Java POI导出EXCEL经典实现 Java导出Excel弹出下载框 [转]

http://blog.csdn.net/evangel_z/article/details/7332535

在web开发中，有一个经典的功能，就是数据的导入导出。特别是数据的导出，在生产管理或者财务系统中用的非常普遍，因为这些系统经常要做一些报表打印的工作。而数据导出的格式一般是EXCEL或者PDF，我这里就用两篇文章分别给大家介绍下。（注意，我们这里说的数据导出可不是数据库中的数据导出！么误会啦^_^）

         呵呵，首先我们来导出EXCEL格式的文件吧。现在主流的操作Excel文件的开源工具有很多,用得比较多的就是Apache的POI及JExcelAPI。这里我们用Apache POI！我们先去Apache的大本营下载POI的jar包：http://poi.apache.org/ ，我这里使用的是3.0.2版本。

        将3个jar包导入到classpath下，什么？忘了怎么导包？不会吧！好，我们来写一个导出Excel的实用类（所谓实用，是指基本不用怎么修改就可以在实际项目中直接使用的！）。我一直强调做类也好，做方法也好，一定要通用性和灵活性强。下面这个类就算基本贯彻了我的这种思想。那么，熟悉许老师风格的人应该知道，这时候该要甩出一长串代码了。没错，大伙请看：

import java.util.Date;  
  
public class Student  
{  
    private long id;  
    private String name;  
    private int age;  
    private boolean sex;  
    private Date birthday;  
  
    public Student()  
    {  
    }  
  
    public Student(long id, String name, int age, boolean sex, Date birthday)  
    {  
        this.id = id;  
        this.name = name;  
        this.age = age;  
        this.sex = sex;  
        this.birthday = birthday;  
    }  
  
    public long getId()  
    {  
        return id;  
    }  
  
    public void setId(long id)  
    {  
        this.id = id;  
    }  
  
    public String getName()  
    {  
        return name;  
    }  
  
    public void setName(String name)  
    {  
        this.name = name;  
    }  
  
    public int getAge()  
    {  
        return age;  
    }  
  
    public void setAge(int age)  
    {  
        this.age = age;  
    }  
  
    public boolean getSex()  
    {  
        return sex;  
    }  
  
    public void setSex(boolean sex)  
    {  
        this.sex = sex;  
    }  
  
    public Date getBirthday()  
    {  
        return birthday;  
    }  
  
    public void setBirthday(Date birthday)  
    {  
        this.birthday = birthday;  
    }  
  
}  
import java.util.Date;

public class Student
{
    private long id;
    private String name;
    private int age;
    private boolean sex;
    private Date birthday;

    public Student()
    {
    }

    public Student(long id, String name, int age, boolean sex, Date birthday)
    {
        this.id = id;
        this.name = name;
        this.age = age;
        this.sex = sex;
        this.birthday = birthday;
    }

    public long getId()
    {
        return id;
    }

    public void setId(long id)
    {
        this.id = id;
    }

    public String getName()
    {
        return name;
    }

    public void setName(String name)
    {
        this.name = name;
    }

    public int getAge()
    {
        return age;
    }

    public void setAge(int age)
    {
        this.age = age;
    }

    public boolean getSex()
    {
        return sex;
    }

    public void setSex(boolean sex)
    {
        this.sex = sex;
    }

    public Date getBirthday()
    {
        return birthday;
    }

    public void setBirthday(Date birthday)
    {
        this.birthday = birthday;
    }

}[java] view plaincopyprint?
public class Book  
{  
    private int bookId;  
    private String name;  
    private String author;  
    private float price;  
    private String isbn;  
    private String pubName;  
    private byte[] preface;  
  
    public Book()  
    {  
    }  
  
    public Book(int bookId, String name, String author, float price,  
            String isbn, String pubName, byte[] preface)  
    {  
        this.bookId = bookId;  
        this.name = name;  
        this.author = author;  
        this.price = price;  
        this.isbn = isbn;  
        this.pubName = pubName;  
        this.preface = preface;  
    }  
  
    public int getBookId()  
    {  
        return bookId;  
    }  
  
    public void setBookId(int bookId)  
    {  
        this.bookId = bookId;  
    }  
  
    public String getName()  
    {  
        return name;  
    }  
  
    public void setName(String name)  
    {  
        this.name = name;  
    }  
  
    public String getAuthor()  
    {  
        return author;  
    }  
  
    public void setAuthor(String author)  
    {  
        this.author = author;  
    }  
  
    public float getPrice()  
    {  
        return price;  
    }  
  
    public void setPrice(float price)  
    {  
        this.price = price;  
    }  
  
    public String getIsbn()  
    {  
        return isbn;  
    }  
  
    public void setIsbn(String isbn)  
    {  
        this.isbn = isbn;  
    }  
  
    public String getPubName()  
    {  
        return pubName;  
    }  
  
    public void setPubName(String pubName)  
    {  
        this.pubName = pubName;  
    }  
  
    public byte[] getPreface()  
    {  
        return preface;  
    }  
  
    public void setPreface(byte[] preface)  
    {  
        this.preface = preface;  
    }  
}  
public class Book
{
    private int bookId;
    private String name;
    private String author;
    private float price;
    private String isbn;
    private String pubName;
    private byte[] preface;

    public Book()
    {
    }

    public Book(int bookId, String name, String author, float price,
            String isbn, String pubName, byte[] preface)
    {
        this.bookId = bookId;
        this.name = name;
        this.author = author;
        this.price = price;
        this.isbn = isbn;
        this.pubName = pubName;
        this.preface = preface;
    }

    public int getBookId()
    {
        return bookId;
    }

    public void setBookId(int bookId)
    {
        this.bookId = bookId;
    }

    public String getName()
    {
        return name;
    }

    public void setName(String name)
    {
        this.name = name;
    }

    public String getAuthor()
    {
        return author;
    }

    public void setAuthor(String author)
    {
        this.author = author;
    }

    public float getPrice()
    {
        return price;
    }

    public void setPrice(float price)
    {
        this.price = price;
    }

    public String getIsbn()
    {
        return isbn;
    }

    public void setIsbn(String isbn)
    {
        this.isbn = isbn;
    }

    public String getPubName()
    {
        return pubName;
    }

    public void setPubName(String pubName)
    {
        this.pubName = pubName;
    }

    public byte[] getPreface()
    {
        return preface;
    }

    public void setPreface(byte[] preface)
    {
        this.preface = preface;
    }
}

 

上面这两个类一目了然，就是两个简单的javabean风格的类。再看下面真正的重点类：

import java.io.BufferedInputStream;  
import java.io.FileInputStream;  
import java.io.FileNotFoundException;  
import java.io.FileOutputStream;  
import java.io.IOException;  
import java.io.OutputStream;  
import java.lang.reflect.Field;  
import java.lang.reflect.InvocationTargetException;  
import java.lang.reflect.Method;  
import java.text.SimpleDateFormat;  
import java.util.ArrayList;  
import java.util.Collection;  
import java.util.Date;  
import java.util.Iterator;  
import java.util.List;  
import java.util.regex.Matcher;  
import java.util.regex.Pattern;  
  
import javax.swing.JOptionPane;  
  
import org.apache.poi.hssf.usermodel.HSSFCell;  
import org.apache.poi.hssf.usermodel.HSSFCellStyle;  
import org.apache.poi.hssf.usermodel.HSSFClientAnchor;  
import org.apache.poi.hssf.usermodel.HSSFComment;  
import org.apache.poi.hssf.usermodel.HSSFFont;  
import org.apache.poi.hssf.usermodel.HSSFPatriarch;  
import org.apache.poi.hssf.usermodel.HSSFRichTextString;  
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.HSSFColor;  
  
/** 
 * 利用开源组件POI3.0.2动态导出EXCEL文档 转载时请保留以下信息，注明出处！ 
 *  
 * @author leno 
 * @version v1.0 
 * @param <T> 
 *            应用泛型，代表任意一个符合javabean风格的类 
 *            注意这里为了简单起见，boolean型的属性xxx的get器方式为getXxx(),而不是isXxx() 
 *            byte[]表jpg格式的图片数据 
 */  
public class ExportExcel<T>  
{  
    public void exportExcel(Collection<T> dataset, OutputStream out)  
    {  
        exportExcel("测试POI导出EXCEL文档", null, dataset, out, "yyyy-MM-dd");  
    }  
  
    public void exportExcel(String[] headers, Collection<T> dataset,  
            OutputStream out)  
    {  
        exportExcel("测试POI导出EXCEL文档", headers, dataset, out, "yyyy-MM-dd");  
    }  
  
    public void exportExcel(String[] headers, Collection<T> dataset,  
            OutputStream out, String pattern)  
    {  
        exportExcel("测试POI导出EXCEL文档", headers, dataset, out, pattern);  
    }  
  
    /** 
     * 这是一个通用的方法，利用了JAVA的反射机制，可以将放置在JAVA集合中并且符号一定条件的数据以EXCEL 的形式输出到指定IO设备上 
     *  
     * @param title 
     *            表格标题名 
     * @param headers 
     *            表格属性列名数组 
     * @param dataset 
     *            需要显示的数据集合,集合中一定要放置符合javabean风格的类的对象。此方法支持的 
     *            javabean属性的数据类型有基本数据类型及String,Date,byte[](图片数据) 
     * @param out 
     *            与输出设备关联的流对象，可以将EXCEL文档导出到本地文件或者网络中 
     * @param pattern 
     *            如果有时间数据，设定输出格式。默认为"yyy-MM-dd" 
     */  
    @SuppressWarnings("unchecked")  
    public void exportExcel(String title, String[] headers,  
            Collection<T> dataset, OutputStream out, String pattern)  
    {  
        // 声明一个工作薄   
        HSSFWorkbook workbook = new HSSFWorkbook();  
        // 生成一个表格   
        HSSFSheet sheet = workbook.createSheet(title);  
        // 设置表格默认列宽度为15个字节   
        sheet.setDefaultColumnWidth((short) 15);  
        // 生成一个样式   
        HSSFCellStyle style = workbook.createCellStyle();  
        // 设置这些样式   
        style.setFillForegroundColor(HSSFColor.SKY_BLUE.index);  
        style.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);  
        style.setBorderBottom(HSSFCellStyle.BORDER_THIN);  
        style.setBorderLeft(HSSFCellStyle.BORDER_THIN);  
        style.setBorderRight(HSSFCellStyle.BORDER_THIN);  
        style.setBorderTop(HSSFCellStyle.BORDER_THIN);  
        style.setAlignment(HSSFCellStyle.ALIGN_CENTER);  
        // 生成一个字体   
        HSSFFont font = workbook.createFont();  
        font.setColor(HSSFColor.VIOLET.index);  
        font.setFontHeightInPoints((short) 12);  
        font.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);  
        // 把字体应用到当前的样式   
        style.setFont(font);  
        // 生成并设置另一个样式   
        HSSFCellStyle style2 = workbook.createCellStyle();  
        style2.setFillForegroundColor(HSSFColor.LIGHT_YELLOW.index);  
        style2.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);  
        style2.setBorderBottom(HSSFCellStyle.BORDER_THIN);  
        style2.setBorderLeft(HSSFCellStyle.BORDER_THIN);  
        style2.setBorderRight(HSSFCellStyle.BORDER_THIN);  
        style2.setBorderTop(HSSFCellStyle.BORDER_THIN);  
        style2.setAlignment(HSSFCellStyle.ALIGN_CENTER);  
        style2.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);  
        // 生成另一个字体   
        HSSFFont font2 = workbook.createFont();  
        font2.setBoldweight(HSSFFont.BOLDWEIGHT_NORMAL);  
        // 把字体应用到当前的样式   
        style2.setFont(font2);  
  
        // 声明一个画图的顶级管理器   
        HSSFPatriarch patriarch = sheet.createDrawingPatriarch();  
        // 定义注释的大小和位置,详见文档   
        HSSFComment comment = patriarch.createComment(new HSSFClientAnchor(0,  
                0, 0, 0, (short) 4, 2, (short) 6, 5));  
        // 设置注释内容   
        comment.setString(new HSSFRichTextString("可以在POI中添加注释！"));  
        // 设置注释作者，当鼠标移动到单元格上是可以在状态栏中看到该内容.   
        comment.setAuthor("leno");  
  
        // 产生表格标题行   
        HSSFRow row = sheet.createRow(0);  
        for (short i = 0; i < headers.length; i++)  
        {  
            HSSFCell cell = row.createCell(i);  
            cell.setCellStyle(style);  
            HSSFRichTextString text = new HSSFRichTextString(headers[i]);  
            cell.setCellValue(text);  
        }  
  
        // 遍历集合数据，产生数据行   
        Iterator<T> it = dataset.iterator();  
        int index = 0;  
        while (it.hasNext())  
        {  
            index++;  
            row = sheet.createRow(index);  
            T t = (T) it.next();  
            // 利用反射，根据javabean属性的先后顺序，动态调用getXxx()方法得到属性值   
            Field[] fields = t.getClass().getDeclaredFields();  
            for (short i = 0; i < fields.length; i++)  
            {  
                HSSFCell cell = row.createCell(i);  
                cell.setCellStyle(style2);  
                Field field = fields[i];  
                String fieldName = field.getName();  
                String getMethodName = "get"  
                        + fieldName.substring(0, 1).toUpperCase()  
                        + fieldName.substring(1);  
                try  
                {  
                    Class tCls = t.getClass();  
                    Method getMethod = tCls.getMethod(getMethodName,  
                            new Class[]  
                            {});  
                    Object value = getMethod.invoke(t, new Object[]  
                    {});  
                    // 判断值的类型后进行强制类型转换   
                    String textValue = null;  
                    // if (value instanceof Integer) {   
                    // int intValue = (Integer) value;   
                    // cell.setCellValue(intValue);   
                    // } else if (value instanceof Float) {   
                    // float fValue = (Float) value;   
                    // textValue = new HSSFRichTextString(   
                    // String.valueOf(fValue));   
                    // cell.setCellValue(textValue);   
                    // } else if (value instanceof Double) {   
                    // double dValue = (Double) value;   
                    // textValue = new HSSFRichTextString(   
                    // String.valueOf(dValue));   
                    // cell.setCellValue(textValue);   
                    // } else if (value instanceof Long) {   
                    // long longValue = (Long) value;   
                    // cell.setCellValue(longValue);   
                    // }   
                    if (value instanceof Boolean)  
                    {  
                        boolean bValue = (Boolean) value;  
                        textValue = "男";  
                        if (!bValue)  
                        {  
                            textValue = "女";  
                        }  
                    }  
                    else if (value instanceof Date)  
                    {  
                        Date date = (Date) value;  
                        SimpleDateFormat sdf = new SimpleDateFormat(pattern);  
                        textValue = sdf.format(date);  
                    }  
                    else if (value instanceof byte[])  
                    {  
                        // 有图片时，设置行高为60px;   
                        row.setHeightInPoints(60);  
                        // 设置图片所在列宽度为80px,注意这里单位的一个换算   
                        sheet.setColumnWidth(i, (short) (35.7 * 80));  
                        // sheet.autoSizeColumn(i);   
                        byte[] bsValue = (byte[]) value;  
                        HSSFClientAnchor anchor = new HSSFClientAnchor(0, 0,  
                                1023, 255, (short) 6, index, (short) 6, index);  
                        anchor.setAnchorType(2);  
                        patriarch.createPicture(anchor, workbook.addPicture(  
                                bsValue, HSSFWorkbook.PICTURE_TYPE_JPEG));  
                    }  
                    else  
                    {  
                        // 其它数据类型都当作字符串简单处理   
                        textValue = value.toString();  
                    }  
                    // 如果不是图片数据，就利用正则表达式判断textValue是否全部由数字组成   
                    if (textValue != null)  
                    {  
                        Pattern p = Pattern.compile("^//d+(//.//d+)?$");  
                        Matcher matcher = p.matcher(textValue);  
                        if (matcher.matches())  
                        {  
                            // 是数字当作double处理   
                            cell.setCellValue(Double.parseDouble(textValue));  
                        }  
                        else  
                        {  
                            HSSFRichTextString richString = new HSSFRichTextString(  
                                    textValue);  
                            HSSFFont font3 = workbook.createFont();  
                            font3.setColor(HSSFColor.BLUE.index);  
                            richString.applyFont(font3);  
                            cell.setCellValue(richString);  
                        }  
                    }  
                }  
                catch (SecurityException e)  
                {  
                    e.printStackTrace();  
                }  
                catch (NoSuchMethodException e)  
                {  
                    e.printStackTrace();  
                }  
                catch (IllegalArgumentException e)  
                {  
                    e.printStackTrace();  
                }  
                catch (IllegalAccessException e)  
                {  
                    e.printStackTrace();  
                }  
                catch (InvocationTargetException e)  
                {  
                    e.printStackTrace();  
                }  
                finally  
                {  
                    // 清理资源   
                }  
            }  
        }  
        try  
        {  
            workbook.write(out);  
        }  
        catch (IOException e)  
        {  
            e.printStackTrace();  
        }  
    }  
  
    public static void main(String[] args)  
    {  
        // 测试学生   
        ExportExcel<Student> ex = new ExportExcel<Student>();  
        String[] headers =  
        { "学号", "姓名", "年龄", "性别", "出生日期" };  
        List<Student> dataset = new ArrayList<Student>();  
        dataset.add(new Student(10000001, "张三", 20, true, new Date()));  
        dataset.add(new Student(20000002, "李四", 24, false, new Date()));  
        dataset.add(new Student(30000003, "王五", 22, true, new Date()));  
        // 测试图书   
        ExportExcel<Book> ex2 = new ExportExcel<Book>();  
        String[] headers2 =  
        { "图书编号", "图书名称", "图书作者", "图书价格", "图书ISBN", "图书出版社", "封面图片" };  
        List<Book> dataset2 = new ArrayList<Book>();  
        try  
        {  
            BufferedInputStream bis = new BufferedInputStream(  
                    new FileInputStream("V://book.bmp"));  
            byte[] buf = new byte[bis.available()];  
            while ((bis.read(buf)) != -1)  
            {  
                //   
            }  
            dataset2.add(new Book(1, "jsp", "leno", 300.33f, "1234567",  
                    "清华出版社", buf));  
            dataset2.add(new Book(2, "java编程思想", "brucl", 300.33f, "1234567",  
                    "阳光出版社", buf));  
            dataset2.add(new Book(3, "DOM艺术", "lenotang", 300.33f, "1234567",  
                    "清华出版社", buf));  
            dataset2.add(new Book(4, "c++经典", "leno", 400.33f, "1234567",  
                    "清华出版社", buf));  
            dataset2.add(new Book(5, "c#入门", "leno", 300.33f, "1234567",  
                    "汤春秀出版社", buf));  
  
            OutputStream out = new FileOutputStream("E://a.xls");  
            OutputStream out2 = new FileOutputStream("E://b.xls");  
            ex.exportExcel(headers, dataset, out);  
            ex2.exportExcel(headers2, dataset2, out2);  
            out.close();  
            JOptionPane.showMessageDialog(null, "导出成功!");  
            System.out.println("excel导出成功！");  
        }  
        catch (FileNotFoundException e)  
        {  
            e.printStackTrace();  
        }  
        catch (IOException e)  
        {  
            e.printStackTrace();  
        }  
    }  
}  
import java.io.BufferedInputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Date;
import java.util.Iterator;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import javax.swing.JOptionPane;

import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.usermodel.HSSFClientAnchor;
import org.apache.poi.hssf.usermodel.HSSFComment;
import org.apache.poi.hssf.usermodel.HSSFFont;
import org.apache.poi.hssf.usermodel.HSSFPatriarch;
import org.apache.poi.hssf.usermodel.HSSFRichTextString;
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.HSSFColor;

/**
 * 利用开源组件POI3.0.2动态导出EXCEL文档 转载时请保留以下信息，注明出处！
 * 
 * @author leno
 * @version v1.0
 * @param <T>
 *            应用泛型，代表任意一个符合javabean风格的类
 *            注意这里为了简单起见，boolean型的属性xxx的get器方式为getXxx(),而不是isXxx()
 *            byte[]表jpg格式的图片数据
 */
public class ExportExcel<T>
{
	public void exportExcel(Collection<T> dataset, OutputStream out)
	{
		exportExcel("测试POI导出EXCEL文档", null, dataset, out, "yyyy-MM-dd");
	}

	public void exportExcel(String[] headers, Collection<T> dataset,
			OutputStream out)
	{
		exportExcel("测试POI导出EXCEL文档", headers, dataset, out, "yyyy-MM-dd");
	}

	public void exportExcel(String[] headers, Collection<T> dataset,
			OutputStream out, String pattern)
	{
		exportExcel("测试POI导出EXCEL文档", headers, dataset, out, pattern);
	}

	/**
	 * 这是一个通用的方法，利用了JAVA的反射机制，可以将放置在JAVA集合中并且符号一定条件的数据以EXCEL 的形式输出到指定IO设备上
	 * 
	 * @param title
	 *            表格标题名
	 * @param headers
	 *            表格属性列名数组
	 * @param dataset
	 *            需要显示的数据集合,集合中一定要放置符合javabean风格的类的对象。此方法支持的
	 *            javabean属性的数据类型有基本数据类型及String,Date,byte[](图片数据)
	 * @param out
	 *            与输出设备关联的流对象，可以将EXCEL文档导出到本地文件或者网络中
	 * @param pattern
	 *            如果有时间数据，设定输出格式。默认为"yyy-MM-dd"
	 */
	@SuppressWarnings("unchecked")
	public void exportExcel(String title, String[] headers,
			Collection<T> dataset, OutputStream out, String pattern)
	{
		// 声明一个工作薄
		HSSFWorkbook workbook = new HSSFWorkbook();
		// 生成一个表格
		HSSFSheet sheet = workbook.createSheet(title);
		// 设置表格默认列宽度为15个字节
		sheet.setDefaultColumnWidth((short) 15);
		// 生成一个样式
		HSSFCellStyle style = workbook.createCellStyle();
		// 设置这些样式
		style.setFillForegroundColor(HSSFColor.SKY_BLUE.index);
		style.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);
		style.setBorderBottom(HSSFCellStyle.BORDER_THIN);
		style.setBorderLeft(HSSFCellStyle.BORDER_THIN);
		style.setBorderRight(HSSFCellStyle.BORDER_THIN);
		style.setBorderTop(HSSFCellStyle.BORDER_THIN);
		style.setAlignment(HSSFCellStyle.ALIGN_CENTER);
		// 生成一个字体
		HSSFFont font = workbook.createFont();
		font.setColor(HSSFColor.VIOLET.index);
		font.setFontHeightInPoints((short) 12);
		font.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);
		// 把字体应用到当前的样式
		style.setFont(font);
		// 生成并设置另一个样式
		HSSFCellStyle style2 = workbook.createCellStyle();
		style2.setFillForegroundColor(HSSFColor.LIGHT_YELLOW.index);
		style2.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);
		style2.setBorderBottom(HSSFCellStyle.BORDER_THIN);
		style2.setBorderLeft(HSSFCellStyle.BORDER_THIN);
		style2.setBorderRight(HSSFCellStyle.BORDER_THIN);
		style2.setBorderTop(HSSFCellStyle.BORDER_THIN);
		style2.setAlignment(HSSFCellStyle.ALIGN_CENTER);
		style2.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);
		// 生成另一个字体
		HSSFFont font2 = workbook.createFont();
		font2.setBoldweight(HSSFFont.BOLDWEIGHT_NORMAL);
		// 把字体应用到当前的样式
		style2.setFont(font2);

		// 声明一个画图的顶级管理器
		HSSFPatriarch patriarch = sheet.createDrawingPatriarch();
		// 定义注释的大小和位置,详见文档
		HSSFComment comment = patriarch.createComment(new HSSFClientAnchor(0,
				0, 0, 0, (short) 4, 2, (short) 6, 5));
		// 设置注释内容
		comment.setString(new HSSFRichTextString("可以在POI中添加注释！"));
		// 设置注释作者，当鼠标移动到单元格上是可以在状态栏中看到该内容.
		comment.setAuthor("leno");

		// 产生表格标题行
		HSSFRow row = sheet.createRow(0);
		for (short i = 0; i < headers.length; i++)
		{
			HSSFCell cell = row.createCell(i);
			cell.setCellStyle(style);
			HSSFRichTextString text = new HSSFRichTextString(headers[i]);
			cell.setCellValue(text);
		}

		// 遍历集合数据，产生数据行
		Iterator<T> it = dataset.iterator();
		int index = 0;
		while (it.hasNext())
		{
			index++;
			row = sheet.createRow(index);
			T t = (T) it.next();
			// 利用反射，根据javabean属性的先后顺序，动态调用getXxx()方法得到属性值
			Field[] fields = t.getClass().getDeclaredFields();
			for (short i = 0; i < fields.length; i++)
			{
				HSSFCell cell = row.createCell(i);
				cell.setCellStyle(style2);
				Field field = fields[i];
				String fieldName = field.getName();
				String getMethodName = "get"
						+ fieldName.substring(0, 1).toUpperCase()
						+ fieldName.substring(1);
				try
				{
					Class tCls = t.getClass();
					Method getMethod = tCls.getMethod(getMethodName,
							new Class[]
							{});
					Object value = getMethod.invoke(t, new Object[]
					{});
					// 判断值的类型后进行强制类型转换
					String textValue = null;
					// if (value instanceof Integer) {
					// int intValue = (Integer) value;
					// cell.setCellValue(intValue);
					// } else if (value instanceof Float) {
					// float fValue = (Float) value;
					// textValue = new HSSFRichTextString(
					// String.valueOf(fValue));
					// cell.setCellValue(textValue);
					// } else if (value instanceof Double) {
					// double dValue = (Double) value;
					// textValue = new HSSFRichTextString(
					// String.valueOf(dValue));
					// cell.setCellValue(textValue);
					// } else if (value instanceof Long) {
					// long longValue = (Long) value;
					// cell.setCellValue(longValue);
					// }
					if (value instanceof Boolean)
					{
						boolean bValue = (Boolean) value;
						textValue = "男";
						if (!bValue)
						{
							textValue = "女";
						}
					}
					else if (value instanceof Date)
					{
						Date date = (Date) value;
						SimpleDateFormat sdf = new SimpleDateFormat(pattern);
						textValue = sdf.format(date);
					}
					else if (value instanceof byte[])
					{
						// 有图片时，设置行高为60px;
						row.setHeightInPoints(60);
						// 设置图片所在列宽度为80px,注意这里单位的一个换算
						sheet.setColumnWidth(i, (short) (35.7 * 80));
						// sheet.autoSizeColumn(i);
						byte[] bsValue = (byte[]) value;
						HSSFClientAnchor anchor = new HSSFClientAnchor(0, 0,
								1023, 255, (short) 6, index, (short) 6, index);
						anchor.setAnchorType(2);
						patriarch.createPicture(anchor, workbook.addPicture(
								bsValue, HSSFWorkbook.PICTURE_TYPE_JPEG));
					}
					else
					{
						// 其它数据类型都当作字符串简单处理
						textValue = value.toString();
					}
					// 如果不是图片数据，就利用正则表达式判断textValue是否全部由数字组成
					if (textValue != null)
					{
						Pattern p = Pattern.compile("^//d+(//.//d+)?$");
						Matcher matcher = p.matcher(textValue);
						if (matcher.matches())
						{
							// 是数字当作double处理
							cell.setCellValue(Double.parseDouble(textValue));
						}
						else
						{
							HSSFRichTextString richString = new HSSFRichTextString(
									textValue);
							HSSFFont font3 = workbook.createFont();
							font3.setColor(HSSFColor.BLUE.index);
							richString.applyFont(font3);
							cell.setCellValue(richString);
						}
					}
				}
				catch (SecurityException e)
				{
					e.printStackTrace();
				}
				catch (NoSuchMethodException e)
				{
					e.printStackTrace();
				}
				catch (IllegalArgumentException e)
				{
					e.printStackTrace();
				}
				catch (IllegalAccessException e)
				{
					e.printStackTrace();
				}
				catch (InvocationTargetException e)
				{
					e.printStackTrace();
				}
				finally
				{
					// 清理资源
				}
			}
		}
		try
		{
			workbook.write(out);
		}
		catch (IOException e)
		{
			e.printStackTrace();
		}
	}

	public static void main(String[] args)
	{
		// 测试学生
		ExportExcel<Student> ex = new ExportExcel<Student>();
		String[] headers =
		{ "学号", "姓名", "年龄", "性别", "出生日期" };
		List<Student> dataset = new ArrayList<Student>();
		dataset.add(new Student(10000001, "张三", 20, true, new Date()));
		dataset.add(new Student(20000002, "李四", 24, false, new Date()));
		dataset.add(new Student(30000003, "王五", 22, true, new Date()));
		// 测试图书
		ExportExcel<Book> ex2 = new ExportExcel<Book>();
		String[] headers2 =
		{ "图书编号", "图书名称", "图书作者", "图书价格", "图书ISBN", "图书出版社", "封面图片" };
		List<Book> dataset2 = new ArrayList<Book>();
		try
		{
			BufferedInputStream bis = new BufferedInputStream(
					new FileInputStream("V://book.bmp"));
			byte[] buf = new byte[bis.available()];
			while ((bis.read(buf)) != -1)
			{
				//
			}
			dataset2.add(new Book(1, "jsp", "leno", 300.33f, "1234567",
					"清华出版社", buf));
			dataset2.add(new Book(2, "java编程思想", "brucl", 300.33f, "1234567",
					"阳光出版社", buf));
			dataset2.add(new Book(3, "DOM艺术", "lenotang", 300.33f, "1234567",
					"清华出版社", buf));
			dataset2.add(new Book(4, "c++经典", "leno", 400.33f, "1234567",
					"清华出版社", buf));
			dataset2.add(new Book(5, "c#入门", "leno", 300.33f, "1234567",
					"汤春秀出版社", buf));

			OutputStream out = new FileOutputStream("E://a.xls");
			OutputStream out2 = new FileOutputStream("E://b.xls");
			ex.exportExcel(headers, dataset, out);
			ex2.exportExcel(headers2, dataset2, out2);
			out.close();
			JOptionPane.showMessageDialog(null, "导出成功!");
			System.out.println("excel导出成功！");
		}
		catch (FileNotFoundException e)
		{
			e.printStackTrace();
		}
		catch (IOException e)
		{
			e.printStackTrace();
		}
	}
}

        写完之后，如果您不是用eclipse工具生成的Servlet,千万别忘了在web.xml上注册这个Servelt。而且同样的，拷贝一张小巧的图书图片命名为book.jpg放置到当前WEB根目录的/WEB-INF/下。部署好web工程，用浏览器访问Servlet看下效果吧！是不是下载成功了。呵呵，您可以将下载到本地的excel报表用打印机打印出来，这样您就大功告成了。完事了我们就思考：我们发现，我们做的方法，不管是本地调用，还是在WEB服务器端用Servlet调用；不管是输出学生列表，还是图书列表信息，代码都几乎一样，而且这些数据我们很容器结合后台的DAO操作数据库动态获取。恩，类和方法的通用性和灵活性开始有点感觉了。好啦，祝您学习愉快！

补充：

Java导出Excel弹出下载框

        将ExportExcel类的main方法改成public void test()，OutputStream out = new FileOutputStream("E://a.xls");这边可以对应Servlet适当改下路径，Servlet代码如下：

public class ExcelServlet extends HttpServlet {  
    public void doGet(HttpServletRequest request, HttpServletResponse response)  
            throws ServletException, IOException {  
        (new ExportExcel()).test();  
        String str = "a.xls";  
        //String path = request.getSession().getServletContext().getRealPath(str);   
        download("E://a.xls", response);  
    }  
    private void download(String path, HttpServletResponse response) {  
        try {  
            // path是指欲下载的文件的路径。   
            File file = new File(path);  
            // 取得文件名。   
            String filename = file.getName();  
            // 以流的形式下载文件。   
            InputStream fis = new BufferedInputStream(new FileInputStream(path));  
            byte[] buffer = new byte[fis.available()];  
            fis.read(buffer);  
            fis.close();  
            // 清空response   
            response.reset();  
            // 设置response的Header   
            response.addHeader("Content-Disposition", "attachment;filename="  
                    + new String(filename.getBytes()));  
            response.addHeader("Content-Length", "" + file.length());  
            OutputStream toClient = new BufferedOutputStream(  
                    response.getOutputStream());  
            response.setContentType("application/vnd.ms-excel;charset=gb2312");  
            toClient.write(buffer);  
            toClient.flush();  
            toClient.close();  
        } catch (IOException ex) {  
            ex.printStackTrace();  
        }  
    }  
}  
public class ExcelServlet extends HttpServlet {
    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        (new ExportExcel()).test();
        String str = "a.xls";
        //String path = request.getSession().getServletContext().getRealPath(str);
        download("E://a.xls", response);
    }
    private void download(String path, HttpServletResponse response) {
        try {
            // path是指欲下载的文件的路径。
            File file = new File(path);
            // 取得文件名。
            String filename = file.getName();
            // 以流的形式下载文件。
            InputStream fis = new BufferedInputStream(new FileInputStream(path));
            byte[] buffer = new byte[fis.available()];
            fis.read(buffer);
            fis.close();
            // 清空response
            response.reset();
            // 设置response的Header
            response.addHeader("Content-Disposition", "attachment;filename="
                    + new String(filename.getBytes()));
            response.addHeader("Content-Length", "" + file.length());
            OutputStream toClient = new BufferedOutputStream(
                    response.getOutputStream());
            response.setContentType("application/vnd.ms-excel;charset=gb2312");
            toClient.write(buffer);
            toClient.flush();
            toClient.close();
        } catch (IOException ex) {
            ex.printStackTrace();
        }
    }
}