[appengine-java] Batch load from DataStore?
Is this the fastest way to load all of the Elements of a given type
from the DataStore?
@SuppressWarnings(unchecked)
public static final ListPage loadAllPagesFromDataStore() {
ListPage pages = new ArrayListPage();
PersistenceManager pm = PMF.get().getPersistenceManager();
Query query = null;
try {
query = pm.newQuery(Page.class);
ListPage results = (ListPage)query.execute();
if(results.iterator().hasNext()) {
IteratorPage it = results.iterator();
while(it.hasNext())
pages.add(pm.detachCopy(it.next()));
}
} finally {
query.closeAll();
pm.close();
}
return pages;
}
I ask because the datastore is meant to be very fast at reading huge
amounts of data, but slow at writing huge amounts of data, yet this
query is quite slow for only 100 elements.
Thanks,
Finbarr
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[appengine-java] Re: Unsupported method contains while parsing expression:
There actually seems to be a mistake in the documentation: // Give me all Employees with lastName equal to Smith or Jones Query query = pm.newQuery(Employee.class, :p.contains(lastName)); query.execute(Arrays.asList(Smith, Jones)); Surely it should be: // Give me all Employees with lastName equal to Smith or Jones Query query = pm.newQuery(Employee.class, p.contains(:lastName)); query.execute(Arrays.asList(Smith, Jones)); On Feb 2, 10:29 pm, Ikai L (Google) ika...@google.com wrote: Oy, this is what I get for not running code before posting it. Good looking out. On Tue, Feb 2, 2010 at 1:06 AM, datanucleus andy_jeffer...@yahoo.comwrote: query.setFilter(aliases == alias); That is invalid JDOQL syntax; the spec is the spec and JDOQL uses Java syntax. If you have a collection field then the filter should be aliases.contains(:alias) The poster put the colon in front of a field name (wrong), and declared a parameter as a variable (wrong). -- You received this message because you are subscribed to the Google Groups Google App Engine for Java group. To post to this group, send email to google-appengine-j...@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.comgoogle-appengine-java%2B unsubscr...@googlegroups.com . For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en. -- Ikai Lan Developer Programs Engineer, Google App Enginehttp://googleappengine.blogspot.com|http://twitter.com/app_engine -- You received this message because you are subscribed to the Google Groups Google App Engine for Java group. To post to this group, send email to google-appengine-j...@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
[appengine-java] Re: Unsupported method contains while parsing expression:
Wow that mistake in the documentation wasted days of my time. Thankyou datanucleus. On Feb 3, 5:40 pm, Ftaylor finbarrtay...@googlemail.com wrote: There actually seems to be a mistake in the documentation: // Give me all Employees with lastName equal to Smith or Jones Query query = pm.newQuery(Employee.class, :p.contains(lastName)); query.execute(Arrays.asList(Smith, Jones)); Surely it should be: // Give me all Employees with lastName equal to Smith or Jones Query query = pm.newQuery(Employee.class, p.contains(:lastName)); query.execute(Arrays.asList(Smith, Jones)); On Feb 2, 10:29 pm, Ikai L (Google) ika...@google.com wrote: Oy, this is what I get for not running code before posting it. Good looking out. On Tue, Feb 2, 2010 at 1:06 AM, datanucleus andy_jeffer...@yahoo.comwrote: query.setFilter(aliases == alias); That is invalid JDOQL syntax; the spec is the spec and JDOQL uses Java syntax. If you have a collection field then the filter should be aliases.contains(:alias) The poster put the colon in front of a field name (wrong), and declared a parameter as a variable (wrong). -- You received this message because you are subscribed to the Google Groups Google App Engine for Java group. To post to this group, send email to google-appengine-j...@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.comgoogle-appengine-java%2B unsubscr...@googlegroups.com . For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en. -- Ikai Lan Developer Programs Engineer, Google App Enginehttp://googleappengine.blogspot.com|http://twitter.com/app_engine -- You received this message because you are subscribed to the Google Groups Google App Engine for Java group. To post to this group, send email to google-appengine-j...@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
[appengine-java] Unsupported method contains while parsing expression:
Code:
Class Page {
ListString aliases;
...
query = pm.newQuery(Page.class);
query.setFilter(:aliases.contains(alias));
query.declareVariables(String alias);
ListPage results = (ListPage)query.execute(alias);
...
}
I want to select Page objects where the aliases property contains a
given alias String value. Is there any way to do this? I tried as
above and got an exception:
Problem with query SELECT FROM getimgs.Page WHERE :aliases.contains
(alias) VARIABLES String alias: Unsupported method contains while
parsing expression: InvokeExpression{[ParameterExpression
{aliases}].contains(VariableExpression{alias})}
If this cannot be done with JDOQL, the only solution I can think of is
selecting every Page object, then looping through them and using
Java's contains method, but this sucks somewhat.
Anyone?
Cheers,
Finbarr
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[appengine-java] Help with One to Many owned relationship and Datastore
I have a class Page with a variable ListIMG images.
@PersistenceCapable(identityType = IdentityType.APPLICATION)
public class Page {
@PrimaryKey
@Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
private Key key;
@Persistent
private final ListIMG images;
...
}
My IMG class looks like this:
@PersistenceCapable(identityType = IdentityType.APPLICATION)
public class IMG {
...
@PrimaryKey
@Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
private final int number;
...
}
I don't fully understand how the one to many key using
KeyFactory.Builder works. In order to make an instance of Page
persistent using the datastore, do I need to loop through every IMG
instance like this:
for(IMG image : images) {
KeyFactory.Builder keyBuilder = new KeyFactory.Builder
(Page.class.getSimpleName(), page-id);
keyBuilder.addChild(IMG.class.getSimpleName(), image.getID());
Key key = keyBuilder.getKey();
image.setKey(key);
pm.makePersistent(image);
}
or can I do this?
KeyFactory.Builder keyBuilder = new KeyFactory.Builder
(Page.class.getSimpleName(), page-id);
for(IMG image : images) {
keyBuilder.addChild(IMG.class.getSimpleName(), image.getID());
}
Key key = keyBuilder.getKey();
for(IMG image : images) {
image.setKey(key);
pm.makePersistent(image);
}
or can I just do this?
Page p;
...
Key key = KeyFactory.createKey(Page.class.getSimpleName(), page.getID
());
pm.makePersistent(page);
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[appengine-java] Need Help with One to Many relationships in Datastore
I have a class Page with a variable ListIMG images.
code
@PersistenceCapable(identityType = IdentityType.APPLICATION)
public class Page {
@PrimaryKey
@Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
private Key key;
@Persistent
private final ListIMG images;
...
}
/code
My IMG class looks like this:
code
@PersistenceCapable(identityType = IdentityType.APPLICATION)
public class IMG {
...
@PrimaryKey
@Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
private Key key;
...
}
/code
I don't fully understand how the one to many key using
KeyFactory.Builder works. In order to make an instance of Page
persistent using the datastore, do I need to loop through every IMG
instance like this:
code
for(IMG image : images) {
KeyFactory.Builder keyBuilder = new KeyFactory.Builder
(Page.class.getSimpleName(), page-id);
keyBuilder.addChild(IMG.class.getSimpleName(), image.getID());
Key key = keyBuilder.getKey();
image.setKey(key);
pm.makePersistent(image);
}
/code
or can I do this?
code
KeyFactory.Builder keyBuilder = new KeyFactory.Builder
(Page.class.getSimpleName(), page-id);
for(IMG image : images) {
keyBuilder.addChild(IMG.class.getSimpleName(), image.getID());
}
Key key = keyBuilder.getKey();
for(IMG image : images) {
image.setKey(key);
pm.makePersistent(image);
}
/code
or can I just do this?
code
Page page;
...
Key key = KeyFactory.createKey(Page.class.getSimpleName(), page.getID
());
pm.makePersistent(page);
/code
I never want to be able to access the IMG instances without the Page
instance, do I even need to give the IMG instances keys at all?
Thanks,
Finbarr
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[appengine-java] Re: java.lang.NullPointerException cannot be cast to javax.servlet.ServletException
This problem still exists.
On Dec 16 2009, 9:42 pm, polyurethan vette...@googlemail.com wrote:
Hey there,
I still get this ClassCastException. When will the JVM be fixed?
It's Dec and the issue was raised in Jul. Is there any progress?
Thanks,
Alexander
On Oct 22, 10:13 am, Marc Guillemot mguille...@yahoo.fr wrote:
Don,
I've tried to produce a unit test to open an issue for Jasper... and failed.
I'm now quite sure that this is a bug in the JVM used for GAE.
The JavaDoc of AccessController.doPrivileged (which is a native method)
says that it propagates unchecked exceptions and throws a
PrivilegedActionException only if a *checked* exception was thrown.
Therefore Jasper code is correct not to await a RuntimeException as a
PrivilegedActionException can't contain a NullPointerException and GAE's
JVM is buggy here.
Cheers,
Marc.
Don Schwarz a écrit : Ah, you're right actually. I hadn't looked closely
enough at that bug.
We'll have to get the Jasper guys to fix that and then upgrade.
Thanks,
Don
On Mon, Oct 19, 2009 at 10:39 AM, Marc Guillemot mguille...@yahoo.fr
mailto:mguille...@yahoo.fr wrote:
This seems to be a really old issue that relates to something
different... or do you mean that GAE uses a 5 years old version of
Jasper?
I've just look at the current sources of PageContextImpl
http://svn.apache.org/repos/asf/tomcat/trunk/java/org/apache/jasper/r...
and it seems to me that the problem still exists there.
Cheers,
Marc.
Don Schwarz a écrit :
Yes, this is:
https://issues.apache.org/bugzilla/show_bug.cgi?id=31171
We need to bundle a later version of Jasper with the App Engine
SDK to
fix this.
On Mon, Oct 19, 2009 at 10:24 AM, Marc Guillemot
mguille...@yahoo.fr mailto:mguille...@yahoo.fr
mailto:mguille...@yahoo.fr mailto:mguille...@yahoo.fr wrote:
Hi,
any progress on this issue?
Is it possible that it comes from a bug in Jasper, not able
to recognize
RuntimeException occurring in a PrivilegedExceptionAction?
// org.apache.jasper.runtime.PageContextImpl
public void handlePageException(final Throwable t) throws
IOException,
ServletException {
if (t == null)
throw new NullPointerException(null Throwable);
if (SecurityUtil.isPackageProtectionEnabled()) {
try {
AccessController.doPrivileged(
new PrivilegedExceptionActionVoid() {
public Void run() throws Exception {
doHandlePageException(t);
return null;
}
});
} catch (PrivilegedActionException e) {
Exception ex = e.getException();
if (ex instanceof IOException) {
throw (IOException) ex;
} else {
throw (ServletException) ex; -- here?
}
}
} else {
doHandlePageException(t);
}
}
Cheers,
Marc.
Toby Reyelts a écrit :
There's an outstanding issue in the version of Jasper App
Engine is
currently using that can cause exceptions escaping a JSP to
be
incorrectly cast to ServletException. As a temporary
workaround,
you can
wrap the body of your JSP in a try-catch block to get the
actual
exception.
On Thu, Jul 30, 2009 at 1:13 PM, Blessed Geek
blessedg...@gmail.com mailto:blessedg...@gmail.com
mailto:blessedg...@gmail.com mailto:blessedg...@gmail.com
mailto:blessedg...@gmail.com
mailto:blessedg...@gmail.com mailto:blessedg...@gmail.com
mailto:blessedg...@gmail.com wrote:
http://cuckooberra.blessed-are-the-geek.com/TableMgr/TableMgr.jsp
Any idea what this error log means? LoggedIn.jsp is a
rather
simple
jsp, getting a temp authtoken and exchanging it for a
permanent one.
My app runs fine on local eclipse plugin, but on
deployment
this error
resulted.
07-30 07:30AM 49.848
/TableMgr/LoggedIn.jsp
java.lang.ClassCastException:
java.lang.NullPointerException
cannot be
cast to javax.servlet.ServletException
at
org.apache.jasper.runtime.PageContextImpl.handlePageException
(PageContextImpl.java:754)
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[appengine-java] Re: File path in App Engine
Hello, I have tried this but I always get a java.security.AccessControlException: access denied (java.io.FilePermission /names.txt read) Anyone know how to resolve this? Thanks, Finbarr On Jan 7, 3:32 am, m seleron seler...@gmail.com wrote: Hi, It might be solved by this though is not a direct answer. Follow this thread:http://groups.google.co.jp/group/google-appengine-java/browse_thread/... Please Try. thanks. Hello, I have recently started using App Engine for a project I am working on, and I have a simple question. I have a file in the war/WEB-INF directory of my app filename.txt. When I try BufferedReader b = new BufferedReader(new FileReader(new File(filename.txt))); I get a FileNotFoundException. What path should I use when trying to access files in the war/WEB-INF directory? I have tried what seem to me to be the obvious ones and I have read the faq on this (which just tells you to put files in that directory). Thanks, Finbarr -- You received this message because you are subscribed to the Google Groups Google App Engine for Java group. To post to this group, send email to google-appengine-j...@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
[appengine-java] Re: File path in App Engine
I got it to work by just using a File. Didn't change anything, it just seemed to start working of its own accord. Finbarr On Jan 7, 10:46 am, Ftaylor finbarrtay...@googlemail.com wrote: Hello, I have tried this but I always get a java.security.AccessControlException: access denied (java.io.FilePermission /names.txt read) Anyone know how to resolve this? Thanks, Finbarr On Jan 7, 3:32 am, m seleron seler...@gmail.com wrote: Hi, It might be solved by this though is not a direct answer. Follow this thread:http://groups.google.co.jp/group/google-appengine-java/browse_thread/... Please Try. thanks. Hello, I have recently started using App Engine for a project I am working on, and I have a simple question. I have a file in the war/WEB-INF directory of my app filename.txt. When I try BufferedReader b = new BufferedReader(new FileReader(new File(filename.txt))); I get a FileNotFoundException. What path should I use when trying to access files in the war/WEB-INF directory? I have tried what seem to me to be the obvious ones and I have read the faq on this (which just tells you to put files in that directory). Thanks, Finbarr -- You received this message because you are subscribed to the Google Groups Google App Engine for Java group. To post to this group, send email to google-appengine-j...@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
