1、MultipartFile转成File然后在转成base64
private String generateDocumentBase64(MultipartFile multipartFile) {File file;InputStream inputStream = null;FileOutputStream outputStream = null;try {file = File.createTempFile("fileName", "pdf");//建临时文件// 获取文件输入流inputStream = multipartFile.getInputStream();if (!file.exists()) {file.createNewFile();}// 创建输出流outputStream = new FileOutputStream(file);byte[] bytes = new byte[1024];int len;// 写入到创建的临时文件while ((len = inputStream.read(bytes)) > 0) {outputStream.write(bytes, 0, len);}} catch (Exception e) {throw new RuntimeException(e);} finally {// 关流try {if (outputStream != null) {outputStream.close();}if (outputStream != null) {inputStream.close();}outputStream.close();} catch (IOException e) {throw new RuntimeException(e);}}String documentBase64 = Base64.encode(file);return documentBase64;}
2、根据url下载File转成base64
public String getFileByHttpURL(String path) {File file = null;InputStream inputStream = null;OutputStream outputStream = null;try {file = File.createTempFile("fileName", "pdf");//创建临时文件URL urlFile = new URL(path);inputStream = urlFile.openStream();outputStream = new FileOutputStream(file);int bytesRead = 0;byte[] buffer = new byte[8192];while ((bytesRead = inputStream.read(buffer, 0, 8192)) != -1) {outputStream.write(buffer, 0, bytesRead);}} catch (Exception e) {e.printStackTrace();} finally {try {if (null != outputStream) {outputStream.close();}if (null != inputStream) {inputStream.close();}} catch (Exception e) {e.printStackTrace();}}String documentBase64 = Base64.encode(file);return documentBase64;}
