【Spring Boot教程】(十八)：Spring Boot实现单文件下载和多文件下载

下载界面：

<a href="../file/download?fileName=text.txt">text.txt</a>

控制器1——不直接下载文件而是点一下展示文件：

@GetMapping("download")
public void download(String fileName, HttpServletResponse response) throws Exception {
    
    
    String realPath = ResourceUtils.getURL("classpath:").getPath()+"/static/files";
    //获取文件输入流
    FileInputStream is = new FileInputStream((new File(realPath, fileName)));
    //相应输出流
    ServletOutputStream os = response.getOutputStream();
    //文件拷贝
    int len = 0;
    byte[] b = new byte[1024];
    while(true) {
    
    
        len = is.read(b);
        if(len==-1) {
    
    
            break;
        }
        os.write(b,0,len);
    }
    is.colse();
    os.close();
}

控制器2——直接下载文件：

@GetMapping("download")
public void download(String fileName, HttpServletResponse response) throws Exception {
    
    
    String realPath = ResourceUtils.getURL("classpath:").getPath()+"/static/files";
    //获取文件输入流
    FileInputStream is = new FileInputStream((new File(realPath, fileName)));
    //相应输出流
    ServletOutputStream os = response.getOutputStream();
    //attachment附件下载，inline是在线打开（图片，pdf等）
    response.setHeader("content-disposition","attachment;fileName="+ URLEncoder.encode(fileName,"UTF-8"));
    //拷贝文件
    /*
    	需要引入依赖
        <groupId>commons-fileupload</groupId>
        <artifactId>commons-fileupload</artifactId>
        <version>1.4</version>
    */
    IOUtils.copy(is,os);
    IOUtils.closeQuietly(is);
    IOUtils.closeQuietly(os);
}