SpringBoot基于Path获取文件二进制流的几种方法小结

Path filePath = Paths.get(directory, file.getFileName());
try {
    byte[] fileBytes = Files.readAllBytes(filePath);
    // 现在你可以使用 fileBytes 进行后续操作
} catch (IOException e) {
    // 处理异常，比如文件不存在或读取失败
    throw new RuntimeException("文件读取失败: " + e.getMessage(), e);
}

import org.apache.commons.io.IOUtils;

Path filePath = Paths.get(directory, file.getFileName());
try (InputStream inputStream = Files.newInputStream(filePath)) {
    byte[] fileBytes = IOUtils.toByteArray(inputStream);
    // 使用 fileBytes
} catch (IOException e) {
    throw new RuntimeException("文件读取失败", e);
}

Path filePath = Paths.get(directory, file.getFileName());
try {
    long fileSize = Files.size(filePath);
    byte[] fileBytes = new byte[(int) fileSize];
    
    try (InputStream inputStream = Files.newInputStream(filePath)) {
        int bytesRead = inputStream.read(fileBytes);
        if (bytesRead != fileSize) {
            throw new IOException("文件读取不完整");
        }
    }
    // 使用 fileBytes
} catch (IOException e) {
    throw new RuntimeException("文件读取失败", e);
}

import org.springframework.web.bind.annotation.*;
import org.springframework.http.ResponseEntity;
import java.nio.file.*;
import java.io.IOException;

@RestController
public class FileController {
    
    @PostMapping("/upload")
    public ResponseEntity<String> handleFile(@RequestParam("file") MultipartFile file) {
        try {
            // 保存文件到指定目录
            String directory = "/path/to/your/directory";
            Path filePath = Paths.get(directory, file.getOriginalFilename());
            
            // 将上传的文件保存到指定路径
            file.transferTo(filePath.toFile());
            
            // 读取文件的二进制数据
            byte[] fileBytes = Files.readAllBytes(filePath);
            
            // 这里可以对 fileBytes 进行后续处理
            System.out.println("文件大小: " + fileBytes.length + " bytes");
            
            return ResponseEntity.ok("文件处理成功，大小: " + fileBytes.length + " bytes");
            
        } catch (IOException e) {
            return ResponseEntity.badRequest().body("文件处理失败: " + e.getMessage());
        }
    }
}

<dependency>
    <groupId>commons-io</groupId>
    <artifactId>commons-io</artifactId>
    <version>2.11.0</version>
</dependency>