POI导出EXCEL经典实现

jopen 5年前

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ApachePOIJExcelAPI这里我们用Apache POI!我们先去Apache的大本营下载POIjar包:http://poi.apache.org/ ,我这里使用的是3.0.2版本。

 

3jar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:

 

package org.leno.export.util;

 

import java.util.Date;

 

public class Student {

 

   private long id;

   private String name;

   private int age;

   private boolean sex;

   private Date birthday;

 

   public Student() {

      super();

      // TODO Auto-generated constructor stub

   }

 

   public Student(long id, String name, int age, boolean sex, Date birthday) {

      super();

      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;

   }

 

}

 

package org.leno.export.util;

 

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() {

      super();

   }

 

   public Book(int bookId, String name, String author, float price,

         String isbn, String pubName, byte[] preface) {

      super();

      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:

package org.leno.export.util;

 

import java.io.*;

import java.lang.reflect.*;

import java.util.*;

import java.util.regex.Matcher;

import java.util.regex.Pattern;

import java.text.SimpleDateFormat;

import javax.swing.JOptionPane;

import org.apache.poi.hssf.usermodel.*;

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xxxget器方式为getXxx(),而不是isXxx()

 * byte[]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 = "";

                   if (!bValue) {

                      textValue ="";

                   }

                } 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 = newHSSFRichTextString(textValue);

                      HSSFFont font3 = workbook.createFont();

                      font3.setColor(HSSFColor.BLUE.index);

                      richString.applyFont(font3);

                      cell.setCellValue(richString);

                   }

                }

            } catch (SecurityException e) {

                // TODO Auto-generated catch block

                e.printStackTrace();

            } catch (NoSuchMethodException e) {

                // TODO Auto-generated catch block

                e.printStackTrace();

            } catch (IllegalArgumentException e) {

                // TODO Auto-generated catch block

                e.printStackTrace();

            } catch (IllegalAccessException e) {

                // TODO Auto-generated catch block

                e.printStackTrace();

            } catch (InvocationTargetException e) {

                // TODO Auto-generated catch block

                e.printStackTrace();

            } finally {

                //清理资源

            }

         }

 

      }

      try {

         workbook.write(out);

      } catch (IOException e) {

         // TODO Auto-generated catch block

         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, truenew Date()));

      dataset.add(new Student(20000002, "李四", 24, falsenew Date()));

      dataset.add(new Student(30000003, "王五", 22, truenew 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("book.jpg"));

         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) {

         // TODO Auto-generated catch block

         e.printStackTrace();

      } catch (IOException e) {

         // TODO Auto-generated catch block

         e.printStackTrace();

      }

   }

}

 

不行,头有点晕^_^。呵呵,又是泛型,又是反射,又是正则表达式,又是重载,还有多参数列表和POI API。一下子蹦出来,实在让人吃不消。不管了,顶住看效果先。在本地运行后,我们发现在E://下生成了两份excel文件:学生记录和图书记录,并且中文,数字,颜色,日期,图片等等一且正常。恩,太棒了。有人看到这里开始苦脸了:喂,我怎么一运行就报错啊!呵呵,看看什么错吧!哦,找不到文件,也就是说你没有book.jpg嘛。好,拷贝一张小巧的图书图片命名为book.jpg放置到当前工程下吧。注意,您千万别把张桌面大小的图片丢进去了^_^!看到效果了吧。现在我们再来简单梳理一下代码,实际上上面就做了一个导出excel的方法和一个本地测试main()方法。并且代码的结构也很清晰,只是涉及的知识点稍微多一点。大家细心看看注释,结合要完成的功能,应该没有太大问题的。好啦,吃杯茶,擦把汗,总算把这个类消化掉,你又进步了。咦,你不是说是在WEB环境下导出的吗?别急,因为导出就是一个下载的过程。我们只需要在服务器端写一个Jsp或者Servlet组件完成输出excel到浏览器客户端的工作就好了。我们以Servlet为例,还是看代码吧:

package org.leno.export.util;

 

import java.io.*;

import java.util.ArrayList;

import java.util.List;

 

import javax.servlet.ServletException;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

 

 /**

 * @author leno

 * 使用servlet导出动态生成的excel文件,数据可以来源于数据库

 * 这样,浏览器客户端就可以访问该servlet得到一份用java代码动态生成的excel文件

 */

public class Export extends javax.servlet.http.HttpServlet{

   static final long serialVersionUID = 1L;

  

   protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

      File file = new File(getServletContext().getRealPath("WEB-INF/book.jpg"));

      response.setContentType("octets/stream");

      response.addHeader("Content-Disposition","attachment;filename=test.xls");

      //测试图书

      ExportExcel<Book> ex = new ExportExcel<Book>();

      String[] headers = { "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> dataset = new ArrayList<Book>();

      try {

         BufferedInputStream bis = new BufferedInputStream(

               new FileInputStream(file));

         byte[] buf = new byte[bis.available()];

         while ((bis.read(buf)) != -1) {

            //将图片数据存放到缓冲数组中

         }

         dataset.add(new Book(1, "jsp""leno", 300.33f, "1234567",

                "清华出版社", buf));

         dataset.add(new Book(2, "java编程思想""brucl", 300.33f, "1234567",

                "阳光出版社", buf));

         dataset.add(new Book(3, "DOM艺术""lenotang", 300.33f, "1234567",

                "清华出版社", buf));

         dataset.add(new Book(4, "c++经典""leno", 400.33f, "1234567",

                "清华出版社", buf));

         dataset.add(new Book(5, "c#入门""leno", 300.33f, "1234567",

                "汤春秀出版社", buf));

         OutputStream out = response.getOutputStream();

         ex.exportExcel(headers, dataset, out);

         out.close();

         System.out.println("excel导出成功!");

      } catch (FileNotFoundException e) {

         // TODO Auto-generated catch block

         e.printStackTrace();

      } catch (IOException e) {

         // TODO Auto-generated catch block

         e.printStackTrace();

      }

   } 

  

   protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

      doGet(request, response);

   }              

}

 

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/。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!

原文地址:http://blog.csdn.net/lenotang/article/details/2823230