Java Guides: Learn, Build, Connect and Troubleshoot - Yenra

Set up and learn

Java Development Setup: JDK, Editor and Reproducible Builds

Align command-line Java, the editor and Maven, verify a small project, and diagnose common runtime and compiler mismatches.

Java Tutorial: Build and Test a Study-Plan Calculator

Write a small Java command-line program, understand its inputs and output, and test normal and invalid cases.

Java Data Structures: Choose Lists, Sets, Maps and Queues

Choose collections by ordering, duplicates, lookup and update needs, then run a worked example and check common pitfalls.

Work with databases and server-rendered pages

Practical JDBC: Prepared Statements, Transactions and Rollback

Run a small in-memory database example, bind query parameters, commit a stock transfer and verify a rollback after failure.

Java Persistence Tools: Choosing JDBC, SQL Mapping or ORM

Compare data-access approaches using SQL control, relationships, transaction ownership and observable query behavior.

JSP Maintenance: Servlets, Escaped Views and Jakarta Migration

Build a small servlet-to-JSP application, verify escaped output and view protection, and plan a compatible Jakarta migration.

Build reliable applications

Java Threads: Executors, Virtual Threads and Shared State

Run bounded concurrency examples, understand cancellation and result ordering, and reproduce a lost update before fixing it.

Java Application Security: A Practical Review and Migration Guide

Review trust boundaries, authorization, TLS, secrets and dependencies, and replace obsolete Security Manager assumptions with explicit controls.

Java Network Programming: HTTP, Sockets and Timeouts

Run local HTTP and TCP examples, distinguish connection and read timeouts, and investigate network failures by layer.

Troubleshooting a Slow Java Application

Collect a useful incident baseline, inspect threads and Flight Recorder evidence, and distinguish CPU work from blocking and database waits.

Historical Java resources

These dated announcements and book descriptions document earlier Java platforms and products. Read them as historical coverage; the guides above provide practical starting points for current development.