cmake: Add java samples (#202)

ortools/java/CMakeTest.java

@@ -0,0 +1,34 @@
+package com.google.ortools;
+
+import com.google.ortools.Loader;
+import com.google.ortools.linearsolver.MPConstraint;
+import com.google.ortools.linearsolver.MPObjective;
+import com.google.ortools.linearsolver.MPSolver;
+import com.google.ortools.linearsolver.MPVariable;
+import org.junit.jupiter.api.Test;
+
+/** @author Mizux */
+public class Test {
+  @Test
+  public void testLP() {
+    Loader.loadNativeLibraries();
+    MPSolver solver =
+      new MPSolver("SimpleLpProgram", MPSolver.OptimizationProblemType.GLOP_LINEAR_PROGRAMMING);
+    MPVariable x = solver.makeNumVar(0.0, 1.0, "x");
+    MPVariable y = solver.makeNumVar(0.0, 2.0, "y");
+    System.out.println("Number of variables = " + solver.numVariables());
+    MPConstraint ct = solver.makeConstraint(0.0, 2.0, "ct");
+    ct.setCoefficient(x, 1);
+    ct.setCoefficient(y, 1);
+    System.out.println("Number of constraints = " + solver.numConstraints());
+    MPObjective objective = solver.objective();
+    objective.setCoefficient(x, 3);
+    objective.setCoefficient(y, 1);
+    objective.setMaximization();
+    solver.solve();
+    System.out.println("Solution:");
+    System.out.println("Objective value = " + objective.value());
+    System.out.println("x = " + x.solutionValue());
+    System.out.println("y = " + y.solutionValue());
+  }
+}