Java 调用Cipher.getInstance进行ftp调用

我的应用程序调用Cipher.getInstance，以便能够解密密码。 在某些环境中，这会产生问题，因为Cipher.getInstance方法最终尝试进行挂起的FTP调用

有人知道如何避免这个FTP呼叫或防止它挂起吗

这是stacktrace

java.net.PlainSocketImpl.socketConnect(Native Method)
    java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:370)
    java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:231)
    java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:213)
    java.net.Socket.connect(Socket.java:643)
    java.net.Socket.connect(Socket.java:590)
    sun.net.ftp.impl.FtpClient.doConnect(FtpClient.java:971)
    sun.net.ftp.impl.FtpClient.tryConnect(FtpClient.java:931)
    sun.net.ftp.impl.FtpClient.connect(FtpClient.java:1026)
    sun.net.ftp.impl.FtpClient.connect(FtpClient.java:1012)
    sun.net.www.protocol.ftp.FtpURLConnection.connect(FtpURLConnection.java:307)
    sun.net.www.protocol.ftp.FtpURLConnection.getInputStream(FtpURLConnection.java:406)
    sun.net.www.protocol.jar.URLJarFile.retrieve(URLJarFile.java:227)
    sun.net.www.protocol.jar.URLJarFile.getJarFile(URLJarFile.java:84)
    sun.net.www.protocol.jar.JarFileFactory.get(JarFileFactory.java:128)
    sun.net.www.protocol.jar.JarURLConnection.connect(JarURLConnection.java:136)
    sun.net.www.protocol.jar.JarURLConnection.getJarFile(JarURLConnection.java:103)
    javax.crypto.a$0.run(Unknown Source)
    java.security.AccessController.doPrivileged(AccessController.java:420)
    javax.crypto.a.a(Unknown Source)
    javax.crypto.a.a(Unknown Source)
    javax.crypto.a.a(Unknown Source)
    javax.crypto.b.a(Unknown Source)
    javax.crypto.d.a(Unknown Source)
    javax.crypto.d.a(Unknown Source)
    javax.crypto.Cipher.c(Unknown Source)
    javax.crypto.Cipher.b(Unknown Source)
    javax.crypto.Cipher.getInstance(Unknown Source)
    javax.crypto.Cipher.getInstance(Unknown Source)

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这些是什么“特定环境”？你有什么特别的JCE提供商吗？我们看到的问题是端口被锁定的环境，但我没有其他相关信息。我们没有专门的JCE提供程序（使用IBMJDK）。