在Android開發中網絡請求是最常用的操作之一， Android SDK中對HTTP(超文本傳輸協議)也提供了很好的支持，這裏包括兩種接口:
1、HttpURLConnection，可以實現簡單的基於URL請求、響應功能；
2、HttpClient，使用起來更方面更強大，使用方便，但是不易於擴展(不推薦使用)。
但在android API23的SDK中Google將HttpClient移除了。Google建議使用httpURLconnection進行網絡訪問操作。
HttpURLconnection是基於http協議的，支持get，post，put，delete等各種請求方式，最常用的就是get和post，下面針對這兩種請求方式進行講解。
以下是自己對HttpURLconnection進行了封裝。
HttpUtils代碼：
public class HttpUtils {
private static ExecutorService threadPool = Executors.newCachedThreadPool();
private static final int HTTP_CONNECT_TIME=5000;
private static final int HTTP_READ_TIME=10000;
/**
* GET請求返回數據會解析成字符串String
* @param context context
* @param urlPath 請求的路徑
* @param listener listener
*/
public static void doGet(final Context context, final String urlPath,
final StringCallbackListener listener) {
threadPool.execute(new Runnable() {
@Override
public void run() {
URL url;
HttpURLConnection httpURLConnection = null;
try {
// 根據URL地址創建URL對象
url = new URL(urlPath);
// 獲取HttpURLConnection對象
httpURLConnection = ( HttpURLConnection ) url.openConnection();
// 設置請求方式，默認爲GET
httpURLConnection.setRequestMethod("GET");
// 設置連接超時
httpURLConnection.setConnectTimeout(HTTP_CONNECT_TIME);
// 設置讀取超時
httpURLConnection.setReadTimeout(HTTP_READ_TIME);
// 響應碼爲200表示成功
if ( httpURLConnection.getResponseCode() == 200 ) {
// 獲取網絡的輸入流
InputStream is = httpURLConnection.getInputStream();
BufferedReader bf = new BufferedReader(new InputStreamReader(is, "UTF-8"));
StringBuffer buffer = new StringBuffer();
String line = "";
while ( (line = bf.readLine()) != null ) {
buffer.append(line);
}
is.close();
bf.close();
new ResponseCall(context, listener).doSuccess(buffer.toString());
} else {
new ResponseCall(context, listener).doFail(
new NetworkErrorException("response error code:" +
httpURLConnection.getResponseCode()));
}
} catch ( MalformedURLException e ) {
if ( listener != null ) {
new ResponseCall(context, listener).doFail(e);
}
} catch ( IOException e ) {
if ( listener != null ) {
new ResponseCall(context, listener).doFail(e);
}
} finally {
if ( httpURLConnection != null ) {
// 釋放資源
httpURLConnection.disconnect();
}
}
}
});
}
/**
* GET請求返回數據會解析成byte[]數組
* @param context context
* @param urlPath 請求的url
* @param listener 回調監聽
*/
public static void doGet(final Context context, final String urlPath,
final BytesCallbackListener listener) {
threadPool.execute(new Runnable() {
@Override
public void run() {
URL url = null;
HttpURLConnection httpURLConnection = null;
try {
// 根據URL地址創建URL對象
url = new URL(urlPath);
// 獲取HttpURLConnection對象
httpURLConnection = ( HttpURLConnection ) url.openConnection();
// 設置請求方式，默認爲GET
httpURLConnection.setRequestMethod("GET");
// 設置連接超時
httpURLConnection.setConnectTimeout(HTTP_CONNECT_TIME);
// 設置讀取超時
httpURLConnection.setReadTimeout(HTTP_READ_TIME);
// 響應碼爲200表示成功，否則失敗。
if ( httpURLConnection.getResponseCode() != 200 ) {
new ResponseCall(context, listener).doFail(
new NetworkErrorException("response error code:" +
httpURLConnection.getResponseCode()));
} else {
// 獲取網絡的輸入流
InputStream is = httpURLConnection.getInputStream();
// 讀取輸入流中的數據
BufferedInputStream bis = new BufferedInputStream(is);
ByteArrayOutputStream baos = new ByteArrayOutputStream();
byte[] bytes = new byte[1024];
int len = -1;
while ( (len = bis.read(bytes)) != -1 ) {
baos.write(bytes, 0, len);
}
bis.close();
is.close();
new ResponseCall(context, listener).doSuccess(baos.toByteArray());
}
} catch ( MalformedURLException e ) {
if ( listener != null ) {
new ResponseCall(context, listener).doFail(e);
}
} catch ( IOException e ) {
if ( listener != null ) {
new ResponseCall(context, listener).doFail(e);
}
} finally {
if ( httpURLConnection != null ) {
httpURLConnection.disconnect();
}
}
}
});
}
/**
* GET請求返回數據會解析成字符串 String
* @param context context
* @param urlPath 請求的路徑
* @param listener 回調監聽
* @param params 參數列表
*/
public static void doPost(final Context context,
final String urlPath, final StringCallbackListener listener,
final Map<String, Object> params) {
final StringBuffer buffer = new StringBuffer();
for (String key : params.keySet()) {
if(buffer.length()!=0){
buffer.append("&");
}
buffer.append(key).append("=").append(params.get(key));
}
threadPool.execute(new Runnable() {
@Override
public void run() {
URL url;
HttpURLConnection httpURLConnection = null;
try {
url = new URL(urlPath);
httpURLConnection = ( HttpURLConnection ) url.openConnection();
httpURLConnection.setRequestProperty("accept", "*/*");
httpURLConnection.setRequestProperty("connection", "Keep-Alive");
httpURLConnection.setRequestProperty("Content-Length", String
.valueOf(buffer.length()));
httpURLConnection.setRequestMethod("POST");
httpURLConnection.setConnectTimeout(HTTP_CONNECT_TIME);
httpURLConnection.setReadTimeout(HTTP_READ_TIME);
// 設置運行輸入
httpURLConnection.setDoInput(true);
// 設置運行輸出
httpURLConnection.setDoOutput(true);
PrintWriter printWriter = new PrintWriter(httpURLConnection.getOutputStream());
// 發送請求參數
printWriter.write(buffer.toString());
// flush輸出流的緩衝
printWriter.flush();
printWriter.close();
if ( httpURLConnection.getResponseCode() == 200 ) {
// 獲取網絡的輸入流
InputStream is = httpURLConnection.getInputStream();
BufferedReader bf = new BufferedReader(new InputStreamReader(is, "UTF-8"));
//最好在將字節流轉換爲字符流的時候 進行轉碼
StringBuffer buffer = new StringBuffer();
String line = "";
while ( (line = bf.readLine()) != null ) {
buffer.append(line);
}
bf.close();
is.close();
new ResponseCall(context, listener).doSuccess(buffer.toString());
} else {
new ResponseCall(context, listener).doFail(
new NetworkErrorException("response error code:" +
httpURLConnection.getResponseCode()));
}
} catch ( MalformedURLException e ) {
if ( listener != null ) {
new ResponseCall(context, listener).doFail(e);
}
} catch ( IOException e ) {
if ( listener != null ) {
new ResponseCall(context, listener).doFail(e);
}
} finally {
if ( httpURLConnection != null ) {
httpURLConnection.disconnect();
}
}
}
});
}
/**
* GET請求 返回數據會解析成Byte[]數組
* @param context context
* @param urlPath 請求的路徑
* @param listener 回調監聽
* @param params 參數列表
*/
public static void doPost(final Context context,
final String urlPath, final BytesCallbackListener listener,
final Map<String, Object> params) {
final StringBuffer buffer = new StringBuffer();
for (String key : params.keySet()) {
if(buffer.length()!=0){
buffer.append("&");
}
buffer.append(key).append("=").append(params.get(key));
}
threadPool.execute(new Runnable() {
@Override
public void run() {
URL url;
HttpURLConnection httpURLConnection = null;
try {
url = new URL(urlPath);
httpURLConnection = ( HttpURLConnection ) url.openConnection();
httpURLConnection.setRequestProperty("accept", "*/*");
httpURLConnection.setRequestProperty("connection", "Keep-Alive");
httpURLConnection.setRequestProperty("Content-Length", String
.valueOf(buffer.length()));
httpURLConnection.setRequestMethod("POST");
httpURLConnection.setConnectTimeout(HTTP_CONNECT_TIME);
httpURLConnection.setReadTimeout(HTTP_READ_TIME);
// 設置運行輸入
httpURLConnection.setDoInput(true);
// 設置運行輸出
httpURLConnection.setDoOutput(true);
PrintWriter printWriter = new PrintWriter(httpURLConnection.getOutputStream());
// 發送請求參數
printWriter.write(buffer.toString());
// flush輸出流的緩衝
printWriter.flush();
printWriter.close();
if ( httpURLConnection.getResponseCode() == 200 ) {
// 獲取網絡的輸入流
InputStream is = httpURLConnection.getInputStream();
// 讀取輸入流中的數據
BufferedInputStream bis = new BufferedInputStream(is);
ByteArrayOutputStream baos = new ByteArrayOutputStream();
byte[] bytes = new byte[1024];
int len = -1;
while ( (len = bis.read(bytes)) != -1 ) {
baos.write(bytes, 0, len);
}
bis.close();
is.close();
// 響應的數據
new ResponseCall(context, listener).doSuccess(baos.toByteArray());
} else {
new ResponseCall(context, listener).doFail(
new NetworkErrorException("response error code:" +
httpURLConnection.getResponseCode()));
}
} catch ( MalformedURLException e ) {
if ( listener != null ) {
new ResponseCall(context, listener).doFail(e);
}
} catch ( IOException e ) {
if ( listener != null ) {
new ResponseCall(context, listener).doFail(e);
}
} finally {
if ( httpURLConnection != null ) {
httpURLConnection.disconnect();
}
}
}
});
}
}
ResponseCall<T> 代碼：
public class ResponseCall<T> {
private static final int FAIL = 0;
private static final int SUCCESS = 1;
private Handler mHandler;
public ResponseCall(Context context, final BytesCallbackListener listener) {
Looper looper = context.getMainLooper();
mHandler = new Handler(looper) {
@Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
if ( msg.what == FAIL ) {
//成功
listener.onSuccess(( byte[] ) msg.obj);
} else if ( msg.what == SUCCESS ) {
//失敗
listener.onError(( Exception ) msg.obj);
}
}
};
}
public ResponseCall(Context context, final StringCallbackListener listener) {
Looper looper = context.getMainLooper();
mHandler = new Handler(looper) {
@Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
if ( msg.what == FAIL ) {
//成功
listener.onSuccess(msg.obj.toString());
} else if ( msg.what == SUCCESS ) {
//失敗
listener.onError(( Exception ) msg.obj);
}
}
};
}
public void doSuccess(T response) {
Message message = Message.obtain();
message.obj = response;
message.what = FAIL;
mHandler.sendMessage(message);
}
public void doFail(Exception e) {
Message message = Message.obtain();
message.obj = e;
message.what = SUCCESS;
mHandler.sendMessage(message);
}
}
BytesCallbackListener:
public interface BytesCallbackListener {
// 網絡請求成功
void onSuccess(byte[] response);
// 網絡請求失敗
void onError(Exception e);
}
StringCallbackListener:
public interface StringCallbackListener {
// 網絡請求成功
void onSuccess(String response);
// 網絡請求失敗
void onError(Exception e);
}