封裝android http框架
阿新 • • 發佈：2019-01-26
目前有幾個開源的android http框架，比如volley、android-async-http，對於初學者來說聽上去可能很高大上，實際就是對常用的網路請求程式碼做了一下封裝，看過一套框架原始碼以後就會感覺沒那麼複雜，我們完全可以自己封裝一個http框架。
需求分析：
1. 支援http協議：GET、POST、PUT、DELETE
2. 支援apache的HttpClient和原生的HttpURLConnection兩種請求方式
3. 非同步請求（使用AsyncTask或Thread+Handler）
4. 支援多執行緒上傳下載（使用RandomAccessFile）
5. 請求錯誤統一處理（可自定義Exception）
6. 預處理服務端返回的資料
7. 上傳下載進度更新
8. 支援斷點續傳
9. 隨時取消網路請求
10. 關聯activity（activity被回收時，請求應終止）
類圖：
時序圖：
關鍵程式碼：
public class RequestTask extends AsyncTask<Object, Integer, Object>{
private Request mRequest;
public RequestTask(Request request){
mRequest = request;
}
@Override
protected Object doInBackground(Object... params) {
try {
/* HttpClient請求方式
HttpResponse httpResponse = HttpClientUtils.request(mRequest);
return mRequest.mCallback.handleResponse(httpResponse, new ProgressCallback() {
@Override
public void onProgressUpdate(int curPos, int contentLength) {
publishProgress(curPos, contentLength);
}
});
*/ public class HttpClientUtils {
public static HttpResponse request(Request request) throws Exception {
switch (request.mRequestMethod){
case GET:
return get(request);
case POST:
return post(request);
default:
throw new IllegalStateException("The request's request method is illegal");
}
}
public static HttpResponse get(Request request) throws Exception{
HttpClient httpClient = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(request.mUrl);
addHeader(httpGet, request.mHeaderMap);
return httpClient.execute(httpGet);
}
public static HttpResponse post(Request request) throws Exception{
HttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(request.mUrl);
httpPost.setEntity(new StringEntity(request.mPostContent));
addHeader(httpPost, request.mHeaderMap);
return httpClient.execute(httpPost);
}
public static void addHeader(HttpUriRequest httpUriRequest, Map<String, String> headers){
if(headers == null){
return;
}
for (Map.Entry<String, String> entry : headers.entrySet()) {
httpUriRequest.addHeader(entry.getKey(), entry.getValue());
}
}
}public class HttpUrlConnUtils {
public static InputStream request(Request request){
switch (request.mRequestMethod){
case GET:
return get(request);
case POST:
return post(request);
}
return null;
}
private static InputStream get(Request request) {
try {
URL url = new URL(request.mUrl);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("GET");
conn.setConnectTimeout(5000);
addHeader(conn, request.mHeaderMap);
return conn.getInputStream();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
private static InputStream post(Request request) {
try {
URL url = new URL(request.mUrl);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("POST");
conn.setConnectTimeout(5000);
addHeader(conn, request.mHeaderMap);
conn.setDoInput(true);
if(!TextUtils.isEmpty(request.mPostContent)){
conn.setDoOutput(true);
OutputStreamWriter osw = new OutputStreamWriter(conn.getOutputStream(), "utf-8");
BufferedWriter bw = new BufferedWriter(osw);
bw.write(request.mPostContent);
bw.flush();
}
return conn.getInputStream();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
private static void addHeader(HttpURLConnection conn, Map<String, String> headerMap) {
if(headerMap == null){
return;
}
conn.addRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0; .NET CLR 2.0.50727)");
for(Map.Entry<String, String> entry : headerMap.entrySet()){
conn.addRequestProperty(entry.getKey(), entry.getValue());
}
}
}public abstract class AbstractCallback implements ICallback{
public String path;
//處理HttpURLConnection請求方式的返回流
@Override
public Object handleResponse(InputStream inputStream, ProgressCallback callback) {
try {
if(!TextUtils.isEmpty(path)){
FileOutputStream fos = new FileOutputStream(path);
byte[] b = new byte[1024];
int len;
while((len = inputStream.read(b)) != -1){
fos.write(b, 0, len);
}
fos.flush();
inputStream.close();
fos.close();
return IOUtils.readFromFile(path);
}else{
return IOUtils.inputStream2Str(inputStream);
}
} catch (FileNotFoundException e) {
e.printStackTrace();
return e;
} catch (IOException e) {
e.printStackTrace();
return e;
}
}
//處理HttpClient請求方式的返回實體
public Object handleResponse(HttpResponse httpResponse, ProgressCallback progressCallback){
try {
HttpEntity httpEntity = httpResponse.getEntity();
int statusCode = httpResponse.getStatusLine().getStatusCode();
switch (statusCode){
case HttpStatus.SC_OK:
if(!TextUtils.isEmpty(path)){
FileOutputStream fos = new FileOutputStream(path);
InputStream is = httpEntity.getContent();
byte[] b = new byte[1024];
int len;
int curPos = 0;
int contentLength = (int) httpEntity.getContentLength();
while((len = is.read(b)) != -1){
curPos += len;
fos.write(b, 0, len);
if(progressCallback != null){
progressCallback.onProgressUpdate(curPos, contentLength);
}
}
fos.flush();
is.close();
fos.close();
return bindData(path);
}else{
return bindData(EntityUtils.toString(httpEntity));
}
}
} catch (IOException e) {
e.printStackTrace();
return e;
}
return null;
}
//子類需複寫該方法
protected Object bindData(String content) {
return content;
}
public AbstractCallback setPath(String path){
this.path = path;
return this;
}
}public abstract class StringCallback extends AbstractCallback{
@Override
protected Object bindData(String content) {
if(!TextUtils.isEmpty(path)){
return IOUtils.readFromFile(path);
}else{
return content;
}
}
}public class IOUtils {
public static String readFromFile(String path){
ByteArrayOutputStream outputStream = null;
FileInputStream fis = null;
try {
outputStream = new ByteArrayOutputStream(4 * 1024);
File file = new File(path);
fis = new FileInputStream(file);
byte[] b = new byte[1024];
int len;
while((len = fis.read(b)) != -1){
outputStream.write(b, 0, len);
}
outputStream.flush();
return new String(outputStream.toByteArray());
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
if(outputStream != null){
try {
outputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if(fis != null){
try {
fis.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return null;
}
public static String inputStream2Str(InputStream is){
try {
String str;
StringBuffer sb = new StringBuffer();
BufferedReader br = new BufferedReader(new InputStreamReader(is, "utf-8"));
while((str = br.readLine()) != null){
sb.append(str);
}
return sb.toString();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return "";
}
}說明：
1.如需要實時顯示當前上傳下載進度的百分比，就需要有服務端返回實體的總長度。但拿到HttpResponse的HttpEntity時，呼叫getContentLength()結果卻是-1。解決方案：
request之前新增header，偽裝成瀏覽器:
httpGet.addHeader("User-Agent", "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0; .NET CLR 2.0.50727)");2.關於多執行緒分段下載和斷點續傳的實現，後續部落格會有更新。