如何在 android 中使用 HTTP Post？
How to work with HTTP Post in android?
我是 android 的新手，我正在遵循可用的简单示例代码 http://androidexample.com/How_To_Make_HTTP_POST_Request_To_Server_-_Android_Example/index.php?view=article_discription&aid=64&aaid=89
这是源代码：
public class HTTPPostEx extends ActionBarActivity {
TextView content;
EditText fname, email, login, pass;
String Name, Email, Login, Pass;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_httppost_ex);
content = (TextView)findViewById( R.id.textView6);
fname = (EditText)findViewById(R.id.editText);
email = (EditText)findViewById(R.id.editText2);
login = (EditText)findViewById(R.id.editText3);
pass = (EditText)findViewById(R.id.editText4);
Button saveme=(Button)findViewById(R.id.button);
saveme.setOnClickListener(new Button.OnClickListener(){
public void onClick(View v)
{
try{
GetText();
}
catch(Exception ex)
{
content.setText(" url exeption! " );
}
}
});
}
public void GetText() throws UnsupportedEncodingException
{
Name = fname.getText().toString();
Email = email.getText().toString();
Login = login.getText().toString();
Pass = pass.getText().toString();
// Create data variable for sent values to server
String data = URLEncoder.encode("name", "UTF-8")+ "=" + URLEncoder.encode(Name, "UTF-8");
data += "&" + URLEncoder.encode("email", "UTF-8")+ "=" + URLEncoder.encode(Email, "UTF-8");
data += "&" + URLEncoder.encode("user", "UTF-8")+ "=" + URLEncoder.encode(Login, "UTF-8");
data += "&" + URLEncoder.encode("pass", "UTF-8")+ "=" + URLEncoder.encode(Pass, "UTF-8");
String text = "";
BufferedReader reader=null;
// Send data
try
{
URL url = new URL("http://androidexample.com/media/webservice/httppost.php");
URLConnection conn = url.openConnection();
conn.setDoOutput(true);
OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream());
wr.write( data );
wr.flush();
// Get the server response
reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
StringBuilder sb = new StringBuilder();
String line = null;
while((line = reader.readLine()) != null)
{
sb.append(line + "\n");
}
text = sb.toString();
}
catch(Exception ex)
{
}
finally
{
try
{
reader.close();
}
catch(Exception ex) {}
}
content.setText( text );
}}
这段代码没有任何问题。但我无法 post 网络上的数据。
这是 logcat 输出：
02-13 14:10:04.986 22550-22550/com.funkiorangetech.httppostexample W/System.err﹕ at dalvik.system.NativeStart.main(Native Method)
02-13 14:10:04.986 22550-22550/com.funkiorangetech.httppostexample E/error﹕ android.os.NetworkOnMainThreadException
at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1128)
at java.net.InetAddress.lookupHostByName(InetAddress.java:385)
at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236)
at java.net.InetAddress.getAllByName(InetAddress.java:214)
at libcore.net.http.HttpConnection.<init>(HttpConnection.java:70)
at libcore.net.http.HttpConnection.<init>(HttpConnection.java:50)
at libcore.net.http.HttpConnection$Address.connect(HttpConnection.java:340)
at libcore.net.http.HttpConnectionPool.get(HttpConnectionPool.java:87)
at libcore.net.http.HttpConnection.connect(HttpConnection.java:128)
at libcore.net.http.HttpEngine.openSocketConnection(HttpEngine.java:316)
at libcore.net.http.HttpEngine.connect(HttpEngine.java:311)
at libcore.net.http.HttpEngine.sendSocketRequest(HttpEngine.java:290)
at libcore.net.http.HttpEngine.sendRequest(HttpEngine.java:240)
at libcore.net.http.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:81)
at libcore.net.http.HttpURLConnectionImpl.getOutputStream(HttpURLConnectionImpl.java:197)
at com.funkiorangetech.httppostexample.HTTPPostEx.GetText(HTTPPostEx.java:93)
at com.funkiorangetech.httppostexample.HTTPPostEx.onClick(HTTPPostEx.java:48)
at android.view.View.performClick(View.java:4432)
at android.view.View$PerformClick.run(View.java:18338)
at android.os.Handler.handleCallback(Handler.java:725)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:5283)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1102)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:869)
at dalvik.system.NativeStart.main(Native Method)
02-13 14:10:04.986 22550-22550/com.funkiorangetech.httppostexample W/System.err﹕ java.lang.NullPointerException
02-13 14:10:04.986 22550-22550/com.funkiorangetech.httppostexample W/System.err﹕ at com.funkiorangetech.httppostexample.HTTPPostEx.GetText(HTTPPostEx.java:124)
02-13 14:10:04.986 22550-22550/com.funkiorangetech.httppostexample W/System.err﹕ at com.funkiorangetech.httppostexample.HTTPPostEx.onClick(HTTPPostEx.java:48)
02-13 14:10:04.986 22550-22550/com.funkiorangetech.httppostexample W/System.err﹕ at android.view.View.performClick(View.java:4432)
02-13 14:10:04.986 22550-22550/com.funkiorangetech.httppostexample W/System.err﹕ at android.view.View$PerformClick.run(View.java:18338)
02-13 14:10:04.986 22550-22550/com.funkiorangetech.httppostexample W/System.err﹕ at android.os.Handler.handleCallback(Handler.java:725)
02-13 14:10:04.986 22550-22550/com.funkiorangetech.httppostexample W/System.err﹕ at android.os.Handler.dispatchMessage(Handler.java:92)
02-13 14:10:04.996 22550-22550/com.funkiorangetech.httppostexample W/System.err﹕ at android.os.Looper.loop(Looper.java:137)
02-13 14:10:04.996 22550-22550/com.funkiorangetech.httppostexample W/System.err﹕ at android.app.ActivityThread.main(ActivityThread.java:5283)
02-13 14:10:04.996 22550-22550/com.funkiorangetech.httppostexample W/System.err﹕ at java.lang.reflect.Method.invokeNative(Native Method)
02-13 14:10:04.996 22550-22550/com.funkiorangetech.httppostexample W/System.err﹕ at java.lang.reflect.Method.invoke(Method.java:511)
02-13 14:10:04.996 22550-22550/com.funkiorangetech.httppostexample W/System.err﹕ at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1102)
02-13 14:10:04.996 22550-22550/com.funkiorangetech.httppostexample W/System.err﹕ at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:869)
02-13 14:10:04.996 22550-22550/com.funkiorangetech.httppostexample W/System.err﹕ at dalvik.system.NativeStart.main(Native Method)
02-13 14:10:04.996 22550-22550/com.funkiorangetech.httppostexample E/error﹕ java.lang.NullPointerException
at com.funkiorangetech.httppostexample.HTTPPostEx.GetText(HTTPPostEx.java:124)
at com.funkiorangetech.httppostexample.HTTPPostEx.onClick(HTTPPostEx.java:48)
at android.view.View.performClick(View.java:4432)
at android.view.View$PerformClick.run(View.java:18338)
at android.os.Handler.handleCallback(Handler.java:725)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:5283)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1102)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:869)
at dalvik.system.NativeStart.main(Native Method)
任何人都请帮助我了解它是如何工作的。提前致谢。
请参考下面的link获取解决方案：
我知道为什么会出现这个错误。我刚刚查看 this link 并了解到我不应该使用这样的代码。相反，我应该使用线程和处理程序来处理 HTTP 调用。好的，谢谢大家的帮助。 :)
我是 android 的新手，我正在遵循可用的简单示例代码 http://androidexample.com/How_To_Make_HTTP_POST_Request_To_Server_-_Android_Example/index.php?view=article_discription&aid=64&aaid=89 这是源代码：
public class HTTPPostEx extends ActionBarActivity {
TextView content;
EditText fname, email, login, pass;
String Name, Email, Login, Pass;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_httppost_ex);
content = (TextView)findViewById( R.id.textView6);
fname = (EditText)findViewById(R.id.editText);
email = (EditText)findViewById(R.id.editText2);
login = (EditText)findViewById(R.id.editText3);
pass = (EditText)findViewById(R.id.editText4);
Button saveme=(Button)findViewById(R.id.button);
saveme.setOnClickListener(new Button.OnClickListener(){
public void onClick(View v)
{
try{
GetText();
}
catch(Exception ex)
{
content.setText(" url exeption! " );
}
}
});
}
public void GetText() throws UnsupportedEncodingException
{
Name = fname.getText().toString();
Email = email.getText().toString();
Login = login.getText().toString();
Pass = pass.getText().toString();
// Create data variable for sent values to server
String data = URLEncoder.encode("name", "UTF-8")+ "=" + URLEncoder.encode(Name, "UTF-8");
data += "&" + URLEncoder.encode("email", "UTF-8")+ "=" + URLEncoder.encode(Email, "UTF-8");
data += "&" + URLEncoder.encode("user", "UTF-8")+ "=" + URLEncoder.encode(Login, "UTF-8");
data += "&" + URLEncoder.encode("pass", "UTF-8")+ "=" + URLEncoder.encode(Pass, "UTF-8");
String text = "";
BufferedReader reader=null;
// Send data
try
{
URL url = new URL("http://androidexample.com/media/webservice/httppost.php");
URLConnection conn = url.openConnection();
conn.setDoOutput(true);
OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream());
wr.write( data );
wr.flush();
// Get the server response
reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
StringBuilder sb = new StringBuilder();
String line = null;
while((line = reader.readLine()) != null)
{
sb.append(line + "\n");
}
text = sb.toString();
}
catch(Exception ex)
{
}
finally
{
try
{
reader.close();
}
catch(Exception ex) {}
}
content.setText( text );
}}
这段代码没有任何问题。但我无法 post 网络上的数据。 这是 logcat 输出：
02-13 14:10:04.986 22550-22550/com.funkiorangetech.httppostexample W/System.err﹕ at dalvik.system.NativeStart.main(Native Method)
02-13 14:10:04.986 22550-22550/com.funkiorangetech.httppostexample E/error﹕ android.os.NetworkOnMainThreadException
at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1128)
at java.net.InetAddress.lookupHostByName(InetAddress.java:385)
at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236)
at java.net.InetAddress.getAllByName(InetAddress.java:214)
at libcore.net.http.HttpConnection.<init>(HttpConnection.java:70)
at libcore.net.http.HttpConnection.<init>(HttpConnection.java:50)
at libcore.net.http.HttpConnection$Address.connect(HttpConnection.java:340)
at libcore.net.http.HttpConnectionPool.get(HttpConnectionPool.java:87)
at libcore.net.http.HttpConnection.connect(HttpConnection.java:128)
at libcore.net.http.HttpEngine.openSocketConnection(HttpEngine.java:316)
at libcore.net.http.HttpEngine.connect(HttpEngine.java:311)
at libcore.net.http.HttpEngine.sendSocketRequest(HttpEngine.java:290)
at libcore.net.http.HttpEngine.sendRequest(HttpEngine.java:240)
at libcore.net.http.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:81)
at libcore.net.http.HttpURLConnectionImpl.getOutputStream(HttpURLConnectionImpl.java:197)
at com.funkiorangetech.httppostexample.HTTPPostEx.GetText(HTTPPostEx.java:93)
at com.funkiorangetech.httppostexample.HTTPPostEx.onClick(HTTPPostEx.java:48)
at android.view.View.performClick(View.java:4432)
at android.view.View$PerformClick.run(View.java:18338)
at android.os.Handler.handleCallback(Handler.java:725)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:5283)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1102)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:869)
at dalvik.system.NativeStart.main(Native Method)
02-13 14:10:04.986 22550-22550/com.funkiorangetech.httppostexample W/System.err﹕ java.lang.NullPointerException
02-13 14:10:04.986 22550-22550/com.funkiorangetech.httppostexample W/System.err﹕ at com.funkiorangetech.httppostexample.HTTPPostEx.GetText(HTTPPostEx.java:124)
02-13 14:10:04.986 22550-22550/com.funkiorangetech.httppostexample W/System.err﹕ at com.funkiorangetech.httppostexample.HTTPPostEx.onClick(HTTPPostEx.java:48)
02-13 14:10:04.986 22550-22550/com.funkiorangetech.httppostexample W/System.err﹕ at android.view.View.performClick(View.java:4432)
02-13 14:10:04.986 22550-22550/com.funkiorangetech.httppostexample W/System.err﹕ at android.view.View$PerformClick.run(View.java:18338)
02-13 14:10:04.986 22550-22550/com.funkiorangetech.httppostexample W/System.err﹕ at android.os.Handler.handleCallback(Handler.java:725)
02-13 14:10:04.986 22550-22550/com.funkiorangetech.httppostexample W/System.err﹕ at android.os.Handler.dispatchMessage(Handler.java:92)
02-13 14:10:04.996 22550-22550/com.funkiorangetech.httppostexample W/System.err﹕ at android.os.Looper.loop(Looper.java:137)
02-13 14:10:04.996 22550-22550/com.funkiorangetech.httppostexample W/System.err﹕ at android.app.ActivityThread.main(ActivityThread.java:5283)
02-13 14:10:04.996 22550-22550/com.funkiorangetech.httppostexample W/System.err﹕ at java.lang.reflect.Method.invokeNative(Native Method)
02-13 14:10:04.996 22550-22550/com.funkiorangetech.httppostexample W/System.err﹕ at java.lang.reflect.Method.invoke(Method.java:511)
02-13 14:10:04.996 22550-22550/com.funkiorangetech.httppostexample W/System.err﹕ at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1102)
02-13 14:10:04.996 22550-22550/com.funkiorangetech.httppostexample W/System.err﹕ at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:869)
02-13 14:10:04.996 22550-22550/com.funkiorangetech.httppostexample W/System.err﹕ at dalvik.system.NativeStart.main(Native Method)
02-13 14:10:04.996 22550-22550/com.funkiorangetech.httppostexample E/error﹕ java.lang.NullPointerException
at com.funkiorangetech.httppostexample.HTTPPostEx.GetText(HTTPPostEx.java:124)
at com.funkiorangetech.httppostexample.HTTPPostEx.onClick(HTTPPostEx.java:48)
at android.view.View.performClick(View.java:4432)
at android.view.View$PerformClick.run(View.java:18338)
at android.os.Handler.handleCallback(Handler.java:725)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:5283)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1102)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:869)
at dalvik.system.NativeStart.main(Native Method)
任何人都请帮助我了解它是如何工作的。提前致谢。
请参考下面的link获取解决方案：
我知道为什么会出现这个错误。我刚刚查看 this link 并了解到我不应该使用这样的代码。相反，我应该使用线程和处理程序来处理 HTTP 调用。好的，谢谢大家的帮助。 :)