SQLite异常无法将BLOB转换为字符串

Question

在我的Android项目中，我从数据库检索数据时遇到一个问题。在这种情况下，我尝试从类似URL的数据库中获取字符串值，但是当执行此代码时，出现此错误 android.database.sqlite.SQLiteException：未知错误：无法将BLOB转换为字符串， 并且只有URL colomn才给我这个错误，弦柱。

我没弄错地方。所以朋友请给我建议，我该如何解决这个问题。在这里，我还打印了LogCat。

谢谢。

08-22 20:08:12.290: WARN/System.err(10844): android.database.sqlite.SQLiteException: unknown error: Unable to convert BLOB to string
08-22 20:08:12.300: WARN/System.err(10844):     at android.database.CursorWindow.getString_native(Native Method)
08-22 20:08:12.300: WARN/System.err(10844):     at android.database.CursorWindow.getString(CursorWindow.java:329)
08-22 20:08:12.300: WARN/System.err(10844):     at android.database.AbstractWindowedCursor.getString(AbstractWindowedCursor.java:49)
08-22 20:08:12.300: WARN/System.err(10844):     at com.catLog.ProductsDetailsHomeTab.getProductDeatilsFromDB(ProductsDetailsHomeTab.java:337)
08-22 20:08:12.300: WARN/System.err(10844):     at com.catLog.ProductsDetailsHomeTab.setFlipperChild1(ProductsDetailsHomeTab.java:201)
08-22 20:08:12.300: WARN/System.err(10844):     at com.catLog.Widget.ViewFlipper_ProductDetails.onRightToLeftSwipe(ViewFlipper_ProductDetails.java:68)
08-22 20:08:12.300: WARN/System.err(10844):     at com.catLog.Widget.ViewFlipper_ProductDetails.onTouchEvent(ViewFlipper_ProductDetails.java:131)
08-22 20:08:12.300: WARN/System.err(10844):     at android.view.View.dispatchTouchEvent(View.java:3766)
08-22 20:08:12.300: WARN/System.err(10844):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:897)
08-22 20:08:12.300: WARN/System.err(10844):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:936)
08-22 20:08:12.300: WARN/System.err(10844):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:936)
08-22 20:08:12.300: WARN/System.err(10844):     at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:1676)
08-22 20:08:12.300: WARN/System.err(10844):     at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1112)
08-22 20:08:12.300: WARN/System.err(10844):     at android.app.Activity.dispatchTouchEvent(Activity.java:2086)
08-22 20:08:12.300: WARN/System.err(10844):     at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1660)
08-22 20:08:12.300: WARN/System.err(10844):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:936)
08-22 20:08:12.300: WARN/System.err(10844):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:936)
08-22 20:08:12.300: WARN/System.err(10844):     at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:1676)
08-22 20:08:12.300: WARN/System.err(10844):     at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1112)
08-22 20:08:12.300: WARN/System.err(10844):     at android.app.Activity.dispatchTouchEvent(Activity.java:2086)
08-22 20:08:12.300: WARN/System.err(10844):     at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1660)
08-22 20:08:12.300: WARN/System.err(10844):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:936)
08-22 20:08:12.300: WARN/System.err(10844):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:936)
08-22 20:08:12.300: WARN/System.err(10844):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:936)
08-22 20:08:12.300: WARN/System.err(10844):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:936)
08-22 20:08:12.300: WARN/System.err(10844):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:936)
08-22 20:08:12.300: WARN/System.err(10844):     at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:1676)
08-22 20:08:12.300: WARN/System.err(10844):     at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1112)
08-22 20:08:12.300: WARN/System.err(10844):     at android.app.Activity.dispatchTouchEvent(Activity.java:2086)
08-22 20:08:12.300: WARN/System.err(10844):     at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1660)
08-22 20:08:12.300: WARN/System.err(10844):     at android.view.ViewRoot.handleMessage(ViewRoot.java:1785)
08-22 20:08:12.300: WARN/System.err(10844):     at android.os.Handler.dispatchMessage(Handler.java:99)
08-22 20:08:12.300: WARN/System.err(10844):     at android.os.Looper.loop(Looper.java:123)
08-22 20:08:12.300: WARN/System.err(10844):     at android.app.ActivityThread.main(ActivityThread.java:4627)
08-22 20:08:12.300: WARN/System.err(10844):     at java.lang.reflect.Method.invokeNative(Native Method)
08-22 20:08:12.300: WARN/System.err(10844):     at java.lang.reflect.Method.invoke(Method.java:521)
08-22 20:08:12.300: WARN/System.err(10844):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
08-22 20:08:12.300: WARN/System.err(10844):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
08-22 20:08:12.300: WARN/System.err(10844):     at dalvik.system.NativeStart.main(Native Method)

Answer 1

使用getBlob（）函数而不是getString（）函数将解决此问题。不过要小心，因为getBlob（）函数返回的是byte []类型的值。要将其转换为字符串，您必须执行以下操作：

String words = "";
try {
     words = new String(words_blob, "UTF-8");
} catch (UnsupportedEncodingException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}