Compile and run java program with mutiple external jar files

Question

I have a simple program that uses apache.poi external libraries in order to manipulate excel files. I used eclipse in a windows environment and now I have to compile and run my program on linux with terminal. I searched how to include those jars that I need but I ended up with the following error:

Error: Could not find or load main class xlsToCsv.

The steps that I followed are this:

javac -cp ./jars/poi-3.13-20150929.jar:./jars/poi-ooxml-schemas-3.13-20150929.jar:./jars/poi-ooxml-3.13-20150929.jar:./jars/xmlbeans-2.6.0.jar xlsToCsv.java

java -cp ./jars/poi-3.13-20150929.jar:./jars/poi-ooxml-schemas-3.13-20150929.jar:./jars/poi-ooxml-3.13-20150929.jar:./jars/xmlbeans-2.6.0.jar xlsToCsv

My current directory is /home/demo/Desktop/xls_to_csv where is the xlsToCsv.java file. The jar files are in /home/demo/Desktop/xls_to_csv/jars.

Anyone can tell me and explain the right syntax? Is possible to call a folder with all jar files instead of call them individualy?

Thanks in advance.

EDIT, MY CODE:

    import java.io.File;
    import java.io.FileInputStream;
    import java.io.FileOutputStream;
    import java.util.Iterator;
    import org.apache.poi.hssf.usermodel.HSSFFormulaEvaluator;
    import org.apache.poi.hssf.usermodel.HSSFWorkbook;
    import org.apache.poi.ss.usermodel.Cell;
    import org.apache.poi.ss.usermodel.DataFormatter;
    import org.apache.poi.ss.usermodel.FormulaEvaluator;
    import org.apache.poi.ss.usermodel.Row;
    import org.apache.poi.ss.usermodel.Sheet;

public class xlsToCsv {

    static void convert(File input, File output) throws Exception {

        StringBuffer data = new StringBuffer();

        FileOutputStream fos = new FileOutputStream(output);
        HSSFWorkbook file = new HSSFWorkbook(new FileInputStream(input));
        DataFormatter objDefaultFormat = new DataFormatter();
        FormulaEvaluator objFormulaEvaluator = new HSSFFormulaEvaluator((HSSFWorkbook) file);

        Sheet sheet;
        Row row;
        Cell cell;

        String sheetName, cellValue;
        int cellType, rowIndex = 0, columnIndex = 0;
        boolean blankRow = true, blankArea = true;


        Iterator<Sheet> sheetIt;
        Iterator<Row> rowIt;
        Iterator<Cell> cellIt;

        sheetIt = file.iterator();
        while(sheetIt.hasNext()) {
            sheet = sheetIt.next();
            sheetName = sheet.getSheetName();

            rowIt = sheet.iterator();
            while(rowIt.hasNext()) {
                row = rowIt.next();

                cellIt = row.iterator();
                while (cellIt.hasNext()) {
                    cell = cellIt.next();
                    cellType = cell.getCellType();

                    if(!isBlankCell(cellType) || !blankArea) {
                        if(rowIndex == 0 && columnIndex == 0)
                            data.append(sheetName + " - Header" + ";");
                        else if(rowIndex > 0 && columnIndex == 0)
                            data.append(sheetName + ";");

                        objFormulaEvaluator.evaluateInCell(cell);
                        cellValue = objDefaultFormat.formatCellValue(cell,objFormulaEvaluator);

                        if(cellValue.isEmpty())
                            data.append(";");
                        else
                            data.append(cellValue + ";");

                        columnIndex++;
                        blankRow = false;
                        blankArea = false;
                    }
                }

                if(!blankRow) {
                    data.append('\n');
                    rowIndex++;
                }

                blankRow = true;
                columnIndex = 0;
            }
            //new sheet => reset control fields
            rowIndex = 0;
            columnIndex = 0;
            blankRow = true;
            blankArea = true;
        }

        fos.write(data.toString().getBytes());
        fos.close();
    }

    private static boolean isBlankCell(int cellType) {
        return cellType == Cell.CELL_TYPE_BLANK
                || cellType == Cell.CELL_TYPE_ERROR
                || cellType == Cell.CELL_TYPE_FORMULA;
    }

    public static void main(String[] args) {

        if(args.length < 2 || args.length > 2) {
            System.err.println("Insert input and output path");
            System.exit(0);
        }

        File input = new File(args[0]);
        File output = new File(args[1]);

        try {
            convert(input, output);
            System.out.println("File " + output.getName() + "created sucessfully");

        } catch(Exception e) {
            e.printStackTrace();
        }
    }
}

Answer 1

If you want to add directory while contains all the required jars for running/ compiling your Java file you can use below command:

In Windows:

java -classpath ".;c:\lib*" MainClass

In UNIX/ Linux

java -classpath ".:/lib/*" MainClass

Note: In windows ; (semicolon) is the separator, while in UNIX/ Linux : (colon) is the separator for multiple jar for directory

. (dot) represents current directory