Question

我正在使用jaxrs上传文件* .xlsx。是否可以上传此文件并在内存中处理它们？我只想读取该文件，使用Apache POI处理并在DataBase中保存信息。 不在服务器中保存

由于

Answer 1

抱歉迟到的回复，这个回答可能对某人有帮助。

是的，可以在内存中读取上传的.xlsx文件的内容[不将上传的内容保存到物理文件]。但这种方法需要更多内存，因为整个文件内容将存储在缓冲区中。

在servlet下面的

是一个很好的例子，如果需要，可以稍加修改，将这段代码转换成JSP。

在创建XSSFWorkbook对象时传递上传文件的输入流，如下所示，您将能够像示例代码一样读取文件内容。

在WEB-INF / lib文件夹中添加apache-poi jars和apache commons-fileupload.jar，以正确使用此代码。

import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.fileupload.*;
import org.apache.commons.fileupload.disk.*;
import org.apache.commons.fileupload.servlet.*;
import org.apache.commons.io.FilenameUtils;
import org.apache.poi.openxml4j.opc.OPCPackage;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

import java.util.List;
import java.util.Iterator;

@WebServlet("/FileUploadServlet")
public class FileUploadServlet extends HttpServlet {


    protected void doPost(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException {
        response.setContentType("text/html");
        PrintWriter out = response.getWriter();
        OPCPackage pkg = null;
        XSSFWorkbook xlsxbook = null;
        InputStream xlsxContentStream = null;

        try {


                boolean isMultipart = ServletFileUpload.isMultipartContent(request);

                if (isMultipart) {

                    List<FileItem> items = new ServletFileUpload(
                            new DiskFileItemFactory()).parseRequest(request);
                    for (FileItem item : items) {
                        if (!item.isFormField()) {
                            String fieldName = item.getFieldName();
                            String fileName = FilenameUtils.getName(item.getName());

                            xlsxContentStream = item.getInputStream();

                            pkg = OPCPackage.open(xlsxContentStream);
                            xlsxbook = new XSSFWorkbook(pkg);
                            XSSFSheet sheet = xlsxbook.getSheetAt(0);

                            Iterator<Row> itr = sheet.iterator();

                            while (itr.hasNext()) {
                                Row row = itr.next();

                                // Iterating over each column of Excel file
                                Iterator<Cell> cellIterator = row.cellIterator();
                                String text = "";
                                double num = 0;
                                while (cellIterator.hasNext()) {

                                    Cell cell = cellIterator.next();

                                    switch (cell.getCellType()) {
                                    case Cell.CELL_TYPE_STRING:
                                        text = cell.getStringCellValue();
                                        break;
                                    case Cell.CELL_TYPE_NUMERIC:
                                        num = cell.getNumericCellValue();
                                        break;
                                    default:

                                    }
                                }

                                out.print(text + " " + num);
                                //call database insert method here and pass the xlsx column values
                            }

                        }
                    }
                }
                out.flush();

            } catch (FileUploadException e) {
                throw new ServletException("Cannot parse multipart request.", e);
            } catch (Exception e) {
                throw new ServletException("", e);
            } finally {
                if(null!=xlsxContentStream){ xlsxContentStream.close();}
                if(null!=pkg){ pkg.close();}

            }

        }


protected void doGet(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException {
        doPost(request, response);
    }

}

你的jsp / html文件应该有enctype =＆＃34; multipart / form-data＆＃34;在表格中

<form action="FileUploadServlet" name="form2" method="post" enctype="multipart/form-data">
Select a .xlsx File to upload :<input type="file" name="file" id="file" size="50" /> 
<input type="submit" value="Upload xlsx File"/>
</form>

是否可以上传file.xlsx，处理它而不将其保存在服务器中？我正在使用jaxrs

1 个答案: