Here I attached two scripts that might help you working with jar files.

Have you tried to verify that a Class must exists in a lib directory that has few dozens jar files? For example I read from a forum that there is a ServerInfo.properties inside one of tomcat jar, so I run this:
$ scala searchjar.scala ServerInfo /opt/tomcat6/lib
/opt/tomcat6/lib/catalina.jar org/apache/catalina/util/ServerInfo.class
/opt/tomcat6/lib/catalina.jar org/apache/catalina/util/ServerInfo.properties
The script can walk over one or more directory and search all jar files for you.

The second thing I do once a while is I want to see the content of a text inside the jar. For the example above, I can run my second script like this:
$ scala displayjar.scala /opt/tomcat6/lib/catalina.jar org/apache/catalina/util/ServerInfo.properties
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements. See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License. You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

server.info=Apache Tomcat/6.0.18
server.number=6.0.18.0
server.built=Jul 22 2008 02:00:36
You can even run the displayjar.scala with just a jar file, and it default to print out the Manifest file content.

Hope these scripts are useful to you.

Views: 57

Attachments:

Happy 10th year, JCertif!

Notes

Welcome to Codetown!

Codetown is a social network. It's got blogs, forums, groups, personal pages and more! You might think of Codetown as a funky camper van with lots of compartments for your stuff and a great multimedia system, too! Best of all, Codetown has room for all of your friends.

When you create a profile for yourself you get a personal page automatically. That's where you can be creative and do your own thing. People who want to get to know you will click on your name or picture and…
Continue

Created by Michael Levin Dec 18, 2008 at 6:56pm. Last updated by Michael Levin May 4, 2018.

Looking for Jobs or Staff?

Check out the Codetown Jobs group.

 

Enjoy the site? Support Codetown with your donation.



InfoQ Reading List

How OpenAI Built a Secure Windows Sandbox for Codex Agents

OpenAI details Codex Windows sandbox architecture, showing how SIDs, ACLs, restricted tokens, and dedicated sandbox accounts enable safe execution of autonomous coding tasks. The design balances isolation with real developer workflows and shows how OS security primitives must be composed for AI agents on local development environments.

By Leela Kumili

Presentation: Platform Teams Enabling AI - MCP/Multi-Agentic Tools Across Linkedin

LinkedIn’s Karthik Ramgopal and Prince Valluri discuss leveraging AI as a new execution model for large-scale engineering. They explain how to move beyond fragmented implementations by building platform abstractions for orchestration, structured context, and safe tooling like MCP. They share architectural insights from real-world coding, observation, and UI testing agents built at LinkedIn.

By Karthik Ramgopal, Prince Valluri

How Netflix Maps Thousands of Microservices in Real-Time

Netflix has shared details about Service Topology. This internal system creates and updates a live dependency graph for thousands of microservices. It helps engineers see how services connect and resolve issues more quickly. The system merges three separate data sources into a single, queryable graph. It updates almost in real-time as traffic patterns shift.

By Claudio Masolo

Dropbox Introduces Nova, an Internal Platform for Running AI Coding Agents at Scale

Dropbox has unveiled Nova, an internal platform designed to orchestrate and operationalize AI coding agents across the company's engineering workflows.

By Craig Risi

Google LiteRT-LM Speeds Up Local Inference Up to 2.2x With Gemma 4 Multi-Token Prediction

LiteRT-LM brings native support for Gemma 4 Multi-Token Prediction (MTP) drafters, enabling up to 2.2x faster inference. The framework is expanding beyond Kotlin and C++ adding support for new Swift and a JavaScript APIs.

By Sergio De Simone

© 2026   Created by Michael Levin.   Powered by

Badges  |  Report an Issue  |  Terms of Service