jar linking : Java Glossary

Let’s say you have two jars and you want to treat them logically as one. This might happen if your program needs some third party library. What are your options?

• mention the second jar in the command line -classpath.
• You can put a Class-Path attribute in the manifest. It must contain URLs (Uniform Resource Locators) of secondary jars and directories
• install the jar in the ext directory.
• extract the members you need from the library and add them all to the main jar.
• extract the members you need from the library and add them to the main jar.
• Add an Class-Path line to the jar manifest giving the location of the secondary jar relative to the location of the main jar.
• Use JNLP (Java Network Launching Protocol) where you can specify secondary jars.
• Use OneJar to embed the secondary jars as members of the main jar.

Don’t change the global classpath. It is too fragile. Too many cooks meddle with it.

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