使用jxl API将HashMap打印到Excel

Question

I want to print a HashMap onto an Excel Sheet. I am iterating through the map and extracting the key, value into a label. However, I am unable to print all the fields of the HashMap. Here's my code.

import java.io.File;
import java.util.HashMap;
import java.util.Map.Entry;

import jxl.Workbook;
import jxl.write.Label;
import jxl.write.WritableSheet;
import jxl.write.WritableWorkbook;

class WriteExcel {

    HashMap<Integer, String> map = new HashMap<Integer, String>();

    public void writeToFile() throws Exception {

        WritableWorkbook wworkbook = Workbook.createWorkbook(new File("D:\\output.xls"));
        WritableSheet wsheet = wworkbook.createSheet("First Sheet", 0);

        Label l1 = new Label(0, 0, "Serial No");
        Label l2 = new Label(1, 0, "Name");
        wsheet.addCell(l1);
        wsheet.addCell(l2);

        map.put(1, "Hello");
        map.put(2, "World");
        map.put(3, "StackOverflow");
        map.put(4, "StackExchange");

        for (Entry<Integer, String> entry : map.entrySet()) {
            int i = 2;
            Label lbl1 = new Label(0, i, entry.getKey().toString());
            Label lbl2 = new Label(1, i, entry.getValue());
            i++;
            wsheet.addCell(lbl1);
            wsheet.addCell(lbl2);
            wworkbook.write();
        }
        wworkbook.write();
        wworkbook.close();
    }
}

public class Test2 {

    public static void main(String[] args) 
    {
        WriteExcel write = new WriteExcel();
        try {
            write.writeToFile();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

I am able to print only first record of map . ---> ie 1 Hello

The other records of map are not printed.

Could someone tell why is that so.?

What's wrong in the code.?

Answer 1

There are two problems with the loop: the first: i should be declared outside in order not to override itself to 2 every time, and the second is that you should call wworkbook.write(); only once after you're done adding all the cells.

The following change made it work on my computer:

    int i = 2;
    for (Entry<Integer, String> entry : map.entrySet()) {
        Label lbl1 = new Label(0, i, entry.getKey().toString());
        Label lbl2 = new Label(1, i, entry.getValue());
        i++;
        wsheet.addCell(lbl1);
        wsheet.addCell(lbl2);
    }
    wworkbook.write();
    wworkbook.close();