Question

我已将我的值存储在数据库中，如下所示：

"CREATE TABLE " + 
        ABezoeAdapter.databasetabel + "(" +
        ABezoeAdapter.recordnummer + " INTEGER, " +
        ABezoeAdapter.bezoekrapportnummer + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
        ABezoeAdapter.bezoekrapportdatum + " DATETIME NOT NULL, " +
        ABezoeAdapter.herstellingsoort + " VARCHAR(1) NOT NULL, " +

但是这给我提供了以下阅读程序的问题

Cursor c = onzedatabase.query(databasetabel, allekolommen, bezoekrapportnummer + "=?", new String[] {bezoeknummer}, null, null, null);

        int i = 0;
        String data[] = new String[30];
        data = null;
        for (c.moveToFirst(); !c.isAfterLast(); c.moveToNext()){
            data[i] = c.getString(i);
            Log.i("abezoeadapter gegevenslezenvanbezoeknummer", "bezoeknummer = " + data[2]);
        }

out logcat我认为我遇到了问题，因为我的值存储为整数，字符串，......

logcat的：

03-24 18:36:06.321: E/AndroidRuntime(785): FATAL EXCEPTION: main
03-24 18:36:06.321: E/AndroidRuntime(785): java.lang.RuntimeException: Unable to start activity      ComponentInfo{com.example.deceunincktechniekers/com.example.deceunincktechniekers.bezoekrapporten}:     java.lang.NullPointerException
03-24 18:36:06.321: E/AndroidRuntime(785):  at     android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
03-24 18:36:06.321: E/AndroidRuntime(785):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
03-24 18:36:06.321: E/AndroidRuntime(785):  at android.app.ActivityThread.access$600(ActivityThread.java:141)
03-24 18:36:06.321: E/AndroidRuntime(785):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
03-24 18:36:06.321: E/AndroidRuntime(785):  at android.os.Handler.dispatchMessage(Handler.java:99)
03-24 18:36:06.321: E/AndroidRuntime(785):  at android.os.Looper.loop(Looper.java:137)
03-24 18:36:06.321: E/AndroidRuntime(785):  at android.app.ActivityThread.main(ActivityThread.java:5041)
03-24 18:36:06.321: E/AndroidRuntime(785):  at java.lang.reflect.Method.invokeNative(Native Method)
03-24 18:36:06.321: E/AndroidRuntime(785):  at java.lang.reflect.Method.invoke(Method.java:511)
03-24 18:36:06.321: E/AndroidRuntime(785):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
03-24 18:36:06.321: E/AndroidRuntime(785):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
03-24 18:36:06.321: E/AndroidRuntime(785):  at dalvik.system.NativeStart.main(Native Method)
03-24 18:36:06.321: E/AndroidRuntime(785): Caused by: java.lang.NullPointerException
03-24 18:36:06.321: E/AndroidRuntime(785):  at com.example.deceunincktechniekers.ABezoeAdapter.gegevenslezenvanbezoeknummer(ABezoeAdapter.java:480)
03-24 18:36:06.321: E/AndroidRuntime(785):  at com.example.deceunincktechniekers.bezoekrapporten.opslaan(bezoekrapporten.java:784)

我的不同类型的价值可以解决什么问题互联网搜索到目前为止没有帮助我

提前致谢

Answer 1

String data[] = new String[30];
data = null;

您将data分配给null，然后尝试为其指定值。因此NPE。删除data = null。

要处理可变数量的条目，请考虑使用例如ArrayList<String>代替String[]。

整数到数据库的字符串

1 个答案: