org.apache.http.util
Class VersionInfo

java.lang.Object
  org.apache.http.util.VersionInfo

public class VersionInfo
extends Object

Provides access to version information for HTTP components. Static methods are used to extract version information from property files that are automatically packaged with HTTP component release JARs.

All available version information is provided in strings, where the string format is informal and subject to change without notice. Version information is provided for debugging output and interpretation by humans, not for automated processing in applications.

Since:

4.0

Field Summary

static String	PROPERTY_MODULE
static String	PROPERTY_RELEASE
static String	PROPERTY_TIMESTAMP
static String	UNAVAILABLE A string constant for unavailable information.
static String	VERSION_PROPERTY_FILE The filename of the version information files.

Constructor Summary

protected

VersionInfo(String pckg, String module, String release, String time, String clsldr) Instantiates version information.

Method Summary

protected static VersionInfo	fromMap(String pckg, Map<?,?> info, ClassLoader clsldr) Instantiates version information from properties.
String	getClassloader() Obtains the classloader used to read the version information.
String	getModule() Obtains the name of the versioned module or informal unit.
String	getPackage() Obtains the package name.
String	getRelease() Obtains the release of the versioned module or informal unit.
String	getTimestamp() Obtains the timestamp of the versioned module or informal unit.
static String	getUserAgent(String name, String pkg, Class<?> cls) Sets the user agent to "<name>/<release> (Java/<java.version>)".
static VersionInfo[]	loadVersionInfo(String[] pckgs, ClassLoader clsldr) Loads version information for a list of packages.
static VersionInfo	loadVersionInfo(String pckg, ClassLoader clsldr) Loads version information for a package.
String	toString() Provides the version information in human-readable format.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

UNAVAILABLE

public static final String UNAVAILABLE

A string constant for unavailable information.

See Also:

Constant Field Values

VERSION_PROPERTY_FILE

public static final String VERSION_PROPERTY_FILE

The filename of the version information files.

See Also:

Constant Field Values

PROPERTY_MODULE

public static final String PROPERTY_MODULE

See Also:

Constant Field Values

PROPERTY_RELEASE

public static final String PROPERTY_RELEASE

See Also:

Constant Field Values

PROPERTY_TIMESTAMP

public static final String PROPERTY_TIMESTAMP

See Also:

Constant Field Values

Constructor Detail

VersionInfo

protected VersionInfo(String pckg,
                      String module,
                      String release,
                      String time,
                      String clsldr)

Instantiates version information.

Parameters:

pckg - the package

module - the module, or null

release - the release, or null

time - the build time, or null

clsldr - the class loader, or null

Method Detail

getPackage

public final String getPackage()

Obtains the package name. The package name identifies the module or informal unit.

Returns:

the package name, never null

getModule

public final String getModule()

Obtains the name of the versioned module or informal unit. This data is read from the version information for the package.

Returns:

the module name, never null

getRelease

public final String getRelease()

Obtains the release of the versioned module or informal unit. This data is read from the version information for the package.

Returns:

the release version, never null

getTimestamp

public final String getTimestamp()

Obtains the timestamp of the versioned module or informal unit. This data is read from the version information for the package.

Returns:

the timestamp, never null

getClassloader

public final String getClassloader()

Obtains the classloader used to read the version information. This is just the toString output of the classloader, since the version information should not keep a reference to the classloader itself. That could prevent garbage collection.

Returns:

the classloader description, never null

toString

public String toString()

Provides the version information in human-readable format.

Overrides:

toString in class Object

Returns:

a string holding this version information

loadVersionInfo

public static VersionInfo[] loadVersionInfo(String[] pckgs,
                                            ClassLoader clsldr)

Loads version information for a list of packages.

Parameters:

pckgs - the packages for which to load version info

clsldr - the classloader to load from, or null for the thread context classloader

Returns:

the version information for all packages found, never null

loadVersionInfo

public static VersionInfo loadVersionInfo(String pckg,
                                          ClassLoader clsldr)

Loads version information for a package.

Parameters:

pckg - the package for which to load version information, for example "org.apache.http". The package name should NOT end with a dot.

clsldr - the classloader to load from, or null for the thread context classloader

Returns:

the version information for the argument package, or null if not available

fromMap

protected static VersionInfo fromMap(String pckg,
                                     Map<?,?> info,
                                     ClassLoader clsldr)

Instantiates version information from properties.

Parameters:

pckg - the package for the version information

info - the map from string keys to string values, for example Properties

clsldr - the classloader, or null

Returns:

the version information

getUserAgent

public static String getUserAgent(String name,
                                  String pkg,
                                  Class<?> cls)

Sets the user agent to "<name>/<release> (Java/<java.version>)".

For example:

"Apache-HttpClient/4.3 (Java/1.6.0_35)"

Parameters:

name - the component name, like "Apache-HttpClient".

pkg - the package for which to load version information, for example "org.apache.http". The package name should NOT end with a dot.

cls - the class' class loader to load from, or null for the thread context class loader

Since:

4.3