Re: NullPointerExecption after Java class import
You could call (import) directly after you've initialised the Gate class:
(gate-init foo)
(import gate.Factory)
; use Factory class as required
Cheers,
Stuart
On 31 August 2010 01:01, zm zygiman...@medelis.lt wrote:
Initialization exception can be avoided if Factory class is
initialized indirectly:
(let [factory (.newInstance (Class/forName gate.Factory))] ...)
The problem is that Factory can only be initialized (its static
fields) after Gate.init was called. But clojure reader (or what it is)
initializes all the classes mentioned in the namespace. Thus Factory
gets created before cojure function calls which do Gate/init.
Is this workaround ok? Or are there better ways to solve it?
On Aug 30, 2:39 pm, zm zygiman...@medelis.lt wrote:
Indeed if exception is thrown in static initializer block then clojure
import throws exception as well.
The following class will cause this:
package aaa;
public class Test {
static{
Object o = null;
o.toString();
}
}
Then in clojure:
(ns x (:import (aaa Test))
Results in:
Exception in thread main java.lang.ExceptionInInitializerError
(core.clj:1)
Why does this happen in clojure? If you do the same in java, import
aaa.Test, then nothing happens. NLP will be thrown when you actualy
try to initialize the class.
On Aug 30, 6:12 am, Stuart Campbell stu...@harto.org wrote:
Hello,
I don't know this library specifically, but the NPE is probably
occurring in
a static initialisation block. I believe static initialisation occurs
when
the class is first loaded.
Regards,
Stuart
On 30 August 2010 06:42, zm zygiman...@medelis.lt wrote:
I am using GATE java libs in my clojure code and behaviour of the
application changes after Java class import. I don't even have to
initialize it.
This runs fine (a bit shorter version than it is):
(ns gate
(:import
(gate Gate)
(java.io File)))
(defn gate-init
[gate-home]
(Gate/setGateHome (File. gate-home))
(Gate/init)))
Now if I import gate.Factory class, like this (gate Gate Factory), I
get the exception:
Caused by: java.lang.NullPointerException
at gate.Factory.createResource(Factory.java:154)
How can import of a class cause this?
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Re: NullPointerExecption after Java class import
Indeed if exception is thrown in static initializer block then clojure
import throws exception as well.
The following class will cause this:
package aaa;
public class Test {
static{
Object o = null;
o.toString();
}
}
Then in clojure:
(ns x (:import (aaa Test))
Results in:
Exception in thread main java.lang.ExceptionInInitializerError
(core.clj:1)
Why does this happen in clojure? If you do the same in java, import
aaa.Test, then nothing happens. NLP will be thrown when you actualy
try to initialize the class.
On Aug 30, 6:12 am, Stuart Campbell stu...@harto.org wrote:
Hello,
I don't know this library specifically, but the NPE is probably occurring in
a static initialisation block. I believe static initialisation occurs when
the class is first loaded.
Regards,
Stuart
On 30 August 2010 06:42, zm zygiman...@medelis.lt wrote:
I am using GATE java libs in my clojure code and behaviour of the
application changes after Java class import. I don't even have to
initialize it.
This runs fine (a bit shorter version than it is):
(ns gate
(:import
(gate Gate)
(java.io File)))
(defn gate-init
[gate-home]
(Gate/setGateHome (File. gate-home))
(Gate/init)))
Now if I import gate.Factory class, like this (gate Gate Factory), I
get the exception:
Caused by: java.lang.NullPointerException
at gate.Factory.createResource(Factory.java:154)
How can import of a class cause this?
--
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Re: NullPointerExecption after Java class import
Initialization exception can be avoided if Factory class is
initialized indirectly:
(let [factory (.newInstance (Class/forName gate.Factory))] ...)
The problem is that Factory can only be initialized (its static
fields) after Gate.init was called. But clojure reader (or what it is)
initializes all the classes mentioned in the namespace. Thus Factory
gets created before cojure function calls which do Gate/init.
Is this workaround ok? Or are there better ways to solve it?
On Aug 30, 2:39 pm, zm zygiman...@medelis.lt wrote:
Indeed if exception is thrown in static initializer block then clojure
import throws exception as well.
The following class will cause this:
package aaa;
public class Test {
static{
Object o = null;
o.toString();
}
}
Then in clojure:
(ns x (:import (aaa Test))
Results in:
Exception in thread main java.lang.ExceptionInInitializerError
(core.clj:1)
Why does this happen in clojure? If you do the same in java, import
aaa.Test, then nothing happens. NLP will be thrown when you actualy
try to initialize the class.
On Aug 30, 6:12 am, Stuart Campbell stu...@harto.org wrote:
Hello,
I don't know this library specifically, but the NPE is probably occurring in
a static initialisation block. I believe static initialisation occurs when
the class is first loaded.
Regards,
Stuart
On 30 August 2010 06:42, zm zygiman...@medelis.lt wrote:
I am using GATE java libs in my clojure code and behaviour of the
application changes after Java class import. I don't even have to
initialize it.
This runs fine (a bit shorter version than it is):
(ns gate
(:import
(gate Gate)
(java.io File)))
(defn gate-init
[gate-home]
(Gate/setGateHome (File. gate-home))
(Gate/init)))
Now if I import gate.Factory class, like this (gate Gate Factory), I
get the exception:
Caused by: java.lang.NullPointerException
at gate.Factory.createResource(Factory.java:154)
How can import of a class cause this?
--
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NullPointerExecption after Java class import
I am using GATE java libs in my clojure code and behaviour of the application changes after Java class import. I don't even have to initialize it. This runs fine (a bit shorter version than it is): (ns gate (:import (gate Gate) (java.io File))) (defn gate-init [gate-home] (Gate/setGateHome (File. gate-home)) (Gate/init))) Now if I import gate.Factory class, like this (gate Gate Factory), I get the exception: Caused by: java.lang.NullPointerException at gate.Factory.createResource(Factory.java:154) How can import of a class cause this? -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: NullPointerExecption after Java class import
Hello, I don't know this library specifically, but the NPE is probably occurring in a static initialisation block. I believe static initialisation occurs when the class is first loaded. Regards, Stuart On 30 August 2010 06:42, zm zygiman...@medelis.lt wrote: I am using GATE java libs in my clojure code and behaviour of the application changes after Java class import. I don't even have to initialize it. This runs fine (a bit shorter version than it is): (ns gate (:import (gate Gate) (java.io File))) (defn gate-init [gate-home] (Gate/setGateHome (File. gate-home)) (Gate/init))) Now if I import gate.Factory class, like this (gate Gate Factory), I get the exception: Caused by: java.lang.NullPointerException at gate.Factory.createResource(Factory.java:154) How can import of a class cause this? -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.comclojure%2bunsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
