1、自定义一个解析Json的Request，这里使用JackSon框架来解析Json。你也可以自定义一个解析XML的Request，或者使用FastSon来解析Json。
2、我们首先来看一下StringRequest的源码。继承自Request<T>，主要是重写parseNetworkResponse()和deliverResponse()方法。
public class StringRequest extends Request<String> {
private final Listener<String> mListener;
/**
* Creates a new request with the given method.
*
* @param method the request {@link Method} to use
* @param url URL to fetch the string at
* @param listener Listener to receive the String response
* @param errorListener Error listener, or null to ignore errors
*/
public StringRequest(int method, String url, Listener<String> listener,
ErrorListener errorListener) {
super(method, url, errorListener);
mListener = listener;
}
/**
* Creates a new GET request.
*
* @param url URL to fetch the string at
* @param listener Listener to receive the String response
* @param errorListener Error listener, or null to ignore errors
*/
public StringRequest(String url, Listener<String> listener, ErrorListener errorListener) {
this(Method.GET, url, listener, errorListener);
}
@Override
protected void deliverResponse(String response) {
mListener.onResponse(response);
}
@Override
protected Response<String> parseNetworkResponse(NetworkResponse response) {
String parsed;
try {
parsed = new String(response.data, HttpHeaderParser.parseCharset(response.headers));
} catch (UnsupportedEncodingException e) {
parsed = new String(response.data);
}
return Response.success(parsed, HttpHeaderParser.parseCacheHeaders(response));
}
}
3、首先定义实体类
public class Weather {
private WeatherInfo weatherinfo;
public WeatherInfo getWeatherinfo() {
return weatherinfo;
}
@JsonProperty("weatherinfo")
public void setWeatherinfo(WeatherInfo weatherinfo) {
this.weatherinfo = weatherinfo;
}
}
public class WeatherInfo {
private String city;
private String cityid;
private String temp;
private String WD;
private String WS;
private String SD;
private String WSE;
private String time;
private String isRadar;
private String Radar;
private String njd;
private String qy;
public String getCity() {
return city;
}
@JsonProperty("city")
public void setCity(String city) {
this.city = city;
}
public String getCityid() {
return cityid;
}
@JsonProperty("cityid")
public void setCityid(String cityid) {
this.cityid = cityid;
}
public String getTemp() {
return temp;
}
@JsonProperty("temp")
public void setTemp(String temp) {
this.temp = temp;
}
public String getWD() {
return WD;
}
@JsonProperty("WD")
public void setWD(String wD) {
WD = wD;
}
public String getWS() {
return WS;
}
@JsonProperty("WS")
public void setWS(String wS) {
WS = wS;
}
public String getSD() {
return SD;
}
@JsonProperty("SD")
public void setSD(String sD) {
SD = sD;
}
public String getWSE() {
return WSE;
}
@JsonProperty("WSE")
public void setWSE(String wSE) {
WSE = wSE;
}
public String getTime() {
return time;
}
@JsonProperty("time")
public void setTime(String time) {
this.time = time;
}
public String getIsRadar() {
return isRadar;
}
@JsonProperty("isRadar")
public void setIsRadar(String isRadar) {
this.isRadar = isRadar;
}
public String getRadar() {
return Radar;
}
@JsonProperty("Radar")
public void setRadar(String radar) {
Radar = radar;
}
public String getNjd() {
return njd;
}
@JsonProperty("njd")
public void setNjd(String njd) {
this.njd = njd;
}
public String getQy() {
return qy;
}
@JsonProperty("qy")
public void setQy(String qy) {
this.qy = qy;
}
}
4、实现JacksonRequest
public class JacksonRequest<T> extends Request<T>{
private final Listener<T> mListener;
private Class<T> mClass;
private static ObjectMapper objectMapper = new ObjectMapper();
public JacksonRequest(int method, String url, Class<T> clazz, Listener<T> listener, ErrorListener errorListener) {
super(method, url, errorListener);
// TODO Auto-generated constructor stub
mListener = listener;
mClass = clazz;
}
public JacksonRequest(String url, Class<T> clazz, Listener<T> listener, ErrorListener errorListener){
this(Method.GET, url, clazz, listener, errorListener);
}
@Override
protected Response<T> parseNetworkResponse(NetworkResponse response) {
// TODO Auto-generated method stub
try {
String jsonString = new String(response.data, HttpHeaderParser.parseCharset(response.headers));
return Response.success(objectMapper.readValue(jsonString, mClass), HttpHeaderParser.parseCacheHeaders(response));
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
return Response.error(new ParseError(e));
} catch (JsonParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (JsonMappingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
@Override
protected void deliverResponse(T response) {
// TODO Auto-generated method stub
mListener.onResponse(response);
}
}
5、Jackson的使用，和StringRequest的使用是一样的。
public class JacksonActivity extends Activity {
private RequestQueue requestQueue;
private TextView mTvShow;
private String result = "";
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_jackson);
initView();
}
public void initView(){
mTvShow = (TextView) findViewById(R.id.tv_jackson);
requestQueue = Volley.newRequestQueue(getBaseContext());
requestQueue.add(jacksonRequest);
requestQueue.start();
}
private JacksonRequest<Weather> jacksonRequest = new JacksonRequest<Weather>("http://www.weather.com.cn/data/sk/101010100.html",
Weather.class,
new Response.Listener<Weather>() {
@Override
public void onResponse(Weather response) {
// TODO Auto-generated method stub
WeatherInfo info = response.getWeatherinfo();
result += info.getCity() + "\n" + info.getTemp() + "\n" +info.getTime();
mTvShow.setText(result);
}
}, new Response.ErrorListener(){
@Override
public void onErrorResponse(VolleyError error) {
// TODO Auto-generated method stub
mTvShow.setText(error.toString());
}
});
}
6、不要忘记加入网络访问权限
<uses-permission android:name="android.permission.INTERNET"/>
7、参考博文：
http://blog.csdn.net/guolin_blog/article/details/17482095/