此帮助类可以将对象通过反射的方式根据类中成员变量的声明顺序将数据映射到Excel表格中，支持设置行样式，代码如下
package com.yc.utils;
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.Calendar;
import java.util.Date;
import java.util.List;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.usermodel.HSSFFont;
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;
/**
* <b> 导出数据的帮助类，用于将数据导出至Excel表格中，可调整导出数据的样式，如：行(分为标题行和数据行)的背景颜色，字体颜色，字体高度，
* 字体是否加粗， 是否条纹展示数据<b>
*
* @author 刘亚楼
*
*/
public class ExportHelper {
// 列宽
private int columWidth;
// 标题行背景颜色
private short headerBackground;
// 标题行字体颜色
private short headerFontColor;
// 标题行字体是否加粗
private boolean isHeaderFontBold;
// 标题行字体高度
private short headerFontWeight;
// 数据行背景颜色
private short dataRowBackground;
// 数据行另一种背景色，用于显示条纹效果
private short dataRowBackground2;
// 数据行字体颜色
private short dataRowFontColor;
// 数据行字体是否加粗
private boolean isDataRowFontBold;
// 数据行字体高度
private short dataRowFontWeight;
// 是否给数据行加条纹
private boolean isStriped;
public ExportHelper() {
this.columWidth = 12;
this.headerBackground = HSSFColor.WHITE.index;
this.headerFontColor = HSSFColor.BLACK.index;
this.isHeaderFontBold = false;
this.headerFontWeight = 0;
this.dataRowBackground = HSSFColor.WHITE.index;
this.dataRowBackground2 = HSSFColor.GREY_25_PERCENT.index;
this.dataRowFontColor = HSSFColor.BLACK.index;
this.isDataRowFontBold = false;
this.dataRowFontWeight = 0;
this.isStriped = false;
}
/**
* 设定列宽
*
* @param columWidth
*/
public void setColumWidth(int columWidth) {
this.columWidth = columWidth;
}
/**
* 设置标题行字体颜色，可通过HSSFColor.colorClass.index设置
*
* @param headerFontColor
*/
public void setHeaderFontColor(short headerFontColor) {
this.headerFontColor = headerFontColor;
}
/**
* 设置数据行字体颜色，可通过HSSFColor.colorClass.index设置
*
* @param dataRowFontColor
*/
public void setDataRowFontColor(short dataRowFontColor) {
this.dataRowFontColor = dataRowFontColor;
}
/**
* 设置标题行的背景颜色，可通过HSSFColor.colorClass.index设置
*
* @param headerBackground
*/
public void setHeaderBackground(short headerBackground) {
this.headerBackground = headerBackground;
}
/**
* 设置数据行的背景颜色，可通过HSSFColor.colorClass.index设置
*
* @param dataRowBackground
*/
public void setDataRowBackground(short dataRowBackground) {
this.dataRowBackground = dataRowBackground;
}
/**
* 设置标题行字体粗度，默认为false
*
* @param isHeaderFontBold
*/
public void setHeaderFontBold(boolean isHeaderFontBold) {
this.isHeaderFontBold = isHeaderFontBold;
}
/**
* 设置数据行字体粗度，默认为false
*
* @param isDataRowFontBold
*/
public void setDataRowFontBold(boolean isDataRowFontBold) {
this.isDataRowFontBold = isDataRowFontBold;
}
/**
* 设置标题行字体高度
*
* @param headerFontWeight
*/
public void setHeaderFontWeight(short headerFontWeight) {
this.headerFontWeight = headerFontWeight;
}
/**
* 设置数据行字体高度
*
* @param dataRowFontWeight
*/
public void setDataRowFontWeight(short dataRowFontWeight) {
this.dataRowFontWeight = dataRowFontWeight;
}
/**
* 设置数据行是否条纹展示
*
* @param isStriped
*/
public void setStriped(boolean isStriped) {
this.isStriped = isStriped;
}
/**
* 数据行另一种背景颜色，用于显示条纹效果
*
* @param dataRowBackground2
*/
public void setDataRowBackground2(short dataRowBackground2) {
this.dataRowBackground2 = dataRowBackground2;
}
/**
* 将list中的对象转换为Workbook，并且将Workbook写到输出流中
*
* @param sheetName
* 表单的名字
* @param headers
* 标题
* @param list
* 包含对象的list集合
* @param os
* 输出流
* @throws NoSuchMethodException
* @throws SecurityException
* @throws IllegalAccessException
* @throws IllegalArgumentException
* @throws InvocationTargetException
* @throws IOException
*/
public <T> void exportToExcel(String sheetName, String[] headers, List<T> list, OutputStream os)
throws NoSuchMethodException, SecurityException, IllegalAccessException, IllegalArgumentException,
InvocationTargetException, IOException {
// 声明一个工作簿，HSSFWorkbook为2007以上的版本
HSSFWorkbook workbook = new HSSFWorkbook();
// 声明一个表格
HSSFSheet sheet = workbook.createSheet(sheetName);
// 设置默认的列宽
sheet.setDefaultColumnWidth(columWidth);
// 创建标题行样式
HSSFCellStyle headerStyle = createRowStyle(workbook, headerBackground, headerFontColor, headerFontWeight,
isHeaderFontBold);
// 创建数据样式
HSSFCellStyle rowStyle = createRowStyle(workbook, dataRowBackground, dataRowFontColor, dataRowFontWeight,
isDataRowFontBold);
HSSFCellStyle rowStyle2 = null;
if (isStriped) {
// 有条纹展示，创建另一种数据行样式
rowStyle2 = createRowStyle(workbook, dataRowBackground2, dataRowFontColor, dataRowFontWeight,
isDataRowFontBold);
}
// 为表格填充内容
fillContentsForSheet(headers, list, sheet, headerStyle, rowStyle, rowStyle2);
// 将表格中的内容写入输出流中
workbook.write(os);
os.flush();
}
/**
* 创建行样式
*
* @param workbook
* 工作簿对象
* @param background
* 行背景颜色
* @param fontColor
* 字体颜色
* @param fontWeight
* 字体高度
* @param isFontBold
* 字体是否加粗
* @return
*/
private HSSFCellStyle createRowStyle(HSSFWorkbook workbook, short background, short fontColor, short fontWeight,
boolean isFontBold) {
// 创建样式
HSSFCellStyle rowStyle = workbook.createCellStyle();
// 设置填充颜色
rowStyle.setFillForegroundColor(background);
// 设置填充样式
rowStyle.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);
// 设置边框
rowStyle.setBorderBottom(HSSFCellStyle.BORDER_THIN);
rowStyle.setBorderLeft(HSSFCellStyle.BORDER_THIN);
rowStyle.setBorderRight(HSSFCellStyle.BORDER_THIN);
rowStyle.setBorderTop(HSSFCellStyle.BORDER_THIN);
// 设置水平对齐方式
rowStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);
// 设置垂直对齐方式
rowStyle.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);
// 创建字体
HSSFFont rowFont = workbook.createFont();
rowFont.setColor(fontColor);
if (fontWeight != 0) {
rowFont.setFontHeightInPoints(fontWeight);
}
// 默认设为normal
rowFont.setBoldweight(HSSFFont.BOLDWEIGHT_NORMAL);
if (isFontBold) {
rowFont.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);
}
// 把字体应用到当前的样式
rowStyle.setFont(rowFont);
return rowStyle;
}
// 为表格填充内容
private <T> void fillContentsForSheet(String[] headers, List<T> list, HSSFSheet sheet, HSSFCellStyle headerStyle,
HSSFCellStyle rowStyle, HSSFCellStyle rowStyle2)
throws NoSuchMethodException, IllegalAccessException, InvocationTargetException {
// 是否存在标题行
boolean isHeaderRowExisted = false;
if (headers != null && headers.length > 0) {
isHeaderRowExisted = true;
// 创建标题行
HSSFRow headerRow = sheet.createRow(0);
for (int i = 0; i < headers.length; i++) {
HSSFCell headerCell = headerRow.createCell(i);
headerCell.setCellStyle(headerStyle);
headerCell.setCellValue(headers[i]);
}
}
if (list != null && list.size() > 0) {
// 获得list中对象的运行时类
Class<T> clazz = (Class<T>) list.get(0).getClass();
List<Method> methodList = getAllGetMethods(clazz);
int rowNum = 0;
if (isHeaderRowExisted) {
rowNum = 1;// 如果有标题行行号则从1开始，没有从0开始
}
HSSFCellStyle style = null;
for (int row = rowNum, index = 0; index < list.size(); row++, index++) {
T t = list.get(index);
// 如果有条纹展示，奇偶行样式各不同
if (rowStyle2 != null && index % 2 == 0) {
style = rowStyle2;
} else {
style = rowStyle;
}
// 创建数据行
HSSFRow dataRow = sheet.createRow(row);
// 一个getXXX方法代表一个字段值，根据字段值生成列的个数
for (int cell = 0; cell < methodList.size(); cell++) {
HSSFCell dataCell = dataRow.createCell(cell);
dataCell.setCellStyle(style);
// 通过反射调用对应的getXXX方法
Object obj = methodList.get(cell).invoke(t);
// 判断数据类型，设置单元格的值
if (obj instanceof Integer) {
Integer value = (Integer) obj;
dataCell.setCellValue(String.valueOf(value));
} else if (obj instanceof Float) {
Float value = (Float) obj;
double doubleValue = Double.parseDouble(String.valueOf(value));
dataCell.setCellValue(doubleValue);
} else if (obj instanceof Long) {
Long value = (Long) obj;
dataCell.setCellValue(String.valueOf(value));
} else if (obj instanceof Double) {
Double value = (Double) obj;
dataCell.setCellValue(value);
} else if (obj instanceof Boolean) {
Boolean value = (Boolean) obj;
dataCell.setCellValue(value);
} else if (obj instanceof Date) {
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
dataCell.setCellValue(sdf.format(obj));
} else if (obj instanceof Calendar) {
Calendar c = (Calendar) obj;
Date date = c.getTime();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
dataCell.setCellValue(sdf.format(date));
} else {
String value = (String) obj;
dataCell.setCellValue(value);
}
}
}
}
}
// 获取类中每个成员变量对应的get方法，存入集合中
private List<Method> getAllGetMethods(Class<?> clazz) throws NoSuchMethodException, SecurityException {
List<Method> methodList = new ArrayList<Method>();
Field[] fields = clazz.getDeclaredFields();
for (Field field : fields) {
// 如果名字为serialVersionUID，代表字段值为序列化编号，应该跳过
if (field.getName().equals("serialVersionUID")) {
continue;
}
String fieldName = field.getName();
String methodName = "get" + fieldName.substring(0, 1).toUpperCase() + fieldName.substring(1);
Method getMethod = clazz.getDeclaredMethod(methodName);
methodList.add(getMethod);
}
return methodList;
}
}