java 使用ＰＯＩ框架进行Excel表格的导出

首先附上代码,是对一个复杂集合进行遍历导出的,集合的类型是

Map<String,List<Attendance>> testMap = new LinkedHashMap<String,List<Attendance>>();

其中attendance是一个实体类,Map的key是拼接字符串,下面直接上代码,套用这个模板可以解决大多数Excel导出问题,且此代码的列数也是动态生成的,话不多说,代码如下

`package cn.test;
import java.io.FileOutputStream;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Date;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
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;

public class Test1 {

public static void main(String[] args) throws Exception {
//创建测试集
Map<String,List<Attendance>> testMap = new LinkedHashMap<String,List<Attendance>>();
ArrayList<Attendance> list1= new ArrayList<Attendance>();
ArrayList<Attendance> list2= new ArrayList<Attendance>();
Person p1 =new Person(1,"大一","研发部");
Person p2 =new Person(2,"老二","门面部");
Person p3 =new Person(3,"老三","产品部");
Person p4 =new Person(4,"老四","事务部");
Person p5 =new Person(5,"老五","海外部");
Attendance kq1=new Attendance(1,timeFormat(),DayBefore(timeFormat()),"normal");
Attendance kq2=new Attendance(2,timeFormat(),DayAfter(timeFormat()),"normal");
Attendance kq3=new Attendance(3,DayBefore(timeFormat()),DayAfter(timeFormat()),"normal");
list1.add(kq1);
list1.add(kq2);
list1.add(kq3);
list2.add(kq2);
list2.add(kq3);
testMap.put(p1.toString(),list1);
testMap.put(p2.toString(),list2);
testMap.put(p3.toString(),list2);
testMap.put(p4.toString(),list1);
testMap.put(p5.toString(),list1);
FileOutputStream output = null;
// 声明一个工作薄
HSSFWorkbook workbook = new HSSFWorkbook();
// 生成一个表格
try{
//页码
HSSFSheet sheet = workbook.createSheet("测试统计");
// 设置表格默认列宽度为18个字节
sheet.setDefaultColumnWidth((short) 18);
// 生成一个样式
HSSFCellStyle style = workbook.createCellStyle();
style.setWrapText(true);
// 设置这些样式
style.setFillForegroundColor(HSSFColor.SKY_BLUE.index);
// 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);

HSSFRow row =sheet.createRow(0);
//创建person类标题
(row.createCell(0)).setCellValue("姓名");
(row.createCell(1)).setCellValue("部门");
//取得list集合的最大值，建立attendance类标题
int listMaxSize=Math.max(list1.size(),list2.size());
for(int i=1;i<=listMaxSize;i++){
HSSFCell cell = row.createCell(i+1);
cell.setCellValue(String.valueOf(i));
}
int index=1;
Iterator<Entry<String, List<Attendance>>> entries = testMap.entrySet().iterator();
while (entries.hasNext()) {
row = sheet.createRow(index);
Map.Entry<String, List<Attendance>> entry = entries.next();
//Person数据
String key[] = entry.getKey().split("-");
//由于key是id-name-department的拼接，所以要切分，并且id不用于显示
(row.createCell(0)).setCellValue(key[1]);
(row.createCell(1)).setCellValue(key[2]);
//Attendance数据
List<Attendance> alist = entry.getValue();

//填充Attendance类中除AID以外的数据
for(int j=0;j<alist.size();j++){
//因为person的信息已经占了两个cell，所以这里的需要j+2
HSSFCell cell = row.createCell(j+2);
cell.setCellStyle(style);
cell.setCellValue("上午:"+alist.get(j).getStartTime() +"\n备注："+alist.get(j).getNote()
+"\n下午："+alist.get(j).getEndTime()+"\n备注："+alist.get(j).getNote());
}
index++;
}
// 写入数据并关闭文件
output=new FileOutputStream("D:\\result.xls");
workbook.write(output);
output.flush();
} catch (Exception e) {
System.out.println(e);
} finally {
if (output != null|| workbook!=null) {
try {
output.close();
workbook.close();
System.out.println("#######导出成功########");
} catch (Exception e) {
e.printStackTrace();
}
}
}

}

/* 获得现在日期 */
private static String timeFormat(){
return new SimpleDateFormat("HH:mm:ss").format(new Date());
}
/* 获得指定日期的前一天 */
public static String DayBefore(String specifiedDay) {
Calendar c = Calendar.getInstance();
Date date = null;
try {
date = new SimpleDateFormat("HH:mm:ss").parse(specifiedDay);
} catch (ParseException e) {
e.printStackTrace();
}
c.setTime(date);
int day = c.get(Calendar.DATE);
c.set(Calendar.DATE, day - 1);
String dayAfter = new SimpleDateFormat("HH:mm:ss").format(c.getTime());
return dayAfter;
}

/* 获得指定日期的后一天 */
public static String DayAfter(String specifiedDay) {
Calendar c = Calendar.getInstance();
Date date = null;
try {
date = new SimpleDateFormat("HH:mm:ss").parse(specifiedDay);
} catch (ParseException e) {
e.printStackTrace();
}
c.setTime(date);
int day = c.get(Calendar.DATE);
c.set(Calendar.DATE, day + 1);
String dayAfter = new SimpleDateFormat("HH:mm:ss").format(c.getTime());
return dayAfter;
}

}

后来又做一个导出涉及到表头的行合并和列合并,下面再附上行列合并的代码,值得注意的是,在进行行列合并前,先注意表头分为几个层级,然后再进行行合并和列合并代码如下

//创建单元格,设置行合并列合并

HSSFSheet sheet = workbook.createSheet("个人薪酬");//创建单元名
sheet.addMergedRegion(new CellRangeAddress(0,0,4,9));//横向合并5-9
sheet.addMergedRegion(new CellRangeAddress(0,0,11,19));
sheet.addMergedRegion(new CellRangeAddress(0,0,20,22));
sheet.addMergedRegion(new CellRangeAddress(0,1,0,0));//纵向：合并第一列的第1行和第2行第
sheet.addMergedRegion(new CellRangeAddress(0,1,1,1));//纵向：合并第二列的第1行和第2行第
sheet.addMergedRegion(new CellRangeAddress(0,1,2,2));
sheet.addMergedRegion(new CellRangeAddress(0,1,3,3));
sheet.addMergedRegion(new CellRangeAddress(0,1,10,10));
sheet.addMergedRegion(new CellRangeAddress(0,1,23,23));
sheet.addMergedRegion(new CellRangeAddress(0,1,24,24));
sheet.addMergedRegion(new CellRangeAddress(0,1,25,25));
sheet.addMergedRegion(new CellRangeAddress(0,1,26,26));
sheet.addMergedRegion(new CellRangeAddress(0,1,27,27));
//首行
HSSFRow row = sheet.createRow(0);

row.createCell(4).setCellStyle(style);
row.createCell(4).setCellValue("代扣项目");
row.createCell(11).setCellStyle(style);
row.createCell(11).setCellValue("福利");
row.createCell(20).setCellStyle(style);
row.createCell(20).setCellValue("其他");`

合并后效果大致如图


再贴上完整的设置样式代码

HSSFWorkbook workbook = new HSSFWorkbook();//创建一个工作表格
//设置样式
HSSFCellStyle style = workbook.createCellStyle();
style.setBorderBottom(HSSFCellStyle.BORDER_THIN); //下边框
style.setBorderLeft(HSSFCellStyle.BORDER_THIN);//左边框
style.setBorderTop(HSSFCellStyle.BORDER_THIN);//上边框
style.setBorderRight(HSSFCellStyle.BORDER_THIN);//右边框
//style.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);
//style.setWrapText(true);
//style.setFillForegroundColor((short) 5);
style.setAlignment(HSSFCellStyle.ALIGN_CENTER); // 居中
//设置字体
HSSFFont font = workbook.createFont();//创建字体格式
//font.setColor(HSSFColor.VIOLET.index);
//font.setFontHeightInPoints((short) 6);//设置字体大小
font.setFontHeight((short) 10);//大小
font.setFontName("仿宋_GB2312");//字体
font.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);//粗体显示

style.setFont(font);
//创建单元格,设置行合并列合并
HSSFSheet sheet = workbook.createSheet("个人薪酬");//创建单元名
sheet.addMergedRegion(new CellRangeAddress(0,0,4,9));//横向合并5-9
sheet.addMergedRegion(new CellRangeAddress(0,0,11,19));
sheet.addMergedRegion(new CellRangeAddress(0,0,20,22));
sheet.addMergedRegion(new CellRangeAddress(0,1,0,0));//纵向：合并第一列的第1行和第2行第
sheet.addMergedRegion(new CellRangeAddress(0,1,1,1));//纵向：合并第二列的第1行和第2行第
sheet.addMergedRegion(new CellRangeAddress(0,1,2,2));
sheet.addMergedRegion(new CellRangeAddress(0,1,3,3));
sheet.addMergedRegion(new CellRangeAddress(0,1,10,10));
sheet.addMergedRegion(new CellRangeAddress(0,1,23,23));
sheet.addMergedRegion(new CellRangeAddress(0,1,24,24));
sheet.addMergedRegion(new CellRangeAddress(0,1,25,25));
sheet.addMergedRegion(new CellRangeAddress(0,1,26,26));
sheet.addMergedRegion(new CellRangeAddress(0,1,27,27));
//首行
HSSFRow row = sheet.createRow(0);

row.createCell(4).setCellStyle(style);
row.createCell(4).setCellValue("代扣项目");
row.createCell(11).setCellStyle(style);
row.createCell(11).setCellValue("福利");
row.createCell(20).setCellStyle(style);
row.createCell(20).setCellValue("其他");
//第二行
HSSFRow row1 = sheet.createRow(1);
row1.setHeight((short) 800);