Now you are ready to put everything together and create a REST service. But solving planning problems on REST threads causes HTTP timeout issues. Therefore, the Spring Boot starter injects a SolverManager, which runs solvers in a separate thread pool and can solve multiple datasets in parallel.
Procedure
Create the src/main/java/com/example/solver/TimeTableController.java class:
package com.example.solver;
import java.util.UUID;
import java.util.concurrent.ExecutionException;
import com.example.domain.TimeTable;
import org.optaplanner.core.api.solver.SolverJob;
import org.optaplanner.core.api.solver.SolverManager;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
@RequestMapping("/timeTable")
public class TimeTableController {
@Autowired
private SolverManager<TimeTable, UUID> solverManager;
@PostMapping("/solve")
public TimeTable solve(@RequestBody TimeTable problem) {
UUID problemId = UUID.randomUUID();
// Submit the problem to start solving
SolverJob<TimeTable, UUID> solverJob = solverManager.solve(problemId, problem);
TimeTable solution;
try {
// Wait until the solving ends
solution = solverJob.getFinalBestSolution();
} catch (InterruptedException | ExecutionException e) {
throw new IllegalStateException("Solving failed.", e);
}
return solution;
}
}
package com.example.solver;
import java.util.UUID;
import java.util.concurrent.ExecutionException;
import com.example.domain.TimeTable;
import org.optaplanner.core.api.solver.SolverJob;
import org.optaplanner.core.api.solver.SolverManager;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
@RequestMapping("/timeTable")
public class TimeTableController {
@Autowired
private SolverManager<TimeTable, UUID> solverManager;
@PostMapping("/solve")
public TimeTable solve(@RequestBody TimeTable problem) {
UUID problemId = UUID.randomUUID();
// Submit the problem to start solving
SolverJob<TimeTable, UUID> solverJob = solverManager.solve(problemId, problem);
TimeTable solution;
try {
// Wait until the solving ends
solution = solverJob.getFinalBestSolution();
} catch (InterruptedException | ExecutionException e) {
throw new IllegalStateException("Solving failed.", e);
}
return solution;
}
}
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In this example, the initial implementation waits for the solver to finish, which can still cause an HTTP timeout. The complete implementation avoids HTTP timeouts much more elegantly.