[Android] Application#onTerminate() does not work on actual devices

Application#onTerminate() never fires on production Android devices — a short note with references.

[Android] Application#onCreate is Called Before Activity, Service, and Receiver Objects Are Created

Application#onCreate fires before Activities, Services, and Receivers — placing analytics there can skew session counts.

[Android] RuntimeException on AsyncTask : NullPointerException on doInBackground

Wrap doInBackground in try/catch, return null on failure, and handle it in onPostExecute to stop AsyncTask crashes.

[Android] RuntimeException: Can't create handler inside thread that has not called Looper.prepare()

Fixing the Looper.prepare() crash caused by touching the UI inside AsyncTask#doInBackground — move UI work to onPostExecute.

[Android] How to Change Package Name

A short memo linking to a reference for changing the package name of an Android app.

[Android] Using Crittercism for Real-time Crash Report Monitoring

Integrating Crittercism real-time crash reporting into an Android app, with permissions, init code, and ProGuard rules.

[Android] Crouton - A Library for Easily Displaying Toast-like Notification Views

Introducing Crouton, an Android library for showing Toast-style notification views easily.

[Android] Facebook Authentication Error: com.facebook.FacebookOperationCanceledException: remote_app_id does not match stored id

Fixing the Facebook "remote_app_id does not match stored id" error by logging the correct Key Hash from the running Android app.

[Android] Facebook SDK Error: Failure delivering result ResultInfo{who=null, request=64206, result=0, data=null} to activity {com.example/com.facebook.LoginActivity}: java.lang.NullPointerException

The Facebook SDK for Android v3.0 login NullPointerException is a known bug fixed by upgrading to v3.0.1.

[Android] Calling getWindowManager inside a fragment

Inside a Fragment, get DisplayMetrics via getActivity().getWindowManager() instead of getWindowManager().

[Android] NoSuchMethodError with getActionBar()

To support Android 2.3, use ActionBarSherlock's getSupportActionBar() instead of getActionBar() to avoid NoSuchMethodError.

[Android] How to Hide Action Bar

Hide the ActionBar in an Android Activity with a single getActionBar().hide() call.

[Android] How to Call Activities from External Packages

A quick note on launching an Activity from another package with Intent#setClassName.

[Android] How to Play Videos in Official YouTube App with Explicit Intent

A working Intent for playing videos in the official YouTube Android app using the vnd.youtube: URI.

[Android] How to Remove/Unset Event Listeners

Clear an Android View's OnClickListener by calling setOnClickListener(null).

How to set environment variables PATH and JAVA_HOME to use Android Studio's JDK in Terminal

Set PATH and JAVA_HOME to reuse Android Studio's bundled JDK from Terminal on macOS.

Managing Multiple Java Versions with asdf

Managing Corretto 17 and 18 on M1 macOS with asdf-java, including JAVA_HOME setup.

Using DefaultCredentialsProvider Instead of ProfileCredentialsProvider [AWS SDK for Java]

Switching AWS SDK for Java from `ProfileCredentialsProvider` to `DefaultCredentialsProvider` and its benefits.

Steps to install Java 1.7 on CentOS 6.3

Installing OpenJDK-based Java 1.7 on CentOS 6.3 with yum.

Steps to install Solr 3.6.1 on CentOS 6.3

Installing Solr 3.6.1 on CentOS 6.3 and starting it with the bundled Jetty sample.

java.io.IOException: Missing root object specification in trailer Error with easy-pdf-merge

Working around a PDFBox bug in the easy-pdf-merge npm package by using a maintained fork.

[Eclipse] Java/Tomcat Configuration Change Memo When Switching Projects

A checklist of Java and Tomcat settings to update when switching between Eclipse projects.

[Mac] Installing Eclipse Kepler (4.3) on Mountain Lion + Japanese Localization

Installing Eclipse Kepler on Mountain Lion and localizing it to Japanese with Pleiades.

Gradle Introduction Articles Summary

A link roundup of Gradle introduction articles referenced when starting Android development.

How to Update dependencies in build.gradle.kts and Reflect Changes to gradle.lockfile in Gradle

Add a dependency to build.gradle.kts and reflect it to gradle.lockfile via ./gradlew dependencies --write-locks.

Resolving 'Resolved xxx which is not part of the dependency lock state' Error in ./gradlew build with ./gradlew resolveAndLockAll --write-locks

Fixing the Gradle 'not part of the dependency lock state' error with ./gradlew resolveAndLockAll --write-locks.

Steps to quickly install Elasticsearch on Mac with Homebrew

Install Java and Elasticsearch via Homebrew, start the service, and add the elasticsearch-head plugin.

How to Install Java 8 on Ubuntu 16

Add the webupd8team PPA and install Oracle Java 8 on Ubuntu 16.04 for a serposcope host.

Steps to Install Search Ranking Checker Tool Serposcope on Ubuntu

Install the Serposcope 2.6.0 deb package on Ubuntu and start the service to expose the rank checker.

[Java] How to Cast ArrayList#toArray to String[]

A short snippet for casting ArrayList#toArray to String[] in Java.

[Java] Calendar Class for Handling Date and Time Information

A short memo of reference links for handling dates and times in Java with the Calendar class.

[Java] Converting Current Date and Time to String

A short SimpleDateFormat snippet for converting the current date and time to a string in Java 1.4.

[Java] Measuring Program Execution Time

Measure Java execution time in ms by wrapping the target block with System.currentTimeMillis().

[Java 1.4] How to Embed Lists in PreparedStatement IN Clauses

Helper snippets for embedding a list into a PreparedStatement IN clause in Java 1.4.

[Java 1.4] How to Embed Lists in PreparedStatement IN Clause

Placeholder helper snippets for embedding a list into a PreparedStatement IN clause in Java 1.4.

[Java] Dynamic Class Generation and Method Invocation Using Reflection

A short set of reference links for dynamic class generation and method invocation via Java reflection.

Accelerating Java and Spring Boot Web App Development with AI Coding Agents — Repository Practices for the Claude Code and Codex Era

The biggest lever for running AI coding agents fast on Java and Spring Boot is not model selection but shaping the repository so the AI cannot misread it. Pin the boundaries with Spring Modulith and hexagonal architecture, enforce them mechanically with ArchUnit and Modulith verify in CI, reproduce databases locally with Testcontainers @ServiceConnection, and expose your running app to AI through the Spring AI 1.1 MCP Server Boot Starter. This post lays out the full setup for AI-native Java and Spring Boot development.

Famous OSS Web Applications Built with Java and Spring Boot — Notable Examples by Category

Spring Boot powers a remarkable range of open-source web applications, from teaching apps like Spring PetClinic to production platforms like ThingsBoard, Apache Fineract, and Apereo CAS. The right project to study depends on whether you want a reference, a production base, or an internal developer tool, so this post groups them by category.

[Java] Differences Between StringUtils.isEmpty and StringUtils.isBlank

A quick comparison of StringUtils.isEmpty vs isBlank, focusing on whitespace handling.

[Android] How to fix garbled characters in keytool command

Fix garbled keytool output on Mac by setting `_JAVA_OPTIONS` to UTF-8 file encoding.

Apache Log4j Vulnerability and Elasticsearch

How CVE-2021-44228 affects Elasticsearch, and the response needed for clusters running on JDK 8 or below.

[Java][Play!] Retrieving Messages Defined in message Using Messages.get()

Looking up conf/messages entries from a Play! controller with Messages.get().

[Mac] Setup Method for Using Sakura VPS VNC Console on Mountain Lion

To use the Sakura VPS VNC console on Mountain Lion, revert Java from 7 back to Java 6.

Points to check when configuration file specified in Serposcope's Dserposcope.conf is not loaded

Serposcope ignored `-Dserposcope.conf` because I had the `java` command options in the wrong order.

[Solr] JapanesePartOfSpeechStopFilterFactory : java.lang.ClassCastException: java.lang.String cannot be cast to [C

Notes on the java.lang.ClassCastException from Solr's JapanesePartOfSpeechStopFilterFactory.

[Tomcat] How to Change Port Number Configuration

Change Tomcat's port from 8080 to 80 by editing the Connector in tomcat/conf/server.xml.