Java导出Excel快速开始

 1 package com.scoremanager.utils;
 2 
 3 import org.apache.poi.hssf.usermodel.*;
 4 
 5 import javax.servlet.http.HttpServletResponse;
 6 import java.io.BufferedOutputStream;
 7 import java.lang.reflect.Field;
 8 import java.lang.reflect.Method;
 9 import java.util.Collection;
10 import java.util.Iterator;
11 
12 /*
13  * 导出Excel的工具类
14  * */
15 public class ExportExcelUtils<T> {
16     public void exportExcel(String[] headers, Collection<T> dataset, String fileName, HttpServletResponse response) {
17         // 声明一个工作薄
18         HSSFWorkbook workbook = new HSSFWorkbook();
19         // 生成一个表格
20         HSSFSheet sheet = workbook.createSheet(fileName);
21         // 设置表格默认列宽度为15个字节
22         sheet.setDefaultColumnWidth((short) 20);
23         // 产生表格标题行
24         HSSFRow row = sheet.createRow(0);
25         for (short i = 0; i < headers.length; i++) {
26             HSSFCell cell = row.createCell(i);
27             HSSFRichTextString text = new HSSFRichTextString(headers[i]);
28             cell.setCellValue(text);
29         }
30         try {
31             // 遍历集合数据，产生数据行
32             Iterator<T> it = dataset.iterator();
33             int index = 0;
34             while (it.hasNext()) {
35                 index++;
36                 row = sheet.createRow(index);
37                 T t = (T) it.next();
38                 // 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
39                 Field[] fields = t.getClass().getDeclaredFields();
40                 for (short i = 0; i < headers.length; i++) {
41                     HSSFCell cell = row.createCell(i);
42                     Field field = fields[i];
43                     String fieldName = field.getName();
44                     String getMethodName = "get" + fieldName.substring(0, 1).toUpperCase() + fieldName.substring(1);
45                     Class tCls = t.getClass();
46                     Method getMethod = tCls.getMethod(getMethodName, new Class[]{});
47                     Object value = getMethod.invoke(t, new Object[]{});
48                     // 判断值的类型后进行强制类型转换
49                     String textValue = null;
50                     // 其它数据类型都当作字符串简单处理
51                     if (value != null && value != "") {
52                         textValue = value.toString();
53                     }
54                     if (textValue != null) {
55                         HSSFRichTextString richString = new HSSFRichTextString(textValue);
56                         cell.setCellValue(richString);
57                     }
58                 }
59             }
60             getExportedFile(workbook, fileName, response);
61         } catch (Exception e) {
62             e.printStackTrace();
63         }
64     }
65 
66     /**
67      * 方法说明: 指定路径下生成EXCEL文件
68      *
69      * @return
70      */
71     public void getExportedFile(HSSFWorkbook workbook, String name, HttpServletResponse response) throws Exception {
72         BufferedOutputStream fos = null;
73         try {
74             String fileName = name + ".xls";
75             response.setContentType("application/x-msdownload");
76             response.setHeader("Content-Disposition", "attachment;filename=" + new String(fileName.getBytes("gb2312"), "ISO8859-1"));
77             fos = new BufferedOutputStream(response.getOutputStream());
78             workbook.write(fos);
79         } catch (Exception e) {
80             e.printStackTrace();
81         } finally {
82             if (fos != null) {
83                 fos.close();
84             }
85         }
86     }
87 }