Like many sysadmins dealing with held-back packages, I attempted the classic uninstall-then-reinstall maneuver on Debian Jessie. Here's what exploded in my face when trying to reinstall openjdk-8-jre-headless:

apt-get install openjdk-8-jre-headless
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Some packages could not be installed...
The following packages have unmet dependencies:
 openjdk-8-jre-headless : Depends: ca-certificates-java but it is not going to be installed
E: Unable to correct problems, you have held broken packages.

The root cause stems from Jessie's outdated package repositories. The default sources.list often points to archived repositories that no longer receive updates. Here's how to verify your current sources:

cat /etc/apt/sources.list
# Typically shows deb.debian.org or archive.debian.org entries

After trying various approaches, this sequence worked reliably:

# First, update your package lists with fixed repositories
echo "deb http://archive.debian.org/debian jessie main contrib non-free" > /etc/apt/sources.list
echo "deb http://archive.debian.org/debian jessie-backports main contrib non-free" >> /etc/apt/sources.list

# Then clean and update
apt-get clean
apt-get update --allow-insecure-repositories
apt-get install -f
apt-get install ca-certificates-java --allow-unauthenticated
apt-get install openjdk-8-jre-headless

Check if Java is properly installed and ElasticSearch can run:

java -version
# Should show OpenJDK 1.8.x output

systemctl start elasticsearch
systemctl status elasticsearch
# Verify service is active (running)

For critical production systems, consider containerization to avoid dependency conflicts:

# Dockerfile snippet for Java 8 environment
FROM debian:jessie-slim

RUN echo "deb http://archive.debian.org/debian jessie main" > /etc/apt/sources.list \
 && apt-get update -o Acquire::Check-Valid-Until=false \
 && apt-get install -y --force-yes openjdk-8-jre-headless \
 && rm -rf /var/lib/apt/lists/*

# Then build and run your ElasticSearch container separately

For long-term maintainability on Jessie systems:

• Regularly check apt-get upgrade --dry-run for held-back packages
• Consider upgrading to a supported Debian version
• Maintain proper backups before package operations

When dealing with Debian's package management system, dependency issues can be particularly frustrating. Here's what happened when I attempted to reinstall openjdk-8-jre-headless:

$ sudo apt-get install openjdk-8-jre-headless
The following packages have unmet dependencies:
 openjdk-8-jre-headless : Depends: ca-certificates-java but it is not going to be installed
E: Unable to correct problems, you have held broken packages.

The root cause appears to be a conflict between package versions in the Jessie repositories. The ca-certificates-java package is a dependency for OpenJDK, but the package manager refuses to install it due to version constraints or conflicts with other installed packages.

Here's the step-by-step process that worked for me:

# First, clean up any partial installations
sudo apt-get clean
sudo apt-get autoclean

# Then attempt to fix broken dependencies
sudo apt-get install -f

# If that doesn't work, try updating everything first
sudo apt-get update
sudo apt-get upgrade

# Force installation of the problematic dependency
sudo apt-get install ca-certificates-java --fix-missing

# Finally, install OpenJDK
sudo apt-get install openjdk-8-jre-headless

If the above fails, you might need to use package pinning. Create or edit /etc/apt/preferences:

Package: *
Pin: release a=stable
Pin-Priority: 500

Package: *
Pin: release a=testing
Pin-Priority: 50

Then run:

sudo apt-get update
sudo apt-get -t stable install openjdk-8-jre-headless

After successful installation, verify Java is working:

$ java -version
openjdk version "1.8.0_242"
OpenJDK Runtime Environment (build 1.8.0_242-8u242-b08-1~deb9u1-b08)
OpenJDK 64-Bit Server VM (build 25.242-b08, mixed mode)

To avoid similar problems in the future:

• Always check held packages with apt-mark showhold before removing
• Consider using aptitude which has better dependency resolution
• Maintain regular system backups before major package operations