使用poi操作导入excel代码示例

package codes;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.text.DecimalFormat;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Date;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFDateUtil;
import org.apache.poi.hssf.usermodel.HSSFFormulaEvaluator;
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.poifs.filesystem.POIFSFileSystem;
import org.apache.poi.ss.usermodel.CellValue;
/***
* 解析excel数据文件：
* 利用poi的jar包解析excel
* operateSingleService方法：只能操作单一一张excel表，返回二维数组[有点小bug]
* operateMulService方法：操作一个完整的excel工作目录，返回map对象【优先】
* 返回字符串的二维数据(如果需要保持入库，就需要获取他的类型，可以考虑使用map来存放, 或根据头字段查DB，转换为相应类型)
*/
public class OperateExcel_POI extends HttpServlet {

private static final long serialVersionUID = 1L;

@SuppressWarnings("unchecked")
protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
request.setCharacterEncoding("UTF-8");
response.setCharacterEncoding("UTF-8");
String sheet = request.getParameter("sheet");
boolean isMultipart = ServletFileUpload.isMultipartContent(request);
try {
if(isMultipart){
DiskFileItemFactory factory = new DiskFileItemFactory();
ServletFileUpload fileUpload = new ServletFileUpload(factory);
fileUpload.setSizeMax(10 * 1024 * 1024);
List<FileItem> items = fileUpload.parseRequest(request);
//System.out.println(items.isEmpty());
if("1".equals(sheet)){
String[][] str = null;
for(FileItem item : items){
str = getSingleData(item.getInputStream(), 1);
}
//下面测试循环出二维数组中的内容
for(int i=0;i<str.length;i++){
System.out.print("第" + i + "行： ");
for(int j=0;j<str.length;j++){
System.out.print(str[i][j] + "  ");
}
System.out.println();
}
}else{
Map<String, Map<String, List<String>>> maps = null;
for(FileItem item : items){
maps = getMulData(item.getInputStream(), 1);
}
Iterator<String> itekeys = maps.keySet().iterator();
while(itekeys.hasNext()){
String sheetName = itekeys.next();
System.out.println("-------------" + sheetName + "---------------");
Map<String, List<String>> mapv = maps.get(sheetName);//返回一张数据表
for(int i = 0; i < mapv.size(); i++){
List<String> listv = mapv.get(String.valueOf(i));
System.out.print("第" + i + "行" + listv.size() + "列: ");
for(int j = 0;j < listv.size(); j++){
System.out.print(listv.get(j) + "  ");
}
System.out.println();
}
}
}
}else{
System.out.println("~~~~(>_<)~~~~ ");
}
} catch (FileUploadException e) {
e.printStackTrace();
}
}

/**
* 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 file 读取数据的源Excel
* @param ignoreRows 读取数据忽略的行数，比喻行头不需要读入 忽略的行数为1
* @return 读出的Excel中数据的内容
* @throws FileNotFoundException
* @throws IOException
*/
public static String[][] getSingleData(File file, int ignoreRows) throws FileNotFoundException, IOException {
BufferedInputStream in = new BufferedInputStream(new FileInputStream(file));
String[][] returnArray = operateSingleService(ignoreRows, in);
return returnArray;
}

public static String[][] getSingleData(InputStream input, int ignoreRows) throws FileNotFoundException, IOException {
BufferedInputStream in = new BufferedInputStream(input);
String[][] returnArray = operateSingleService(ignoreRows, in);
return returnArray;
}

public static Map<String, Map<String, List<String>>> getMulData(InputStream input, int ignoreRows) throws FileNotFoundException, IOException {
BufferedInputStream in = new BufferedInputStream(input);
Map<String, Map<String, List<String>>> returnMaps = operateMulService(ignoreRows, in);
return returnMaps;
}

/***
* 这个方法只能操作单一工作表，
* 方法有缺陷未修改，可以考虑使用多表操作的operateMulService方法
* @param ignoreRows
* @param in
* @return 一张数据表的二维数组
* @throws IOException
*/
private static String[][] operateSingleService(int ignoreRows, BufferedInputStream in) throws IOException {
List<String[]> result = new ArrayList<String[]>();
int rowSize = 0;
// 打开HSSFWorkbook
POIFSFileSystem fs = new POIFSFileSystem(in);
HSSFWorkbook wb = new HSSFWorkbook(fs);
HSSFFormulaEvaluator evaluator = new HSSFFormulaEvaluator(wb);
HSSFCell cell = null;
for (int sheetIndex = 0; sheetIndex < wb.getNumberOfSheets(); sheetIndex++) {
HSSFSheet st = wb.getSheetAt(sheetIndex);
// 第一行为标题，不取
for (int rowIndex = ignoreRows; rowIndex <= st.getLastRowNum(); rowIndex++) {
HSSFRow row = st.getRow(rowIndex);
if (row == null) {
continue;
}
int tempRowSize = row.getLastCellNum() + 1;
if (tempRowSize > rowSize) {
rowSize = tempRowSize;
}
String[] values = new String[rowSize];
Arrays.fill(values, "");
boolean hasValue = false;
for (int columnIndex = 0; columnIndex <= row.getLastCellNum(); columnIndex++) {
String value = "";
cell = row.getCell(columnIndex);
if (cell != null) {
switch (cell.getCellType()) {
case HSSFCell.CELL_TYPE_STRING://字符串格式
value = cell.getStringCellValue();
break;
case HSSFCell.CELL_TYPE_NUMERIC://数值格式
if (HSSFDateUtil.isCellDateFormatted(cell)) {
Date date = cell.getDateCellValue();
if (date != null) {
value = new SimpleDateFormat("yyyy-MM-dd").format(date);
}else{
value = "";
}
}else{
value = new DecimalFormat("0").format(cell.getNumericCellValue());
}
break;
case HSSFCell.CELL_TYPE_FORMULA://公式格式
CellValue cellValue = evaluator.evaluate(cell);//对格式生成的值进行计算
if(cellValue.getCellType() == HSSFCell.CELL_TYPE_NUMERIC){//如果为数字类型
value = String.valueOf(new DecimalFormat("0").format(cellValue.getNumberValue()));
}else if(cellValue.getCellType() == HSSFCell.CELL_TYPE_STRING){//如果为字符串类型
value = cellValue.getStringValue();
}else{//如果未error类型
value = "";
}
break;
case HSSFCell.CELL_TYPE_BLANK://空白格式
break;
case HSSFCell.CELL_TYPE_ERROR://错误格式
value = "";
break;
case HSSFCell.CELL_TYPE_BOOLEAN://boolean格式
value = (cell.getBooleanCellValue() == true ? "Y" : "N");
break;
default:
value = "";
}
}
if (columnIndex == 0 && value.trim().equals("")) {
break;
}
values[columnIndex] = rightTrim(value);
hasValue = true;
}
if (hasValue) {
result.add(values);
}
}
}
in.close();
String[][] returnArray = new String[result.size()][rowSize];
for (int i = 0; i < returnArray.length; i++) {
returnArray[i] = (String[]) result.get(i);
}
return returnArray;
}

/**
* @param ignoreRows 代表忽略的行
* @param in 输入工作流
* @return Map对象[一个工作薄]
* @throws IOException
*/
private static Map<String, Map<String, List<String>>> operateMulService(int ignoreRows, BufferedInputStream in) throws IOException {
//代表一个excel工作薄
Map<String, Map<String, List<String>>> maps = new HashMap<String, Map<String, List<String>>>();
//代表一个单一工作表
Map<String, List<String>> singleMap = null;
//一行的多列内容集合
List<String> singleList = null;
// 打开HSSFWorkbook
POIFSFileSystem fs = new POIFSFileSystem(in);
HSSFWorkbook wb = new HSSFWorkbook(fs);
HSSFFormulaEvaluator evaluator = new HSSFFormulaEvaluator(wb);
HSSFCell cell = null;
for (int sheetIndex = 0; sheetIndex < wb.getNumberOfSheets(); sheetIndex++) {//循环工作薄
singleMap = new HashMap<String, List<String>>();
HSSFSheet st = wb.getSheetAt(sheetIndex);
// 第一行为标题，不取
int rowNum = 0;//定义一个变量用于标志数据行数
for (int rowIndex = ignoreRows; rowIndex < st.getLastRowNum(); rowIndex++) {//循环单一表中的行
HSSFRow row = st.getRow(rowIndex);
if (row == null) {
continue;
}
singleList = new ArrayList<String>();//定义一个集合用于存放列的数据内容
for (int columnIndex = 0; columnIndex < row.getLastCellNum(); columnIndex++) {//循环单一表中的列
String value = "";
cell = row.getCell(columnIndex);
if (cell != null) {
switch (cell.getCellType()) {
case HSSFCell.CELL_TYPE_STRING://字符串格式
value = cell.getStringCellValue();
break;
case HSSFCell.CELL_TYPE_NUMERIC://数值格式
if (HSSFDateUtil.isCellDateFormatted(cell)) {
Date date = cell.getDateCellValue();
if (date != null) {
value = new SimpleDateFormat("yyyy-MM-dd").format(date);
}else{
value = "";
}
}else{
value = new DecimalFormat("0").format(cell.getNumericCellValue());
}
break;
case HSSFCell.CELL_TYPE_FORMULA://公式格式
CellValue cellValue = evaluator.evaluate(cell);//对格式生成的值进行计算
if(cellValue.getCellType() == HSSFCell.CELL_TYPE_NUMERIC){//如果为数字类型
value = String.valueOf(new DecimalFormat("0").format(cellValue.getNumberValue()));
}else if(cellValue.getCellType() == HSSFCell.CELL_TYPE_STRING){//如果为字符串类型
value = cellValue.getStringValue();
}else{//如果未error类型
value = "";
}
break;
case HSSFCell.CELL_TYPE_BLANK://空白格式
break;
case HSSFCell.CELL_TYPE_ERROR://错误格式
value = "";
break;
case HSSFCell.CELL_TYPE_BOOLEAN://boolean格式
value = (cell.getBooleanCellValue() == true ? "Y" : "N");
break;
default:
value = "";
}
}
singleList.add(value);//一行中所有列的值的集合
}
//System.out.println(String.valueOf(rowIndex - 1)+"行，有" + singleList.size()+"列");
singleMap.put(String.valueOf(rowNum++), singleList);//行号、列数据
}
rowNum = 0;
maps.put(st.getSheetName(), singleMap);//工作表、表数据
}
in.close();
return maps;
}

/**
* 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);
}
}