CertPath)
and certificate revocation list (CRL) objects from their encodings.
For encodings consisting of multiple certificates, use
generateCertificates when you want to
parse a collection of possibly unrelated certificates. Otherwise,
use generateCertPath when you want to generate
a CertPath (a certificate chain) and subsequently
validate it with a CertPathValidator.
A certificate factory for X.509 must return certificates that are an
instance of java.security.cert.X509Certificate, and CRLs
that are an instance of java.security.cert.X509CRL.
The following example reads a file with Base64 encoded certificates,
which are each bounded at the beginning by -----BEGIN CERTIFICATE-----, and
bounded at the end by -----END CERTIFICATE-----. We convert the
FileInputStream (which does not support mark
and reset) to a BufferedInputStream (which
supports those methods), so that each call to
generateCertificate consumes only one certificate, and the
read position of the input stream is positioned to the next certificate in
the file:
FileInputStream fis = new FileInputStream(filename);
BufferedInputStream bis = new BufferedInputStream(fis);
CertificateFactory cf = CertificateFactory.getInstance("X.509");
while (bis.available() > 0) {
Certificate cert = cf.generateCertificate(bis);
System.out.println(cert.toString());
}
The following example parses a PKCS#7-formatted certificate reply stored in a file and extracts all the certificates from it:
FileInputStream fis = new FileInputStream(filename);
CertificateFactory cf = CertificateFactory.getInstance("X.509");
Collection c = cf.generateCertificates(fis);
Iterator i = c.iterator();
while (i.hasNext()) {
Certificate cert = (Certificate)i.next();
System.out.println(cert);
}
The equals method implements an equivalence relation
on non-null object references:
x, x.equals(x) should return
true.
x and y, x.equals(y)
should return true if and only if
y.equals(x) returns true.
x, y, and z, if
x.equals(y) returns true and
y.equals(z) returns true, then
x.equals(z) should return true.
x and y, multiple invocations of
x.equals(y) consistently return true
or consistently return false, provided no
information used in equals comparisons on the
objects is modified.
x,
x.equals(null) should return false.
The equals method for class Object implements
the most discriminating possible equivalence relation on objects;
that is, for any non-null reference values x and
y, this method returns true if and only
if x and y refer to the same object
(x == y has the value true).
Note that it is generally necessary to override the hashCode method whenever this method is overridden, so as to maintain the general contract for the hashCode method, which states that equal objects must have equal hash codes.
inStream.
In order to take advantage of the specialized certificate format
supported by this certificate factory,
the returned certificate object can be typecast to the corresponding
certificate class. For example, if this certificate
factory implements X.509 certificates, the returned certificate object
can be typecast to the X509Certificate class.
In the case of a certificate factory for X.509 certificates, the
certificate provided in inStream must be DER-encoded and
may be supplied in binary or printable (Base64) encoding. If the
certificate is provided in Base64 encoding, it must be bounded at
the beginning by -----BEGIN CERTIFICATE-----, and must be bounded at
the end by -----END CERTIFICATE-----.
Note that if the given input stream does not support
mark
and
reset
, this method will
consume the entire input stream. Otherwise, each call to this
method consumes one certificate and the read position of the
input stream is positioned to the next available byte after
the inherent end-of-certificate marker. If the data in the input stream
does not contain an inherent end-of-certificate marker (other
than EOF) and there is trailing data after the certificate is parsed, a
CertificateException is thrown.
inStream.
In order to take advantage of the specialized certificate format
supported by this certificate factory, each element in
the returned collection view can be typecast to the corresponding
certificate class. For example, if this certificate
factory implements X.509 certificates, the elements in the returned
collection can be typecast to the X509Certificate class.
In the case of a certificate factory for X.509 certificates,
inStream may contain a sequence of DER-encoded certificates
in the formats described for
generateCertificate
.
In addition, inStream may contain a PKCS#7 certificate
chain. This is a PKCS#7 SignedData object, with the only
significant field being certificates. In particular, the
signature and the contents are ignored. This format allows multiple
certificates to be downloaded at once. If no certificates are present,
an empty collection is returned.
Note that if the given input stream does not support mark and reset , this method will consume the entire input stream.
CertPath object and initializes it with
the data read from the InputStream inStream. The data
is assumed to be in the default encoding. The name of the default
encoding is the first element of the Iterator returned by
the getCertPathEncodings
method.CertPath object and initializes it with
the data read from the InputStream inStream. The data
is assumed to be in the specified encoding. See Appendix A in the
Java Certification Path API Programmer's Guide
for information about standard encoding names and their formats.CertPath object and initializes it with
a List of Certificates.
The certificates supplied must be of a type supported by the
CertificateFactory. They will be copied out of the supplied
List object.
inStream.
In order to take advantage of the specialized CRL format
supported by this certificate factory,
the returned CRL object can be typecast to the corresponding
CRL class. For example, if this certificate
factory implements X.509 CRLs, the returned CRL object
can be typecast to the X509CRL class.
Note that if the given input stream does not support
mark
and
reset
, this method will
consume the entire input stream. Otherwise, each call to this
method consumes one CRL and the read position of the input stream
is positioned to the next available byte after the the inherent
end-of-CRL marker. If the data in the
input stream does not contain an inherent end-of-CRL marker (other
than EOF) and there is trailing data after the CRL is parsed, a
CRLException is thrown.
inStream.
In order to take advantage of the specialized CRL format
supported by this certificate factory, each element in
the returned collection view can be typecast to the corresponding
CRL class. For example, if this certificate
factory implements X.509 CRLs, the elements in the returned
collection can be typecast to the X509CRL class.
In the case of a certificate factory for X.509 CRLs,
inStream may contain a sequence of DER-encoded CRLs.
In addition, inStream may contain a PKCS#7 CRL
set. This is a PKCS#7 SignedData object, with the only
significant field being crls. In particular, the
signature and the contents are ignored. This format allows multiple
CRLs to be downloaded at once. If no CRLs are present,
an empty collection is returned.
Note that if the given input stream does not support mark and reset , this method will consume the entire input stream.
CertPath encodings supported
by this certificate factory, with the default encoding first. See
Appendix A in the
Java Certification Path API Programmer's Guide for information about
standard encoding names and their formats.
Attempts to modify the returned Iterator via its
remove method result in an
UnsupportedOperationException.
provider doesn't have to be registered.java.util.Hashtable.
The general contract of hashCode is:
hashCode method on each of
the two objects must produce the same integer result.
As much as is reasonably practical, the hashCode method defined by class Object does return distinct integers for distinct objects. (This is typically implemented by converting the internal address of the object into an integer, but this implementation technique is not required by the JavaTM programming language.)
wait methods.
The awakened thread will not be able to proceed until the current thread relinquishes the lock on this object. The awakened thread will compete in the usual manner with any other threads that might be actively competing to synchronize on this object; for example, the awakened thread enjoys no reliable privilege or disadvantage in being the next thread to lock this object.
This method should only be called by a thread that is the owner of this object's monitor. A thread becomes the owner of the object's monitor in one of three ways:
synchronized statement
that synchronizes on the object.
Class, by executing a
synchronized static method of that class.
Only one thread at a time can own an object's monitor.
wait methods.
The awakened threads will not be able to proceed until the current thread relinquishes the lock on this object. The awakened threads will compete in the usual manner with any other threads that might be actively competing to synchronize on this object; for example, the awakened threads enjoy no reliable privilege or disadvantage in being the next thread to lock this object.
This method should only be called by a thread that is the owner
of this object's monitor. See the notify method for a
description of the ways in which a thread can become the owner of
a monitor.
toString method returns a string that
"textually represents" this object. The result should
be a concise but informative representation that is easy for a
person to read.
It is recommended that all subclasses override this method.
The toString method for class Object
returns a string consisting of the name of the class of which the
object is an instance, the at-sign character `@', and
the unsigned hexadecimal representation of the hash code of the
object. In other words, this method returns a string equal to the
value of:
getClass().getName() + '@' + Integer.toHexString(hashCode())
The current thread must own this object's monitor. The thread
releases ownership of this monitor and waits until another thread
notifies threads waiting on this object's monitor to wake up
either through a call to the notify method or the
notifyAll method. The thread then waits until it can
re-obtain ownership of the monitor and resumes execution.
As in the one argument version, interrupts and spurious wakeups are possible, and this method should always be used in a loop:
synchronized (obj) {
while (<condition does not hold>)
obj.wait();
... // Perform action appropriate to condition
}
This method should only be called by a thread that is the owner
of this object's monitor. See the notify method for a
description of the ways in which a thread can become the owner of
a monitor.The current thread must own this object's monitor.
This method causes the current thread (call it T) to place itself in the wait set for this object and then to relinquish any and all synchronization claims on this object. Thread T becomes disabled for thread scheduling purposes and lies dormant until one of four things happens:
A thread can also wake up without being notified, interrupted, or timing out, a so-called spurious wakeup. While this will rarely occur in practice, applications must guard against it by testing for the condition that should have caused the thread to be awakened, and continuing to wait if the condition is not satisfied. In other words, waits should always occur in loops, like this one:
synchronized (obj) {
while (<condition does not hold>)
obj.wait(timeout);
... // Perform action appropriate to condition
}
(For more information on this topic, see Section 3.2.3 in Doug Lea's
"Concurrent Programming in Java (Second Edition)" (Addison-Wesley,
2000), or Item 50 in Joshua Bloch's "Effective Java Programming
Language Guide" (Addison-Wesley, 2001).
If the current thread is interrupted by another thread while it is waiting, then an InterruptedException is thrown. This exception is not thrown until the lock status of this object has been restored as described above.
Note that the wait method, as it places the current thread into the wait set for this object, unlocks only this object; any other objects on which the current thread may be synchronized remain locked while the thread waits.
This method should only be called by a thread that is the owner
of this object's monitor. See the notify method for a
description of the ways in which a thread can become the owner of
a monitor.
This method is similar to the wait method of one
argument, but it allows finer control over the amount of time to
wait for a notification before giving up. The amount of real time,
measured in nanoseconds, is given by:
1000000*timeout+nanos
In all other respects, this method does the same thing as the method of one argument. In particular, wait(0, 0) means the same thing as wait(0).
The current thread must own this object's monitor. The thread releases ownership of this monitor and waits until either of the following two conditions has occurred:
notify method
or the notifyAll method.
timeout
milliseconds plus nanos nanoseconds arguments, has
elapsed.
The thread then waits until it can re-obtain ownership of the monitor and resumes execution.
As in the one argument version, interrupts and spurious wakeups are possible, and this method should always be used in a loop:
synchronized (obj) {
while (<condition does not hold>)
obj.wait(timeout, nanos);
... // Perform action appropriate to condition
}
This method should only be called by a thread that is the owner
of this object's monitor. See the notify method for a
description of the ways in which a thread can become the owner of
a monitor.