View file headers for different types of files

To view a file's binary header information, you need to read the first few bytes of the file and interpret them as file header data. The structure and content of the file header depend on the type of file. Here is a sample code for reading the first few bytes of a file and displaying them as hexadecimal:

import java.io.*;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;

@RestController
@RequestMapping("/your-upload-endpoint")
public class YourController {
    
    

    @PostMapping("/upload")
    public String uploadFile(@RequestParam("file") MultipartFile file) {
    
    
        try {
    
    
            // 获取上传文件的字节数组
            byte[] fileBytes = file.getBytes();

            // 读取文件的前几个字节并显示为十六进制字符串
            int headerLength = 16; // 读取的字节数
            StringBuilder headerHex = new StringBuilder();
            for (int i = 0; i < Math.min(headerLength, fileBytes.length); i++) {
    
    
                headerHex.append(String.format("%02X ", fileBytes[i]));
            }

            // 输出文件头的十六进制表示
            System.out.println("File Header: " + headerHex.toString());

            // 在此可以进一步处理文件头信息或上传的文件

            return "File uploaded successfully!";
        } catch (Exception e) {
    
    
            // 处理异常情况
            e.printStackTrace();
            return "File upload failed!";
        }
    }
}

In this example, we first get the byte array of the uploaded file, then read the first few bytes of the file and display them as a hex string. This example is just a basic demonstration. In fact, the content and structure of the file header will vary depending on the file type, and you need to interpret the file header data according to the specific file type.