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Java POI 导出EXCEL经典实现 Java导出Excel弹出下载框

2017-08-31 10:10 721 查看
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:

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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;

}

}

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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:

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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();

&nb
1f497
sp; 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();

out2.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!


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:

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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();

}

}

}
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