问题描述
我正在开发一个基于 NFC 的安卓应用程序。使用 Handler 类发送带有 Message 的对象时,出现 arrayindexoutofboundsexception length = 0 index = 0 错误。
Process: com.telpo.tps530_demo,PID: 8949
java.lang.Arrayindexoutofboundsexception: length=0; index=0
at com.telpo.tps530_demo.NFCdesfire$MyHandler.handleMessage(NFCdesfire.java:169)
处理程序类
private class MyHandler extends Handler{
private WeakReference<NFCdesfire> activityWeakReference;
public MyHandler(NFCdesfire activity){
activityWeakReference = new WeakReference<>(activity);
}
覆盖
@Override
public void handleMessage(Message msg) {
NFCdesfire activity = activityWeakReference.get();
Context context = activity.getApplicationContext();
if(activity!=null) {
switch (msg.what) {
case CHECK_NFC_TIMEOUT: {
Toast.makeText(context,"TIME OUT !",Toast.LENGTH_LONG).show();
activity.nfc_open_btn.setVisibility(4);
activity.nfc_close_btn.setVisibility(4);
activity.nfc_check_btn.setVisibility(4);
}
break;
case SHOW_NFC_DATA: {
byte[] uid_data = (byte[]) msg.obj;
if (uid_data[0] == 0x41) {
Toast.makeText(NFCdesfire.this,"Başarılı",Toast.LENGTH_SHORT).show();
byte[] atqa = new byte[2];
byte[] sak = new byte[1];
byte[] uid = new byte[uid_data[5]];
System.arraycopy(uid_data,2,atqa,2);
System.arraycopy(uid_data,4,sak,1);
System.arraycopy(uid_data,6,uid,uid_data[5]);
Log.e("yw"," " + atqa[0] + " " + atqa[1] + " " + sak[0]);
islemBitti = false;
uid_data[0] == 0x41
我应该在这里做什么?有人有解决方案吗?有代码的延续,所以如果需要,我可以分享源代码。
解决方法
您必须在任何处理之前检查 msg.obj 的长度;似乎 msg.obj 是空的,而您正试图访问它的第一个元素,因此它会抛出 ArrayIndexOutOfBoundsException。