目录
2.2、HTTPRequest 读取Excel InputStream方式导入读取Excel文件内容
1、使用场景
目前大多数人做项目，都会使用Excel文件做导入导出功能。于是本人也观察了好些项目，无外乎以下两种实现方式：
- 把导入的Excel文件上传至Java应用服务器方式
- 直接从Http的Request请求之中获得上传的Excel文件流的方式直接读取内容
- 如果增加数据要求极高情况建议记录导入数据日志记录
其中使用把Exce文件上传到服务器方式，有如下优缺点：
优点：
因为文件上传到服务器，可以查看上传导入文件内容；并且可以查看具体上传导入文件的时间(服务器查看)
导入文件的操作是在文件上传至服务器后再执行的，意味着保障的Excel文件完整性，避免的导入过程突然断网风险。
缺点：
也是因为把文件上传至应用服务器啦，并且导入的操作仅仅执行完毕一次之后；后面的文件将没有多大意义啦，造成此类文件的占用空间。也许有人会说在服务器端写过shell脚本定时清除即可。
直接从Http的Request请求之中获得上传的Excel文件流的方式 优缺点比较
优点：
能够直接使得导入过程从以前两个步骤，先上传然后在导入过程；可以直接从HttpRequest请求之中获得Excel的InputStream文件流直接读取Excel文件之中的内容进行导入。
不用存储多余的Excel文件到Java应用服务器上，节省磁盘空间。
缺点：
正因为不用先上传文件到应用服务器上，可能出现文件如果Excel文件内容较大；读取文件流过程比较慢。同时有风险如果上传过程之中突然断网；可能读取文件流不完整的情况。
如果增加数据要求极高情况建议记录导入数据日志记录
如果系统要求针对入库数据比较严格的情况下；建议吧数据导入的相关操作记录 是谁、什么时间、导入了哪些数据进入日志操作记录以备核查。
本文将主要使用直接通过读取HttpRequest之中Excel文件流的方式实现Excel的文件到导入的实现。
2、代码实现
2.1、Pom.xml导入 jar包
<!-- Excel 使用POI操作相关jar start -->
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi</artifactId>
<version>4.1.1</version>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml</artifactId>
<version>4.1.1</version>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml-schemas</artifactId>
<version>4.1.1</version>
</dependency>
<dependency>
<groupId>org.apache.xmlbeans</groupId>
<artifactId>xmlbeans</artifactId>
<version>3.1.0</version>
</dependency>
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-collections4</artifactId>
<version>4.4</version>
</dependency>
<dependency>
<groupId>dom4j</groupId>
<artifactId>dom4j</artifactId>
<version>1.6.1</version>
</dependency>
<!-- Excel 使用POI操作相关jar end -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.62</version>
</dependency>
<dependency>
<groupId>commons-fileupload</groupId>
<artifactId>commons-fileupload</artifactId>
<version>1.4</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>1.7.28</version>
</dependency>2.2、HTTPRequest 读取Excel InputStream方式导入读取Excel文件内容
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.multipart.MultipartHttpServletRequest;
import org.springframework.web.multipart.commons.CommonsMultipartResolver;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.Part;
import java.io.IOException;
import java.io.InputStream;
import java.util.Collection;
import java.util.Iterator;
/**
* @Classname ExcelDirectRequestInputStreamUtil
* @Description 直接从Request之中获得导入的Excel文件流内容
* @Date 2019/11/9 11:46
* @Created by jianxiapc
*/
public class ExcelImportByRequestInputStreamUtil {
private static Logger logger = LoggerFactory.getLogger(ExcelImportByRequestInputStreamUtil.class);
/**
* 获得上传文件未单个Excel文件时候 通过MultipartFile参数获得文件流信息
* @param request
* @param response
* @param file
* @return
* @throws IOException
*/
public static InputStream getInputStreamByMultipartFileParameter(HttpServletRequest request, HttpServletResponse response,MultipartFile file) throws IOException {
InputStream excelInputStream = file.getInputStream();
int length=excelInputStream.available();
logger.info("length： "+length);
logger.info("excelInputStream： "+excelInputStream.toString());
return excelInputStream;
}
/**
* 通过request获得InputStream获得文件内容
* @param request
* @param response
* @param frontEndFileInputName
* @return
* @throws IOException
*/
public static InputStream getInputStreamByRequestAndFileInputName(HttpServletRequest request, HttpServletResponse response,String frontEndFileInputName) throws IOException {
MultipartHttpServletRequest params=((MultipartHttpServletRequest) request);
MultipartFile fileContent = ((MultipartHttpServletRequest) request).getFiles(frontEndFileInputName).get(0);
// fis 既是上传的文件流
InputStream excelInputStream = fileContent.getInputStream();
int length=excelInputStream.available();
logger.info("length： "+length);
logger.info("excelInputStream： "+excelInputStream.toString());
return excelInputStream;
}
/**
* 通过request之中获得file的Parts
*
* @param request
* @param response
* @throws IOException
* @throws ServletException
*/
public static InputStream getInputStreamByRequestParts(HttpServletRequest request, HttpServletResponse response,String frontEndFileInputName) throws IOException, ServletException {
logger.info("request.getContentType(): " + request.getContentType());
if (!request.getContentType().split(";")[0].equals("multipart/form-data"))
return null;
Collection<Part> parts = request.getParts();
InputStream excelInputStream =null;
//通过获得part信息组装为InputStream流用读取文件内容
int i=0;
for (Iterator<Part> iterator = parts.iterator(); iterator.hasNext(); ) {
Part part = iterator.next();
logger.info("-----类型名称------->" + part.getName());
logger.info("-----类型------->" + part.getContentType());
logger.info("-----提交的类型名称------->" + part.getSubmittedFileName());
logger.info("----流-------->" + part.getInputStream());
logger.info("循环次数=== "+i);
excelInputStream=part.getInputStream();
i++;
}
return excelInputStream;
}
/**
* 使用 commons-fileupload 上传Excel文件返回文件流信息
* @param request
* @param response
* @return
* @throws IOException
*/
public static InputStream getInputStreamByMultipartHttpServletRequest(HttpServletRequest request, HttpServletResponse response) throws IOException {
InputStream excelInputStream =null;
//将当前上下文初始化给 CommonsMutipartResolver （多部分解析器）
CommonsMultipartResolver multipartResolver = new CommonsMultipartResolver(
request.getSession().getServletContext());
// 判断是否是多数据段提交格式
if (multipartResolver.isMultipart(request)) {
MultipartHttpServletRequest multiRequest = (MultipartHttpServletRequest) request;
Iterator<String> iter = multiRequest.getFileNames();
logger.info("iter.hasNext(): " + iter.hasNext());
Integer fileCount = 0;
while (iter.hasNext()) {
MultipartFile multipartFile = multiRequest.getFile(iter.next());
String fileName = multipartFile.getOriginalFilename();
logger.info("upload filename: " + fileName);
if (fileName == null || fileName.trim().equals("")) {
continue;
}
//20170207 针对IE环境下filename是整个文件路径的情况而做以下处理
Integer index = fileName.lastIndexOf("\\");
String newStr = "";
if (index > -1) {
newStr = fileName.substring(index + 1);
} else {
newStr = fileName;
}
if (!newStr.equals("")) {
fileName = newStr;
}
logger.info("new filename: " + fileName);
if (multipartFile != null) {
excelInputStream= multipartFile.getInputStream();
long fileSize= multipartFile.getSize();
logger.info("fileSize: " + fileSize);
}
}
}
return excelInputStream;
}
}2.2、导出数据内容到Excel之中
import org.apache.poi.ss.usermodel.Font;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.XSSFCellStyle;
import org.apache.poi.xssf.usermodel.XSSFColor;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import org.apache.poi.xssf.usermodel.extensions.XSSFCellBorder.BorderSide;
import org.spring.springboot.excel.poi.export.model.ExcelModelData;
import javax.servlet.http.HttpServletResponse;
import java.awt.Color;
import java.io.OutputStream;
import java.net.URLEncoder;
import java.util.List;
/**
* @Classname ExportExcelUtils
* @Description Excel导出工具集合
* @Date 2019/11/7 14:41
* @Created by jianxiapc
*/
public class ExcelWriterExportUtils {
public static void exportExcel(HttpServletResponse response, String fileName, ExcelModelData data) throws Exception {
// 告诉浏览器用什么软件可以打开此文件
response.setHeader("content-Type", "application/vnd.ms-excel");
// 下载文件的默认名称
response.setHeader("Content-Disposition", "attachment;filename="+URLEncoder.encode(fileName, "utf-8"));
exportExcel(data, response.getOutputStream());
}
public static void exportExcel(ExcelModelData data, OutputStream out) throws Exception {
XSSFWorkbook wb = new XSSFWorkbook();
try {
String sheetName = data.getName();
if (null == sheetName) {
sheetName = "Sheet1";
}
XSSFSheet sheet = wb.createSheet(sheetName);
writeExcel(wb, sheet, data);
wb.write(out);
} finally {
wb.close();
}
}
private static void writeExcel(XSSFWorkbook wb, Sheet sheet, ExcelModelData data) {
int rowIndex = 0;
rowIndex = writeTitlesToExcel(wb, sheet, data.getHeadTitles());
writeRowsToExcel(wb, sheet, data.getRows(), rowIndex);
autoSizeColumns(sheet, data.getHeadTitles().size() + 1);
}
private static int writeTitlesToExcel(XSSFWorkbook wb, Sheet sheet, List<String> titles) {
int rowIndex = 0;
int colIndex = 0;
Font titleFont = wb.createFont();
titleFont.setFontName("simsun");
titleFont.setBold(true);
// titleFont.setFontHeightInPoints((short) 14);
titleFont.setColor(IndexedColors.BLACK.index);
XSSFCellStyle titleStyle = wb.createCellStyle();
titleStyle.setAlignment(HorizontalAlignment.CENTER);
titleStyle.setVerticalAlignment(VerticalAlignment.CENTER);
titleStyle.setFillForegroundColor(new XSSFColor(new Color(182, 184, 192)));
titleStyle.setFillPattern(FillPatternType.SOLID_FOREGROUND);
titleStyle.setFont(titleFont);
setBorder(titleStyle, BorderStyle.THIN, new XSSFColor(new Color(0, 0, 0)));
Row titleRow = sheet.createRow(rowIndex);
// titleRow.setHeightInPoints(25);
colIndex = 0;
for (String field : titles) {
Cell cell = titleRow.createCell(colIndex);
cell.setCellValue(field);
cell.setCellStyle(titleStyle);
colIndex++;
}
rowIndex++;
return rowIndex;
}
private static int writeRowsToExcel(XSSFWorkbook wb, Sheet sheet, List<List<Object>> rows, int rowIndex) {
int colIndex = 0;
Font dataFont = wb.createFont();
dataFont.setFontName("simsun");
// dataFont.setFontHeightInPoints((short) 14);
dataFont.setColor(IndexedColors.BLACK.index);
XSSFCellStyle dataStyle = wb.createCellStyle();
dataStyle.setAlignment(HorizontalAlignment.CENTER);
dataStyle.setVerticalAlignment(VerticalAlignment.CENTER);
dataStyle.setFont(dataFont);
setBorder(dataStyle, BorderStyle.THIN, new XSSFColor(new Color(0, 0, 0)));
for (List<Object> rowData : rows) {
Row dataRow = sheet.createRow(rowIndex);
// dataRow.setHeightInPoints(25);
colIndex = 0;
for (Object cellData : rowData) {
Cell cell = dataRow.createCell(colIndex);
if (cellData != null) {
cell.setCellValue(cellData.toString());
} else {
cell.setCellValue("");
}
cell.setCellStyle(dataStyle);
colIndex++;
}
rowIndex++;
}
return rowIndex;
}
private static void autoSizeColumns(Sheet sheet, int columnNumber) {
for (int i = 0; i < columnNumber; i++) {
int orgWidth = sheet.getColumnWidth(i);
sheet.autoSizeColumn(i, true);
int newWidth = (int) (sheet.getColumnWidth(i) + 100);
if (newWidth > orgWidth) {
sheet.setColumnWidth(i, newWidth);
} else {
sheet.setColumnWidth(i, orgWidth);
}
}
}
private static void setBorder(XSSFCellStyle style, BorderStyle border, XSSFColor color) {
style.setBorderTop(border);
style.setBorderLeft(border);
style.setBorderRight(border);
style.setBorderBottom(border);
style.setBorderColor(BorderSide.TOP, color);
style.setBorderColor(BorderSide.LEFT, color);
style.setBorderColor(BorderSide.RIGHT, color);
style.setBorderColor(BorderSide.BOTTOM, color);
}
}
2.3、如果导入文件需要读取多个表并且有关联关系实现
如果我们实际开发之中可能会针对读取的Excel文件内容；同时涉及到过个Excel的Sheet表格；并且每个表格之间有导入的前后关系。于是会使用读取Excel文件之中Sheet表格循环读取，具体代码如下所示：
/**
* 通过读取Excel的文件路径 读取 .xls or .xlsx 都行
* @param excelFileDirPath
* @param titleRow
* @return
*/
public static List<Map<String,Object>> readExcelFileContentToList(String excelFileDirPath,String titleRow[]) throws IOException, InvalidFormatException {
//通过工厂模式创建Excel Workbook from an Excel file (.xls or .xlsx)
Workbook workbook = WorkbookFactory.create(new File(excelFileDirPath));
logger.info(" Excel Workbook 包含有 " + workbook.getNumberOfSheets() + " 张 Sheets : ");
List<Map<String,Object>> readExcelFileRowsContentList=new ArrayList<Map<String,Object>>();
/*
=============================================================
迭代在workbook之中的所有的sheets (多种方式)
=============================================================
*/
//1、 获得一个sheetIterator 和 iterate 覆盖它
Iterator<Sheet> sheetIterator = workbook.sheetIterator();
logger.info("使用 Iterator 返回 Sheets ");
while (sheetIterator.hasNext()) {
Sheet sheet = sheetIterator.next();
logger.info("=> " + sheet.getSheetName());
}
/**
//2、 使用 for-each loop 返回 workbook之中的 sheet
logger.info("使用 for-each loop 返回 Sheets ");
for(Sheet sheet: workbook) {
logger.info("=> " + sheet.getSheetName());
}
// 3、使用 Java 8 forEach wih lambda
logger.info("使用 Java 8 forEach with lambda 返回 Sheets ");
workbook.forEach(sheet -> {
logger.info("=> " + sheet.getSheetName());
});
*/
/*
==================================================================
遍历工作表(Sheet)中的所有行(rows)和列(columns) (Multiple ways)
==================================================================
*/
// 获得 索引为0 的 Sheet
Sheet sheet = workbook.getSheetAt(0);
// 创建一个数据格式器 目的是为 格式化 获得每cell的值为字符串
DataFormatter dataFormatter = new DataFormatter();
// 1、 你能够 obtain a rowIterator and columnIterator and iterate over them
logger.info(" 使用 Iterator Iterating over Rows and Columns ");
Iterator<Row> rowIterator = sheet.rowIterator();
boolean isFirstRow=true;//是否是第一行
while (rowIterator.hasNext()) {
Row row = rowIterator.next();
Map<String,Object> rowMap= new HashMap<String,Object>();
// Now let's iterate over the columns of the current row
Iterator<Cell> cellIterator = row.cellIterator();
int titleIndex=0;
if(!isFirstRow){
while (cellIterator.hasNext()) {
Cell cell = cellIterator.next();
String cellValue = dataFormatter.formatCellValue(cell);
rowMap.put(titleRow[titleIndex],cellValue);
logger.info(titleRow[titleIndex]+" ===>"+cellValue);
titleIndex++;
}
logger.info("row content: "+rowMap.toString());
readExcelFileRowsContentList.add(rowMap);
}
isFirstRow=false;
}3、成果展现
3.1、使用HTTPRequest 的读取InputStream文件楼方式获得文件内容
3.2、导出Excel功能
4、总结
本文探讨了脱离传统模式，直接从HTTPRequest请求之中 读取到Excel的 InputStream文件流方式直接实现导入的功能。
同时本文将分析源码如何读取Excel文件之中多张表之中内容实现方式。
源码地址：https://github.com/jianxia612/springboot-excel-import-export-fileupload.git
5、参考文章
HttpRequest获取文件流,HttpResponse输出文件流
文件上传 servlet 从HttpServletRequest.getInputStream()中获得消息内容
此文章的代码相当丰富
https://github.com/callicoder/java-read-write-excel-file-using-apache-poi