Excel操作(poi)
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：
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;
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);
}
@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) {
// 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, 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("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;
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);
}
}