POI 使用总结

  之前用POI做了一段时间的报表，也对POI的一些方法重写了，用起来还算方便。也没什么特别的，主要就是对HSSFWorkbook，HSSFSheet，HSSFRow， HSSFCell的操作了，掌握了对这四个东西的控制，你想怎么写就怎么写。
1，首先写一个abstract class用来overwrite HSSF。

package com.eagle.excel;

import java.util.ArrayList;

import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFCellStyle;

/**
 * @author eyas
 * @version 1.0
 * @date Apr 28, 2007 10:41:26 PM
 */
public abstract class ExportInfoToExcel
{	
        /**
         * create report header
        */
	protected abstract void createHead();

        /**
         *create report body
         *columns:table header
         *itemList:row data
         */
	protected abstract void createBody(String[] columns, ArrayList itemlist);

        /**
         *create report footer, ex:someone total information.
         */
	protected abstract void createFoot();
         
        /**
         * write data to a Excel cell.this method is overloadabled.
         */
	public void createCell(HSSFCellStyle cellStyle, HSSFCell cell, String  value)
	{
		cell.setEncoding(HSSFCell.ENCODING_UTF_16);
		cell.setCellStyle(cellStyle);
		cell.setCellValue(value);
	}
}

2,再写一个interface 用来给Excel 传递数据，并生成Excel file,

package com.eagle.excel;

import java.io.File;
import java.util.ArrayList;
import java.util.Calendar;

/**
 * @author eyas
 * @version 1.0
 * @date Apr 28, 2007 10:41:26 PM
 */
public interface ExportInfoInterface
{

	public void setDate(Calendar startDate); // report print date
	public void setColumns(String[] columns); // report columns

	public void setDataList(ArrayList itemList); //data

	public void produceExportFile(File exportfile) throws Exception;//create excel file
	public void setOtherArg(Object arg1);// other arguments
}

3，然后就可以写一个类，用来接收数据，extends ,implements 上面的abstract class and interface.

package com.eagle.excel;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Calendar;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hssf.util.Region;

/**
 * @author eyas
 * @version 1.0
 * @date Apr 28, 2007 10:43:26 PM
 */
public class CreateExcelFile extends ExportInfoToExcel implements ExportInfoInterface
{
	private HSSFWorkbook workbook;
	private HSSFSheet sheet;
	private ArrayList dataList;
	private Calendar date;
        private String[] columns;
        private int lineX = 0;
	public CreateExcelFile ()
	{
           //initialized someone arguments
	}

	@Override
	protected void createBody()
	{	
		HSSFRow bodyTile = sheet.createRow(lineX++);
		for (int i = 0; i < columns.length; i++)
		{
			createCell(bodyTile.createCell((short) i), columns[i]);
		}
		HSSFRow bodyRow;
		for (int i = 0; i < dataList.size(); i++)
		{
		    bodyRow = sheet.createRow(lineX++);
                    createCell(null,bodyRow.createCell((short) 0),(i+1));
                    createCell(null,bodyRow.createCell((short) 1),"eyas");
                    createCell(null,bodyRow.createCell((short) 2),"software");
                        ...
		}
	}

	@Override
	protected void createFoot()
	{
		HSSFRow totalRow = sheet.createRow(lineX++);
                createCell(null,bodyRow.createCell((short) 0),"total data");
	}

	@Override
	protected void createHead()
	{
		lineX = 0;
		sheet.addMergedRegion(new Region(0, (short) 0, 0, (short) 12));
		HSSFRow headRow0 = sheet.createRow(lineX++);
		createCell(null,headRow0.createCell((short) 0), "My Excel Report");

	}

	public void produceExportFile(File exportfile) throws Exception
	{
		try
		{
			workbook = new HSSFWorkbook();
			sheet = workbook.createSheet("First Page");
			createHead();
			createBody();
			FileOutputStream fw = new FileOutputStream(exportfile);
			workbook.write(fw);
			fw.flush();
			fw.close();
			workbook = null;
			sheet = null;
			fw = null;
                         System.out.println("Export success!");
		} catch (IOException ioe)
		{
			ioe.printStackTrace();
		}catch (Exception e)
		{
			e.printStackTrace();
		}
	}

	public void setColumns(String[] columns)
	{
		this.columns = columns;
	}

	public void setDataList(ArrayList dataList)
	{
		this.dataList = dataList;
	}

	public void setOtherArg(Object arg1)
	{

	}

	public void setDate(Calendar date)
	{
		this.date = date;
	}

}

仅对产生Excel报表，使用POI几个步骤的总结，不能保证代码完全 runable,如有改进建议，敬请发表。