How to adapt and OPL code to Java API using Eclipse IDE

Question

I am trying to adapt an OPL formulation using the Java API in Eclipse IDE. Extraction of the original OPL code is the following:

using CP;

int nbJobs = ...;                               
int nbMchs = ...;       

range Jobs = 0..nbJobs-1;                                                   
range Mchs = 0..nbMchs-1; 

int OpDurations[j in Jobs][m in Mchs] = ...;                                

dvar interval itvs[j in Jobs][m in Mchs] size OpDurations[j][m];                    
dvar sequence mchs[m in Mchs] in all(j in Jobs) itvs[j][m] types all(j in Jobs) j;      
dvar sequence jobs[j in Jobs] in all(m in Mchs) itvs[j][m];

I want to replicate the same above but now using the Java API. I had tried the following: (filename is a file with the values of an instance where is specified the number of jobs, number of machines and the processing time of every job in every machine):

IloCP cp = new IloCP();
DataReader data = new DataReader(filename);

int nbJobs = data.next();
int nbMachines = data.next();
int OpDurations = data.next();

IloIntRange Jobs = cp.intRange(0,nbJobs-1);
IloIntRange Mchs = cp.intRange(0,nbMachines-1);

But I don't know if that is correct and also how to replicate in Java the definition of the interval and sequences variables previously defined in OPL.

Any help would be highly appreciated.

Answer 1

Your code looks correct at first glance.

For creation of variables take a look at the reference documentation of IloIntervalVar and IloIntervalSequenceVar as well as functions IloCP.intervalVar() and IloCP.intervalSequenceVar() here.

Moreover, in your distribution you have a folder cpoptimizer/examples/src/java in which you can find examples Sched*.java. These use interval variables and you can learn from them how to do scheduling with interval variables.