如何在java servlet中处理multipart/form-data POST请求？

import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.IOException;
import java.util.List;

@WebServlet("/upload")
public class FileUploadServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // 检查请求是否为multipart/form-data类型
        boolean isMultipart = ServletFileUpload.isMultipartContent(request);

        if (isMultipart) {
            // 创建文件上传组件
            DiskFileItemFactory factory = new DiskFileItemFactory();

            // 设置临时文件存储路径
            String tempDir = "path/to/temp/dir";
            factory.setRepository(new File(tempDir));

            ServletFileUpload upload = new ServletFileUpload(factory);

            try {
                // 解析请求，获取multipart/form-data请求中的各个部分
                List<FileItem> items = upload.parseRequest(request);

                for (FileItem item : items) {
                    if (item.isFormField()) {
                        // 处理表单字段
                        String fieldName = item.getFieldName();
                        String fieldValue = item.getString();

                        // 进行表单字段的处理
                        // ...
                    } else {
                        // 处理文件上传
                        String fileName = item.getName();
                        String filePath = "path/to/save/file/" + fileName;

                        // 保存上传的文件
                        item.write(new File(filePath));

                        // 进行文件的处理
                        // ...
                    }
                }

                // 文件上传成功后的处理
                // ...
            } catch (Exception e) {
                // 文件上传失败的处理
                // ...
            }
        } else {
            // 非multipart/form-data请求的处理
            // ...
        }
    }
}