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，并且我将 CSV 作为表单数据从邮递员传递，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这个字符串。

----------------------------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,"$162,700 "2,Angelica Ramos,47,London,London,10/9/2009,"$162,700 "3,Ashton Cox,66,San Francisco,San Francisco,1/12/2009,"$86,000 "4,Bradley Greer,41,London,London,10/13/2012,"$132,000 "5,Brenden Wagner,28,San Francisco,San Francisco,6/7/2011,"$206,850 "6,Brielle Williamson,61,New York,New York,12/2/2012,"$372,000 "7,Bruno Nash,38,London,London,5/3/2011,"$163,500 "8,Caesar Vance,21,New York,New York,12/12/2011,"$106,450 "9,Cara Stevens,46,New York,New York,12/6/2011,"$145,600 "10,Cedric Kelly,22,Edinburgh,Edinburgh,3/29/2012,"$433,060 "----------------------------140780421327043896517058--

你能帮我吗，如何读取CSV数据。

Answer 1

使用request.getParts()orrequest.getPart(name)读取多部分内容并向 servlet 添加 @MultipartConfig 注释。干得好：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")@MultipartConfigpublic 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();    }}