I'd like to crossjoin two streams of tuples in Cascading. Let's suppose there are two lists: ladies and gentlemen, and the goal is to write all the possible lady-gentleman combinations out to a file (e.g. all the possible matches from the "women seeking men" section of a hypothetical dating website).
I found a similar example on this blog and attempted to tweak the code to make a crossjoin (see https://github.com/alexwoolford/cascading-crossjoin-stackoverflow-question).
The operate method in the Crossjoin class throws a null-pointer. Firstly, the getJoinerClosure() call in this line returns null:
JoinerClosure joinerClosure = bufferCall.getJoinerClosure();
... and then the if statement that immediately follows tries to get the size of null:
if( joinerClosure.size() != 2 )
[...]
... resulting in a null-pointer exception.
Can you see where I'm going wrong?
It worked when I removed the rhsGroupFields argument from the new CoGroup constructor, i.e. changed from:
Pipe pipeLadiesAndGentlemen = new CoGroup(pipeLadies, Fields.NONE, pipeGentlemen, Fields.NONE, new Fields("lady", "gentleman"), new BufferJoin());
.. to:
Pipe pipeLadiesAndGentlemen = new CoGroup(pipeLadies, Fields.NONE, pipeGentlemen, Fields.NONE, new BufferJoin());
Related
I have the following objects:
ITeamRepository repo;
IProjectArea projArea;
ITeamArea teamArea;
The process of obtaining the projArea and the teamArea is quite straightforward (despite the quantity of objects involved). However I can't seem to find a way to obtain a list with all the Workitems associated with these objects in a direct way. Is this directly possible, probably via the IQueryClient objects?
This 2012 thread (so it might have changed since) suggests:
I used the following code to get the work items associated with each project area:
auditableClient = (IAuditableClient) repository.getClientLibrary(IAuditableClient.class);
IQueryClient queryClient = (IQueryClient) repository.getClientLibrary(IQueryClient.class);
IQueryableAttribute attribute = QueryableAttributes.getFactory(IWorkItem.ITEM_TYPE).findAttribute(currProject, IWorkItem.PROJECT_AREA_PROPERTY, auditableClient, null);
Expression expression = new AttributeExpression(attribute, AttributeOperation.EQUALS, currProject);
IQueryResult<IResolvedResult<IWorkItem>> results = queryClient.getResolvedExpressionResults(currProject, expression, IWorkItem.FULL_PROFILE);
In my code, currProject would be the IProjectArea pointer to the current project as you loop through the List of project areas p in your code.
The IQueryResult object 'results' then contains a list of IResolvedResult records with all of the work items for that project you can iterate through and find properties for each work item.
I am creating my list like this and passing to a method withInitialListeners and then I don't see any compilation error and it works fine.
List<Host.StateListener> cassListener = new ArrayList<>(); // line 1
cassListener.add(new CassListener()); // // line 2
Builder clusterBuilder = Cluster.builder();
Cluster cluster =
clusterBuilder
.withInitialListeners(cassListener).build();
Now I was thinking to coming line1 and line2 in a single line and pass it directly to withInitialListeners method so I did something like this:
Builder clusterBuilder = Cluster.builder();
cluster =
clusterBuilder
.withInitialListeners(Arrays.asList(new CassListener())).build();
But with this approach it gives me compilation error as shown below:
The method withInitialListeners(Collection<Host.StateListener>) in the type Cluster.Builder is not applicable for the arguments (List<CassListener>)
What is wrong and how can I fix it? I am working with Java 7.
Ideally, you should change the signature of withInitialListeners to withInitialListeners(Collection<? extends Host.StateListener>).
If that is not an option, you can force the generic types of a method by placing explicit types in <…> before the method call:
Arrays.<Host.StateListener>asList(new CassListener())
As you can see, it’s pretty weird to write, and it may befuddle future developers who have to maintain it. The first option is preferred. But sometimes, explicit generic typing is unavoidable.
In a PreProcessor I am writing I can successfully update GET query string via sampler.
However if I use the same approach with POST, while I can list the FORM fields via getArguments(), the value does not get set.
Arguments arguments = sampler.getArguments();
for (int i=0; i<arguments.getArgumentCount(); i++) {
Argument argument = arguments.getArgument(i);
if (argument.getName().equals("page_submission_id")) {
String newVal = "8743718386872";
argument.setValue(newVal);
System.out.println("Setting arg["+argument.getName()+"] to["+newVal+"]");
}
}
sampler.setArguments(arguments);
printArgs(arguments);
The output from this shows Arguments values are unchanged.
Setting arg[page_submission_id] to[8743718386872]
Arguments After
...
Found arg[page_submission_id] is[XXXXXXXXXXXXX]
...
Having dug into the jmeter code a bit further, there is a "runningVersion" attribute of an Attribute object which (via isRunningVersion()) is set true.
I have tried a few ways to get round this:
force runningVersion to false - then values are set but a GET message is sent
create a new Arguments object and add new Argument entries to it with values - this does not change the values
Can anyone point out the official way to set POST FORM field values before they get sent?
Thanks
Well, you assigning a new value to an argument, but I fail to see where you updating sampler's arguments with the argument having the new value.
I'm a strong believer of KISS principle so instead of adding some more lines I would recommend simplifying your script as follows:
import org.apache.jmeter.config.Argument;
sampler.getArguments().removeArgument("page_submission_id");
sampler.addArgument("page_submission_id","8743718386872");
Also I hope you're using JSR223 PreProcessor and Groovy language.
I managed to resolve this:
(initially) by cleaning up the Thread Pool, as my initial
attempts had included a number of things like "Regular Expression
Extractors" and "User defined variables". Once those were removed
the approach I was using successfully changed the argument values, and
(when deeper in to my setup the problem came back) by adding the creation of a new Argments object and inserting (in the same order) new Argument objects with the value set as I require. Then setting the sampler to use that new Arguments object.
Arguments newArgs = new Arguments();
Arguments arguments = sampler.getArguments();
for (int i=0; i<arguments.getArgumentCount(); i++) {
Argument argument = arguments.getArgument(i);
HTTPArgument newArg = new HTTPArgument();
newArg.setName(arguments.getName());
if (arguments.getName().equals("field_to_replace")) {
newArg.setValue("new value");
}
else {
newArg.setValue(arguments.getValue());
}
newArgs.addArgument(newArg);
}
sampler.setArguments(newArgs);
My take is that this down to the "if (isRunningVersion())" test within setProperty() used by "Argument.setValue()" which I'm tripping over.
While this appears to work (for my test cases so far) I appreciate that overriding this may not be the correct formal approach.
My program has two parts, one data structure and second operations.
Data Structure part is, basically and object & set of that object. This set is a class that extends ArrayList. Set and Objects are unique, what I mean is if I have a class named A then I have aSet which keeps the all A objects in it.
Operation part is doing some operations on those sets and most of the times it is also creates a new class in the runtime (write the class in a java file and compile it then call it from Reflect library functions e.g. constructor.newInstance(args);) and creates an object from new class then fill inside of it and return it. Since I didn't wanted to overwrite classes I use UUID trimmed for naming the new classes that created at the runtime.
I had noticed something odd. I run my code and it works, then I run it again and at the creation of set, it gives me "java.lang.IllegalArgumentException: wrong number of arguments". I run it again exception, again and again then I run it again then no exception. (Every time it created a new class like I wanted)
So why my code can act like this?
I am using Oracle Java 1.8 on Ubuntu 14.04 with Intellij Idea (tried also Eclipse no change).
Edit for code:
"I removed the codes unrelated to the problem"
And this is the part that gives error at my operation; (Initial innerInnerName is the random generated class name)
final String outerClassName = "" + initialInnerName + "Table";
final String innerClassName = "" + initialInnerName;
File file = new File("./src/");
URL url = file.toURI().toURL();
URL urls[] = new URL[]{url};
URLClassLoader loader1 = new URLClassLoader(urls);
Class<?> innerClass = loader1.loadClass(innerClassName);
Set<Template> newTable = null;
Class<?> outerClass = loader1.loadClass(outerClassName);
Constructor<?> constructorOfOuterClass = outerClass.getDeclaredConstructors()[0];
Object[] objArg = {innerClass,10};
newTable = (Set<Template>) constructorOfOuterClass.newInstance(objArg);
Edit 2
Exception being thrown at last line of last code which is:
newTable = (Set<Template>) constructorOfOuterClass.newInstance(objArg);
Well I had tried to do MCVE as much as possible.
Your "Outer Class" has two constructors, one that takes one argument and one that takes two. When you go to instantiate the outer class, you get the first in the list of constructors:
Constructor<?> constructorOfOuterClass = outerClass.getDeclaredConstructors()[0];
and then you try to invoke it with two arguments:
Object[] objArg = {innerClass,10};
newTable = (Set<Template>) constructorOfOuterClass.newInstance(objArg);
The problem is that the constructors aren't necessarily in the order you expect. No particular order is guaranteed, so sometimes you will get the one argument constructor and sometimes the two argument constructor. When you get the two argument constructor, all is well. But when you get the one argument constructor and invoke it with two arguments, well, you know all too well what happens then.
You need to determine which of the constructors is the one you want, and select it, rather than assuming that it is the first one in the list.
I'm in the process of writing a cleanup routine for a mongodb collection for a unit test via the java driver (i tried the "native" matlab driver but the documentation is, well, scarce).
I can get a connection going (at least i think i can), but i'm stuck at invoking the remove method on a DBCollection object.
I'm running the following code:
javaaddpath(pathToJarFile)
import com.mongodb.*;
mongoClient = MongoClient(mHost);
mongoConn = mongoClient.getDB(dbName);
auth = mongoConn.authenticate(user,password);
events = mongoConn.getCollection('events');
events.remove();
On the last line i get the error
No method 'remove' with matching signature found for class 'com.mongodb.DBCollectionImpl'.
Since i know that the ´remove´ method exists for the DBCollection class, i'm a bit at a loss currently.
Any help would be appreciated. Note that i'm essentially illiterate when it comes to OOP :-S
Edit:
Please note that i also tried
events.remove({});
which results in the same error message.
According to the API documentation of DBCollection.remove, you must provide a DBObject that simply specifies the deletion criteria. It further says to pass an empty document to delete all documents in the collection. At least you must provide an argument.
According to the documentation on how to remove all documents from a collection, you simply pass the argument {} indicating an empty document to that method. So you must call
events.remove( {} );
To answer your question in the comments: The argument must be a DBObject that describes the remove criteria. A cursor is not such a document.
It seems that {} isn't passed correctly by MATLAB, so creating an empty document and passing it to remove does indeed work.
The working code looks like this:
javaaddpath(pathToJarFile)
import com.mongodb.*;
mongoClient = MongoClient(mHost);
mongoConn = mongoClient.getDB(dbName);
auth = mongoConn.authenticate(user,password);
events = mongoConn.getCollection('events');
empty = BasicDBObject();
events.remove(empty);