Jave SE Tutorials & Examples

Java SE Tutorials & Examples

1. Basic

A brief in Java string format

Brief about Java string format syntax. How to print strings into a table-like style.

Play with Java byte array

Tutorial on how to init byte array and convert between byte array and String for different purposes.

How to simply print object content to String in Java

Simplest way to print content of an Java object into a String. It's useful for debug and log.

How to invoke an object’s private method in Java

Two ways to invoke a instance's private method. It's mainly useful in unit test.

Understand Java primitives wrapper class comparison

Understand how the JVM autoboxes a primitive type to its wrapper class, avoid the comparison pitfall.

Generate a random String of specified length in Java

Generate a randome String of certain length with 1 line code

2. Regular Expression

The basic regular expression API in Java

How to use regular expression in Java.

Case-insensitive regular expression in Java

Using Pattern flag for case insensitive String match

Use Java regular expression for multiline string

The way to use regular express to match multi-line String. The main difference between single and multiple line mode.

3. Generic Type

How to create instance from generic type

How to create object from generic type parameter in Java

How to understand < ? extends Parent> in Java Generics

Understand when to use <? extends Parent> in practical

How to understand < ? super Child> in Java Generics

Understand when to use <? super Child> in practical

4. Concurrency

Low-level synchronization in Java

Understand low-level sync mechanism in Java (synchronized,wait(),notify())

In practical the most used thread methods before thread.start()

Some most used thread instance methods in real-life project before start the thread

How to use Java parallel Fork/Join framework - Hello world example

The hello wolrd level example using fork/join framework to process a big collection of data

Break down package java.util.concurrent.locks

Understand locks hierarchy in Java by going through java.util.concurrent.locks package

5. IO/NIO

Glob in Java file name related match

Rules on glob match on file name filtering

Break down class "Files" of java 7 NIO.2

Disintegration of core Java 7 NIO2 class "Files". Leave you no doubts with most used file operations

6. JDBC/JavaDB(Derby)

How to use embedded Java DB (Derby) in maven project

How to use embedded Java DB(Derby) in maven project

How to use H2 embedded DB in spring project

How to use embedded H2 database. This demo uses H2 in a spring project, and it's pretty much same for all maven projects.

Understand Glassfish JDBC configuration by inspecting JDBC DataSource API

A better way to understand glassfish jdbc config by inspecting the JDBC DataSource hierarchy

7. Lambda and Stream

Method Reference in Java 8

What is "method reference" in Java 8

Break down package java.util.stream

Understand the main notions of stream new in Java 8 by going thought java.util.stream package