "77%",
         "WD" : "东南风",
         "WS" : "2级",
         "WSE" : "2",
         "city" : "广州",
         "cityid" : "101280101",
         "isRadar" : "1",
         "njd" : "暂无实况",
         "qy" : "1004",
         "temp" : "24",
         "time" : "10:45"
      }
   }

首先创建javaBean:

1. package com.soyoungboy.volleydemo.bean;
   import java.io.Serializable;
   import com.soyoungboy.volleydemo.utils.GsonImpl;
   public class WeathBean implements Serializable {
       /**
        * 
        */
       private static final long serialVersionUID = 1L;
       public Weatherinfo weatherinfo;
       @Override
       public String toString() {
           return "WeathBean [weatherinfo=" + weatherinfo + "]";
       }
       public  static WeathBean getBeanFromJson(String response){
           WeathBean weathBean= GsonImpl.get().toObject(response, WeathBean.class);
           return weathBean ;
       }
       /**
        * Temporary class name, create by Json2Class.
        */
       public static class Weatherinfo implements Serializable {
           public String SD;
           public int isRadar;
           public String time;
           public int WSE;
           public String WS;
           public String WD;
           public String njd;
           public int qy;
           public String Radar;
           public int temp;
           public int cityid;
           public String city;
           public String getSD() {
               return SD;
           }
           public void setSD(String sD) {
               SD = sD;
           }
           public int getIsRadar() {
               return isRadar;
           }
           public void setIsRadar(int isRadar) {
               this.isRadar = isRadar;
           }
           public String getTime() {
               return time;
           }
           public void setTime(String time) {
               this.time = time;
           }
           public int getWSE() {
               return WSE;
           }
           public void setWSE(int wSE) {
               WSE = wSE;
           }
           public String getWS() {
               return WS;
           }
           public void setWS(String wS) {
               WS = wS;
           }
           public String getWD() {
               return WD;
           }
           public void setWD(String wD) {
               WD = wD;
           }
           public String getNjd() {
               return njd;
           }
           public void setNjd(String njd) {
               this.njd = njd;
           }
           public int getQy() {
               return qy;
           }
           public void setQy(int qy) {
               this.qy = qy;
           }
           public String getRadar() {
               return Radar;
           }
           public void setRadar(String radar) {
               Radar = radar;
           }
           public int getTemp() {
               return temp;
           }
           public void setTemp(int temp) {
               this.temp = temp;
           }
           public int getCityid() {
               return cityid;
           }
           public void setCityid(int cityid) {
               this.cityid = cityid;
           }
           public String getCity() {
               return city;
           }
           public void setCity(String city) {
               this.city = city;
           }
           @Override
           public String toString() {
               return "Weatherinfo [SD=" + SD + ", isRadar=" + isRadar + ", time="
                       + time + ", WSE=" + WSE + ", WS=" + WS + ", WD=" + WD
                       + ", njd=" + njd + ", qy=" + qy + ", Radar=" + Radar
                       + ", temp=" + temp + ", cityid=" + cityid + ", city="
                       + city + "]";
           }
       }
   }

   创建界面：

activity_json.xml

1. <?xml version="1.0" encoding="utf-8"?>
   <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
       android:layout_width="match_parent"
       android:layout_height="match_parent"
       android:orientation="vertical" >
       <TextView
           android:id="@+id/lvWeatherTv"
           android:layout_width="match_parent"
           android:layout_height="match_parent" >
       </TextView>
   </LinearLayout>

   主要的逻辑：

1. 首先创建请求队列 mqueue;
2. 创建json请求jsonObjectRequest，实现请求成功和失败的逻辑编写；
3. 将请求放入请求队列中去。

public class JsonActivity extends Activity {
    private static final String TAG = "com.soyoungboy.volleydemo.JsonActivity";
    private RequestQueue mQueue;
    private static final String WEATHER_LINK = "http://www.weather.com.cn/data/sk/101280101.html";
    private TextView lvWeatherTv;
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_json);
        lvWeatherTv = (TextView) findViewById(R.id.lvWeatherTv);
        mQueue = Volley.newRequestQueue(this);
        getWeatherInfo();
    }
    public void getWeatherInfo() {
        JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(
                WEATHER_LINK, null, new Response.Listener<JSONObject>() {
                    @Override
                    public void onResponse(JSONObject response) {
                        if (!TextUtils.isEmpty(response.toString())) {
                            WeathBean weathBean = WeathBean
                                    .getBeanFromJson(response.toString());
                            lvWeatherTv.setText(weathBean.toString());
                        }
                    }
                }, new Response.ErrorListener() {
                    @Override
                    public void onErrorResponse(VolleyError error) {
                        ToastUtils.toastL(getApplicationContext(),
                                error.getMessage());
                    }
                });
        mQueue.add(jsonObjectRequest);
    }
}

显示结果：