Java实现PDF在线预览
前言：之前一直PDF一直是下载后再查看，一直在想如何如何在线预览，现已找到方法，作此笔记，也希望都对其他人有所帮助
之前的pdf预览新增了文件路径的加密后面加入了word,excel,ppt的预览，不过需要下载: openoffice，具体教程可以自己搜索
代码实现
@Slf4j
@Controller
@RequestMapping("/file/view")
public class FileViewController {
/**
* 预览pdf
* @param request
* @param response
*/
@GetMapping("/pdf")
public void preViewPDF(HttpServletRequest request, HttpServletResponse response) {
String fileName = request.getParameter("fileName");
int dotIndex = fileName.lastIndexOf(".");
String encryptPdfFilePath = fileName.substring(0, dotIndex).replaceAll(" ", "+");
String pdfFilePath = AESUtil.decryptCBC(encryptPdfFilePath, SystemUtils.FILE_AES_PRIVATE_KEY);
String suffix = FilenameUtils.getExtension(fileName); // 获取文件后缀
pdfFilePath = pdfFilePath + "." + suffix;
String replace = pdfFilePath.replace('_', File.separatorChar);
try (
FileInputStream inputStream = new FileInputStream(replace);
OutputStream outputStream = response.getOutputStream()
) {
MimeTypeEnum mimeTypeEnum = MimeTypeEnum.findByExtension(suffix);
if (mimeTypeEnum == null || StringUtils.equalsAny(mimeTypeEnum.name(),
MimeTypeEnum.PDF.name(),
MimeTypeEnum.PNG.name(),
MimeTypeEnum.JPG.name(),
MimeTypeEnum.JPEG.name())) {
throw new FileException(101, "该文件类型不支持预览");
}
response.setContentType(mimeTypeEnum.getMimeType());
IOUtils.write(IOUtils.toByteArray(inputStream), outputStream);
} catch (FileNotFoundException e) {
log.error("pdf路径不存在", e);
} catch (IOException e) {
log.error("写入出现IO异常", e);
}
}
@GetMapping("/pdf_base64")
@ResponseBody
public String htmlViewPDF(String pdfFilePath){
String base64 = "";
String replace = pdfFilePath.replace('_', File.separatorChar);
try (FileInputStream inputStream = new FileInputStream(replace)){
byte[] data = IOUtils.toByteArray(inputStream);
base64 = Base64Utils.encodeToString(data);
base64 = base64.replaceAll("\r\n",""); // 去除空格和换行替换
base64 = base64.replaceAll("\\+","%2B"); // 对base64中的”+“进行转义
base64 = "data:application/pdf;base64," + base64;
} catch (FileNotFoundException e) {
log.error("pdf路径不存在", e);
} catch (IOException e) {
log.error("写入出现IO异常", e);
}
return base64;
}
/**
* 预览office文件
*/
@GetMapping("/office")
public void onlinePreview(HttpServletRequest request, HttpServletResponse response) throws Exception {
String fileName = request.getParameter("fileName");
int dotIndex = fileName.lastIndexOf(".");
String encryptPdfFilePath = fileName.substring(0, dotIndex).replaceAll(" ", "+");
String pdfFilePath = AESUtil.decryptCBC(encryptPdfFilePath, SystemUtils.FILE_AES_PRIVATE_KEY);
String suffix = FilenameUtils.getExtension(fileName); // 获取文件后缀
pdfFilePath = pdfFilePath + "." + suffix;
String replace = pdfFilePath.replace('_', File.separatorChar);
try (
InputStream in = FileConvertUtil.convertLocaleFile(replace, suffix);
OutputStream outputStream = response.getOutputStream();
) {
if (!StringUtils.equalsAnyIgnoreCase(suffix,
MimeTypeEnum.TXT.getExtension(),
MimeTypeEnum.DOC.getExtension(),
MimeTypeEnum.XLS.getExtension(),
MimeTypeEnum.PPT.getExtension())) {
throw new FileException(101, "该文件类型不支持预览");
}
byte[] buff = new byte[1024]; //创建存放文件内容的数组
int n; //所读取的内容使用n来接收
while ((n = in.read(buff)) != -1) { //当没有读取完时,继续读取,循环
outputStream.write(buff, 0, n); //将字节数组的数据全部写入到输出流中
}
outputStream.flush(); //强制将缓存区的数据进行输出
} catch (Exception e) {
log.error("预览文件失败：", e);
}
}@Getter
@NoArgsConstructor
@AllArgsConstructor
public enum MimeTypeEnum {
AAC("acc","AAC音频","audio/aac"),
ABW("abw","AbiWord文件","application/x-abiword"),
ARC("arc","存档文件","application/x-freearc"),
AVI("avi","音频视频交错格式","video/x-msvideo"),
AZW("azw","亚马逊Kindle电子书格式","application/vnd.amazon.ebook"),
BIN("bin","任何类型的二进制数据","application/octet-stream"),
BMP("bmp","Windows OS / 2位图图形","image/bmp"),
BZ("bz","BZip存档","application/x-bzip"),
BZ2("bz2","BZip2存档","application/x-bzip2"),
CSH("csh","C-Shell脚本","application/x-csh"),
CSS("css","级联样式表（CSS）","text/css"),
CSV("csv","逗号分隔值（CSV）","text/csv"),
DOC("doc","微软Word文件","application/msword"),
DOCX("docx","Microsoft Word（OpenXML）","application/vnd.openxmlformats-officedocument.wordprocessingml.document"),
EOT("eot","MS Embedded OpenType字体","application/vnd.ms-fontobject"),
EPUB("epub","电子出版物（EPUB）","application/epub+zip"),
GZ("gz","GZip压缩档案","application/gzip"),
GIF("gif","图形交换格式（GIF）","image/gif"),
HTM("htm","超文本标记语言（HTML）","text/html"),
HTML("html","超文本标记语言（HTML）","text/html"),
ICO("ico","图标格式","image/vnd.microsoft.icon"),
ICS("ics","iCalendar格式","text/calendar"),
JAR("jar","Java存档","application/java-archive"),
JPEG("jpeg","JPEG图像","image/jpeg"),
JPG("jpg","JPEG图像","image/jpeg"),
JS("js","JavaScript","text/javascript"),
JSON("json","JSON格式","application/json"),
JSONLD("jsonld","JSON-LD格式","application/ld+json"),
MID("mid","乐器数字接口（MIDI）","audio/midi"),
MIDI("midi","乐器数字接口（MIDI）","audio/midi"),
MJS("mjs","JavaScript模块","text/javascript"),
MP3("mp3","MP3音频","audio/mpeg"),
MPEG("mpeg","MPEG视频","video/mpeg"),
MPKG("mpkg","苹果安装程序包","application/vnd.apple.installer+xml"),
ODP("odp","OpenDocument演示文稿文档","application/vnd.oasis.opendocument.presentation"),
ODS("ods","OpenDocument电子表格文档","application/vnd.oasis.opendocument.spreadsheet"),
ODT("odt","OpenDocument文字文件","application/vnd.oasis.opendocument.text"),
OGA("oga","OGG音讯","audio/ogg"),
OGV("ogv","OGG视频","video/ogg"),
OGX("ogx","OGG","application/ogg"),
OPUS("opus","OPUS音频","audio/opus"),
OTF("otf","otf字体","font/otf"),
PNG("png","便携式网络图形","image/png"),
PDF("pdf","Adobe 可移植文档格式（PDF）","application/pdf"),
PHP("php","php","application/x-httpd-php"),
PPT("ppt","Microsoft PowerPoint","application/vnd.ms-powerpoint"),
PPTX("pptx","Microsoft PowerPoint（OpenXML）","application/vnd.openxmlformats-officedocument.presentationml.presentation"),
RAR("rar","RAR档案","application/vnd.rar"),
RTF("rtf","富文本格式","application/rtf"),
SH("sh","Bourne Shell脚本","application/x-sh"),
SVG("svg","可缩放矢量图形（SVG）","image/svg+xml"),
SWF("swf","小型Web格式（SWF）或Adobe Flash文档","application/x-shockwave-flash"),
TAR("tar","磁带存档（TAR）","application/x-tar"),
TIF("tif","标记图像文件格式（TIFF）","image/tiff"),
TIFF("tiff","标记图像文件格式（TIFF）","image/tiff"),
TS("ts","MPEG传输流","video/mp2t"),
TTF("ttf","ttf字体","font/ttf"),
TXT("txt","文本（通常为ASCII或ISO 8859- n","text/plain"),
VSD("vsd","微软Visio","application/vnd.visio"),
WAV("wav","波形音频格式","audio/wav"),
WEBA("weba","WEBM音频","audio/webm"),
WEBM("webm","WEBM视频","video/webm"),
WEBP("webp","WEBP图像","image/webp"),
WOFF("woff","Web开放字体格式（WOFF）","font/woff"),
WOFF2("woff2","Web开放字体格式（WOFF）","font/woff2"),
XHTML("xhtml","XHTML","application/xhtml+xml"),
XLS("xls","微软Excel","application/vnd.ms-excel"),
XLSX("xlsx","微软Excel（OpenXML）","application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"),
XML("xml","XML","application/xml"),
XUL("xul","XUL","application/vnd.mozilla.xul+xml"),
ZIP("zip","ZIP","application/zip"),
MIME_3GP("3gp", "3GPP audio/video container", "video/3gpp"),
MIME_3GP_WITHOUT_VIDEO("3gp", "3GPP audio/video container doesn't contain video", "audio/3gpp2"),
MIME_3G2("3g2", "3GPP2 audio/video container", "video/3gpp2"),
MIME_3G2_WITHOUT_VIDEO("3g2", "3GPP2 audio/video container doesn't contain video", "audio/3gpp2"),
MIME_7Z("7z","7-zip存档","application/x-7z-compressed")
;
private String extension;
private String explain;
private String mimeType;
public static MimeTypeEnum findByExtension(String extension) {
if(StringUtils.isBlank(extension)){
return null;
}
for (MimeTypeEnum typesEnum : MimeTypeEnum.values()) {
if (extension.equals(typesEnum.getExtension())) {
return typesEnum;
}
}
return null;
}
public static String getContentType(String fileType) {
MimeTypeEnum mimeTypeEnum = MimeTypeEnum.findByExtension(fileType);
if(mimeTypeEnum != null){
return mimeTypeEnum.getMimeType();
}
return "application/octet-stream";
}
}AES加密算法代码
@Slf4j
public class AESUtil {
/**
* 编码
*/
private static final String ENCODING = "UTF-8";
/**
* 算法定义
*/
private static final String AES_ALGORITHM = "AES";
/**
* 指定填充方式
*/
private static final String CIPHER_PADDING = "AES/ECB/PKCS5Padding";
private static final String CIPHER_CBC_PADDING = "AES/CBC/PKCS5Padding";
/**
* AES加密
*
* @param content 待加密内容
* @param aesKey 密码
* @return
*/
public static String encrypt(String content, String aesKey) {
if (StringUtils.isBlank(content)) {
log.info("AES加密内容不能为空");
return null;
}
if (StringUtils.isNotBlank(aesKey) && aesKey.length() == 16) { //判断秘钥是否为16位
try {
byte[] bytes = aesKey.getBytes(ENCODING); //对密码进行编码
SecretKeySpec skeySpec = new SecretKeySpec(bytes, AES_ALGORITHM); //设置加密算法，生成秘钥
Cipher cipher = Cipher.getInstance(CIPHER_PADDING); // "算法/模式/补码方式"
cipher.init(Cipher.ENCRYPT_MODE, skeySpec); //选择加密
byte[] encrypted = cipher.doFinal(content.getBytes(ENCODING)); //根据待加密内容生成字节数组
return Base64Utils.encodeToString(encrypted); //返回base64字符串
} catch (Exception e) {
log.info("AES加密失败:", e);
throw new RuntimeException(e.getMessage());
}
} else {
log.info("AES加密失败");
return null;
}
}
/**
* 解密
*
* @param content 待解密内容
* @param aesKey 密码
* @return
*/
public static String decrypt(String content, String aesKey) {
if (StringUtils.isBlank(content)) {
log.info("AES解密内容不能为空");
return null;
}
if (StringUtils.isNotBlank(aesKey) && aesKey.length() == 16) { //判断秘钥是否为16位
try {
byte[] bytes = aesKey.getBytes(ENCODING); //对密码进行编码
SecretKeySpec skeySpec = new SecretKeySpec(bytes, AES_ALGORITHM); //设置解密算法，生成秘钥
Cipher cipher = Cipher.getInstance(CIPHER_PADDING); // "算法/模式/补码方式"
cipher.init(Cipher.DECRYPT_MODE, skeySpec); //选择解密
byte[] decodeBase64 = Base64Utils.decodeFromString(content); //先进行Base64解码
byte[] decrypted = cipher.doFinal(decodeBase64); //根据待解密内容进行解密
return new String(decrypted, ENCODING); //将字节数组转成字符串
} catch (Exception e) {
log.error("AES解密失败:",e);
throw new RuntimeException(e.getMessage());
}
} else {
log.info("AES解密失败");
return null;
}
}
/**
* AES_CBC加密
*
* @param content 待加密内容
* @param aesKey 密码
* @return
*/
public static String encryptCBC(String content, String aesKey) {
if (StringUtils.isBlank(content)) {
log.info("AES_CBC加密内容不能为空");
return null;
}
if (StringUtils.isNotBlank(aesKey) && aesKey.length() == 16) { //判断秘钥是否为16位
try {
byte[] bytes = aesKey.getBytes(ENCODING); //对密码进行编码
SecretKeySpec skeySpec = new SecretKeySpec(bytes, AES_ALGORITHM); //设置加密算法，生成秘钥
Cipher cipher = Cipher.getInstance(CIPHER_CBC_PADDING); // "算法/模式/补码方式"
IvParameterSpec iv = new IvParameterSpec(SystemUtils.FILE_AES_IV_SEED_KEY.getBytes(ENCODING)); //偏移
cipher.init(Cipher.ENCRYPT_MODE, skeySpec, iv); //选择加密
byte[] encrypted = cipher.doFinal(content.getBytes(ENCODING)); //根据待加密内容生成字节数组
return Base64Utils.encodeToString(encrypted); //返回base64字符串
} catch (Exception e) {
log.error("AES_CBC加密失败:",e);
throw new RuntimeException(e.getMessage());
}
} else {
log.info("AES_CBC加密失败");
return null;
}
}
/**
* AES_CBC解密
*
* @param content 待解密内容
* @param aesKey 密码
* @return
*/
public static String decryptCBC(String content, String aesKey) {
if (StringUtils.isBlank(content)) {
log.info("AES_CBC解密内容不能为空");
return null;
}
//判断秘钥是否为16位
if (StringUtils.isNotBlank(aesKey) && aesKey.length() == 16) {
try {
//对密码进行编码
byte[] bytes = aesKey.getBytes(ENCODING);
//设置解密算法，生成秘钥
SecretKeySpec skeySpec = new SecretKeySpec(bytes, AES_ALGORITHM);
//偏移
IvParameterSpec iv = new IvParameterSpec(SystemUtils.FILE_AES_IV_SEED_KEY.getBytes(ENCODING));
// "算法/模式/补码方式"
Cipher cipher = Cipher.getInstance(CIPHER_CBC_PADDING);
//选择解密
cipher.init(Cipher.DECRYPT_MODE, skeySpec, iv);
//先进行Base64解码
byte[] decodeBase64 = Base64Utils.decodeFromString(content);
//根据待解密内容进行解密
byte[] decrypted = cipher.doFinal(decodeBase64);
//将字节数组转成字符串
return new String(decrypted, ENCODING);
} catch (Exception e) {
log.error("AES_CBC解密失败",e);
throw new
RuntimeException(e.getMessage());
}
} else {
log.info("AES_CBC解密失败");
return null;
}
}
}office文件转为pdf代码
/**
* 文件格式转换工具类
*/
@Slf4j
public class FileConvertUtil {
private FileConvertUtil() {
}
/**
* office文档转换为PDF(处理本地文件)
*
* @param sourcePath 源文件路径
* @param suffix 源文件后缀
* @return InputStream 转换后文件输入流
*/
public static InputStream convertLocaleFile(String sourcePath, String suffix) {
try (InputStream inputStream = Files.newInputStream(Paths.get(sourcePath))) {
return covertCommonByStream(inputStream, suffix);
} catch (Exception e) {
log.error("office文档转换为PDF(处理本地文件)失败:",e);
throw new FileException(10000, e.getMessage());
}
}
/**
* office文档转换为PDF(处理网络文件)
*
* @param netFileUrl 网络文件路径
* @param suffix 文件后缀
* @return InputStream 转换后文件输入流
*/
public static InputStream convertNetFile(String netFileUrl, String suffix) {
try {
URL url = new URL(netFileUrl); // 创建URL
URLConnection urlConn = url.openConnection(); // 试图连接并取得返回状态码
urlConn.connect();
HttpURLConnection httpConn = (HttpURLConnection) urlConn;
int httpResult = httpConn.getResponseCode();
if (httpResult == HttpURLConnection.HTTP_OK) {
InputStream inputStream = urlConn.getInputStream();
return covertCommonByStream(inputStream, suffix);
}
return null;
} catch (Exception e) {
log.error("office文档转换为PDF(处理网络文件)失败:",e);
throw new FileException(10000, e.getMessage());
}
}
/**
* 方法描述 将文件以流的形式转换
*
* @param inputStream 源文件输入流
* @param suffix 源文件后缀
* @return InputStream 转换后文件输入流
*/
public static InputStream covertCommonByStream(InputStream inputStream, String suffix) {
try {
ByteArrayOutputStream out = new ByteArrayOutputStream();
OpenOfficeConnection connection = new SocketOpenOfficeConnection(Integer.parseInt(SystemUtils.OPEN_OFFICE_PORT));
connection.connect();
DocumentConverter converter = new StreamOpenOfficeDocumentConverter(connection);
DefaultDocumentFormatRegistry formatReg = new DefaultDocumentFormatRegistry();
DocumentFormat targetFormat = formatReg.getFormatByFileExtension(MimeTypeEnum.PDF.getExtension());
DocumentFormat sourceFormat = formatReg.getFormatByFileExtension(suffix);
converter.convert(inputStream, sourceFormat, out, targetFormat);
connection.disconnect();
return outputStreamConvertInputStream(out);
} catch (Exception e) {
log.error("文件转换为流失败:",e);
throw new FileException(10000, e.getMessage());
}
}
/**
* outputStream转inputStream
*/
public static ByteArrayInputStream outputStreamConvertInputStream(final OutputStream out) {
ByteArrayOutputStream baos = (ByteArrayOutputStream) out;
return new ByteArrayInputStream(baos.toByteArray());
}
}配置文件
# 文件加密密钥
file.aes.private.key=qcmbkwses77vhft4
# 偏移量
file.aes.iv.seed=1234567812345678
# OpenOffice端口号
open.office.port=8100@Slf4j
public class SystemUtils {
private SystemUtils(){}
private static Properties prop = null;
//初始化静态代码块
static {
prop = new Properties();
InputStream inputStream = Thread.currentThread().getContextClassLoader().getResourceAsStream("system.properties");
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
try {
prop.load(reader);
initProperties(prop);
} catch (IOException e) {
log.info("获取配置文件失败：{}",e.getMessage());
}
}
/**
* 文件AES加密密钥
*/
public static String FILE_AES_PRIVATE_KEY;
/**
* 偏移量(CBC中使用，增强加密算法强度)
*/
public static String FILE_AES_IV_SEED_KEY;
public static String OPEN_OFFICE_PORT;
private static void initProperties(Properties properties) {
String fileAesKey = properties.getProperty("file.aes.private.key");
if (StringUtils.isNotBlank(fileAesKey)) {
FILE_AES_PRIVATE_KEY = fileAesKey;
} else {
log.error("=======获取文件加密AES密钥失败=======");
}
String fileAesIvSeedKey = properties.getProperty("file.aes.iv.seed");
if (StringUtils.isNotBlank(fileAesIvSeedKey)) {
FILE_AES_IV_SEED_KEY = fileAesIvSeedKey;
} else {
log.error("=======获取文件加密AES偏移量失败========");
}
String openOfficePort = properties.getProperty("open.office.port");
if (StringUtils.isNotBlank(openOfficePort)) {
OPEN_OFFICE_PORT = openOfficePort;
} else {
log.error("=======获取OpenOffice端口号失败========");
}
}
}同理，图片也可以使用这种方法进行实现
提示：fileName这个参数是你服务器上存储PDF的文件地址
修改：之前的代码流没有关掉，现在修改了，然后如果你的pdf文件如果是保存在服务器上，这个fileName这个字段就是你服务器上存储PDF的文件地址，当然也可以做些处理，比如加密啥的，只要能保证解析到这个pdf文件就行，最后这个是预览pdf的地址，如果有需求要预览连接的，就自己在写业务需求的时候把这个连接拼接一下就行了，然后返回给前端
因为有时候需要pdf在页面嵌入展示，因此这边增加了一个可以在页面嵌入展示的方法，原理就是将pdf转为base64的格式，方便页面展示后面加入了office文件的在线预览，其作用就是将其文件转为pdf流，使用的openoffice，但是这个需要安装软件，比较麻烦，而且，这边测试发现是支持2003版本的文档格式，后面这边看看还有其他好的方法没有，会再此更新
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