Java如何实现base64上传图片？-杰瑞科技汇

在Java中处理Base64编码的图片上传

在Java中处理Base64编码的图片上传通常涉及以下几个步骤：解码Base64字符串、将解码后的字节数组保存为图片文件，以下是完整的实现方案：

（图片来源网络，侵删）

基本实现方法

import java.io.*;
import java.util.Base64;
public class Base64ImageUploader {
    public static void uploadBase64Image(String base64String, String outputPath) throws IOException {
        // 移除Base64前缀（如果有）
        if (base64String.contains(",")) {
            base64String = base64String.split(",")[1];
        }
        // 解码Base64字符串
        byte[] imageBytes = Base64.getDecoder().decode(base64String);
        // 写入文件
        try (FileOutputStream fos = new FileOutputStream(outputPath)) {
            fos.write(imageBytes);
        }
    }
    public static void main(String[] args) {
        try {
            // 示例Base64字符串（实际应用中从前端获取）
            String base64Image = "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNkYPhfDwAChwGA60e6kgAAAABJRU5ErkJggg==";
            // 保存路径
            String outputPath = "C:/uploads/uploaded_image.png";
            uploadBase64Image(base64Image, outputPath);
            System.out.println("图片上传成功！");
        } catch (IOException e) {
            e.printStackTrace();
            System.out.println("图片上传失败：" + e.getMessage());
        }
    }
}

Spring Boot控制器实现（Web应用）

如果是在Spring Boot应用中处理Base64图片上传，可以这样实现：

import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Base64;
import java.util.UUID;
@RestController
@RequestMapping("/api")
public class ImageUploadController {
    @PostMapping("/upload")
    public ResponseEntity<String> uploadImage(@RequestBody ImageUploadRequest request) {
        try {
            String base64String = request.getImageData();
            String fileName = UUID.randomUUID().toString() + ".png";
            String outputPath = "C:/uploads/" + fileName;
            // 处理Base64字符串并保存
            saveBase64Image(base64String, outputPath);
            return ResponseEntity.ok("图片上传成功: " + fileName);
        } catch (IOException e) {
            return ResponseEntity.status(500).body("上传失败: " + e.getMessage());
        }
    }
    private void saveBase64Image(String base64String, String outputPath) throws IOException {
        // 移除Base64前缀
        String imageData = base64String.split(",")[1];
        // 解码并保存
        byte[] imageBytes = Base64.getDecoder().decode(imageData);
        try (FileOutputStream fos = new FileOutputStream(outputPath)) {
            fos.write(imageBytes);
        }
    }
}
class ImageUploadRequest {
    private String imageData;
    public String getImageData() {
        return imageData;
    }
    public void setImageData(String imageData) {
        this.imageData = imageData;
    }
}

前端JavaScript发送Base64图片的示例

// 前端将图片转换为Base64并发送到后端
function uploadImage() {
    const fileInput = document.getElementById('imageInput');
    const file = fileInput.files[0];
    const reader = new FileReader();
    reader.onload = function(e) {
        const base64Image = e.target.result;
        fetch('/api/upload', {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json',
            },
            body: JSON.stringify({
                imageData: base64Image
            })
        })
        .then(response => response.json())
        .then(data => console.log(data))
        .catch(error => console.error('Error:', error));
    };
    reader.readAsDataURL(file);
}