我的申请遇到了一些问题。代码中没有错误，但我看到了logcat中的错误。
Warning: Ignoring platform 'android-4': build.prop is missing.
[2014-08-15 21:35:27 - Dex Loader] Unable to execute dex: java.nio.BufferOverflowException. Check the Eclipse log for stack trace.
[2014-08-15 21:35:27 - AndroidLoginAndRegistrationWithMySQLPHPSQLite] Conversion to Dalvik format failed: Unable to execute dex: java.nio.BufferOverflowException. Check the Eclipse log for stack trace
08-15 11:14:01.087: E/AndroidRuntime(1063): FATAL EXCEPTION: main
08-15 11:14:01.087: E/AndroidRuntime(1063): Process: com.example.androidhive, PID: 1063
08-15 11:14:01.087: E/AndroidRuntime(1063): android.os.NetworkOnMainThreadException
08-15 11:14:01.087: E/AndroidRuntime(1063): at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1145)
08-15 11:14:01.087: E/AndroidRuntime(1063): at libcore.io.BlockGuardOs.connect(BlockGuardOs.java:84)
08-15 11:14:01.087: E/AndroidRuntime(1063): at libcore.io.IoBridge.connectErrno(IoBridge.java:127)
08-15 11:14:01.087: E/AndroidRuntime(1063): at libcore.io.IoBridge.connect(IoBridge.java:112)
08-15 11:14:01.087: E/AndroidRuntime(1063): at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:192)
08-15 11:14:01.087: E/AndroidRuntime(1063): at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:459)
08-15 11:14:01.087: E/AndroidRuntime(1063): at java.net.Socket.connect(Socket.java:843)
08-15 11:14:01.087: E/AndroidRuntime(1063): at org.apache.http.conn.scheme.PlainSocketFactory.connectSocket(PlainSocketFactory.java:119)
08-15 11:14:01.087: E/AndroidRuntime(1063): at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:144)
08-15 11:14:01.087: E/AndroidRuntime(1063): at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
08-15 11:14:01.087: E/AndroidRuntime(1063): at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
08-15 11:14:01.087: E/AndroidRuntime(1063): at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360)
08-15 11:14:01.087: E/AndroidRuntime(1063): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
08-15 11:14:01.087: E/AndroidRuntime(1063): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
08-15 11:14:01.087: E/AndroidRuntime(1063): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
08-15 11:14:01.087: E/AndroidRuntime(1063): at com.example.androidhive.library.JSONParser.getJSONFromUrl(JSONParser.java:47)
08-15 11:14:01.087: E/AndroidRuntime(1063): at com.example.androidhive.library.UserFunctions.registerUser(UserFunctions.java:64)
08-15 11:14:01.087: E/AndroidRuntime(1063): at com.example.androidhive.RegisterActivity$1.onClick(RegisterActivity.java:60)
08-15 11:14:01.087: E/AndroidRuntime(1063): at android.view.View.performClick(View.java:4438)
08-15 11:14:01.087: E/AndroidRuntime(1063): at android.view.View$PerformClick.run(View.java:18422)
08-15 11:14:01.087: E/AndroidRuntime(1063): at android.os.Handler.handleCallback(Handler.java:733)
08-15 11:14:01.087: E/AndroidRuntime(1063): at android.os.Handler.dispatchMessage(Handler.java:95)
08-15 11:14:01.087: E/AndroidRuntime(1063): at android.os.Looper.loop(Looper.java:136)
08-15 11:14:01.087: E/AndroidRuntime(1063): at android.app.ActivityThread.main(ActivityThread.java:5017)
08-15 11:14:01.087: E/AndroidRuntime(1063): at java.lang.reflect.Method.invokeNative(Native Method)
08-15 11:14:01.087: E/AndroidRuntime(1063): at java.lang.reflect.Method.invoke(Method.java:515)
08-15 11:14:01.087: E/AndroidRuntime(1063): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
08-15 11:14:01.087: E/AndroidRuntime(1063): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
08-15 11:14:01.087: E/AndroidRuntime(1063): at dalvik.system.NativeStart.main(Native Method)