Create Jackson custom serializers and deserializers

Jackson is a popular library to handle JSON in Java. It has built-in serializers and deserializers to handle common data types. If you want to serialize and deserialize custom types, you can add custom serializers and deserializers. The code in this post is tested using Jackson 2.7.2 and should work with Jackson after 1.7.

The class we want to serialize and deserialize is com.github.zafarkhaja.semver.Version from the jsemver library. We want objects of this class to be serialized as simple strings, e.g. 1.0.0.

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React Native - Build Android APK bundle

This guide is for React Native 0.42.

When working on an app with many static images, I found out that those images were displayed correctly on the emulator, but were blank when testing on a real device. It turns out that those images need to be bundled as assets when running on a device. Google search gave me this SO answer. However, this answer doesn’t work for the RN 0.42 version.

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Return value from Python script to bash shell

We have a legacy Python script to launch a new AWS EC2 instance. The current version of this script just lauches the instance and prints out some logs. Now we need to terminate the EC2 instance created by the script. To use the aws ec2 terminate-instances command, we need to get the instance id.

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Use proxy in Angular CLI

It’s common for an Angular 4 project to use proxy during development to workround the same-orign policy, especially when the server-side is not developed using Node.js. If the Angular 4 project is created using Angular CLI, we can add a proxy.conf.json file in the root directory to configure the proxy.

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