Volley 擅长用于填充 UI 的 RPC 类型的操作，例如
获取一页搜索结果作为结构化数据。它集成了
轻松使用任何协议，开箱即用，支持原始
字符串、图像和 JSON。通过提供内置支持
您需要的功能，Volley 将您从编写样板代码和
允许您专注于特定于您的应用的逻辑。
如何使用 Volley 创建通用 GET/POST 方法。
创建应用程序类
Android 中的 Application 类是 Android 中的基类
包含所有其他组件（例如活动和服务）的应用
public class MyApplication extends Application {
public static final String TAG = MyApplication.class
.getSimpleName();
private RequestQueue mRequestQueue;
private static MyApplication mInstance;
@Override
public void onCreate() {
super.onCreate();
mInstance = this;
}
public static synchronized MyApplication getInstance() {
return mInstance;
}
public RequestQueue getRequestQueue() {
if (mRequestQueue == null) {
mRequestQueue = Volley.newRequestQueue(getApplicationContext());
}
return mRequestQueue;
}
public <T> void addToRequestQueue(Request<T> req, String tag) {
// set the default tag if tag is empty
req.setTag(TextUtils.isEmpty(tag) ? TAG : tag);
getRequestQueue().add(req);
}
public <T> void addToRequestQueue(Request<T> req) {
req.setTag(TAG);
getRequestQueue().add(req);
}
public void cancelPendingRequests(Object tag) {
if (mRequestQueue != null) {
mRequestQueue.cancelAll(tag);
}
}
}
确保添加此 Manifest 部分。
<application
.....
android:name=".MyApplication"
>
现在，您需要创建 Singleton 类。
单例模式说只定义一个只有一个的类
实例并提供对其的全局访问点。
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)
{
mRequestQueue = Volley.newRequestQueue(mCtx.getApplicationContext());
}
return mRequestQueue;
}
public <T> void addToRequestQueue(Request<T> req)
{
getRequestQueue().add(req);
}
}
现在通用类
public class VolleyUtils {
public static void GET_METHOD(Context context, String url, final VolleyResponseListener listener)
{
// Initialize a new StringRequest
StringRequest stringRequest = new StringRequest(
Request.Method.GET,
url,
new Response.Listener<String>() {
@Override
public void onResponse(String response) {
listener.onResponse(response);
}
},
new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
listener.onError(error.toString());
}
})
{
};
// Access the RequestQueue through singleton class.
MySingleton.getInstance(context).addToRequestQueue(stringRequest);
}
public static void POST_METHOD(Context context, String url,final Map<String,String> getParams, final VolleyResponseListener listener)
{
// Initialize a new StringRequest
StringRequest stringRequest = new StringRequest(
Request.Method.POST,
url,
new Response.Listener<String>() {
@Override
public void onResponse(String response) {
listener.onResponse(response);
}
},
new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
listener.onError(error.toString());
}
})
{
/**
* Passing some request headers
* */
@Override
public Map<String, String> getHeaders() throws AuthFailureError {
HashMap<String, String> headers = new HashMap<String, String>();
getParams.put("Content-Type", "application/json; charset=utf-8");
return headers;
}
};
// Access the RequestQueue through singleton class.
MySingleton.getInstance(context).addToRequestQueue(stringRequest);
}
}
现在您应该创建 Interface 。
一个类实现一个接口，从而继承抽象
接口的方法。
/**
* Created by Intellij Amiyo on 10-06-2017.
* Please follow standard Java coding conventions.
* http://source.android.com/source/code-style.html
*/
public interface VolleyResponseListener {
void onError(String message);
void onResponse(Object response);
}
如何打电话
public void _loadAPI()
{
//GET
String URL_GET = "";
VolleyUtils.GET_METHOD(MainActivity.this, URL_GET, new VolleyResponseListener() {
@Override
public void onError(String message) {
System.out.println("Error" + message);
}
@Override
public void onResponse(Object response) {
System.out.println("SUCCESS" + response);
}
});
//POST
String URL_POST=" ";
VolleyUtils.POST_METHOD(MainActivity.this, URL_POST,getParams(), new VolleyResponseListener() {
@Override
public void onError(String message) {
System.out.println("Error" + message);
}
@Override
public void onResponse(Object response) {
System.out.println("SUCCESS" + response);
}
});
}
public Map<String,String> getParams()
{
Map<String, String> params = new HashMap<String, String>();
params.put("YOUR_KEY", "VALUE");
return params;
}
对于演示，您应该下载Volley-Common-Method