我不明白为什么当我运行调试时应用程序崩溃了。有谁能告诉我哪里错了？
package com.example.locali;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.Vector;
import liuk.presences.R;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.StatusLine;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONArray;
import org.json.JSONObject;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.widget.ArrayAdapter;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.Toast;
public class MainActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ListView listView = (ListView) findViewById(R.id.mylist);
Vector v = new Vector();
String readTwitterFeed = readTwitterFeed();
try {
JSONArray jsonArray = new JSONArray(readTwitterFeed);
for (int i = 0; i < jsonArray.length(); i++)
{
JSONObject jsonObject = jsonArray.getJSONObject(i);
v.add(jsonArray.getJSONObject(i).getString("Nome") +" "+ jsonArray.getJSONObject(i).getString("Cognome"));
}
} catch (Exception e) {
Toast.makeText(this, "Exception" + e,Toast.LENGTH_LONG).show();
e.printStackTrace();
}
ListAdapter listaContatti = new ArrayAdapter(this, android.R.layout.simple_list_item_1, v);
listView.setAdapter(listaContatti);
//Toast.makeText(this, "END OF APPLICATION",Toast.LENGTH_LONG).show();
} //end onCreate
public String readTwitterFeed() {
StringBuilder builder = new StringBuilder();
HttpClient client = new DefaultHttpClient();
HttpGet httpGet = new HttpGet("http://locali.altervista.org/php/locali.php");
try {
HttpResponse response = client.execute(httpGet);
StatusLine statusLine = response.getStatusLine();
int statusCode = statusLine.getStatusCode();
if (statusCode == 200) {
HttpEntity entity = response.getEntity();
InputStream content = entity.getContent();
BufferedReader reader = new BufferedReader(new InputStreamReader(content));
String line;
while ((line = reader.readLine()) != null)
{
builder.append(line);
} //end while
} else {
Toast.makeText(this, "Failed to download file",Toast.LENGTH_LONG).show();
}
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return builder.toString();
}
}
我用这个应用程序读了一个在线数据库，我在互联网上找到了这个例子。感谢。
03-07 18:21:10.490: D/AndroidRuntime(10119): Shutting down VM
03-07 18:21:10.490: W/dalvikvm(10119): threadid=1: thread exiting with uncaught exception (group=0x41da6da0)
03-07 18:21:10.500: E/AndroidRuntime(10119): FATAL EXCEPTION: main
03-07 18:21:10.500: E/AndroidRuntime(10119): Process: liuk.presences, PID: 10119
03-07 18:21:10.500: E/AndroidRuntime(10119): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{liuk.presences/liuk.presences.LiukPresencesActivity}: java.lang.ClassNotFoundException: Didn't find class "liuk.presences.LiukPresencesActivity" on path: DexPathList[[zip file "/data/app/liuk.presences-2.apk"],nativeLibraryDirectories= [/data/app-lib/liuk.presences-2, /vendor/lib, /system/lib]]
03-07 18:21:10.500: E/AndroidRuntime(10119): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2231)
03-07 18:21:10.500: E/AndroidRuntime(10119): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2363)
03-07 18:21:10.500: E/AndroidRuntime(10119): at android.app.ActivityThread.access$900(ActivityThread.java:161)
03-07 18:21:10.500: E/AndroidRuntime(10119): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1265)
03-07 18:21:10.500: E/AndroidRuntime(10119): at android.os.Handler.dispatchMessage(Handler.java:102)
03-07 18:21:10.500: E/AndroidRuntime(10119): at android.os.Looper.loop(Looper.java:157)
03-07 18:21:10.500: E/AndroidRuntime(10119): at android.app.ActivityThread.main(ActivityThread.java:5356)
03-07 18:21:10.500: E/AndroidRuntime(10119): at java.lang.reflect.Method.invokeNative(Native Method)
03-07 18:21:10.500: E/AndroidRuntime(10119): at java.lang.reflect.Method.invoke(Method.java:515)
03-07 18:21:10.500: E/AndroidRuntime(10119): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1265)
03-07 18:21:10.500: E/AndroidRuntime(10119): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1081)
03-07 18:21:10.500: E/AndroidRuntime(10119): at dalvik.system.NativeStart.main(Native Method)
03-07 18:21:10.500: E/AndroidRuntime(10119): Caused by: java.lang.ClassNotFoundException: Didn't find class "liuk.presences.LiukPresencesActivity" on path: DexPathList[[zip file "/data/app/liuk.presences-2.apk"],nativeLibraryDirectories=[/data/app-lib/liuk.presences-2, /vendor/lib, /system/lib]]
03-07 18:21:10.500: E/AndroidRuntime(10119): at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:67)
03-07 18:21:10.500: E/AndroidRuntime(10119): at java.lang.ClassLoader.loadClass(ClassLoader.java:497)
03-07 18:21:10.500: E/AndroidRuntime(10119): at java.lang.ClassLoader.loadClass(ClassLoader.java:457)
03-07 18:21:10.500: E/AndroidRuntime(10119): at android.app.Instrumentation.newActivity(Instrumentation.java:1079)
03-07 18:21:10.500: E/AndroidRuntime(10119): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2222)
03-07 18:21:10.500: E/AndroidRuntime(10119): ... 11 more
03-07 18:21:12.772: I/Process(10119): Sending signal. PID: 10119 SIG: 9
答案 0 :(得分：0)
java.lang.ClassNotFoundException: Didn't find class "liuk.presences.LiukPresencesActivity"
您已在清单中声明liuk.presences.LiukPresencesActivity。您发布的代码为com.example.locali.MainActivity。确保完全限定的类名（包名称）在清单和代码中一致。
答案 1 :(得分：-1)
您似乎忘记在AndroidManifest.xml文件中声明您的活动
你应该在应用程序标记的清单xml文件中有这样的（或类似于你的活动名称的文本）文本
<activity android:name="liuk.presences.LiukPresencesActivity" />