私が最終的に得たものは次のとおりです。スーパーから例外をキャッチし、それがスローされた理由が製品が利用できないためかどうかを判断します。その場合は 404 ページにリダイレクトし、そうでない場合は例外を再スローします。
実装：
public void performExecute( ) throws ECException {
try {
super.performExecute();
} catch (final ECApplicationException e) {
// Let's see if the problem is something that should really be causing a redirect
makeProductHelperAndRedirectTo404IfProductNotAvailable(e);
// If we get here, noting else was thrown
log.error("The reason super.performExecute threw an ECException is unknown and so we can't recover. Re-throwing it.");
throw e;
}
...そして makeProductblablabla メソッドで:
private ProductDataHelper makeProductHelperAndRedirectTo404IfProductNotAvailable(final ECException cause) throws ECSystemException,
ECApplicationException {
final ProductDataHelper productHelper;
try {
log.trace("Trying to determine if the reason super.performExecute threw an ECException is that the product is unavailable in the store. The execption is attached to this logline.", cause);
productHelper = makeProductHelper(getProductId());
if (productHelper != null) {
if (!productHelper.isActiveInClub()) {
log.trace("Decided that the reason super.performExecute threw an ECException is that the product is unavailable in the store. The execption is attached to this logline. NB! That exception is DISCARDED", cause);
final String pn = productHelper.getISBN();
final ECApplicationException systemException = new ECApplicationException(ECMessage._ERR_PROD_NOT_EXISTING, this.getClass().getName(), "productIsPublished", new Object[]{ pn });
systemException.setErrorTaskName("ProductDisplayErrorView");
throw systemException;
}
}
return productHelper;
} catch (RemoteException e) {
log.error("I was trying to determine if the reason super.performExecute threw an ECException is that the product is unavailable in the store. The original ECException is attached to this logline. NB! That exception is DISCARDED", cause);
throw new ECSystemException(ECMessage._ERR_GENERIC, super.getClass().getName(), "performExecute",ECMessageHelper.generateMsgParms(e.getMessage()), e);
} catch (NamingException e) {
log.error("I was trying to determine if the reason super.performExecute threw an ECException is that the product is unavailable in the store. The original ECException is attached to this logline. NB! That exception is DISCARDED", cause);
throw new ECSystemException(ECMessage._ERR_GENERIC, super.getClass().getName(), "performExecute",ECMessageHelper.generateMsgParms(e.getMessage()), e);
} catch (FinderException e) {
log.error("I was trying to determine if the reason super.performExecute threw an ECException is that the product is unavailable in the store. The original ECException is attached to this logline. NB! That exception is DISCARDED", cause);
throw new ECSystemException(ECMessage._ERR_GENERIC, super.getClass().getName(), "performExecute",ECMessageHelper.generateMsgParms(e.getMessage()), e);
} catch (CreateException e) {
log.error("I was trying to determine if the reason super.performExecute threw an ECException is that the product is unavailable in the store. The original ECException is attached to this logline. NB! That exception is DISCARDED", cause);
throw new ECSystemException(ECMessage._ERR_GENERIC, super.getClass().getName(), "performExecute",ECMessageHelper.generateMsgParms(e.getMessage()), e);
}
}