lpurlwriter.java

著名IT公司ILog的APS高级排产优化引擎

package com.power.lpsolver.LPSolve;
import java.util.*;
import java.io.*;
import java.net.*;

import com.power.pipe.*;

import com.power.util.Message.*;
import com.power.util.urltools.*;

public class LPURLWriter
{
   private static final LPURLWriter INSTANCE =
                              new LPURLWriter();

    private BufferedWriter _myFileWriter; //initialized in subclass

   // Private constructor supresses
   // default public constructor
    private LPURLWriter( ) {
    }

    public static LPURLWriter getInstance( ) {
        return INSTANCE;
    }

    private StringBuffer content = new StringBuffer();
    private String urlAddr = GlobalConfig.getInstance().getLPServerURL() +
                             "com.power.pipeengine.LP_ReadWriteFile";


	public void write( String outDir ) {

        printObj();

        Vector allCons = Model.getInstance().getModelConstraints().getConstraints();
        MessageArea.getInstance().addMessage( "Total number of constraints: " + allCons.size() + "\n");

		for( int i=0; i<allCons.size(); i++ ) {
			Constraint con = (Constraint) allCons.elementAt( i );
			printCon( con );

            if( (i%100) == 0 ) {
                MessageArea.getInstance().addMessage( "Number of consrtaints generated: " + i+ "\n");
            }
		}


        URLFileWriter.getInstance().write( urlAddr,
                                           "c:\\paraster\\lpsolver\\model.lp",
                                           "WriteModel",
                                           content.toString() );

	}


	public void printObj() {
		content.append( "Min" + ": ");
		Enumeration allElems = Model.getInstance().getObjectiveFunction().getElements().elements();
		ModelVariables mdlVars = Model.getInstance().getModelVariables();

		while( allElems.hasMoreElements() ) {
			Element elem = (Element) allElems.nextElement();
			Variable var = mdlVars.getVariable( elem.getColumnNumber() );
			if( elem.getCoefficient() > 0 ) {
				content.append(" + ");
			} else {
				content.append(" - ");
			}
			content.append(Math.abs( elem.getCoefficient() ));
			content.append(var.getMPSName());
		}

		content.append(";\n");
	}

    /**
     * Prints the constraint in a readable format (LP format).
     */
	public void printCon( Constraint con ) {
		Enumeration allElems = con.getElements().elements();
		ModelVariables mdlVars = Model.getInstance().getModelVariables();


		while( allElems.hasMoreElements() ) {
			Element elem = (Element) allElems.nextElement();
			Variable var = mdlVars.getVariable( elem.getColumnNumber() );
			if( elem.getCoefficient() > 0 ) {
				content.append(" + ");
			} else {
				content.append(" - ");
			}
			content.append(Math.abs( elem.getCoefficient() ));
			content.append(var.getMPSName());
		}

		content.append(" " + con.getSign() + " " + con.getRHS() + ";\n");
	}

}