If you want to be an excellent Java programmer, please ask yourself, are you familiar with the following knowledge points?
Object-Oriented Concepts
Abstract Classes and Interfaces
Execution Order of Constructors and Initialization Functions
File Reading and Writing and Serialization
Collections - List, Map, Set
Access Control
Exception Handling
Generic
Java Keywords - Static , Final , volatile, synchronized , transient,
Multithreading and thread synchronization
design patterns such as this super
Reflect
Lambda expressions
If you focus on network distributed applications, then please pay attention to a few questions:
familiarize yourself with some communication protocols, including IP, HTTP, TCP, FTP, UDP, etc., if necessary, read some documents related to RFCs.
Synchronous and asynchronous communication
Sockets communication
RMI and RCP technology
Message queue
API interface - JMC, JDBC, ORM, Hibernate
If your job is Java Web-based application development, then please pay attention to the following issues:
JSP/Servlets
WEB frameworks, such as Structs and Spring
service-based architecture or WEB services - SOAP/Rest
focus on a WEB development blog - —such as @WEB development home
WEB development technology, such as HTML, CSS, Javascript and jQuery
commonly used markup languages, such as XML and JSON
WEB application server, such as Tomcat
cache
WEB application server, such as WebLogic and WebSphere
Some cloud services, such as AWS, SoftLayer , BlueMix and
other practical class libraries, such as Java mail, log4j, Jackson JSON, etc.
If you are interested in Java UI interface development, please pay attention to the following issues:
Applets
some UI frameworks, similar to Swing, SWT, AWT
advanced UI frameworks, similar to JavaFX, JMF
Any Java programmer must know some database related knowledge:
SQL query statement - Inner Outer Joins, Group By, Having, etc.
Stored procedure
trigger
cursor
database driver (JDBC)
JavaBeans