Re: addliteral() vs setpropertyvalue()
> Yes its true that it returns Null Pointer Exception. It returns NULL, not a NullPointerException! That's totally different! > > But what you people suggest I suppose to do? One thing in my mind is to > include first: > employee.addLiteral(Property, 1) > Then employee.getPropertyValue() > Then Perform calculation/addition > And last, employee.setPropertyValue(Property, sum/calculated value). I don't know your programming skills, but this is more than obvious... get the value - if this is NULL - simply set the new value - ELSE set the existing value + the new value > > On Mon, Oct 17, 2016 at 12:52 AM, Lorenz B. < > buehm...@informatik.uni-leipzig.de> wrote: > >> Hello Tina, >> >> >> >> >>> I want to sum 5 with the value already stored in a property. >>> >>> //Property "Hours" must be started from 1 and then sum 5 with it. >>> employee.getPropertyValue(No_of_Hours); >>> //Then perform calculations. >>> >>> The problem is that if I directly use employee.getPropertyValue(), it >> gives >>> me "Exception" (and rightly, because I did not set setPropertyValue() >>> first). >> That's not true. It returns null if there is no such value - and you >> have to handle this in the code indeed. >>> But the problem is that when I set employee.getPropertyValue(No_ >> of_Hours); >>> to 1 (one), it will always set the value 1(one) and not the recent >>> added(sum) value in the property. >>> >>> employee.setPropertyValue(No_of_Hours, 1); //1 is literal >>> employee.getPropertyValue(No_of_Hours); >>> //calculations >>> My requirement is like: int sum=No_of_Hours+1; >>> Then No_of_Hours plus what in the *variable sum*. >>> >>> So can I use employee.addLiteral(No_of_Hours, 1) instead of >>> employee.setPropertyValue(). >>> >>> I hope you have understood what my issue is? >>> >>> Kindest regards >>> >>> >>> >>> On Sun, Oct 16, 2016 at 11:10 AM, Dave Reynolds < >> dave.e.reyno...@gmail.com> >>> wrote: >>> On 16/10/16 16:59, tina sani wrote: > Hi > > What is the difference between addLiteral() and setpropertyvalue() >> when we > want to assign values to an individual.? > For example, > > //myEmployee is an instance. > > myEmplyee.addliteral(property, value) > myEmployee.setpropertyvalue(property, value) > > addLiteral adds a value, so if there is already a value there you will >> now have multiple values. setPropertyValue removes all existing values before adding the new value so you will only have the new value at the end. Dave >> -- >> Lorenz Bühmann >> AKSW group, University of Leipzig >> Group: http://aksw.org - semantic web research center >> >> -- Lorenz Bühmann AKSW group, University of Leipzig Group: http://aksw.org - semantic web research center
Re: addliteral() vs setpropertyvalue()
Yes its true that it returns Null Pointer Exception. But what you people suggest I suppose to do? One thing in my mind is to include first: employee.addLiteral(Property, 1) Then employee.getPropertyValue() Then Perform calculation/addition And last, employee.setPropertyValue(Property, sum/calculated value). On Mon, Oct 17, 2016 at 12:52 AM, Lorenz B. < buehm...@informatik.uni-leipzig.de> wrote: > Hello Tina, > > > > > > I want to sum 5 with the value already stored in a property. > > > > //Property "Hours" must be started from 1 and then sum 5 with it. > > employee.getPropertyValue(No_of_Hours); > > //Then perform calculations. > > > > The problem is that if I directly use employee.getPropertyValue(), it > gives > > me "Exception" (and rightly, because I did not set setPropertyValue() > > first). > That's not true. It returns null if there is no such value - and you > have to handle this in the code indeed. > > > > But the problem is that when I set employee.getPropertyValue(No_ > of_Hours); > > to 1 (one), it will always set the value 1(one) and not the recent > > added(sum) value in the property. > > > > employee.setPropertyValue(No_of_Hours, 1); //1 is literal > > employee.getPropertyValue(No_of_Hours); > > //calculations > > My requirement is like: int sum=No_of_Hours+1; > > Then No_of_Hours plus what in the *variable sum*. > > > > So can I use employee.addLiteral(No_of_Hours, 1) instead of > > employee.setPropertyValue(). > > > > I hope you have understood what my issue is? > > > > Kindest regards > > > > > > > > On Sun, Oct 16, 2016 at 11:10 AM, Dave Reynolds < > dave.e.reyno...@gmail.com> > > wrote: > > > >> On 16/10/16 16:59, tina sani wrote: > >> > >>> Hi > >>> > >>> What is the difference between addLiteral() and setpropertyvalue() > when we > >>> want to assign values to an individual.? > >>> For example, > >>> > >>> //myEmployee is an instance. > >>> > >>> myEmplyee.addliteral(property, value) > >>> myEmployee.setpropertyvalue(property, value) > >>> > >>> > >> addLiteral adds a value, so if there is already a value there you will > now > >> have multiple values. > >> > >> setPropertyValue removes all existing values before adding the new value > >> so you will only have the new value at the end. > >> > >> Dave > >> > >> > -- > Lorenz Bühmann > AKSW group, University of Leipzig > Group: http://aksw.org - semantic web research center > >
Re: addliteral() vs setpropertyvalue()
Hello Tina, > I want to sum 5 with the value already stored in a property. > > //Property "Hours" must be started from 1 and then sum 5 with it. > employee.getPropertyValue(No_of_Hours); > //Then perform calculations. > > The problem is that if I directly use employee.getPropertyValue(), it gives > me "Exception" (and rightly, because I did not set setPropertyValue() > first). That's not true. It returns null if there is no such value - and you have to handle this in the code indeed. > > But the problem is that when I set employee.getPropertyValue(No_of_Hours); > to 1 (one), it will always set the value 1(one) and not the recent > added(sum) value in the property. > > employee.setPropertyValue(No_of_Hours, 1); //1 is literal > employee.getPropertyValue(No_of_Hours); > //calculations > My requirement is like: int sum=No_of_Hours+1; > Then No_of_Hours plus what in the *variable sum*. > > So can I use employee.addLiteral(No_of_Hours, 1) instead of > employee.setPropertyValue(). > > I hope you have understood what my issue is? > > Kindest regards > > > > On Sun, Oct 16, 2016 at 11:10 AM, Dave Reynolds > wrote: > >> On 16/10/16 16:59, tina sani wrote: >> >>> Hi >>> >>> What is the difference between addLiteral() and setpropertyvalue() when we >>> want to assign values to an individual.? >>> For example, >>> >>> //myEmployee is an instance. >>> >>> myEmplyee.addliteral(property, value) >>> myEmployee.setpropertyvalue(property, value) >>> >>> >> addLiteral adds a value, so if there is already a value there you will now >> have multiple values. >> >> setPropertyValue removes all existing values before adding the new value >> so you will only have the new value at the end. >> >> Dave >> >> -- Lorenz Bühmann AKSW group, University of Leipzig Group: http://aksw.org - semantic web research center
Re: addliteral() vs setpropertyvalue()
I want to sum 5 with the value already stored in a property. //Property "Hours" must be started from 1 and then sum 5 with it. employee.getPropertyValue(No_of_Hours); //Then perform calculations. The problem is that if I directly use employee.getPropertyValue(), it gives me "Exception" (and rightly, because I did not set setPropertyValue() first). But the problem is that when I set employee.getPropertyValue(No_of_Hours); to 1 (one), it will always set the value 1(one) and not the recent added(sum) value in the property. employee.setPropertyValue(No_of_Hours, 1); //1 is literal employee.getPropertyValue(No_of_Hours); //calculations My requirement is like: int sum=No_of_Hours+1; Then No_of_Hours plus what in the *variable sum*. So can I use employee.addLiteral(No_of_Hours, 1) instead of employee.setPropertyValue(). I hope you have understood what my issue is? Kindest regards On Sun, Oct 16, 2016 at 11:10 AM, Dave Reynolds wrote: > On 16/10/16 16:59, tina sani wrote: > >> Hi >> >> What is the difference between addLiteral() and setpropertyvalue() when we >> want to assign values to an individual.? >> For example, >> >> //myEmployee is an instance. >> >> myEmplyee.addliteral(property, value) >> myEmployee.setpropertyvalue(property, value) >> >> > addLiteral adds a value, so if there is already a value there you will now > have multiple values. > > setPropertyValue removes all existing values before adding the new value > so you will only have the new value at the end. > > Dave > >
Re: addliteral() vs setpropertyvalue()
Using Javadoc quite often helps... Given that you have an Individual, you can find links at [1] to explanations for both methods [2] [3] [1] https://jena.apache.org/documentation/javadoc/jena/org/apache/jena/ontology/Individual.html [2] https://jena.apache.org/documentation/javadoc/jena/org/apache/jena/rdf/model/Resource.html#addLiteral-org.apache.jena.rdf.model.Property-boolean- [3] https://jena.apache.org/documentation/javadoc/jena/org/apache/jena/ontology/OntResource.html#setPropertyValue-org.apache.jena.rdf.model.Property-org.apache.jena.rdf.model.RDFNode- On 16.10.2016 17:59, tina sani wrote: > Hi > > What is the difference between addLiteral() and setpropertyvalue() when we > want to assign values to an individual.? > For example, > > //myEmployee is an instance. > > myEmplyee.addliteral(property, value) > myEmployee.setpropertyvalue(property, value) >
Re: addliteral() vs setpropertyvalue()
On 16/10/16 16:59, tina sani wrote: Hi What is the difference between addLiteral() and setpropertyvalue() when we want to assign values to an individual.? For example, //myEmployee is an instance. myEmplyee.addliteral(property, value) myEmployee.setpropertyvalue(property, value) addLiteral adds a value, so if there is already a value there you will now have multiple values. setPropertyValue removes all existing values before adding the new value so you will only have the new value at the end. Dave
