概述:
Volley提供的功能
簡單的講,提供瞭如下主要的功能:
1、封裝了的異步的RESTful 請求API;
2、一個優雅和穩健的請求隊列;
3、一個可擴展的架構,它使開發人員能夠實現自定義的請求和響應處理機制;
4、能夠使用外部HTTP Client庫;
5、緩存策略;
6、自定義的網絡圖像加載視圖(NetworkImageView,ImageLoader等);
Volley也有兩種加載方式DoGet和DoPost。
代碼:
將volley框架單例封裝成一個方法:
/**
* Created by Administrator on 2015/9/14.
* 單例模式的RequestQueue,可以防止內存溢出
*/
public class MySingleTon {
private static MySingleTon mInstance;
private RequestQueue mRequestQueue;
private static Context mCtx;
private MySingleTon(Context context) {
mCtx = context;
mRequestQueue = getRequestQueue();
}
public static synchronized MySingleTon getInstance(Context context) {
if (mInstance == null) {
mInstance = new MySingleTon(context);
}
return mInstance;
}
public RequestQueue getRequestQueue() {
if (mRequestQueue == null) {
// getApplicationContext() is key, it keeps you from leaking the
// Activity or BroadcastReceiver if someone passes one in.
mRequestQueue = Volley.newRequestQueue(mCtx.getApplicationContext());
}
return mRequestQueue;
}
public <T> void addToRequestQueue(Request<T> req) {
getRequestQueue().add(req);
}
}
DoGet方式:
private void volleyDoGet() {
//RequestQueue queue = Volley.newRequestQueue(getApplicationContext());
//response的監聽有兩種,一個是正確響應的監聽,一個是錯誤響應的監聽,當沒有網絡時,網絡連接會出錯
StringRequest request = new StringRequest(Request.Method.GET, "http://www.360.com", new Response.Listener<String>() {
@Override
public void onResponse(String response) {
mTextViewContent.setText(response);
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
mTextViewContent.setText("網絡連接錯誤!");
}
});
MySingleTon.getInstance(getApplicationContext()).addToRequestQueue(request);
}
DoPost方式:
private void volleyDoPost() {
//RequestQueue queue = Volley.newRequestQueue(getApplicationContext());
StringRequest request = new StringRequest(Request.Method.POST, "http://192.168.0.30:8080/MyWebTest/MyTestServerlet", new Response.Listener<String>() {
@Override
public void onResponse(String response) {
mTextViewContent.setText(response);
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
mTextViewContent.setText("網絡連接錯誤!");
}
}){
@Override
protected Map<String, String> getParams() throws AuthFailureError {
HashMap<String,String> map = new HashMap<>();
map.put("username","zhaoliu");
return map;
}
};
MySingleTon.getInstance(getApplicationContext()).addToRequestQueue(request);
}
結果演示: