如何在 servlet 上读取 CSV 文件数据，作为表单数据发送

Question

我设计了一个 servlet 来读取 CSV，我将 CSV 作为表单数据从 postman 传递，但我无法获得任何读取该数据的选项。

我试过下面的代码

String body = request.getReader().lines().collect(Collectors.joining());

我得到了一个巨大的字符串，但我不知道如何解析它。

----------------------------140780421327043896517058Content-Disposition: form-data; name="CSVfile"; filename="dummyDataSet.csv"Content-Type: text/csvID,Name ,Age,Address,State,Date,Salary1,Airi Satou,33,Tokyo,Tokyo,11/28/2008,"2,700 "2,Angelica Ramos,47,London,London,10/9/2009,"2,700 "3,Ashton Cox,66,San Francisco,San Francisco,1/12/2009,",000 "4,Bradley Greer,41,London,London,10/13/2012,"2,000 "5,Brenden Wagner,28,San Francisco,San Francisco,6/7/2011,"6,850 "6,Brielle Williamson,61,New York,New York,12/2/2012,"2,000 "7,Bruno Nash,38,London,London,5/3/2011,"3,500 "8,Caesar Vance,21,New York,New York,12/12/2011,"6,450 "9,Cara Stevens,46,New York,New York,12/6/2011,"5,600 "10,Cedric Kelly,22,Edinburgh,Edinburgh,3/29/2012,"3,060 "----------------------------140780421327043896517058--

请问如何读取CSV数据。

Answer 1

使用request.getParts()或request.getPart(name)读取多部分内容并向servlet添加@MultipartConfig注解。

给你：

import javax.servlet.ServletException;
import javax.servlet.annotation.MultipartConfig;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.Part;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.stream.Collectors;

@WebServlet(urlPatterns = "/upload")
@MultipartConfig
public class MyFileUploadServelt extends HttpServlet {
    private static final String CONTENT_DISPOSITION_KEY = "content-disposition";
    private static final String FILE_NAME_KEY = "filename";
    private static final int BUFFER_SIZE = 2048;

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        System.out.println("Content Type: " + req.getContentType());
        System.out.println("Content Length: " + req.getContentLength());
        System.out.println("Parts: " + req.getParts().toString());
        System.out.println("Part 1: " + req.getPart("myfile"));
        // Read parts. Also can be read by directly calling req.getPart(fileName)
        for (Part part : req.getParts()) {
            System.out.println("File Name: " + getFileName(part));
            System.out.println("File Content: " + getTextFromPart(part));
        }
    }

    private String getFileName(Part part) {
        for (String contentDisposition : part.getHeader(CONTENT_DISPOSITION_KEY).split(";")) {
            if (contentDisposition.trim().startsWith(FILE_NAME_KEY)) {
                return contentDisposition.substring(contentDisposition.indexOf('=') + 1).trim().replace("\"", "");
            }
        }
        return null;
    }


    private String getTextFromPart(Part part) throws IOException {
        BufferedReader reader =
                new BufferedReader(new InputStreamReader(part.getInputStream(), "UTF-8"));
        StringBuilder value = new StringBuilder();
        char[] buffer = new char[BUFFER_SIZE];
        for (int length = 0; (length = reader.read(buffer)) > 0; ) {
            value.append(buffer, 0, length);
        }
        return value.toString();
    }
}

如何在 servlet 上读取 CSV 文件数据，作为表单数据发送

How to read CSV file data on servlet ,send as form-data

java

csv

servlets

jersey

postman