✨Response 响应流遇到的坑

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private void downloadFileByPath(String path, String fileName, HttpServletResponse response) {
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    try {
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        // 设置内容格式
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        response.setContentType("image/png");
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        response.addHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(sysFileDTO.get().getFileName(), "UTF-8"));
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        response.setHeader("Content-Length", sysFileDTO.get().getFileSize() + "");
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        // 内容安全策略
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        response.setHeader("Content-Security-Policy", "script-src 'self' 'unsafe-inline' 'unsafe-eval';style-src 'self' 'unsafe-inline';img-src 'self' data:;connect-src 'self' <http://127.0.0.1:8080> data:;font-src 'self';object-src 'self';");
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    } catch (UnsupportedEncodingException e) {
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        log.error("文件编码异常 : {}", e.getMessage());
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    }
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    // 将文件流写入输出流
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    File file = new File(path);
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    if (file.exists()) {
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        InputStream is = null;
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        try {
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            is = new FileInputStream(file);
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            IOUtils.copy(is, response.getOutputStream());
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            response.getOutputStream().flush();
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        } catch (FileNotFoundException e) {
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            log.error("文件未找到异常 : {}", path);
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            throw new RuntimeException("文件未找到");
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        } catch (IOException e) {
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            log.error("文件读写异常 : {}", path);
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            throw new RuntimeException("文件读写异常");
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        } finally {
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            try {
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                is.close();
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            } catch (IOException e) {
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                throw new RuntimeException("文件关闭异常");
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            }
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        }
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    } else {
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        log.error("文件未找到异常 : {}", path);
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        throw new RuntimeException("文件未找到");
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    }
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}

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private void downloadFileByPath(String path, String fileName, HttpServletResponse response) {
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    try {
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        // 设置内容格式
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        response.setContentType("image/png");
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        response.addHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(sysFileDTO.get().getFileName(), "UTF-8"));
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        response.setHeader("Content-Length", sysFileDTO.get().getFileSize() + "");
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        // 内容安全策略
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        response.setHeader("Content-Security-Policy", "script-src 'self' 'unsafe-inline' 'unsafe-eval';style-src 'self' 'unsafe-inline';img-src 'self' data:;connect-src 'self' <http://127.0.0.1:8080> data:;font-src 'self';object-src 'self';");
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    } catch (UnsupportedEncodingException e) {
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        log.error("文件编码异常 : {}", e.getMessage());
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    }
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    // 将文件流写入输出流
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    File file = new File(path);
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    if (file.exists()) {
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        InputStream is = null;
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        try {
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            is = new FileInputStream(file);
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            // 必须使用赋值的方式
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            ServletOutputStream outputStream = response.getOutputStream();
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            IOUtils.copy(is, outputStream);
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            response.getOutputStream().flush();
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        } catch (FileNotFoundException e) {
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            log.error("文件未找到异常 : {}", path);
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            throw new RuntimeException("文件未找到");
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        } catch (IOException e) {
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            log.error("文件读写异常 : {}", path);
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            throw new RuntimeException("文件读写异常");
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        } finally {
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            try {
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                is.close();
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            } catch (IOException e) {
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                throw new RuntimeException("文件关闭异常");
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            }
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        }
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    } else {
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        log.error("文件未找到异常 : {}", path);
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        throw new RuntimeException("文件未找到");
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    }
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}

1
private void downloadFileByPath(String path, String fileName, HttpServletResponse response) {
2
    try {
3
        // 设置内容格式
4
        response.setContentType("image/png");
5
        response.addHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(sysFileDTO.get().getFileName(), "UTF-8"));
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        response.setHeader("Content-Length", sysFileDTO.get().getFileSize() + "");
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        // 内容安全策略
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        response.setHeader("Content-Security-Policy", "script-src 'self' 'unsafe-inline' 'unsafe-eval';style-src 'self' 'unsafe-inline';img-src 'self' data:;connect-src 'self' <http://127.0.0.1:8080> data:;font-src 'self';object-src 'self';");
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    } catch (UnsupportedEncodingException e) {
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        log.error("文件编码异常 : {}", e.getMessage());
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    }
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    // 将文件流写入输出流
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    File file = new File(path);
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    if (file.exists()) {
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        InputStream is = null;
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        ServletOutputStream outputStream = null;
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        try {
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            is = new FileInputStream(file);
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            // 必须使用赋值的方式
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            out = response.getOutputStream();
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            // 创建缓冲区
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            byte buffer[] = new byte[4096];
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            int len = 0;
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            // 循环将输入流中的内容读取到缓冲区当中
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            while ((len = in.read(buffer)) > 0) {
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                // 输出缓冲区的内容到浏览器，实现文件下载
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                out.write(buffer, 0, len);
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            }
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        } catch (FileNotFoundException e) {
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            log.error("文件未找到异常 : {}", path);
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            throw new RuntimeException("文件未找到");
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        } catch (IOException e) {
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            log.error("文件读写异常 : {}", path);
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            throw new RuntimeException("文件读写异常");
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        } finally {
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            try {
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                is.close();
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                out.close();
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            } catch (IOException e) {
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                throw new RuntimeException("文件关闭异常");
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            }
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        }
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    } else {
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        log.error("文件未找到异常 : {}", path);
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        throw new RuntimeException("文件未找到");
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    }
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}