I was working on the new try with resources block which automatically invokes close() method of AutoCloseable
I wanted to know that why doesnt the compiler allow me to re-assign a value to the varable after has been declared.
Check this out:-
try (FileInputStream fs = new FileInputStream("c:\\code\\audit.txt");ObjectInputStream is= new ObjectInputStream(fs);fs = new FileInputStream("c:\\code\\log.txt")) {
Compilation error:-
VariableDeclaratorId expected after this token
fs cannot be resolved to a type
As mentioned in API
The try-with-resources statement is a try statement that declares one or more resources. A resource is an object that must be closed after the program is finished with it. The try-with-resources statement ensures that each resource is closed at the end of the statement.
It clearly says, it only declares variables, not assigned.
So this gives compilation error. Here is use-full link which explains that.
Additionally, Then it says,
Note that the close methods of resources are called in the opposite order of their creation.
So its obvious, so it can't close a resource which already closed.
if Resource reference variable start reassigning then resource which was previously pointing resource will be opened still and that will be waist , so only new pointing resource will be closed , due to this reason compiler raise Compile time error. "auto-closeable resource xxx may not be assigned" . based on java 1.7
Related
I am tryint to reuse the code in following documentation : https://geode.apache.org/docs/guide/11/developing/region_options/dynamic_region_creation.html
The first problem that i met is that
Cache cache = CacheFactory.getAnyInstance();
Region<String,RegionAttributes<?,?>> regionAttributesMetadataRegion = createRegionAttributesMetadataRegion(cache);
should not be executed in constructor. In case it is , the code is executed in client instance , it is failed on not server error.When this fixed i receive
[fatal 2021/02/15 16:38:24.915 EET <ServerConnection on port 40527 Thread 1> tid=81] Serialization filter is rejecting class org.restcomm.cache.geode.CreateRegionFunction
java.lang.Exception:
at org.apache.geode.internal.ObjectInputStreamFilterWrapper.lambda$createSerializationFilter$0(ObjectInputStreamFilterWrapper.java:233)
The problem is that code is getting executed on dunit MemberVM and the required class is actually the part of the package under which the test is getting executed.
So i guess i should somehow register the classes ( or may be jar ) separately to dunit MemberVM. How it can be done?
Another question is: currently the code is checking if the region exists and if not it calls the method. In both cases it also tries to create the clientRegion. The question is whether this is a correct approach?
Region<?,?> cache = instance.getRegion(name);
if(cache==null) {
Execution execution = FunctionService.onServers(instance);
ArrayList argList = new ArrayList();
argList.add(name);
Function function = new CreateRegionFunction();
execution.setArguments(argList).execute(function).getResult();
}
ClientRegionFactory<Object, Object> cf=this.instance.createClientRegionFactory(ClientRegionShortcut.CACHING_PROXY).addCacheListener(new ExtendedCacheListener());
this.cache = cf.create(name);
BR
Yulian Oifa
The first problem that i met is that
Cache cache = CacheFactory.getAnyInstance();
should not be executed in constructor. In case it is , the code is executed in client instance , it is failed on not server error.When this fixed i receive
Once the Function is registered on server side, you can execute it by ID instead of sending the object across the wire (so you won't need to instantiate the function on the client), in which case you'll also avoid the Serialization filter error. As an example, FunctionService.onServers(instance).execute(CreateRegionFunction.ID).
The problem is that code is getting executed on dunit MemberVM and the required class is actually the part of the package under which the test is getting executed. So i guess i should somehow register the classes ( or may be jar ) separately to dunit MemberVM. How it can be done?
Indeed, for security reasons Geode doesn't allow serializing / deserializing arbitrary classes. Internal Geode distributed tests use the MemberVM and set a special property (serializable-object-filter) to circumvent this problem. Here's an example of how you can achieve that within your own tests.
Another question is: currently the code is checking if the region exists and if not it calls the method. In both cases it also tries to create the clientRegion. The question is whether this is a correct approach?
If the dynamically created region is used by the client application then yes, you should create it, otherwise you won't be able to use it.
As a side note, there's a lot of internal logic implemented by Geode when creating a Region so I wouldn't advice to dynamically create regions on your own. Instead, it would be advisable to use the gfsh create region command directly, or look at how it works internally (see here) and try to re-use that.
I have a Puppet custom function that returns information about a user defined in OpenStack's Keystone identity service. Usage is something along the lines of:
$tenant_id = lookup_tenant_by_name($username, $password, "mytenant")
The problem is that the credentials used in this query ($username) are supposed to be created by another resource during the Puppet run (a Keystone_user resource from puppet-keystone). As far as I can tell, the call to the lookup_tenant_by_name function is being evaluated before any resource ordering happens, because no amount of dependencies in the calling code is able to force the credentials to be created prior to this function being executed.
In general, it is possible to write custom functions -- or place them appropriately in a manifest -- such that they will not be executed by Puppet until after some specified resource has been instantiated?
Short answer: You cannot make your manifest's behavior depend on resources declared inside of it.
Long answer: Parser functions are called during the compilation phase (on the master if you use one, or the agent if you use puppet apply). In neither case can it ever run before any resource is synced, because that will happen after the compiler has done all its work (including invocation of your functions).
To query information from the agent machine, you generally want to use custom facts. Still, those will be populated before even the compiler run.
Likely the best approach in this situation is to make the manifest tolerate the absence of the information, so that anything that depends on the value that your lookup_tenant_by_name function returns will only be evaluated if that value is available. This will usually be during the second Puppet run.
if $tenant_id == "" {
notify { "cannot yet find tenant $username": }
}
else {
# your code using the tenant ID
}
Problem:
Attempting to use the JYTHON command below and I cannot retrieve the id of my active specification defined at a node-server level in Websphere. I believe its a syntax issue but I'm not sure what.
Code:
AdminConfig.getid('/Cell:mycell/Node:mynode/Server:myserver/J2CActivationSpec:myActiveSpecName/')
Problem Notes:
I do not get a invalid object error so I believe I have the syntax right but it just cannot find the resource even though it exists.
I am using the AdminConfig.getid() as a way to check if the resource already exists in order to do a modify or a create.
If I use the following code: AdminConfig.getid('/J2CActivationSpec:myActiveSpecName/') it will find it but not if I use a more specific path listed above.
Reference Material:
IBM Documentation
Containment paths are always a little tricky. In my (limited) experience, even if you can trace the path by AdminConfig.parents, you may not always be able to use getid.
Are you restricted to using getid? If not, here are some alternatives that will get you an ActivationSpec at the /Cell/Node/Server level:
Querying using AdminConfig.list
This approach will list the Activation Specifications at the specified scope (in our case, the server), and grab the one that has it's name attribute equal to 'myActiveSpecName'.
server = AdminConfig.getid('/Cell:mycell/Node:mynode/Server:myserver')
activationSpec = ''
for as in AdminConfig.list('J2CActivationSpec', server).splitlines():
if AdminConfig.showAttribute(as, 'name') == 'myActiveSpecName'
activationSpec = as
print 'found it :)'
Using Wildcards
This approah uses AdminConfig.list as well, but with a pattern to narrow down your list. If you know your activation spec's configuration begins with myActiveSpecName, then you can do the following:
activationSpec = AdminConfig.list('J2CActivationSpec', 'myActiveSpecName*')
In QTP is there any way in the code to check to see if a specific object exists in the object repository. I have tried the following code:
If JavaWindow(className).JavaDialog(dialogName).Exist Then
doThisStuff
Else
doThisStuffInstead
End If
But from what I have gleamed from the Internets, this is similar to a isVisible method, only resulting in true if the specified object is currently visible. When I use the above code I receive a "JavaDialog object was not found in the Object Repository." Is there a method or any way to prevent this very error and check to see if the object does indeed exist?
Thank you for your time
I'm not sure what you're trying to accomplish here, one typically knows if an object exists in the object repository before using it. The doubt is usually whether there is a corresponding control in the AUT (Application Under Test).
If you really face the situation that sometimes the object is in the repository and sometimes it isn't (I can think of several ways for this to happen but none of them make much sense) then you can use VBScript's error handling mechanism.
On Error Resume Next ' Turn off error handling
' Just check if object is in repository, there's no need to do anything with it
Dim Exists: Exists=JavaWindow(className).JavaDialog(dialogName).Exist
If Err.Number <> 0 Then
doThisStuff 'Exists is still empty
Else
doThisStuffInstead ' Exists is properly set
End If
On Error Goto 0 ' Resume regular error handling
So, from the error you get, either the dialog that appears is different from the one you've stored in the repository or you don't have it there.
Have you checked it is really present in the Repository? You can try to just locate this element button.
Using the method of "if object not in the repository - skip the step" is not really a good idea. 1. Why would you want to skip the test/part of the test if the object was not saved in the repository?
2. If it's not there, so you need to make sure to store it.
I would assume that this "missing" object might have some values by which it's matched to the object from the repository different from test to test. You can tune the "matching" mechanism by manually setting the values by which you want QTP to locate it.
I have a script that makes use of a package (PKG_MY_PACKAGE). I will change some of the fields in a query in that package and then recompile it (I don't change or compile any other packages). I run the script and I get an error that looks like
ORA-04068: existing state of packages has been discarded
ORA-04061: existing state of package body "USER3.PKG_MY_PACKAGE" has been invalidated
ORA-04065: not executed, altered or dropped package body "USER3.PKG_MY_PACKAGE"
ORA-06508: PL/SQL: could not find program unit being called: "USER3.PKG_MY_PACKAGE"
ORA-06512: at line 34
I run the script again (without changing anything else in the system) and the script executes successfully.
I thought that when I compiled before I executed the script that would fix any invalid references. This is 100% reproducible, and the more I use this script the more annoying it gets. What could cause this, and what would fix it?
(oracle 10g, using PL/SQL Developer 7)
Background
existing state of packages has been discarded means, that your Package had some sort of state.
This is caused by a global variable stored in your Package Body.
Until 11.2.0.2, constants did also cause this behavior (see documentation).
Since the package has already been used in your session, Oracle assumes that this state is relevant for you. Some of these variables might have different values now, and when you recompile the Body, the values are reset.
This exception is thrown, so that your clients know that they can't rely on those variables any more.
Solutions
Remove all global variables and constants (before 11gR2) from the Package Body if possible
Replace global variables by DETERMINISTIC functions (as suggested by this answer)
Defining packages with PRAGMA SERIALLY_REUSABLE causes Oracle to re-initialize the global variables with every call to the server.
Close your session and reconnect before calling the package again.
Reset the state manually (see Paul James' answer)
If you're running stuff in a script try these commands in there prior to running the re-compiled code..
exec DBMS_SESSION.RESET_PACKAGE
exec DBMS_SESSION.MODIFY_PACKAGE_STATE( DBMS_SESSION.REINITIALIZE )
They do what the name might suggest.
Possible issues you can have is:
The package/procedure you are calling is invalid (though it can work if called independently)
check this query whether you have an entry of your package or objects used in your package in this all_objects view
select * from all_objects where status = 'INVALID' and owner = 'SCHEMA_NAME';
Check your package is having global variables? if yes then check if those variable is not being changed by any other session preferable remove those global variables/use function
Run below script to compile all the objects in your schema
begin
dbms_utility.compile_schema('SCHEMA_NAME', false);
end;
Last option if none of the above works then remove all the procedures/function from your package, add new function and try to run your function from the trigger. check if this works then your package is in special lock. After adding a new function/proc it's state will be valid again and then you can add all your actual funcs/procs and remove the newly added function/proc.
The above error : ORA-06508: PL/SQL: could not find program unit being called.
is caused when an attempt was made to call a stored program that could not be found. The program may have been dropped or incompatibly modified, or have compiled with errors.
Check that all referenced programs, including their package bodies, exist and are compatible.
You can run this query to find invalid objects, which may cause the ORA-06508 error:
select
comp_id,
comp_name,
version,
status,
namespace,
schema
from
dba_registry;