在httpconn.connect（）处获取exception；（代码的最后一行）代码和exception错误如下所示..我正在尝试将Android应用程序连接到Internet..我从Internet获取了此代码..但它给出了异常..代码完全被授予了权限..我已经添加了清单权限
我不知道什么是铁
代码..
public class httpsData extends Activity {
ImageView img;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
String str = DownloadText("http://www.edumobile.org/android/");
TextView txt = (TextView) findViewById(R.id.text);
txt.setText(str);
}
private String DownloadText(String URL)
{ Log.v("Wasim ","11");
int BUFFER_SIZE = 2000;
InputStream in = null;
try {
in = OpenHttpConnection(URL);
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
return "";
}
InputStreamReader isr = new InputStreamReader(in);
int charRead;
String str = "";
char[] inputBuffer = new char[BUFFER_SIZE];
try {
while ((charRead = isr.read(inputBuffer))>0)
{
//---convert the chars to a String---
String readString = String.copyValueOf(inputBuffer, 0, charRead);
str += readString;
inputBuffer = new char[BUFFER_SIZE];
}
in.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
return "";
}
return str;
}
private InputStream OpenHttpConnection(String urlString)
throws IOException
{
InputStream in = null;
int response = -1;
URL url = new URL(urlString);
URLConnection conn = url.openConnection();
if (!(conn instanceof HttpURLConnection))
{
throw new IOException("Not an HTTP connection");
}
HttpURLConnection httpConn = (HttpURLConnection) conn;
httpConn.setAllowUserInteraction(false);
httpConn.setInstanceFollowRedirects(true);
httpConn.setRequestMethod("GET");
httpConn.connect();
response = httpConn.getResponseCode();
if (response == HttpURLConnection.HTTP_OK) {
in = httpConn.getInputStream();
}
return in;
}
}
错误如下：
12-04 14:57:34.947: E/AndroidRuntime(5851): FATAL EXCEPTION: main
12-04 14:57:34.947: E/AndroidRuntime(5851): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.apps.httpsData/com.apps.httpsData.httpsData}: android.os.NetworkOnMainThreadException
12-04 14:57:34.947: E/AndroidRuntime(5851): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2059)
12-04 14:57:34.947: E/AndroidRuntime(5851): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
12-04 14:57:34.947: E/AndroidRuntime(5851): at android.app.ActivityThread.access$600(ActivityThread.java:130)
12-04 14:57:34.947: E/AndroidRuntime(5851): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
12-04 14:57:34.947: E/AndroidRuntime(5851): at android.os.Handler.dispatchMessage(Handler.java:99)
12-04 14:57:34.947: E/AndroidRuntime(5851): at android.os.Looper.loop(Looper.java:137)
12-04 14:57:34.947: E/AndroidRuntime(5851): at android.app.ActivityThread.main(ActivityThread.java:4745)
12-04 14:57:34.947: E/AndroidRuntime(5851): at java.lang.reflect.Method.invokeNative(Native Method)
12-04 14:57:34.947: E/AndroidRuntime(5851): at java.lang.reflect.Method.invoke(Method.java:511)
12-04 14:57:34.947: E/AndroidRuntime(5851): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
12-04 14:57:34.947: E/AndroidRuntime(5851): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
12-04 14:57:34.947: E/AndroidRuntime(5851): at dalvik.system.NativeStart.main(Native Method)
12-04 14:57:34.947: E/AndroidRuntime(5851): Caused by: android.os.NetworkOnMainThreadException
12-04 14:57:34.947: E/AndroidRuntime(5851): at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1117)
12-04 14:57:34.947: E/AndroidRuntime(5851): at java.net.InetAddress.lookupHostByName(InetAddress.java:385)
12-04 14:57:34.947: E/AndroidRuntime(5851): at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236)
12-04 14:57:34.947: E/AndroidRuntime(5851): at java.net.InetAddress.getAllByName(InetAddress.java:214)
12-04 14:57:34.947: E/AndroidRuntime(5851): at libcore.net.http.HttpConnection.<init>(HttpConnection.java:70)
12-04 14:57:34.947: E/AndroidRuntime(5851): at libcore.net.http.HttpConnection.<init>(HttpConnection.java:50)
12-04 14:57:34.947: E/AndroidRuntime(5851): at libcore.net.http.HttpConnection$Address.connect(HttpConnection.java:341)
12-04 14:57:34.947: E/AndroidRuntime(5851): at libcore.net.http.HttpConnectionPool.get(HttpConnectionPool.java:87)
12-04 14:57:34.947: E/AndroidRuntime(5851): at libcore.net.http.HttpConnection.connect(HttpConnection.java:128)
12-04 14:57:34.947: E/AndroidRuntime(5851): at libcore.net.http.HttpEngine.openSocketConnection(HttpEngine.java:315)
12-04 14:57:34.947: E/AndroidRuntime(5851): at libcore.net.http.HttpEngine.connect(HttpEngine.java:310)
12-04 14:57:34.947: E/AndroidRuntime(5851): at libcore.net.http.HttpEngine.sendSocketRequest(HttpEngine.java:289)
12-04 14:57:34.947: E/AndroidRuntime(5851): at libcore.net.http.HttpEngine.sendRequest(HttpEngine.java:239)
12-04 14:57:34.947: E/AndroidRuntime(5851): at libcore.net.http.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:80)
12-04 14:57:34.947: E/AndroidRuntime(5851): at com.apps.httpsData.httpsData.OpenHttpConnection(httpsData.java:97)
12-04 14:57:34.947: E/AndroidRuntime(5851): at com.apps.httpsData.httpsData.DownloadText(httpsData.java:42)
12-04 14:57:34.947: E/AndroidRuntime(5851): at com.apps.httpsData.httpsData.onCreate(httpsData.java:30)
12-04 14:57:34.947: E/AndroidRuntime(5851): at android.app.Activity.performCreate(Activity.java:5008)
12-04 14:57:34.947: E/AndroidRuntime(5851): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
12-04 14:57:34.947: E/AndroidRuntime(5851): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023)
12-04 14:57:34.947: E/AndroidRuntime(5851): ... 11 more
最佳答案
试试这个..
TextView txt;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
txt = (TextView) findViewById(R.id.text);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB)
new DownloadText("http://www.edumobile.org/android/").executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR, new String[]{null});
else
new DownloadText("http://www.edumobile.org/android/").execute(new String[]{null});
}
public class DownloadText extends AsyncTask<String, Void, String> {
// variables passed in:
String urls;
// constructor
public DownloadText(String urls) {
this.urls = urls;
}
@Override
protected void onPreExecute() {
pDialog = ProgressDialog.show(httpsData.this, "Fetching Details..", "Please wait...", true);
}
@Override
protected String doInBackground(String... params) {
// TODO Auto-generated method stub
int BUFFER_SIZE = 2000;
InputStream in = null;
try {
InputStream in = null;
int response = -1;
URL url = new URL(urls);
URLConnection conn = url.openConnection();
if (!(conn instanceof HttpURLConnection))
{
throw new IOException("Not an HTTP connection");
}
HttpURLConnection httpConn = (HttpURLConnection) conn;
httpConn.setAllowUserInteraction(false);
httpConn.setInstanceFollowRedirects(true);
httpConn.setRequestMethod("GET");
httpConn.connect();
response = httpConn.getResponseCode();
if (response == HttpURLConnection.HTTP_OK) {
in = httpConn.getInputStream();
}
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
return "";
}
InputStreamReader isr = new InputStreamReader(in);
int charRead;
String str = "";
char[] inputBuffer = new char[BUFFER_SIZE];
try {
while ((charRead = isr.read(inputBuffer))>0)
{
//---convert the chars to a String---
String readString = String.copyValueOf(inputBuffer, 0, charRead);
str += readString;
inputBuffer = new char[BUFFER_SIZE];
}
in.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
return "";
}
}
@Override
protected void onPostExecute(String result) {
// Now we have your JSONObject, play around with it.
if (pDialog.isShowing())
pDialog.dismiss();
if(!result.equals(""))
txt.setText(result);
}
}
关于android - 在HttpConnection.connect()Android上获取异常，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/20372480/