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

30+ Updates per Second per Account: Uber Scales Ledger Processing with Batching

Uber introduced a high-throughput financial ledger processing system designed to handle hot account write contention at scale. Using 250ms batching, Redis coordination, and optimistic atomic updates, the system supports 30+ updates per second per account while preserving consistency and auditability, reducing multi-hour processing pipelines to minutes in its distributed accounting infrastructure.

By Leela Kumili

How a Culture of Data-Driven Conversations Can Support Platform Engineering

To provide SRE as a service, a team built a center of excellence, introducing Federated SREs and roles like production manager and technical tribe lead. They created a culture of data-driven conversations where SLOs and SLAs were democratised. Surviving growing cognitive load meant continuously simplifying architecture and embedding sovereignty and resilience into platform design decisions.

By Ben Linders

Presentation: Architecting a Centralized Platform for Data Deletion at Netflix

The speakers discuss the architectural challenges of executing safe data deletion across distributed datastores. Balancing durability, availability & correctness, they explain how to orchestrate multi-system deletion propagation without impacting live traffic. They share lessons on controlling tombstone accumulation, building continuous audit loops, and gaining trust with a centralized platform.

By Vidhya Arvind, Shawn Liu

Article: Architectural Change Cases: A Practical Tool for Evolutionary Architectures

Architectural change cases extend architecture decision record (ADR) thinking by evaluating how decisions may evolve over time. Change cases expose hidden assumptions and help teams estimate the reversibility and cost of change.

By Pierre Pureur, Kurt Bittner

AWS Replaces Fat-Tree Data Center Networks with Random Graph Theory, Cutting Routers by 69%

AWS disclosed that Resilient Network Graphs, a flat network architecture based on quasi-random graph theory, is now the default for most new data center builds. The design replaces fat-tree hierarchies with direct ToR-to-ToR mesh connections using passive optical ShuffleBoxes, cutting routers by 69%, boosting throughput by 33%, and reducing network power consumption by 40%.

By Steef-Jan Wiggers

© 2026   Created by Michael Levin.   Powered by

Badges  |  Report an Issue  |  Terms of Service