Java Reference
In-Depth Information
from
isCompatibleWith()
becausethe
logging
packagedoesnotcontainaspe-
cification version number in dotted form (it is null).
Perhaps the simplest way to place package information into the
logging
package
Listing 4-4.
manifest.mf
containing the package information
Implementation-Title: Logging Implementation
Implementation-Vendor: Jeff Friesen
Implementation-Version: 1.0a
Specification-Title: Logging Specification
Specification-Vendor: Jeff Friesen
Specification-Version: 1.0
Sealed: true
Note
MakesuretopresstheReturn/Enterkeyattheendofthefinalline(
Sealed:
true
).Otherwise,youwillprobablyobserve
Sealed: false
intheoutputbecause
thisentrywillnotbestoredinthe
logging
packagebytheJDK's
jar
tool—
jar
is
a bit quirky.
ExecutethefollowingcommandlinetocreateaJARfilethatincludes
logging
and
itsfiles,andwhose
manifest
,aspecialfilenamed
MANIFEST.MF
thatstoresinforma-
tion about the contents of a JAR file, contains the contents of
Listing 4-4
:
jar cfm logging.jar manifest.mf logging/*.class
ThiscommandlinecreatesaJARfilenamed
logging.jar
(viathe
c
[create]and
f
[file] options). It also merges the contents of
manifest.mf
(via the
m
[manifest]
option) into
MANIFEST.MF
, which is stored in the package's
META-INF
directory.
Note
To learn more about a JAR file's manifest, read the “JAR Manifest” section
of the JDK documentation's “JAR File Specification” page (
ht-
Assuming that the
jar
tool presents no error messages, execute the following
Windows-orientedcommandline(oracommandlinesuitableforyourplatform)torun
PackageInfo
and extract the package information from the
logging
package:
