NoIDE Java Development

play with Java, Kotlin, Gradle without Ecllipse or IntelliJ IDEA.

mainly tested with following tools on Windows 10.

• OpenJDK 18 https://jdk.java.net/18/
• Gradle 7.5.1 https://gradle.org/releases/
• Kotlin https://github.com/JetBrains/kotlin/releases

Compatibility

Java	class file format	Gradle support
7	51	N/A
8	52	2.0
...	...	...
17	61	7.3
18	62	7.5
19	63	TBD@Aug2022

Notes about Java

From JDK11, java can run single *.java file directly. This is useful when running samples in this repository.

From JDK18, java API uses UTF-8 by default. Previously, java API used system's default encoding, which is MS932 (CP932/SJIS) in Japanese version Windows. For JDK17 and below, java compiler cannot compile *.java that contains UTF-8 characters. Following option must be enabled.

// specify source encoding
javac -encoding UTF-8 app.java
// specify source encoding, also modifies encoding for I/Os.
javac -J"-Dfile.encoding=UTF-8" app.java

Even if JDK18 is used, java.exe converts the output in MS932 so that cmd/powershell can display the text properly. To output and print unicode letters properly, change text encoding of your terminal to UTF-8 with chcp 65001 will change the terminal text encoding to utf-8.

Notes about Gradle

Gradle spawns javac, and the messages sent to stdout/err is captured by gradle. This is proably always UTF-8, so it is not readable in Windows. Change the terminal encoding to UTF-8 to fix this.

Gradle launches daemon by default. Add --no-daemon to avoid this. Use gradle --stop to stop daemon.