jsp上传文件代码

JSP（JavaServer Pages）是一种用于创建动态Web页面的技术，它允许在HTML或XML等文档中嵌入Java代码。文件上传是Web应用中常见的功能之一，允许用户通过浏览器上传文件到服务器。下面是一个简单的JSP文件上传代码示例，包括HTML表单和JSP处理脚本。

HTML表单（uploadForm.jsp）

<!DOCTYPE html>
<html>
<head>
    <title>File Upload Form</title>
</head>
<body>
    <h1>Upload File to Server</h1>
    <form action="uploadProcess.jsp" method="post" enctype="multipart/form-data">
        Select file to upload:
        <input type="file" name="file" />
        <input type="submit" value="Upload File" />
    </form>
</body>
</html>

解释：

enctype="multipart/form-data" 是必须的，因为它告诉浏览器正在上传文件。
action 属性指定了处理上传文件的JSP页面。

JSP处理脚本（uploadProcess.jsp）

<%@ page import="java.io.*, java.util.*, javax.servlet.http.*" %>
<%@ page import="org.apache.commons.fileupload.*, org.apache.commons.fileupload.disk.*, org.apache.commons.fileupload.servlet.*" %>
<%@ page import="org.apache.commons.io.output.*" %>

<%
    // Check that we have a file upload request
    boolean isMultipart = ServletFileUpload.isMultipartContent(request);

    if (!isMultipart) {
        out.println("No file uploaded");
        return;
    }

    // Create a factory for disk-based file items
    DiskFileItemFactory factory = new DiskFileItemFactory();

    // Create a new file upload handler
    ServletFileUpload upload = new ServletFileUpload(factory);

    try {
        // Parse the request to get file items.
        List<FileItem> fileItems = upload.parseRequest(request);

        // Process the uploaded file items
        Iterator<FileItem> i = fileItems.iterator();

        while (i.hasNext()) {
            FileItem fi = i.next();

            if (!fi.isFormField()) {
                String fieldName = fi.getFieldName();
                String fileName = fi.getName();
                String contentType = fi.getContentType();
                boolean isInMemory = fi.isInMemory();
                long sizeInBytes = fi.getSize();

                // Write the file
                if (fileName.lastIndexOf("\\") >= 0) {
                    fileName = fileName.substring(fileName.lastIndexOf("\\") + 1);
                } else {
                    fileName = fileName.substring(fileName.lastIndexOf("/") + 1);
                }

                // Define the upload directory
                String uploadPath = getServletContext().getRealPath("") + "uploads/";
                File uploadDir = new File(uploadPath);
                if (!uploadDir.exists()) uploadDir.mkdir();

                File uploadedFile = new File(uploadDir + File.separator + fileName);
                fi.write(uploadedFile);

                out.println("Uploaded Filename: " + fileName + "<br>");
            }
        }
    } catch (Exception ex) {
        out.println("There was an error: " + ex.getMessage());
    }
%>

解释：