java操作excel之poi读取excel
1.介绍
Apache POI是Apache软件基金会的开放源码函式库，POI提供API给Java程序对Microsoft Office格式档案读和写的功能。
2.依赖
首先引入maven依赖：
org.apache.poi
poi
3.14
3.工具类ExcelUtils
package com.tl.util.core.helper;
import org.apache.poi.hssf.usermodel.*;
import org.apache.poi.poifs.filesystem.POIFSFileSystem;
import java.io.IOException;
import java.io.InputStream;
import java.text.SimpleDateFormat;
import java.util.*;
/**
* Excel工具类
*
*/
public class ExcelUtils {
/**
* EXCEL第一行索引
*/
public static final int EXCEL_FIRST_ROW_INDEX = 0;
public static final String TRUE_VALUE = "Y";
public static final String FALSE_VALUE = "N";
/**
* 获取单元格字符串内容
*
* @param cell
* @return
*/
private static String getCellValue(HSSFCell cell) {
String value = "";
// 注意：一定要设成这个，否则可能会出现乱码
//cell.setEncoding(HSSFCell.ENCODING_UTF_16);
switch (cell.getCellType()) {
case HSSFCell.CELL_TYPE_STRING:
value = cell.getStringCellValue();
break;
case HSSFCell.CELL_TYPE_NUMERIC:
if (HSSFDateUtil.isCellDateFormatted(cell)) {
Date date = cell.getDateCellValue();
if (date != null) {
value = new SimpleDateFormat("yyyy-MM-dd").format(date);
} else {
value = "";
}
} else {
long longVal = Math.round(cell.getNumericCellValue());
if (Double.parseDouble(longVal + ".0") == cell.getNumericCellValue())
value = String.valueOf(longVal);
else
value = String.valueOf(cell.getNumericCellValue());
//value =cell.getStringCellValue();
}
break;
case HSSFCell.CELL_TYPE_FORMULA:
// 导入时如果为公式生成的数据则无值
if (!cell.getCellFormula().equals("")) {
try {
value = String.valueOf(cell.getNumericCellValue());
} catch (Exception ex) {
value = cell.getStringCellValue();
}
} else {
value = cell.getStringCellValue() + "";
}
break;
case HSSFCell.CELL_TYPE_BLANK:
break;
case HSSFCell.CELL_TYPE_ERROR:
value = "";
break;
case HSSFCell.CELL_TYPE_BOOLEAN:
value = (cell.getBooleanCellValue() ? TRUE_VALUE : FALSE_VALUE);
break;
default:
value = "";
}
return value;
}
/**
* 去掉字符串右边的空格
*
* @param str 要处理的字符串
* @return 处理后的字符串
*/
private static String rightTrim(String str) {
if (str == null) {
return "";
}
int length = str.length();
for (int i = length - 1; i >= 0; i--) {
if (str.charAt(i) != 0x20) {
break;
}
length--;
}
return str.substring(0, length);
}
/**
* 读取Excel的内容，第一维数组存储的是一行中格列的值，二维数组存储的是多少个行
*
* @param inputStream 读取数据的源Excel
* @param headerIndex 表单头所在的索引
* @return 读出的Excel中数据的内容
* @throws IOException
*/
public static List> parse(InputStream inputStream, int headerIndex) throws IOException {
List> result = new ArrayList>();
int maxcolumnIndex = 0;
POIFSFileSystem fs = new POIFSFileSystem(inputStream);
HSSFWorkbook wb = new HSSFWorkbook(fs);
HSSFCell cell = null;
for (int sheetIndex = 0; sheetIndex < wb.getNumberOfSheets(); sheetIndex++) {
HSSFSheet st = wb.getSheetAt(sheetIndex);
List headers = new ArrayList();
for (int rowIndex = 0; rowIndex <= st.getLastRowNum(); rowIndex++) {
HSSFRow row = st.getRow(rowIndex);
if (row == null) {
continue;
}
int currentcolumnIndex = row.getLastCellNum() + 1;
if (currentcolumnIndex > maxcolumnIndex) {
maxcolumnIndex = currentcolumnIndex;
}
Map rows = new LinkedHashMap();
for (int columnIndex = 0; columnIndex <= row.getLastCellNum(); columnIndex++) {
String value = "";
cell = row.getCell(columnIndex);
if (cell != null) {
value = getCellValue(cell);
}
if (rowIndex == headerIndex && value != null && !value.trim().equals("")) {
headers.add(value.trim());
} else {
if (columnIndex < headers.size()) {
rows.put(headers.get(columnIndex), value);
}
}
}
if (!isEmptyMap(rows)) {
result.add(rows);
}
}
}
return result;
}
private static boolean isEmptyMap(Map map) {
boolean empty = map.isEmpty();
if (!empty) {
Collection values = map.values();
for (Object value : values) {
if (value != null && !value.toString().equals("")) {
return false;
}
}
return true;
}
return empty;
}
}
注意事项：
HSSFWorkbook:是操作Excel2003以前（包括2003）的版本，扩展名是.xls
XSSFWorkbook:是操作Excel2007的版本，扩展名是.xlsx
所以上面的代码仅支持excel2003，因为excel具有向下兼容的特性，同时也可以将07版的转为03版。
需要注意的是在读取list结果集的时候，获取某一列的数据的时候，一定要跟excel的列头字段保持一致，否则将读不到数据！
所以上面的代码仅支持excel2003，因为excel具有向下兼容的特性，同时也可以将07版的转为03版。
4.测试
/**
* 员工excel数据读取并导入staff表中
*
* @param request
* @param stream
* @param consumer
* @return
*/
@Override
public ImportExcelResult importStaff(ImportStaffRequest request, InputStream stream, Consumer consumer) {
ImportExcelResult result = new ImportExcelResult();
List> data = null;
try {
data = ExcelUtils.parse(stream, ExcelUtils.EXCEL_FIRST_ROW_INDEX);
} catch (Exception ex) {
result.addFail("读取excel文件失败:" + ex.getMessage());
consumer.accept(result);
throw new ImportFailedException("读取excel文件失败:" + ex.getMessage());
}
if (data == null) {
result.addFail("读取excel失败,或excel为空\"");
consumer.accept(result);
throw new ImportFailedException("读取excel失败,或excel为空");
}
result.setRowQuantity(data.size());
for (Map row : data) {
String departmentName = row.get("部门名称");
String code = row.get("人员编号");
String name = row.get("人员姓名");
String positionName = row.get("人员职位");
String certificate = row.get("身份证号码");
String sex = row.get("性别");
String education = row.get("学历");
String hiredate = row.get("入职年月");
int age = Integer.valueOf(row.get("年龄"));
String domicile = row.get("户籍");
String address = row.get("现居地址");
String mobile = row.get("手机号");
Position position = positionRepository.findOneByName(positionName);
if (position == null) {
result.addFail("职位名称信息缺失:" + positionName);
consumer.accept(result);
continue;
}
Department department = departmentRepository.findOneByName(departmentName);
if (position == null) {
result.addFail("部门名称信息缺失:" + positionName);
consumer.accept(result);
continue;
}
Staff staff = findByCode(code);
if (staff == null) {
staff = new Staff();
}
if (Strings.isNotBlank(hiredate)) {
Date date = strToDate(hiredate);
staff.setHiredate(date);
}
staff.setCode(code);
staff.setDepartment(department.getId());
staff.setPosition(position.getId());
staff.setRealname(name);
staff.setCertificate(certificate);
staff.setSex(Staff.Sex.fromDescription(sex));
staff.setEducation(Staff.Education.fromDescription(education));
staff.setDomicile(domicile);
staff.setAge(age);
staff.setAddress(address);
staff.setMobile(mobile);
staff.setUser(request.getUser());
store(staff);
result.addSuccess();
consumer.accept(result);
}
return result;
} 需要注意的是在读取list结果集的时候，获取某一列的数据的时候，一定要跟excel的列头字段保持一致，否则将读不到数据！