Importing Trusted Certificate to all your JVM cacerts

Sometimes when you work in a corporate company there are proxies that require certificates to validate Java applications. Usually your company will provide a valid certificate that will validate any requests coming in and going out from your local machine. In order to use your Java applications successfully with your corporation's certificate you need to import it using keytool to the cacerts file for your installed JVM. 

The problem is however you may have multiple JVMs installed and the location may differ from machine to machine. The following bash script locates all the cacerts on your machine and adds the appropriate certificate to them.

#!/usr/bin/env sh
 
PROXY_CERT="${HOME}/Your_Company_Proxy_CA.cer"
KEYSTORE_ALIAS="proxy-root"

echo "Finding cacerts..."
KEYSTORES=$(find / -name cacerts -type f -print 2>/dev/null)
 
while IFS= read -r KEYSTORE
do
  echo "Finding alias ${KEYSTORE_ALIAS} from JDK Keystore ${KEYSTORE}"
  sudo keytool -list -alias ${KEYSTORE_ALIAS} -keystore "${KEYSTORE}" -storepass changeit -v && {
    echo "Deleting alias ${KEYSTORE_ALIAS} from JDK Keystore ${KEYSTORE}"
    sudo keytool -delete -alias ${KEYSTORE_ALIAS} -storepass changeit -noprompt -keystore "${KEYSTORE}"
  } || echo "Adding cert to JDK Keystore ${KEYSTORE}"
  
  sudo keytool -import -trustcacerts -storepass changeit -noprompt -alias ${KEYSTORE_ALIAS} -keystore "${KEYSTORE}" -file "${PROXY_CERT}"
done <<< "${KEYSTORES}"

Presenting about Quarkus at the Java Meet Up

Quarkus is a framework designed for Kubernetes to improve the startup time and memory footprint of Java apps running in docker containers

Recursive CTE to List Years Without Gaps

If I have a requirement to list the years from a start year incrementing to the current year without any gap years, I can write the following simple SELECT statement within a CTE.

WITH FINANCIAL_YEARS AS (
    SELECT 2020 AS FINANCIAL_YEAR
    UNION SELECT 2021
    UNION SELECT 2022
    UNION SELECT 2023  
)

However its pretty easy to see how tedious this can be especially when trying to maintain it when a new year ticks over. I found this neat trick using recursive CTEs to avoid gaps in dates and tweaked it to deal with year increments:

WITH FINANCIAL_YEARS AS (
    SELECT '2020-01-01'::DATE AS YEAR_DATE
    UNION ALL
    SELECT DATEADD(YEAR, 1, YEAR_DATE) AS YEAR_DATE
    FROM FINANCIAL_YEARS
    WHERE YEAR_DATE < DATEADD(YEAR, -1, DATEADD(MONTH, 6, CURRENT_DATE())
)
SELECT DATE_PART(YEAR, YEAR_DATE) AS FINANCIAL_YEAR FROM FINANCIAL_YEARS

Its even simpler if you only want the year component or any other kind of numeric increment from a starting number:

WITH FINANCIAL_YEARS AS (
    SELECT 2020 AS FINANCIAL_YEAR
    UNION ALL
    SELECT FINANCIAL_YEAR + 1 AS FINANCIAL_YEAR
    FROM FINANCIAL_YEARS
    WHERE FINANCIAL_YEAR < YEAR(DATEADD(MONTH, 6, CURRENT_DATE()))
)
SELECT FINANCIAL_YEAR FROM FINANCIAL_YEARS