spring boot实现base64上传

一：依赖安装

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<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>

二：base64上传示例

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package com.example.demo.controller;

import org.springframework.web.bind.annotation.*;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Base64;
import java.util.UUID;

@RestController
@RequestMapping("/base64")
public class Base64Controller {

    private static final String UPLOAD_PATH = "upload/";

    //base64上传
    @PostMapping
    public String upload(@RequestBody Base64FileDTO dto)
    {

        String base64Str = dto.getBase64();

        if (base64Str == null || base64Str.isEmpty()) {
            return "base64不能为空";
        }

        // 去除base64前缀：data:image/png;base64,
        String[] parts = base64Str.split(",");
        String base64Content;
        if (parts.length > 1) {
            base64Content = parts[1];
        } else {
            base64Content = base64Str;
        }

        byte[] bytes;
        try {
            bytes = Base64.getDecoder().decode(base64Content);
        } catch (IllegalArgumentException e) {
            return "base64格式有误";
        }
        //定义保存文件名
        String suffix = "png";
        if (parts[0].contains("jpeg")) {
            suffix = "jpg";
        } else if (parts[0].contains("png")) {
            suffix = "png";
        } else if (parts[0].contains("gif")) {
            suffix = "gif";
        }
        String fileName = UUID.randomUUID() + "." + suffix;

        File dest = new File(UPLOAD_PATH, fileName).getAbsoluteFile();

        File dir = dest.getParentFile();
        if (!dir.exists() && !dir.mkdirs()) {
            return "上传失败：目录创建失败";
        }

        try (FileOutputStream fos = new FileOutputStream(dest)) {
            fos.write(bytes);
        } catch (IOException e) {
            e.printStackTrace();
            return "文件保存失败";
        }

        return "上传成功，文件名：" + fileName;
    }

    // DTO
    static class Base64FileDTO {
        private String base64;

        public String getBase64() {
            return base64;
        }
        public void setBase64(String base64) {
            this.base64 = base64;
        }
    }
}

三：调用base64上传示例

使用postman调用上传测试

POST：http://127.0.0.1:8080/base64

请求体 raw JSON：

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{
    "base64": "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAA..."
}

四：配置远程访问资源

如果需要直接通过 url 访问上传图片，需要配置静态资源映射

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package com.example.demo.config;
 
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
 
@Configuration
public class WebConfig implements WebMvcConfigurer {
    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry)
    {
        // 访问路径 /upload/** 映射到本地 /upload/
        registry.addResourceHandler("upload/**")
                .addResourceLocations("file:upload/");
    }
}