android常用代碼總結（二）
今天起了一個大早（相對于我以前），時不我待，沒有多少時間可以浪費了，繼續總結
先說說兩種方式的網絡操作吧,當然這些代碼我都是看過很多類似的代碼之后,覺得總結得非常之好的,拿來mark一下
一.java.net包中的HttpUrlConnection
// Get方式請求
public static void requestByGet() throws Exception {
String path = "https://reg.163.com/logins.jsp?id=helloworld&pwd=android";
//新建一個URL對象
URL url = new URL(path);
//打開一個HttpURLConnection連接
HttpURLConnection urlConn = (HttpURLConnection) url.openConnection();
//設置連接超時時間
urlConn.setConnectTimeout(5 * 1000);
//開始連接
urlConn.connect();
//判斷請求是否成功
if (urlConn.getResponseCode() == HTTP_200) {
//獲取返回的數據
byte[] data = readStream(urlConn.getInputStream());
Log.i(TAG_GET, "Get方式請求成功，返回數據如下：");
Log.i(TAG_GET, new String(data, "UTF-8"));
} else {
Log.i(TAG_GET, "Get方式請求失敗");
}
//關閉連接
urlConn.disconnect();
}
Post方式
// Post方式請求
public static void requestByPost() throws Throwable {
String path = "https://reg.163.com/logins.jsp";
//請求的參數轉換為byte數組
String params = "id=" + URLEncoder.encode("helloworld", "UTF-8")
+ "&pwd=" + URLEncoder.encode("android", "UTF-8");
byte[] postData = params.getBytes();
//新建一個URL對象
URL url = new URL(path);
//打開一個HttpURLConnection連接
HttpURLConnection urlConn = (HttpURLConnection) url.openConnection();
//設置連接超時時間
urlConn.setConnectTimeout(5 * 1000);
// Post請求必須設置允許輸出
urlConn.setDoOutput(true);
// Post請求不能使用緩存
urlConn.setUseCaches(false);
//設置為Post請求
urlConn.setRequestMethod("POST");
urlConn.setInstanceFollowRedirects(true);
//配置請求Content-Type
urlConn.setRequestProperty("Content-Type",
"application/x-www-form-urlencode");
//開始連接
urlConn.connect();
//發送請求參數
DataOutputStream dos = new DataOutputStream(urlConn.getOutputStream());
dos.write(postData);
dos.flush();
dos.close();
//判斷請求是否成功
if (urlConn.getResponseCode() == HTTP_200) {
//獲取返回的數據
byte[] data = readStream(urlConn.getInputStream());
Log.i(TAG_POST, "Post請求方式成功，返回數據如下：");
Log.i(TAG_POST, new String(data, "UTF-8"));
} else {
Log.i(TAG_POST, "Post方式請求失敗");
}
}
二.org.apache.http包中的HttpGet和HttpPost類
get方式
// HttpGet方式請求
public static void requestByHttpGet() throws Exception {
String path = "https://reg.163.com/logins.jsp?id=helloworld&pwd=android";
//新建HttpGet對象
HttpGet httpGet = new HttpGet(path);
//獲取HttpClient對象
HttpClient httpClient = new DefaultHttpClient();
//獲取HttpResponse實例
HttpResponse httpResp = httpClient.execute(httpGet);
//判斷是夠請求成功
if (httpResp.getStatusLine().getStatusCode() == HTTP_200) {
//獲取返回的數據
String result = EntityUtils.toString(httpResp.getEntity(), "UTF-8");
Log.i(TAG_HTTPGET, "HttpGet方式請求成功，返回數據如下：");
Log.i(TAG_HTTPGET, result);
} else {
Log.i(TAG_HTTPGET, "HttpGet方式請求失敗");
}
}
Post方式
// HttpPost方式請求
public static void requestByHttpPost() throws Exception {
String path = "https://reg.163.com/logins.jsp";
//新建HttpPost對象
HttpPost httpPost = new HttpPost(path);
// Post參數
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("id", "helloworld"));
params.add(new BasicNameValuePair("pwd", "android"));
//設置字符集
HttpEntity entity = new UrlEncodedFormEntity(params, HTTP.UTF_8);
//設置參數實體
httpPost.setEntity(entity);
//獲取HttpClient對象
HttpClient httpClient = new DefaultHttpClient();
//獲取HttpResponse實例
HttpResponse httpResp = httpClient.execute(httpPost);
//判斷是夠請求成功
if (httpResp.getStatusLine().getStatusCode() == HTTP_200) {
//獲取返回的數據
String result = EntityUtils.toString(httpResp.getEntity(), "UTF-8");
Log.i(TAG_HTTPGET, "HttpPost方式請求成功，返回數據如下：");
Log.i(TAG_HTTPGET, result);
} else {
Log.i(TAG_HTTPGET, "HttpPost方式請求失敗");
}
}
再談談文件操作吧,真的是毫無邏輯了,而且這些都是一些引子,引導我在今后的學習中不斷擴展.言歸正傳,文件分兩類,一類是手機內存,一類是SD Card,這兩種文件讀寫方式存在著差異,具體情況請看下面的代碼:
一. 手機內存
private String read() {
try {
FileInputStream fis = openFileInput(FILE);
byte[] buffer = new byte[1024];
int hasRead = 0;
StringBuilder sb = new StringBuilder("");
while ((hasRead = fis.read(buffer))> 0) {
sb.append(new String(buffer, 0, hasRead));
}
return sb.toString();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
private void write(String content)
{
try
{
// 以追加模式打開文件輸出流
FileOutputStream fos = openFileOutput(FILE, MODE_APPEND);
// 將FileOutputStream包裝成PrintStream
PrintStream ps = new PrintStream(fos);
// 輸出文件內容
ps.println(content);
ps.close();
}
catch (Exception e)
{
e.printStackTrace();
}
}
}
二. SD card
private String read() {
// 如果手機插入了SD卡，而且應用程序具有訪問SD的權限
try {
if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
// 獲取SD卡的目錄
File sdDirFile = Environment.getExternalStorageDirectory();
//獲取指定文件對應的輸入流
FileInputStream fis = new FileInputStream(sdDirFile.getCanonicalPath()+ FILE);
//將指定輸入流包裝成BufferedReader
BufferedReader br = new BufferedReader(new InputStreamReader(fis));
StringBuilder sb = new StringBuilder("");
String line = null;
while ((line =br.readLine())!=null) {
sb.append(line);
}
return sb.toString();
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
private void write(String context){
try {
if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){
File sdDir = Environment.getExternalStorageDirectory();
File targetFile = new File(sdDir.getCanonicalPath()+ FILE);
RandomAccessFile raf = new RandomAccessFile(targetFile, "rw");
raf.seek(targetFile.length());
raf.write(context.getBytes());
raf.close();
}
} catch (Exception e) {
}
}
}
等我實際在操練一番，再繼續總結我所學到的東西吧，這里很多經驗都來自open 經驗庫，感謝那些分享的人