Android:HttpURLConnection接口
在Http通信中,我們使用POST和GET請求方式進行通信。GET可以獲得靜态頁面,也可以把參數放在URL字元串後面,傳遞給伺服器。而POST方法的參數是放在Http請求中。是以,在程式設計之前,應當首先明确使用的請求方法,然後再根據所使用的方式選擇相應的程式設計方式。
HttpURLConnection是繼承于URLConnection類,二者都是抽象類。其對象主要通過URL的openConnection方法獲得。建立方法如下代碼所示:
Java代碼
URL url = new URL("http://www.51cto.com/index.jsp?par=123456");
HttpURLConnection urlConn=(HttpURLConnection)url.openConnection();
URL url = newURL("http://www.51cto.com/index.jsp?par=123456");
HttpURLConnectionurlConn=(HttpURLConnection)url.openConnection();
通過以下方法可以對請求的屬性進行一些設定,如下所示
Java代碼
//設定輸入和輸出流
urlConn.setDoOutput(true);
urlConn.setDoInput(true);
//設定請求方式為POST
urlConn.setRequestMethod("POST");
//POST請求不能使用緩存
urlConn.setUseCaches(false);
//關閉連接配接
urlConn.disConnection();
//設定輸入和輸出流
urlConn.setDoOutput(true);
urlConn.setDoInput(true);
//設定請求方式為POST
urlConn.setRequestMethod("POST");
//POST請求不能使用緩存
urlConn.setUseCaches(false);
//關閉連接配接
urlConn.disConnection();
Manifest檔案中權限的設定:
Xml代碼
<uses-permission android:name="android.permission.INTERNET" />
<uses-permissionandroid:name="android.permission.INTERNET" />
HttpURLConnection預設使用GET方式,例如下面代碼所示:
Java代碼
//以Get方式上傳參數
public class Activity03 extends Activity
{
private final String DEBUG_TAG = "Activity03";
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.http);
TextView mTextView = (TextView)this.findViewById(R.id.TextView_HTTP);
//http位址"?par=abcdefg"是我們上傳的參數
String httpUrl = "http://192.168.1.110:8080/httpget.jsp?par=abcdefg";
//獲得的資料
String resultData = "";
URL url = null;
try
{
//構造一個URL對象
url = new URL(httpUrl);
}
catch (MalformedURLException e)
{
Log.e(DEBUG_TAG, "MalformedURLException");
}
if (url != null)
{
try
{
// 使用HttpURLConnection打開連接配接
HttpURLConnection urlConn = (HttpURLConnection) url.openConnection();
//得到讀取的内容(流)
InputStreamReader in = new InputStreamReader(urlConn.getInputStream());
// 為輸出建立BufferedReader
BufferedReader buffer = new BufferedReader(in);
String inputLine = null;
//使用循環來讀取獲得的資料
while (((inputLine = buffer.readLine()) != null))
{
//我們在每一行後面加上一個"\n"來換行
resultData += inputLine + "\n";
}
//關閉InputStreamReader
in.close();
//關閉http連接配接
urlConn.disconnect();
//設定顯示取得的内容
if ( resultData != null )
{
mTextView.setText(resultData);
}
else
{
mTextView.setText("讀取的内容為NULL");
}
}
catch (IOException e)
{
Log.e(DEBUG_TAG, "IOException");
}
}
else
{
Log.e(DEBUG_TAG, "Url NULL");
}
}
//以Get方式上傳參數
public class Activity03 extendsActivity
{
private final String DEBUG_TAG = "Activity03";
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.http);
TextView mTextView =(TextView)this.findViewById(R.id.TextView_HTTP);
//http位址"?par=abcdefg"是我們上傳的參數
String httpUrl ="http://192.168.1.110:8080/httpget.jsp?par=abcdefg";
//獲得的資料
String resultData = "";
URL url = null;
try
{
//構造一個URL對象
url = new URL(httpUrl);
}
catch (MalformedURLException e)
{
Log.e(DEBUG_TAG, "MalformedURLException");
}
if (url != null)
{
try
{
// 使用HttpURLConnection打開連接配接
HttpURLConnection urlConn = (HttpURLConnection)url.openConnection();
//得到讀取的内容(流)
InputStreamReader in = newInputStreamReader(urlConn.getInputStream());
// 為輸出建立BufferedReader
BufferedReader buffer = new BufferedReader(in);
String inputLine = null;
//使用循環來讀取獲得的資料
while (((inputLine = buffer.readLine()) != null))
{
//我們在每一行後面加上一個"\n"來換行
resultData += inputLine + "\n";
}
//關閉InputStreamReader
in.close();
//關閉http連接配接
urlConn.disconnect();
//設定顯示取得的内容
if ( resultData != null )
{
mTextView.setText(resultData);
}
else
{
mTextView.setText("讀取的内容為NULL");
}
}
catch (IOException e)
{
Log.e(DEBUG_TAG, "IOException");
}
}
else
{
Log.e(DEBUG_TAG, "Url NULL");
}
}
如果需要使用POST方式,則需要setRequestMethod設定。代碼如下:
Java代碼
//以post方式上傳參數
public class Activity04 extends Activity
{
private final String DEBUG_TAG = "Activity04";
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.http);
TextView mTextView = (TextView)this.findViewById(R.id.TextView_HTTP);
//http位址"?par=abcdefg"是我們上傳的參數
String httpUrl = "http://192.168.1.110:8080/httpget.jsp";
//獲得的資料
String resultData = "";
URL url = null;
try
{
//構造一個URL對象
url = new URL(httpUrl);
}
catch (MalformedURLException e)
{
Log.e(DEBUG_TAG, "MalformedURLException");
}
if (url != null)
{
try
{
// 使用HttpURLConnection打開連接配接
HttpURLConnection urlConn = (HttpURLConnection) url.openConnection();
//因為這個是post請求,設立需要設定為true
urlConn.setDoOutput(true);
urlConn.setDoInput(true);
// 設定以POST方式
urlConn.setRequestMethod("POST");
// Post 請求不能使用緩存
urlConn.setUseCaches(false);
urlConn.setInstanceFollowRedirects(true);
// 配置本次連接配接的Content-type,配置為application/x-www-form-urlencoded的
urlConn.setRequestProperty("Content-Type","application/x-www-form-urlencoded");
// 連接配接,從postUrl.openConnection()至此的配置必須要在connect之前完成,
// 要注意的是connection.getOutputStream會隐含的進行connect。
urlConn.connect();
//DataOutputStream流
DataOutputStream out = new DataOutputStream(urlConn.getOutputStream());
//要上傳的參數
String content = "par=" + URLEncoder.encode("ABCDEFG", "gb2312");
//将要上傳的内容寫入流中
out.writeBytes(content);
//重新整理、關閉
out.flush();
out.close();
//擷取資料
BufferedReader reader = new BufferedReader(new InputStreamReader(urlConn.getInputStream()));
String inputLine = null;
//使用循環來讀取獲得的資料
while (((inputLine = reader.readLine()) != null))
{
//我們在每一行後面加上一個"\n"來換行
resultData += inputLine + "\n";
}
reader.close();
//關閉http連接配接
urlConn.disconnect();
//設定顯示取得的内容
if ( resultData != null )
{
mTextView.setText(resultData);
}
else
{
mTextView.setText("讀取的内容為NULL");
}
}
catch (IOException e)
{
Log.e(DEBUG_TAG, "IOException");
}
}
else
{
Log.e(DEBUG_TAG, "Url NULL");
}
}
}
//以post方式上傳參數
public class Activity04 extends Activity
{
private final String DEBUG_TAG = "Activity04";
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.http);
TextView mTextView =(TextView)this.findViewById(R.id.TextView_HTTP);
//http位址"?par=abcdefg"是我們上傳的參數
String httpUrl ="http://192.168.1.110:8080/httpget.jsp";
//獲得的資料
String resultData = "";
URL url = null;
try
{
//構造一個URL對象
url = new URL(httpUrl);
}
catch (MalformedURLException e)
{
Log.e(DEBUG_TAG, "MalformedURLException");
}
if (url != null)
{
try
{
// 使用HttpURLConnection打開連接配接
HttpURLConnection urlConn = (HttpURLConnection)url.openConnection();
//因為這個是post請求,設立需要設定為true
urlConn.setDoOutput(true);
urlConn.setDoInput(true);
// 設定以POST方式
urlConn.setRequestMethod("POST");
// Post 請求不能使用緩存
urlConn.setUseCaches(false);
urlConn.setInstanceFollowRedirects(true);
// 配置本次連接配接的Content-type,配置為application/x-www-form-urlencoded的
urlConn.setRequestProperty("Content-Type","application/x-www-form-urlencoded");
// 連接配接,從postUrl.openConnection()至此的配置必須要在connect之前完成,
// 要注意的是connection.getOutputStream會隐含的進行connect。
urlConn.connect();
//DataOutputStream流
DataOutputStreamout = new DataOutputStream(urlConn.getOutputStream());
//要上傳的參數
String content ="par=" + URLEncoder.encode("ABCDEFG", "gb2312");
//将要上傳的内容寫入流中
out.writeBytes(content);
//重新整理、關閉
out.flush();
out.close();
//擷取資料
BufferedReaderreader = new BufferedReader(new InputStreamReader(urlConn.getInputStream()));
String inputLine = null;
//使用循環來讀取獲得的資料
while (((inputLine = reader.readLine()) != null))
{
//我們在每一行後面加上一個"\n"來換行
resultData += inputLine + "\n";
}
reader.close();
//關閉http連接配接
urlConn.disconnect();
//設定顯示取得的内容
if ( resultData != null )
{
mTextView.setText(resultData);
}
else
{
mTextView.setText("讀取的内容為NULL");
}
}
catch (IOException e)
{
Log.e(DEBUG_TAG, "IOException");
}
}
else
{
Log.e(DEBUG_TAG, "Url NULL");
}
}
}
Android:HttpClient接口
使用Apache提供的HttpClient接口同樣可以進行HTTP操作。
對于GET和POST請求方法的操作有所不同。GET方法的操作代碼示例如下:
Java代碼
public class Activity02 extends Activity
{
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.http);
TextView mTextView = (TextView) this.findViewById(R.id.TextView_HTTP);
// http位址
String httpUrl = "http://192.168.1.110:8080/httpget.jsp?par=HttpClient_android_Get";
//HttpGet連接配接對象
HttpGet httpRequest = new HttpGet(httpUrl);
try
{
//取得HttpClient對象
HttpClient httpclient = new DefaultHttpClient();
//請求HttpClient,取得HttpResponse
HttpResponse httpResponse = httpclient.execute(httpRequest);
//請求成功
if (httpResponse.getStatusLine().getStatusCode() == HttpStatus.SC_OK)
{
//取得傳回的字元串
String strResult = EntityUtils.toString(httpResponse.getEntity());
mTextView.setText(strResult);
}
else
{
mTextView.setText("請求錯誤!");
}
}
catch (ClientProtocolException e)
{
mTextView.setText(e.getMessage().toString());
}
catch (IOException e)
{
mTextView.setText(e.getMessage().toString());
}
catch (Exception e)
{
mTextView.setText(e.getMessage().toString());
}
}
}
public class Activity02 extendsActivity
{
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.http);
TextView mTextView = (TextView)this.findViewById(R.id.TextView_HTTP);
// http位址
String httpUrl ="http://192.168.1.110:8080/httpget.jsp?par=HttpClient_android_Get";
//HttpGet連接配接對象
HttpGet httpRequest = new HttpGet(httpUrl);
try
{
//取得HttpClient對象
HttpClient httpclient = new DefaultHttpClient();
//請求HttpClient,取得HttpResponse
HttpResponse httpResponse = httpclient.execute(httpRequest);
//請求成功
if (httpResponse.getStatusLine().getStatusCode() ==HttpStatus.SC_OK)
{
//取得傳回的字元串
String strResult = EntityUtils.toString(httpResponse.getEntity());
mTextView.setText(strResult);
}
else
{
mTextView.setText("請求錯誤!");
}
}
catch (ClientProtocolException e)
{
mTextView.setText(e.getMessage().toString());
}
catch (IOException e)
{
mTextView.setText(e.getMessage().toString());
}
catch (Exception e)
{
mTextView.setText(e.getMessage().toString());
}
}
}
使用POST方法進行參數傳遞時,需要使用NameValuePair來儲存要傳遞的參數,另外,還需要設定所使用的字元集。代碼如下所示:
Java代碼
public class Activity03 extends Activity
{
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.http);
TextView mTextView = (TextView) this.findViewById(R.id.TextView_HTTP);
// http位址
String httpUrl = "http://192.168.1.110:8080/httpget.jsp";
//HttpPost連接配接對象
HttpPost httpRequest = new HttpPost(httpUrl);
//使用NameValuePair來儲存要傳遞的Post參數
List<NameValuePair> params = new ArrayList<NameValuePair>();
//添加要傳遞的參數
params.add(new BasicNameValuePair("par", "HttpClient_android_Post"));
try
{
//設定字元集
HttpEntity httpentity = new UrlEncodedFormEntity(params, "gb2312");
//請求httpRequest
httpRequest.setEntity(httpentity);
//取得預設的HttpClient
HttpClient httpclient = new DefaultHttpClient();
//取得HttpResponse
HttpResponse httpResponse = httpclient.execute(httpRequest);
//HttpStatus.SC_OK表示連接配接成功
if (httpResponse.getStatusLine().getStatusCode() == HttpStatus.SC_OK)
{
//取得傳回的字元串
String strResult = EntityUtils.toString(httpResponse.getEntity());
mTextView.setText(strResult);
}
else
{
mTextView.setText("請求錯誤!");
}
}
catch (ClientProtocolException e)
{
mTextView.setText(e.getMessage().toString());
}
catch (IOException e)
{
mTextView.setText(e.getMessage().toString());
}
catch (Exception e)
{
mTextView.setText(e.getMessage().toString());
}
}
}
public class Activity03 extendsActivity
{
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.http);
TextView mTextView = (TextView)this.findViewById(R.id.TextView_HTTP);
// http位址
String httpUrl = "http://192.168.1.110:8080/httpget.jsp";
//HttpPost連接配接對象
HttpPost httpRequest = new HttpPost(httpUrl);
//使用NameValuePair來儲存要傳遞的Post參數
List<NameValuePair> params = newArrayList<NameValuePair>();
//添加要傳遞的參數
params.add(new BasicNameValuePair("par","HttpClient_android_Post"));
try
{
//設定字元集
HttpEntity httpentity = new UrlEncodedFormEntity(params,"gb2312");
//請求httpRequest
httpRequest.setEntity(httpentity);
//取得預設的HttpClient
HttpClient httpclient = new DefaultHttpClient();
//取得HttpResponse
HttpResponse httpResponse = httpclient.execute(httpRequest);
//HttpStatus.SC_OK表示連接配接成功
if (httpResponse.getStatusLine().getStatusCode() ==HttpStatus.SC_OK)
{
//取得傳回的字元串
String strResult =EntityUtils.toString(httpResponse.getEntity());
mTextView.setText(strResult);
}
else
{
mTextView.setText("請求錯誤!");
}
}
catch (ClientProtocolException e)
{
mTextView.setText(e.getMessage().toString());
}
catch (IOException e)
{
mTextView.setText(e.getMessage().toString());
}
catch (Exception e)
{
mTextView.setText(e.getMessage().toString());
}
}
}
HttpClient實際上是對Java提供方法的一些封裝,在HttpURLConnection中的輸入輸出流操作,在這個接口中被統一封裝成了HttpPost(HttpGet)和HttpResponse,這樣,就減少了操作的繁瑣性。本文節選自上海Android教育訓練學校課程。