入门Java CLASSPATH问题： - 未名空间MITBBS历史存档

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入门Java CLASSPATH问题：

入门Java CLASSPATH问题：# Java - 爪哇娇娃

a*n2003-06-05 07:06

1 楼

只写一个目录，会不会包含该目录下的所有.jar里的class?
如果是.zip呢，是不是要写目录+包文件的全名？

z*g2003-06-05 07:06

2 楼

1. no. no jar file will be included.
2. I don't think java classpath would recognize zip file at all.

【在 a***n 的大作中提到】

: 只写一个目录，会不会包含该目录下的所有.jar里的class?
: 如果是.zip呢，是不是要写目录+包文件的全名？

m*c2003-06-05 07:06

3 楼

Wrong. Java archive files can be in either JAR or ZIP format. For example,
Oracle JDBC (thin) driver is packaged as "classes12.zip". You can tread just
ZIP file as JAR file:
(Windows) set CLASSPATH=...\classes12.zip;...
(UNIX) export CLASSPATH=.../classes12.zip:...

【在 z****g 的大作中提到】

: 1. no. no jar file will be included.
: 2. I don't think java classpath would recognize zip file at all.

a*n2003-06-05 07:06

4 楼

我的关键问题是，如果是.jar，可不可以只写目录名，它会自动找目录里所有jar
里面包含的class?
为什么我装的J2SDK，默认的classpath是 jdk/lib/tools.jar:jdk/jre/lib
其中jdk/jre/lib里有java所需的所有class包:rt.jar。
它为什么不用jdk/jre/lib/rt.jar，或者干脆用 jdk/share/src.zip呢(src.zip也包含
java所需的所有class)。
是不是jdk1.4放宽要求，对jar内建支持，不用些全jar的文件名，只要目录它就可以搜？

【在 m**c 的大作中提到】

:
: Wrong. Java archive files can be in either JAR or ZIP format. For example,
: Oracle JDBC (thin) driver is packaged as "classes12.zip". You can tread just
: ZIP file as JAR file:
: (Windows) set CLASSPATH=...\classes12.zip;...
: (UNIX) export CLASSPATH=.../classes12.zip:...

a*n2003-06-05 07:06

5 楼

太武断了，答案作废

【在 z****g 的大作中提到】

: 1. no. no jar file will be included.
: 2. I don't think java classpath would recognize zip file at all.

e*g2003-06-05 07:06

6 楼

never heard of. jre/lib as classpath is for resources like font.properties,
images/...gif. rt.jar is in bootclasspath and not affected by classpath

【在 a***n 的大作中提到】

: 我的关键问题是，如果是.jar，可不可以只写目录名，它会自动找目录里所有jar
: 里面包含的class?
: 为什么我装的J2SDK，默认的classpath是 jdk/lib/tools.jar:jdk/jre/lib
: 其中jdk/jre/lib里有java所需的所有class包:rt.jar。
: 它为什么不用jdk/jre/lib/rt.jar，或者干脆用 jdk/share/src.zip呢(src.zip也包含
: java所需的所有class)。
: 是不是jdk1.4放宽要求，对jar内建支持，不用些全jar的文件名，只要目录它就可以搜？

m*c2003-06-05 07:06

7 楼

I don't not quite understand with the translated terminology (in Chinese) as
you mentioned above :-) Let's use an example: you have "my.jar", if you
include "my.jar" in CLASSPATH, every classes (compiled bytecode) in "my.jar"
will be loaded to JVM:
set CLASSPATH=\my.jar (Windows)
export CLASSPATH=/my.jar (Unix)
Since "src.zip" only contains the source code (*.java) not compiled bytecode
(*.classes). Therefore, you cannot add "src.zip" to CLASSPATH (in fact, you
could do it, but J

【在 a***n 的大作中提到】

a*n2003-06-05 07:06

8 楼

多谢,完全明白了.
那么安装的j2sdk,它默认设classpath=.:/lib/tools.jar:/jre/lib
里的"/jre/lib"根本没有意义嘛,除非你想把一个个的class文件放那里,谁干?

目录它=目录,它:)

【在 m**c 的大作中提到】

:
: I don't not quite understand with the translated terminology (in Chinese) as
: you mentioned above :-) Let's use an example: you have "my.jar", if you
: include "my.jar" in CLASSPATH, every classes (compiled bytecode) in "my.jar"
: will be loaded to JVM:
: set CLASSPATH=\my.jar (Windows)
: export CLASSPATH=/my.jar (Unix)
: Since "src.zip" only contains the source code (*.java) not compiled bytecode
: (*.classes). Therefore, you cannot add "src.zip" to CLASSPATH (in fact, you
: could do it, but J

z*g2003-06-05 07:06

9 楼

我知道的是.jar，如果只指明目录的话，是不会被搜索到的。
这个时候，用ant就显出优势来了。
ant可以指出目录就可以了。而且可以搜索子目录。

【在 a***n 的大作中提到】

m*c2003-06-05 07:06

10 楼

Remember, sometimes, not only class file needs to be in the CLASSPATH, but
also other type of files. For example, properties file. If you take a look
at /jre/lib, you will see some files with extension ".properties". Those
files are used as configuration files which must be in the CLASSPATH,
otherwise, some classes will complain about it. When a directory is included
in the CLASSPATH, you can load any file using
"obj.getClass().getResourcesAsStream(...)". This can be very useful: let

【在 a***n 的大作中提到】

: 多谢,完全明白了.
: 那么安装的j2sdk,它默认设classpath=.:/lib/tools.jar:/jre/lib
: 里的"/jre/lib"根本没有意义嘛,除非你想把一个个的class文件放那里,谁干?
:
: 目录它=目录,它:)