原理
chrome自59版本开始 提供了一个无界面，命令行调用的html转pdf方法
cmd可以执行 chrome --headless --disable-gpu --print-to-pdf=${outputPath} ${url}
将http的url地址生成pdf到output地址。
具体课件文档 https://developer.chrome.com/blog/headless-chrome/
实现
1. 服务器选择windows，使用chrome离线安装包，安装chrome。
2. 使用hutool的命令行调用工具执行命令即可。注意此命令不会创建中间文件夹，需要使用已经存在文件夹的位置写入pdf。
3. 生成过程中会弹出一个框，本例出现以下提示，但是pdf正常生成了。
可用参数
来自文档
// The background color to be used if the page doesn't specify one. Provided as
// RGBA integer value in hex, e.g. 'ff0000ff' for red or '00000000' for
// transparent.
const char kDefaultBackgroundColor[] = 'default-background-color';
// Whether cookies stored as part of user profile are encrypted.
const char kDisableCookieEncryption[] = 'disable-cookie-encryption';
// Whether or not begin frames should be issued over DevToolsProtocol
// (experimental).
const char kEnableBeginFrameControl[] = 'enable-begin-frame-control';
// Enable crash reporter for headless.
const char kEnableCrashReporter[] = 'enable-crash-reporter';
// Disable crash reporter for headless. It is enabled by default in official
// builds.
const char kDisableCrashReporter[] = 'disable-crash-reporter';
// The directory breakpad should store minidumps in.
const char kCrashDumpsDir[] = 'crash-dumps-dir';
// A meta flag. This sets a number of flags which put the browser into
// deterministic mode where begin frames should be issued over DevToolsProtocol
// (experimental).
const char kDeterministicMode[] = 'deterministic-mode';
// Use a specific disk cache location, rather than one derived from the
// UserDatadir.
const char kDiskCacheDir[] = 'disk-cache-dir';
// Instructs headless_shell to print document.body.innerHTML to stdout.
const char kDumpDom[] = 'dump-dom';
// Specifies which encryption storage backend to use. Possible values are
// kwallet, kwallet5, gnome, gnome-keyring, gnome-libsecret, basic. Any other
// value will lead to Chrome detecting the best backend automatically.
// TODO(crbug.com/571003): Once PasswordStore no longer uses the Keyring or
// KWallet for storing passwords, rename this flag to stop referencing
// passwords. Do not rename it sooner, though; developers and testers might
// rely on it keeping large amounts of testing passwords out of their Keyrings
// or KWallets.
const char kPasswordStore[] = 'password-store';
// Save a pdf file of the loaded page.
const char kPrintToPDF[] = 'print-to-pdf';
// Do not display header and footer in the pdf file.
const char kPrintToPDFNoHeader[] = 'print-to-pdf-no-header';
// Do not emit tags when printing PDFs.
const char kDisablePDFTagging[] = 'disable-pdf-tagging';
// Specifies a list of hosts for whom we bypass proxy settings and use direct
// connections. Ignored unless --proxy-server is also specified. This is a
// comma-separated list of bypass rules. See:
// 'net/proxy_resolution/proxy_bypass_rules.h' for the format of these rules.
const char kProxyBypassList[] = 'proxy-bypass-list';
// Uses a specified proxy server, overrides system settings. This switch only
// affects HTTP and HTTPS requests.
const char kProxyServer[] = 'proxy-server';
// Do not use system proxy configuration service.
const char kNoSystemProxyConfigService[] = 'no-system-proxy-config-service';
// Use the given address instead of the default loopback for accepting remote
// debugging connections. Should be used together with --remote-debugging-port.
// Note that the remote debugging protocol does not perform any authentication,
// so exposing it too widely can be a security risk.
const char kRemoteDebuggingAddress[] = 'remote-debugging-address';
// Runs a read-eval-print loop that allows the user to evaluate Javascript
// expressions.
const char kRepl[] = 'repl';
// Save a screenshot of the loaded page.
const char kScreenshot[] = 'screenshot';
// Issues a stop after the specified number of milliseconds. This cancels all
// navigation and causes the DOMContentLoaded event to fire.
const char kTimeout[] = 'timeout';
// Sets the GL implementation to use. Use a blank string to disable GL
// rendering.
const char kUseGL[] = 'use-gl';
// Sets the ANGLE implementation to use. Only relevant if 'use-gl' is set to
// 'angle'
const char kUseANGLE[] = 'use-angle';
// A string used to override the default user agent with a custom one.
const char kUserAgent[] = 'user-agent';
// Directory where the browser stores the user profile. Note that if this switch
// is added, the session will no longer be Incognito, unless Incognito mode is
// forced with --incognito switch.
const char kUserDataDir[] = 'user-data-dir';
// Forces Incognito mode even if user data directory is specified using the
// --user-data-dir switch.
const char kIncognito[] = 'incognito';
// If set the system waits the specified number of virtual milliseconds before
// deeming the page to be ready. For determinism virtual time does not advance
// while there are pending network fetches (i.e no timers will fire). Once all
// network fetches have completed, timers fire and if the system runs out of
// virtual time is fastforwarded so the next timer fires immediatley, until the
// specified virtual time budget is exhausted.
const char kVirtualTimeBudget[] = 'virtual-time-budget';
// Sets the initial window size. Provided as string in the format '800,600'.
const char kWindowSize[] = 'window-size';
// Allowlist for Negotiate Auth servers.
const char kAuthServerAllowlist[] = 'auth-server-allowlist';
// Sets font render hinting when running headless, affects Skia rendering and
// whether glyph subpixel positioning is enabled.
// Possible values: none|slight|medium|full|max. Default: full.
const char kFontRenderHinting[] = 'font-render-hinting';
// If true, then all pop-ups and calls to window.open will fail.
const char kBlockNewWebContents[] = 'block-new-web-contents';
// Allows overriding the list of restricted ports by passing a comma-separated
// list of port numbers.
const char kExplicitlyAllowedPorts[] = 'explicitly-allowed-ports';
使用devTool工具可以进行更多参数的控制
见文档：
https://chromedevtools.github.io/devtools-protocol/tot/Page/#method-printToPDF
https://github.com/kklisura/chrome-devtools-java-client