java excel导出工具类

使用的是apache poi与注解类实现：

1.注解类

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * 
 * @Description: excel导出注解类
 * @author kang
 * @date 2016年8月24日
 */
@Target({ ElementType.METHOD, ElementType.FIELD, ElementType.TYPE })
@Retention(RetentionPolicy.RUNTIME)
public @interface ExcelField 
{
//导出字段在excel中的名字
String title();
}

2.工具类：

import java.io.IOException;
import java.io.OutputStream;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Date;
import java.util.List;

import javax.servlet.http.HttpServletResponse;

import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.usermodel.HSSFFont;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hssf.util.HSSFColor;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.CellStyle;
import org.apache.poi.ss.usermodel.Font;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;

/**
 * 
 * @Description: excel导出封装类
 * @author kang
 * @date 2016年8月24日
 */
public class ExcelUtil
{
//通用
public static <Q> void writeExcel(HttpServletResponse response, String fileName, List<Q> list, Class<Q> cls) throws IOException, IllegalArgumentException, IllegalAccessException
{
HSSFWorkbook wb = new HSSFWorkbook();

Field[] fields = cls.getDeclaredFields();
ArrayList<String> headList = new ArrayList<String>();

for (Field f : fields)
{
ExcelField field = f.getAnnotation(ExcelField.class);
if (field != null)
{
headList.add(field.title());
}
}

CellStyle style = getCellStyle(wb);
Sheet sheet = wb.createSheet();
/**
 * 设置Excel表的第一行即表头
 */
Row row = sheet.createRow(0);
for (int i = 0; i < headList.size(); i++)
{
Cell headCell = row.createCell(i);
headCell.setCellType(Cell.CELL_TYPE_STRING);
headCell.setCellStyle(style);//设置表头样式  
headCell.setCellValue(String.valueOf(headList.get(i)));
//sheet.autoSizeColumn((short) i);// 设置单元格自适应
sheet.setColumnWidth(0, 15 * 256);
}

for (int i = 0; i < list.size(); i++)
{
Row rowdata = sheet.createRow(i + 1);//创建数据行  
Q q = list.get(i);
Field[] ff = q.getClass().getDeclaredFields();
int j = 0;
for (Field f : ff)
{
ExcelField field = f.getAnnotation(ExcelField.class);
if (field == null)
{
continue;
}
f.setAccessible(true);
Object obj = f.get(q);
Cell cell = rowdata.createCell(j);
cell.setCellType(Cell.CELL_TYPE_STRING);
// 当数字时
if (obj instanceof Integer) cell.setCellValue((Integer) obj);
// 当为字符串时
if (obj instanceof String) cell.setCellValue((String) obj);
// 当为布尔时
if (obj instanceof Boolean) cell.setCellValue((Boolean) obj);
// 当为时间时
if (obj instanceof Date) cell.setCellValue(MyUtils.getFormatDate("yyyy/MM/dd", (Date) obj));
// 当为时间时
if (obj instanceof Calendar) cell.setCellValue((Calendar) obj);
// 当为小数时
if (obj instanceof Double) cell.setCellValue((Double) obj);
//将序号替换为123456
if (j == 0) cell.setCellValue(i + 1);
j++;
}
}
response.setContentType("application/vnd.ms-excel");
response.setHeader("Content-disposition", "attachment; filename=" + MyUtils.urlEncode(fileName));
OutputStream ouputStream = null;
try
{
ouputStream = response.getOutputStream();
wb.write(ouputStream);
}
finally
{
ouputStream.close();
}
}

/**
 * 
 * @Description:设置表头样式
 * @author kang
 * @date 2016年8月24日
 */
public static CellStyle getCellStyle(Workbook wb)
{
CellStyle style = wb.createCellStyle();
Font font = wb.createFont();
font.setFontName("宋体");
font.setFontHeightInPoints((short) 12);//设置字体大小  
font.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);//加粗  
style.setFillForegroundColor(HSSFColor.LIME.index);// 设置背景色  
style.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);
style.setAlignment(HSSFCellStyle.SOLID_FOREGROUND);//让单元格居中  
style.setAlignment(HSSFCellStyle.ALIGN_CENTER);// 左右居中   
style.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);// 上下居中   
style.setWrapText(true);//设置自动换行  
style.setFont(font);
return style;
}

}

3.使用方法

在需要导出实体类的字段加上注解，如：

public class Module1 {
@ExcelField(title = "序号")
private String id;

@ExcelField(title = "部门")
private String deptName;

controller:

/**
 * @Description: 查询模块1表格数据
 * @author kang
 * @throws Exception
 * @date 2016年8月25日
 */
@RequestMapping(value = "exportExcel", method = RequestMethod.POST)
public void exportExcel(Parameters parameters, HttpServletResponse response) throws Exception
{
List<Module1> list = module1Service.selectByParameters(parameters);
String fileName = "xxx.xls";
ExcelUtil.writeExcel(response, fileName, list, Module1.class);
}

jsp: jsp中得有一个隐藏form，调用form的submit方法，下载完成后浏览器下方才会显示已下载的文件

<form id="exportExcel" action="${pageContext.request.contextPath}/module3/exportExcel" method="post">
<input name="param" type="hidden">
</form>