使用Android Volley网络请求框架请求数据步骤

1、需要导入volley的jar包

2、使用实例

使用Volley必须在AndroidManifest.xml中添加 android.permission.INTERNET权限，使用Volley时Google建议创建volley单例工具类

package cn.hnshangyu.officeautomationsystem.net;

import android.content.Context;
import android.graphics.Bitmap;
import android.support.v4.util.LruCache;

import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.toolbox.ImageLoader;
import com.android.volley.toolbox.Volley;

/**
* Created by Administrator on 2016/10/17
*/
public class VolleySingleton {
private static VolleySingleton volleySingleton;
private RequestQueue mRequestQueue;
private ImageLoader mImageLoader;
private Context mContext;

public VolleySingleton(Context context) {
this.mContext = context;
mRequestQueue = getRequestQueue();
mImageLoader = new ImageLoader(mRequestQueue,
new ImageLoader.ImageCache() {
private final LruCache<String, Bitmap> cache = new LruCache<String, Bitmap>(20);

@Override
public Bitmap getBitmap(String url) {
return cache.get(url);
}

@Override
public void putBitmap(String url, Bitmap bitmap) {
cache.put(url, bitmap);
}
});
}

public static synchronized VolleySingleton getVolleySingleton(Context context) {
if (volleySingleton == null) {
volleySingleton = new VolleySingleton(context);
}
return volleySingleton;
}

public RequestQueue getRequestQueue() {
if (mRequestQueue == null) {
mRequestQueue = Volley.newRequestQueue(mContext.getApplicationContext());
}
return mRequestQueue;
}

public <T> void addToRequestQueue(Request<T> req) {
getRequestQueue().add(req);
}

public ImageLoader getImageLoader() {
return mImageLoader;
}
}

3、封装Response.Listener

package cn.hnshangyu.officeautomationsystem.net;

import com.android.volley.Response;

import org.json.JSONException;
import org.json.JSONObject;

/**
* Created by Administrator on 2016/10/27.
* <p>
* 请求服务器获得的数据
*/

public abstract class DefaultListener<T> implements Response.Listener<String> {

@Override
public void onResponse(String response) {

try {
JSONObject jsonObject = new JSONObject(response);
String code = jsonObject.optString("retcode");
String msg = "";
if (code.equals("0")) {
String data = "";
if (jsonObject.has("data")) {
data = jsonObject.optString("data");
onSuccess(0, data);
} else {
onSuccess(0, "");
}
} else {
if (jsonObject.has("mesg")) {
msg = jsonObject.optString("mesg");
} else {
msg = "对不起，服务器返回数据有错误！";
}
onResponseFailed(1, msg, new RuntimeException(msg));
}
} catch (JSONException e) {

e.printStackTrace();
onResponseFailed(2, "数据解析失败！", e);
}
}

public abstract void onSuccess(int code, String data);

public abstract void onResponseFailed(int code, String errorMsg, Exception e);
}

4、封装Response.ErrorListener

package cn.hnshangyu.officeautomationsystem.net;

import com.android.volley.AuthFailureError;
import com.android.volley.NetworkError;
import com.android.volley.NoConnectionError;
import com.android.volley.ParseError;
import com.android.volley.Response;
import com.android.volley.ServerError;
import com.android.volley.TimeoutError;
import com.android.volley.VolleyError;

/**
* Created by Administrator on 2016/10/27.
* 请求数据错误信息
*/

public abstract class DefaultErrorListener implements Response.ErrorListener {
@Override
public void onErrorResponse(VolleyError volleyError) {
String errorMesg = "";
if (volleyError instanceof NetworkError) {
errorMesg = "网络连接失败";
} else if (volleyError instanceof ServerError) {
errorMesg = "服务器的响应错误";
} else if (volleyError instanceof AuthFailureError) {
errorMesg = "请求身份验证错误";
} else if (volleyError instanceof ParseError) {
errorMesg = "服务器返回数据有误";
} else if (volleyError instanceof NoConnectionError) {
errorMesg = "网络连接失败";
} else if (volleyError instanceof TimeoutError) {
errorMesg = "服务器太忙或网络延迟";
}
onErrorResponseFailed(errorMesg, volleyError);
}

protected abstract void onErrorResponseFailed(String errorMesg, VolleyError volleyError);
}

5、构建网络请求接口

package cn.hnshangyu.officeautomationsystem.net;

import android.content.Context;

import com.android.volley.Response;

import java.util.Map;

/**
* Created by Administrator on 2016/10/27.
*/

public interface VolleyHttpClient {
String HOST = "http://soft.********.org/";
/**
* 通讯录
*/
String AppSysUserController = HOST + "/app/user/treeDept.json";

/**
* 得到好友通讯录
*
* @param tag
* @param context
* @param map
* @param listener
* @param errorListener
*/
void getAppSysUserController(String tag, Context context, Map<String, String> map, DefaultListener<String> listener,
DefaultErrorListener errorListener);

}

6、构建HttpApi使用类 我们一般使用Post请求

package cn.hnshangyu.officeautomationsystem.net;

import android.content.Context;

import com.android.volley.AuthFailureError;
import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.toolbox.StringRequest;

import java.util.Map;

/**
* Created by Administrator on 2016/10/27.
*/

public class VolleyHttpApi implements VolleyHttpClient {

private StringRequest stringRequest;
private static VolleyHttpApi mInstance;
private RequestQueue mRequestQueue;

public static VolleyHttpApi getInstance() {
if (mInstance == null) {
synchronized (VolleyHttpApi.class) {
if (mInstance == null)
mInstance = new VolleyHttpApi();
}
}
return mInstance;
}

/**
* POST 请求网络
*
* @param tag
* @param context
* @param url
* @param map
* @param listener
* @param errorListener
*/
private void getStringRequest(String tag, Context context, String url, final Map<String, String> map, DefaultListener<String> listener, DefaultErrorListener errorListener) {
stringRequest = new StringRequest(Request.Method.POST, url, listener, errorListener) {
@Override
protected Map<String, String> getParams() throws AuthFailureError {
return map;
}
};

VolleySingleton volleySingleton = VolleySingleton.getVolleySingleton(context);
//获得队列
mRequestQueue = volleySingleton.getRequestQueue();
//添加tag
stringRequest.setTag(tag);
//将StringRequest对象添加进RequestQueue请求队列中
mRequestQueue.add(stringRequest);

}

/**
* Activity的onStop()方法
* 取消网络请求
*
* @param tag
*/
public void cancelQueue(String tag) {
if (null != mRequestQueue) {
mRequestQueue.cancelAll(tag);
}
}

/**
* 得到好友通讯录
*
* @param tag
* @param context
* @param map
* @param listener
* @param errorListener
*/
@Override
public void getAppSysUserController(String tag, Context context, Map<String, String> map, DefaultListener<String> listener, DefaultErrorListener errorListener) {
getStringRequest(tag, context, AppSysUserController, map, listener, errorListener);
}
}

7、在BaseActivity的onCreate方法中初始化网络请求

/**
* 初始化网络请求
*/
protected VolleyHttpApi volleyHttp;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
synchronized (activities) {
activities.add(this);
}
mActivity = this;
mContext = this;

volleyHttp = VolleyHttpApi.getInstance();

}

8、在需要的地方请求数据

private void initData() {
HashMap<String, String> map = new HashMap<>();
map.put("sessionId", "402880ec57fb58460157fb604cbc0000");
volleyHttp.getAppSysUserController(tag, mContext, map, new DefaultListener<String>() {
@Override
public void onSuccess(int code, String data) {
try {
JSONObject jsonObject = new JSONObject(data);
String dept = jsonObject.optString("dept");
LogUtil.i(dept);
} catch (JSONException e) {
e.printStackTrace();
}
}

@Override
public void onResponseFailed(int code, String errorMsg, Exception e) {
UIUtils.showToast(errorMsg);
}
}, new DefaultErrorListener() {
@Override
protected void onErrorResponseFailed(String errorMesg, VolleyError volleyError) {
UIUtils.showToast(errorMesg);
}
});
}

9、取消网络连接

@Override
protected void onStop() {
super.onStop();
if (null != volleyHttp)
volleyHttp.cancelQueue(tag);
}