The JAVA and JAVAC commands are described in detail

JAVA and JAVAC commands

The -classpath option on the javac and java command lines

This is a very basic question, but because most java programs are developed using existing IDE tools, very few people realize this point.

javac

-classpath, setting the path of the class to be searched, can be a directory, jar file, zip file (all class files inside), will overwrite all Settings inside CLASSPATH.

-sourcepath, set the path to search the java files required for compilation, which can be directories, jar files, zip files (all of which are java files).

So a full javac command line should look like this,

Assuming abc.java is in the path c:\src, you can compile in any directory by executing the following command.

javac -classpath c:\classes;c:\jar\abc.jar;c:\zip\abc.zip -sourcepath c:\source\project1\src;c:\source\project2 \lib\src.jar;c:\source\project3\lib\src.zip c:\src\abc.java

class file below c:\classed, class file inside c:\jar\ abc. jar, c:\zip\ abc. zip
c:\source\project1\src, c:\source\project2 \lib\ src. jar, c:\source\project3\lib\ src. zip,

Note: the source files in jar, zip will not be changed. The source files in the directory may be recompiled.

java

-classpath, set the path of the class to be searched, can be a directory, jar files, zip files (inside are all class files), will overwrite all CLASSPATH Settings.

Since the class to be executed is also part 1 of the class to be searched, 1 must put the class path in the -classpath setting as well.
In this case, when executing java in the path of the class to be executed, 1 must be marked (.) to indicate that this directory is also to be searched.

Suppose abc.class is in the path c:\src

The following command can be executed under any path

java -classpath c:\classes;c:\jar\abc.jar;c:\zip\abc.zip;c:\src abc

Question: if main.class belongs to c:\jar\ abc.jar and is in the package com.cnblogs.jeffchen, then java-classpath c:\classes; c: \ jar \ abc jar; c: \ zip \ abc zip; com. cnblogs. jeffchen. main can, but if classpath include multiple jar package? And what happens to other jar packages that have com.cnblogs.jeffchen? The mistake?

Under the windows,
The file path is separated by a backslash \
The delimiter of the class or java file list is a semicolon;

Under linux
The delimiter bit slash/for the file path
The delimiter of the class or java file list is a colon:

1 example of compile and run under linux

 /usr/local/java/bin/javac -classpath /tmp/javatest/lib/mail-1.3.3.jar -d /tmp/javatest/bin/ /tmp/javatest/src/jp/co/realseed/Capability.java

/usr/local/java/bin/java -classpath /tmp/javatest/lib/mail-1.3.3.jar:/tmp/javatest/bin/ jp.co.realseed.Capability

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