java - 在Java类路径的目录中包含所有jar(Including all the jars in a directory within the Java classpath)

Question

Is there a way to include all the jar files within a directory in the classpath?

(有没有办法将所有jar文件包含在类路径的目录中？)

I'm trying java -classpath lib/*.jar:. my.package.Program

(我正在尝试java -classpath lib/*.jar:. my.package.Program)

java -classpath lib/*.jar:. my.package.Program and it is not able to find class files that are certainly in those jars.

(java -classpath lib/*.jar:. my.package.Program ，它无法找到这些jar中肯定存在的类文件。)

Do I need to add each jar file to the classpath separately?

(我是否需要将每个jar文件分别添加到类路径？)

  ask by Chris Serra translate from so

Answer 1

Using Java 6 or later, the classpath option supports wildcards.

(使用Java 6或更高版本时，classpath选项支持通配符。)

Note the following:

(请注意以下几点：)

• Use straight quotes ( " )

  (使用双引号（ " ）)

• Use * , not *.jar

  (使用* ，而不是*.jar)

Windows

(视窗)

java -cp "Test.jar;lib/*" my.package.MainClass

Unix

(Unix系统)

java -cp "Test.jar:lib/*" my.package.MainClass

This is similar to Windows, but uses : instead of ;

(这类似于Windows，但使用:代替;)

.

(。)

If you cannot use wildcards, bash allows the following syntax (where lib is the directory containing all the Java archive files):

(如果不能使用通配符，则bash允许使用以下语法（其中lib是包含所有Java归档文件的目录）：)

java -cp $(echo lib/*.jar | tr ' ' ':')

(Note that using a classpath is incompatible with the -jar option. See also: Execute jar file with multiple classpath libraries from command prompt )

(（请注意，使用类路径与-jar选项不兼容。另请参见： 在命令提示符下执行具有多个类路径库的jar文件 ）)

Understanding Wildcards

(了解通配符)

From the Classpath document:

(从类路径文档中：)

Class path entries can contain the basename wildcard character * , which is considered equivalent to specifying a list of all the files in the directory with the extension .jar or .JAR .

(类路径条目可以包含基本名称通配符* ，这被认为等效于指定目录中所有扩展名为.jar或.JAR的文件的列表。)

For example, the class path entry foo/* specifies all JAR files in the directory named foo.

(例如，类路径条目foo/*指定目录foo中的所有JAR文件。)

A classpath entry consisting simply of * expands to a list of all the jar files in the current directory.

(仅由*组成的类路径条目将扩展为当前目录中所有jar文件的列表。)

A class path entry that contains * will not match class files.

(包含*类路径条目将与类文件不匹配。)

To match both classes and JAR files in a single directory foo, use either foo;foo/* or foo/*;foo .

(要在单个目录foo中匹配类和JAR文件，请使用foo;foo/*或foo/*;foo 。)

The order chosen determines whether the classes and resources in foo are loaded before JAR files in foo , or vice versa.

(选择的顺序确定是否在类和资源foo中之前在JAR文件加载foo ，或反之亦然。)

Subdirectories are not searched recursively.

(子目录不是递归搜索的。)

For example, foo/* looks for JAR files only in foo , not in foo/bar , foo/baz , etc.

(例如， foo/*仅在foo查找JAR文件，而不在foo/bar ， foo/baz等中查找。)

The order in which the JAR files in a directory are enumerated in the expanded class path is not specified and may vary from platform to platform and even from moment to moment on the same machine.

(在扩展的类路径中枚举目录中JAR文件的顺序未指定，并且可能因平台而异，甚至在同一台计算机上有时也有所不同。)

A well-constructed application should not depend upon any particular order.

(结构良好的应用程序不应依赖于任何特定顺序。)

If a specific order is required then the JAR files can be enumerated explicitly in the class path.

(如果需要特定顺序，则可以在类路径中显式枚举JAR文件。)

Expansion of wildcards is done early, prior to the invocation of a program's main method, rather than late, during the class-loading process itself.

(通配符的扩展是在类加载过程本身的早期，而不是在程序的主要方法调用之前完成的。)

Each element of the input class path containing a wildcard is replaced by the (possibly empty) sequence of elements generated by enumerating the JAR files in the named directory.

(输入类路径中包含通配符的每个元素都将由（可能为空）元素序列替换，这些元素序列是通过枚举命名目录中的JAR文件生成的。)

For example, if the directory foo contains a.jar , b.jar , and c.jar , then the class path foo/* is expanded into foo/a.jar;foo/b.jar;foo/c.jar , and that string would be the value of the system property java.class.path .

(例如，如果目录foo包含a.jar ， b.jar和c.jar ，则类路径foo/*将扩展为foo/a.jar;foo/b.jar;foo/c.jar ，以及该字符串将是系统属性java.class.path的值。)

The CLASSPATH environment variable is not treated any differently from the -classpath (or -cp ) command-line option.

(CLASSPATH环境变量与-classpath （或-cp ）命令行选项没有任何区别。)

That is, wildcards are honored in all these cases.

(也就是说，在所有这些情况下都应使用通配符。)

However, class path wildcards are not honored in the Class-Path jar-manifest header.

(但是，类路径通配符在Class-Path jar-manifest标头中不被接受。)

Note: due to a known bug in java 8, the windows examples must use a backslash preceding entries with a trailing asterisk: https://bugs.openjdk.java.net/browse/JDK-8131329

(注意：由于Java 8中的一个已知错误，Windows示例必须在前面的条目中使用反斜杠，并在其后加上星号： https : //bugs.openjdk.java.net/browse/JDK-8131329)