CertificateFactory

java.lang.Object
- java.security.cert.CertificateFactory

```
public class CertificateFactory
extends Object
```
This class defines the functionality of a certificate factory, which is used to generate certificate, certification path (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);
 }
 
```
Every implementation of the Java platform is required to support the following standard CertificateFactory type:
- X.509
and the following standard CertPath encodings:
- PKCS7
- PkiPath
The type and encodings are described in the CertificateFactory section and the CertPath Encodings section of the Java Cryptography Architecture Standard Algorithm Name Documentation. Consult the release documentation for your implementation to see if any other types or encodings are supported.
从以下版本开始:

1.2

另请参阅:

Certificate, X509Certificate, CertPath, CRL, X509CRL

构造器概要

构造器
限定符	构造器	说明
`protected`	`CertificateFactory(CertificateFactorySpi certFacSpi, Provider provider, String type)`	Creates a CertificateFactory object of the given type, and encapsulates the given provider implementation (SPI object) in it.

方法概要

所有方法静态方法实例方法具体方法
限定符和类型	方法	说明
`Certificate`	`generateCertificate(InputStream inStream)`	Generates a certificate object and initializes it with the data read from the input stream `inStream`.
`Collection<? extends Certificate>`	`generateCertificates(InputStream inStream)`	Returns a (possibly empty) collection view of the certificates read from the given input stream `inStream`.
`CertPath`	`generateCertPath(InputStream inStream)`	Generates a `CertPath` object and initializes it with the data read from the `InputStream` inStream.
`CertPath`	`generateCertPath(InputStream inStream, String encoding)`	Generates a `CertPath` object and initializes it with the data read from the `InputStream` inStream.
`CertPath`	`generateCertPath(List<? extends Certificate> certificates)`	Generates a `CertPath` object and initializes it with a `List` of `Certificate`s.
`CRL`	`generateCRL(InputStream inStream)`	Generates a certificate revocation list (CRL) object and initializes it with the data read from the input stream `inStream`.
`Collection<? extends CRL>`	`generateCRLs(InputStream inStream)`	Returns a (possibly empty) collection view of the CRLs read from the given input stream `inStream`.
`Iterator<String>`	`getCertPathEncodings()`	Returns an iteration of the `CertPath` encodings supported by this certificate factory, with the default encoding first.
`static CertificateFactory`	`getInstance(String type)`	Returns a certificate factory object that implements the specified certificate type.
`static CertificateFactory`	`getInstance(String type, String provider)`	Returns a certificate factory object for the specified certificate type.
`static CertificateFactory`	`getInstance(String type, Provider provider)`	Returns a certificate factory object for the specified certificate type.
`Provider`	`getProvider()`	Returns the provider of this certificate factory.
`String`	`getType()`	Returns the name of the certificate type associated with this certificate factory.

从类继承的方法 java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- 构造器详细资料
  - CertificateFactory
```
protected CertificateFactory(CertificateFactorySpi certFacSpi,
                             Provider provider,
                             String type)
```
    Creates a CertificateFactory object of the given type, and encapsulates the given provider implementation (SPI object) in it.
    
    参数:
    
    certFacSpi - the provider implementation.
    
    provider - the provider.
    
    type - the certificate type.
- 方法详细资料
  - getInstance
```
public static final CertificateFactory getInstance(String type)
                                            throws CertificateException
```
    Returns a certificate factory object that implements the specified certificate type.
    This method traverses the list of registered security Providers, starting with the most preferred Provider. A new CertificateFactory object encapsulating the CertificateFactorySpi implementation from the first Provider that supports the specified type is returned.
    Note that the list of registered providers may be retrieved via the Security#getProviders() method.
    
    参数:
    
    type - the name of the requested certificate type. See the CertificateFactory section in the Java Cryptography Architecture Standard Algorithm Name Documentation for information about standard certificate types.
    
    返回:
    
    a certificate factory object for the specified type.
    
    抛出:
    
    CertificateException - if no Provider supports a CertificateFactorySpi implementation for the specified type.
    
    另请参阅:
    
    Provider
  - getInstance
```
public static final CertificateFactory getInstance(String type,
                                                   String provider)
                                            throws CertificateException,
                                                   NoSuchProviderException
```
    Returns a certificate factory object for the specified certificate type.
    A new CertificateFactory object encapsulating the CertificateFactorySpi implementation from the specified provider is returned. The specified provider must be registered in the security provider list.
    Note that the list of registered providers may be retrieved via the Security#getProviders() method.
    
    参数:
    
    type - the certificate type. See the CertificateFactory section in the Java Cryptography Architecture Standard Algorithm Name Documentation for information about standard certificate types.
    
    provider - the name of the provider.
    
    返回:
    
    a certificate factory object for the specified type.
    
    抛出:
    
    CertificateException - if a CertificateFactorySpi implementation for the specified algorithm is not available from the specified provider.
    
    NoSuchProviderException - if the specified provider is not registered in the security provider list.
    
    IllegalArgumentException - if the provider name is null or empty.
    
    另请参阅:
    
    Provider
  - getInstance
```
public static final CertificateFactory getInstance(String type,
                                                   Provider provider)
                                            throws CertificateException
```
    Returns a certificate factory object for the specified certificate type.
    A new CertificateFactory object encapsulating the CertificateFactorySpi implementation from the specified Provider object is returned. Note that the specified Provider object does not have to be registered in the provider list.
    
    参数:
    
    type - the certificate type. See the CertificateFactory section in the Java Cryptography Architecture Standard Algorithm Name Documentation for information about standard certificate types.
    
    provider - the provider.
    
    返回:
    
    a certificate factory object for the specified type.
    
    抛出:
    
    CertificateException - if a CertificateFactorySpi implementation for the specified algorithm is not available from the specified Provider object.
    
    IllegalArgumentException - if the provider is null.
    
    从以下版本开始:
    
    1.4
    
    另请参阅:
    
    Provider
  - getProvider
```
public final Provider getProvider()
```
    Returns the provider of this certificate factory.
    
    返回:
    
    the provider of this certificate factory.
  - getType
```
public final String getType()
```
    Returns the name of the certificate type associated with this certificate factory.
    
    返回:
    
    the name of the certificate type associated with this certificate factory.
  - generateCertificate
```
public final Certificate generateCertificate(InputStream inStream)
                                      throws CertificateException
```
    Generates a certificate object and initializes it with the data read from the input stream 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.
    
    参数:
    
    inStream - an input stream with the certificate data.
    
    返回:
    
    a certificate object initialized with the data from the input stream.
    
    抛出:
    
    CertificateException - on parsing errors.
  - getCertPathEncodings
```
public final Iterator<String> getCertPathEncodings()
```
    Returns an iteration of the CertPath encodings supported by this certificate factory, with the default encoding first. See the CertPath Encodings section in the Java Cryptography Architecture Standard Algorithm Name Documentation for information about standard encoding names and their formats.
    Attempts to modify the returned Iterator via its remove method result in an UnsupportedOperationException.
    
    返回:
    
    an Iterator over the names of the supported CertPath encodings (as Strings)
    
    从以下版本开始:
    
    1.4
  - generateCertPath
```
public final CertPath generateCertPath(InputStream inStream)
                                throws CertificateException
```
    Generates a 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.
    
    参数:
    
    inStream - an InputStream containing the data
    
    返回:
    
    a CertPath initialized with the data from the InputStream
    
    抛出:
    
    CertificateException - if an exception occurs while decoding
    
    从以下版本开始:
    
    1.4
  - generateCertPath
```
public final CertPath generateCertPath(InputStream inStream,
                                       String encoding)
                                throws CertificateException
```
    Generates a CertPath object and initializes it with the data read from the InputStream inStream. The data is assumed to be in the specified encoding. See the CertPath Encodings section in the Java Cryptography Architecture Standard Algorithm Name Documentation for information about standard encoding names and their formats.
    
    参数:
    
    inStream - an InputStream containing the data
    
    encoding - the encoding used for the data
    
    返回:
    
    a CertPath initialized with the data from the InputStream
    
    抛出:
    
    CertificateException - if an exception occurs while decoding or the encoding requested is not supported
    
    从以下版本开始:
    
    1.4
  - generateCertPath
```
public final CertPath generateCertPath(List<? extends Certificate> certificates)
                                throws CertificateException
```
    Generates a 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.
    
    参数:
    
    certificates - a List of Certificates
    
    返回:
    
    a CertPath initialized with the supplied list of certificates
    
    抛出:
    
    CertificateException - if an exception occurs
    
    从以下版本开始:
    
    1.4
  - generateCertificates
```
public final Collection<? extends Certificate> generateCertificates(InputStream inStream)
                                                             throws CertificateException
```
    Returns a (possibly empty) collection view of the certificates read from the given input stream 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.
    
    参数:
    
    inStream - the input stream with the certificates.
    
    返回:
    
    a (possibly empty) collection view of java.security.cert.Certificate objects initialized with the data from the input stream.
    
    抛出:
    
    CertificateException - on parsing errors.
  - generateCRL
```
public final CRL generateCRL(InputStream inStream)
                      throws CRLException
```
    Generates a certificate revocation list (CRL) object and initializes it with the data read from the input stream 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 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.
    
    参数:
    
    inStream - an input stream with the CRL data.
    
    返回:
    
    a CRL object initialized with the data from the input stream.
    
    抛出:
    
    CRLException - on parsing errors.
  - generateCRLs
```
public final Collection<? extends CRL> generateCRLs(InputStream inStream)
                                             throws CRLException
```
    Returns a (possibly empty) collection view of the CRLs read from the given input stream 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.
    
    参数:
    
    inStream - the input stream with the CRLs.
    
    返回:
    
    a (possibly empty) collection view of java.security.cert.CRL objects initialized with the data from the input stream.
    
    抛出:
    
    CRLException - on parsing errors.

类 CertificateFactory

构造器概要

方法概要

从类继承的方法 java.lang.Object

构造器详细资料

CertificateFactory

方法详细资料

getInstance

getInstance

getInstance

getProvider

getType

generateCertificate

getCertPathEncodings

generateCertPath

generateCertPath

generateCertPath

generateCertificates

generateCRL

generateCRLs