apis/examples_java/Transport1_8java_source.html

package com.gams.examples.transport;


 import java.io.*;


 import com.gams.api.*;


 public class Transport1 {


     public static void main(String[] args) {

         GAMSWorkspace ws = null;

         // check workspace info from command line arguments

         if (args.length > 0) {

             GAMSWorkspaceInfo wsInfo = new GAMSWorkspaceInfo();

             wsInfo.setSystemDirectory(args[0]);

             // create GAMSWorkspace "ws" with user-specified system directory and the default working directory

             // (the directory named with current date and time under System.getProperty("java.io.tmpdir"))

             ws = new GAMSWorkspace(wsInfo);

         } else {

             // create GAMSWorkspace "ws" with default system directory and default working directory

             // (the directory named with current date and time under System.getProperty("java.io.tmpdir"))

             ws = new GAMSWorkspace();

         }


         // create GAMSJob "t1" from "trnsport" model in GAMS Model Libraries

         GAMSJob t1 = ws.addJobFromGamsLib("trnsport");

         // run GAMSJob "t1"

         t1.run();


         // retrieve GAMSVariable "x" from GAMSJob's output databases

         System.out.println("Ran with Default:");

         GAMSVariable x = t1.OutDB().getVariable("x");

         for (GAMSVariableRecord rec :  x) {

             System.out.print("x(" + rec.getKey(0) + ", " + rec.getKey(1) + "):");

             System.out.print(", level    = " + rec.getLevel());

             System.out.println(", marginal = " + rec.getMarginal());

         }


         // create GAMSOptions "opt1"

         GAMSOptions opt1 = ws.addOptions();

         // set all model types of "opt1" for "xpress"

         opt1.setAllModelTypes("xpress");

         // run GAMSJob "t1" with GAMSOptions "opt1"

         t1.run(opt1);


         // retrieve GAMSVariable "x" from GAMSJob's output databases

         GAMSDatabase db1 = t1.OutDB();

         System.out.println("Ran with XPRESS:");

         for (GAMSVariableRecord rec : db1.getVariable("x")) {

             System.out.print("x(" + rec.getKey(0) + ", " + rec.getKey(1) + "):");

             System.out.print(", level    = " + rec.getLevel());

             System.out.println(", marginal = " + rec.getMarginal());

         }


         // write file "xpress.opt" under GAMSWorkspace's working directory

         try {

             BufferedWriter optFile = new BufferedWriter(new FileWriter(ws.workingDirectory() + GAMSGlobals.FILE_SEPARATOR + "xpress.opt"));

             optFile.write("algorithm=barrier");

             optFile.close();

          } catch(IOException e) {

               e.printStackTrace();

               System.exit(-1);

          }


         // create GAMSOptions "opt2"

         GAMSOptions opt2 = ws.addOptions();

         // set all model types of "opt2" for "xpress"

         opt2.setAllModelTypes( "xpress" );

         // for "opt2", use "xpress.opt" as solver's option file

         opt2.setOptFile(1);


         try {

            // run GAMSJob "t2" with GAMSOptions "opt2" and capture log into "transport1_xpress.log".

            PrintStream output = new PrintStream(new File(ws.workingDirectory() + GAMSGlobals.FILE_SEPARATOR +"transport1_xpress.log"));

            t1.run(opt2, output);

         } catch (FileNotFoundException e) {

            // run GAMSJob "t2" with GAMSOptions "opt2" and log is written to standard output

            t1.run(opt2);

         }


         // retrieve GAMSVariable "x" from GAMSJob's output databases

         GAMSDatabase db2 = t1.OutDB();

         System.out.println("Ran with XPRESS with non-default option:");

         for (GAMSVariableRecord rec : db2.getVariable("x")) {

             System.out.print("x(" + rec.getKey(0) + ", " + rec.getKey(1) + "):");

             System.out.print(", level    = " + rec.getLevel());

             System.out.println(", marginal = " + rec.getMarginal());

         }


         // dispose option and database

         opt1.dispose();

         opt2.dispose();

         db1.dispose();

         db2.dispose();

         // cleanup GAMSWorkspace's working directory

         cleanup(ws.workingDirectory());

         // terminate program

         System.exit(0);

     }


     static void cleanup(String directory)  {

         File directoryToDelete = new File(directory);

         String files[] = directoryToDelete.list();

         for (String file : files) {

             File fileToDelete = new File(directoryToDelete, file);

             try {

                  fileToDelete.delete();

             } catch(Exception e){

                  e.printStackTrace();

             }

         }

         try {

            directoryToDelete.delete();

         } catch(Exception e) {

             e.printStackTrace();

         }

     }

 }