一、前言
最近做一个推送服务将系统某些报表,通过邮件附件的形式推送给指定的人,首先我们需要在服务端生成报表的excel文档。生成excel文档采用的是POI的方式。
二、pom引入相应的jar包
引入三个poi相关的jar包
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi</artifactId>
<version>4.1.2</version>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml</artifactId>
<version>4.1.2</version>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml-schemas</artifactId>
<version>4.1.2</version>
</dependency>
注意:这三个jar包的版本号一定要保持一致。否则的话会引起异常,无法创建XSSFWorkbook
三、导出方法封装类
import lombok.extern.slf4j.Slf4j;
import org.apache.http.client.utils.DateUtils;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import java.io.FileOutputStream;
import java.io.IOException;
import java.sql.Timestamp;
import java.util.*;
/**
* POI导出Excel封装
* @author lenny
* @date 20210715
*/
@Slf4j
public class ExcelUtil {
/**
* @param fileName excel文件名
* @param headMap 表头map
* @param dataList 表格数据
*/
public static String exportExcel(String fileName,Map<String, String> headMap, List<Map<String, Object>> dataList) {
String fullPath="";
Workbook workbook = exportXlsx(fileName, headMap, dataList);
FileOutputStream outputStream=null;
try {
//将生成的excel存储在系统根目录下excel文件夹中
String path=CommonUtil.getRunningDirectory()+"\\excel\\";
fullPath=path+fileName;
outputStream = new FileOutputStream(path+fileName);
workbook.write(outputStream);
} catch (Exception e) {
e.printStackTrace();
} finally {
if (outputStream != null) {
try {
outputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
//返回文件所在的目录
return fullPath;
}
/**
* 导出数据
*
* @param headMap 表头map
* @param dataList 导出的数据
*/
public static Workbook exportXlsx(String sheetName, Map<String, String> headMap, List<Map<String, Object>> dataList) {
try {
XSSFWorkbook workbook = new XSSFWorkbook();
Sheet sheet = workbook.createSheet(sheetName);
//初始化行列索引
int rowIndex = 0, columnIndex = 0;
Set<String> keys = headMap.keySet();
//表头
Row row = sheet.createRow(rowIndex++);
for (String key : keys) {
Cell cell = row.createCell(columnIndex++);
cell.setCellValue(headMap.get(key));
}
//内容
if (dataList != null && !dataList.isEmpty()) {
for (Map<String, Object> map : dataList) {
row = sheet.createRow(rowIndex++);
columnIndex = 0;
for (String key : keys) {
Cell cell = row.createCell(columnIndex++);
setCellValue(cell, map.get(key));
}
}
}
return workbook;
}catch (Exception e){
log.error(e.toString());
return null;
}
}
/**
* 填充单元格内容
* @param cell
* @param obj
*/
private static void setCellValue(Cell cell, Object obj) {
if (obj == null) {
return;
}
if (obj instanceof String) {
cell.setCellValue((String) obj);
} else if (obj instanceof Date) {
Date date = (Date) obj;
if (date != null) {
cell.setCellValue(DateUtils.formatDate(date));
}
} else if (obj instanceof Calendar) {
Calendar calendar = (Calendar) obj;
if (calendar != null) {
cell.setCellValue(DateUtils.formatDate(calendar.getTime()));
}
} else if (obj instanceof Timestamp) {
Timestamp timestamp = (Timestamp) obj;
if (timestamp != null) {
cell.setCellValue(DateUtils.formatDate(new Date(timestamp.getTime())));
}
} else if (obj instanceof Double) {
cell.setCellValue((Double) obj);
} else {
cell.setCellValue(obj.toString());
}
}
}
其中使用到了封装的获取系统根目录的方法,方法实现如下:
/**
* 得到程序运行的根目录
* @return
*/
public static String getRunningDirectory()
{
return System.getProperty("user.dir");
}
四、调用方法执行生成excel操作
/**
* 导出Adas报警
* @param reportAdasList
* @param language
* @param timeDiff
* @return
*/
public static String exportAdasReport(List<ReportAdasList> reportAdasList, int language, int timeDiff) {
//表头
Map<String, String> headNameMap = new LinkedHashMap<String, String>();
headNameMap.put("agentName", getHeadName("agentName",language));
headNameMap.put("vehicleName", getHeadName("vehicleName",language));
headNameMap.put("assetID", getHeadName("assetID",language));
headNameMap.put("alarmType", getHeadName("alarmType",language));
headNameMap.put("alarmLevel", getHeadName("alarmLevel",language));
headNameMap.put("startTime", getHeadName("startTime",language));
headNameMap.put("endTime", getHeadName("endTime",language));
headNameMap.put("driverName", getHeadName("driverName",language));
headNameMap.put("startAddress", getHeadName("startAddress",language));
headNameMap.put("endAddress", getHeadName("endAddress",language));
headNameMap.put("processStatus", getHeadName("processStatus",language));
headNameMap.put("processContext", getHeadName("processContext",language));
headNameMap.put("processTime", getHeadName("processTime",language));
//表格数据
List<Map<String, Object>> dataList = new ArrayList<Map<String, Object>>();
for(ReportAdasList item : reportAdasList){
Map<String, Object> map = new HashMap<String, Object>();
map.put("agentName", item.getAgentName());
map.put("vehicleName", item.getVehicleName());
map.put("assetID", item.getAssetID());
map.put("alarmType", language==1?item.getCnName():item.getEnName());
map.put("alarmLevel", getAlarmLevel(item.getAlarmLevel(),language));
map.put("startTime", CommonUtil.getLocalTime(item.getStartTime(),timeDiff));
map.put("endTime", CommonUtil.getLocalTime(item.getEndTime(),timeDiff));
map.put("driverName", item.getDriverName());
map.put("startAddress", CommonUtil.geoCoding(String.valueOf(item.getStartLatitude()),String.valueOf(item.getStartLongitude()),language));
map.put("endAddress", CommonUtil.geoCoding(String.valueOf(item.getEndLatitude()),String.valueOf(item.getEndLongitude()),language));
map.put("processStatus", getProcessStatus(item.getProcessStatus(),language));
map.put("processContext", item.getProcessContext());
map.put("processTime", CommonUtil.getLocalTime(item.getProcessTime(),timeDiff));
dataList.add(map);
}
String fileName = "";
if(language==1) {
fileName= CommonConstants.CN_REPORT_ADAS;
}else {
fileName=CommonConstants.EN_REPORT_ADAS;
}
fileName=fileName+".xlsx";
String fullPath = ExcelUtil.exportExcel(fileName,headNameMap,dataList);
return fullPath;
}
这里大家可以根据自己的系统自行调整,最后封装成headMap(表头字段)与List<Map<String, Object>>(数据列表)即可。