我正在开发我的第一个 Android 应用程序。
我尝试从网站获取 HTML 源代码，我使用以下代码：
HttpClient client = new DefaultHttpClient();
HttpGet request = new HttpGet(urlWeb);
HttpResponse response = client.execute(request);
String html = "";
InputStream in = response.getEntity().getContent();
BufferedReader reader = new BufferedReader(new InputStreamReader(in));
StringBuilder str = new StringBuilder();
String line = null;
while((line = reader.readLine()) != null)
{
str.append(line);
}
in.close();
html = str.toString();
我还在清单中添加了互联网权限。
但总是得到这个错误：
05-02 18:56:56.967: E/AndroidRuntime(17659): FATAL EXCEPTION: main
05-02 18:56:56.967: E/AndroidRuntime(17659): java.lang.IllegalStateException: Could not execute method of the activity
05-02 18:56:56.967: E/AndroidRuntime(17659): at android.view.View$1.onClick(View.java:3597)
05-02 18:56:56.967: E/AndroidRuntime(17659): at android.view.View.performClick(View.java:4202)
05-02 18:56:56.967: E/AndroidRuntime(17659): at android.view.View$PerformClick.run(View.java:17340)
05-02 18:56:56.967: E/AndroidRuntime(17659): at android.os.Handler.handleCallback(Handler.java:725)
05-02 18:56:56.967: E/AndroidRuntime(17659): at android.os.Handler.dispatchMessage(Handler.java:92)
05-02 18:56:56.967: E/AndroidRuntime(17659): at android.os.Looper.loop(Looper.java:137)
05-02 18:56:56.967: E/AndroidRuntime(17659): at android.app.ActivityThread.main(ActivityThread.java:5191)
05-02 18:56:56.967: E/AndroidRuntime(17659): at java.lang.reflect.Method.invokeNative(Native Method)
05-02 18:56:56.967: E/AndroidRuntime(17659): at java.lang.reflect.Method.invoke(Method.java:511)
05-02 18:56:56.967: E/AndroidRuntime(17659): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:795)
05-02 18:56:56.967: E/AndroidRuntime(17659): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:562)
05-02 18:56:56.967: E/AndroidRuntime(17659): at dalvik.system.NativeStart.main(Native Method)
05-02 18:56:56.967: E/AndroidRuntime(17659): Caused by: java.lang.reflect.InvocationTargetException
05-02 18:56:56.967: E/AndroidRuntime(17659): at java.lang.reflect.Method.invokeNative(Native Method)
05-02 18:56:56.967: E/AndroidRuntime(17659): at java.lang.reflect.Method.invoke(Method.java:511)
05-02 18:56:56.967: E/AndroidRuntime(17659): at android.view.View$1.onClick(View.java:3592)
05-02 18:56:56.967: E/AndroidRuntime(17659): ... 11 more
05-02 18:56:56.967: E/AndroidRuntime(17659): Caused by: android.os.NetworkOnMainThreadException
05-02 18:56:56.967: E/AndroidRuntime(17659): at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1117)
05-02 18:56:56.967: E/AndroidRuntime(17659): at java.net.InetAddress.lookupHostByName(InetAddress.java:385)
05-02 18:56:56.967: E/AndroidRuntime(17659): at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236)
05-02 18:56:56.967: E/AndroidRuntime(17659): at java.net.InetAddress.getAllByName(InetAddress.java:214)
05-02 18:56:56.967: E/AndroidRuntime(17659): at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:137)
05-02 18:56:56.967: E/AndroidRuntime(17659): at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
05-02 18:56:56.967: E/AndroidRuntime(17659): at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
05-02 18:56:56.967: E/AndroidRuntime(17659): at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360)
05-02 18:56:56.967: E/AndroidRuntime(17659): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
05-02 18:56:56.967: E/AndroidRuntime(17659): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
05-02 18:56:56.967: E/AndroidRuntime(17659): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
05-02 18:56:56.967: E/AndroidRuntime(17659): at com.example.icpcgb.MainActivity.btn_Show(MainActivity.java:72)
可能是什么问题呢？