利用java反射机制实现动态导出excel
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 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("导出EXCEL文档", null, dataset, out, "yyyy-MM-dd");
}
public void exportExcel(String[] headers, Collection<T> dataset,
OutputStream out) {
exportExcel("导出EXCEL文档", headers, dataset, out, "yyyy-MM-dd");
}
public void exportExcel(String title, String[] headers,
Collection<T> dataset, OutputStream out) {
exportExcel(title, headers, dataset, out, "yyyy-MM-dd");
}
public void exportExcel(String[] headers, Collection<T> dataset,
OutputStream out, String pattern) {
exportExcel("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", "deprecation", "rawtypes" })
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();
// 生成一个样式
HSSFCellStyle style = workbook.createCellStyle();
// 设置这些样式
style.setFillForegroundColor(HSSFColor.WHITE.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.BLACK.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.WHITE.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);
int sheetCount = 1000;
if (dataset.size() > sheetCount) {
Iterator<T> it = dataset.iterator();
for (int i = 0; i <= 4; i++) {
int index = 0;
List<T> list = new ArrayList<T>();
while (it.hasNext()) {
index++;
if (index < sheetCount) {
list.add(it.next());
} else {
break;
}
}
generateSheet(list, style, style2, workbook, pattern, headers,
title + "_" + (i + 1));
}
} else {
generateSheet(dataset, style, style2, workbook, pattern, headers,
title);
}
try {
workbook.write(out);
} catch (IOException e) {
e.printStackTrace();
}
}
public void generateSheet(Collection<T> dataset, HSSFCellStyle style,
HSSFCellStyle style2, HSSFWorkbook workbook, String pattern,
String[] headers, String title) {
// 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);
// 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("author");
// 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++) {
Field field = fields[i];
if (field.toString().contains("static")) {
continue;
}
HSSFCell cell = row.createCell(i);
cell.setCellStyle(style2);
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 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
if (value == null) {
value = "";
}
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+)?{1}quot;");
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.BLACK.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
}
}
}
}
// 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) {
// e.printStackTrace();
// } catch (IOException e) {
// e.printStackTrace();
// }
// }
}