Sun Java SE Development Kit (JDK)

      JDK (Java Development Kit)It is a software development kit (SDK) for the Java language. It is a software used to build a Java application development environment. Currently, if you want to run and compile Java programs, using JDK is the only way. JAVA JDK has won high popularity due to its simple operation, practicality, stability, security and efficiency. Huajun Software Park provides you with JDK (Java Development Kit) free download!

JAVA JDK FAQ

​​ 1.How to uninstall JAVA JDK

Many friends may have the need to uninstall the JAVA JDK software, but they are afraid that they will not be able to install it next time after uninstalling it. How to uninstall JAVA efficiently JDK software? The editor will bring you detailed uninstallation methods. After uninstalling, if you still want to install it, the installation can proceed smoothly!

We need to open the control panel of the computer. You can use the shortcut keys to open it. First press the Win key + R key, and then enter control + enter in the pop-up interface to open the control panel. Then we click on the programs and functions of the control panel interface, and you can find all the java options in the program. We right-click the option to uninstall, and then select uninstall.

​ 2. How to test whether the JDK in this machine can run normally?

​​ 1. Open the Windows Run dialog box (shortcut key: Win key + R key to the left of the Alt key), enter cmd and press Enter. As shown below.

​ ​ 2. Enter java -version in the command window that opens. If the Java version number and other information appears as shown in the figure below, the Java SE JDK installation is successful.

The red arrow indicates that the currently installed JDK version is 1.8, and the official name is Java SE JDK 8.

How to use JAVA JDK

We downloaded and installed JAVA on this site After using the JDK software, if you want to use the software, you also need to configure the jdk environment variables. Many friends don’t know how to use it. The editor will bring you detailed configuration methods. let's see.

​​Configuring environment variables;

Add environment variables in "My Computer" - "Properties" - "Advanced System Settings" - "Environment Variables";

                      Add the two variables as shown in the figure below, and the additional content of PATH;

After completing the above installation and configuration, enter the command prompt window to verify;

​ ​ java -version command to view the current JDK version:

​ ​ java command, view command usage;

javac command, view command usage;

At this point, the Java (JDK) environment configuration under Windows system is completed!

JAVA JDK official functions

Java compiler (javac)

Compile Java source code (.java file) into JVM executable bytecode (.class file).

Supports syntax checking, annotation processing (such as @Override) and generic erasure.

Java Runtime Environment (JRE)

JVM (Java Virtual Machine): cross-platform execution of bytecode, supports just-in-time compilation (JIT) and garbage collection (GC).

Core class library: Provides APIs such as java.lang (basic types), java.util (collection framework), java.io (IO operations), and enterprise-level libraries (such as javax.servlet).

Development tool chain

Debugging tools: jdb (command line debugger), jconsole/VisualVM (graphical monitoring).

Documentation tool: javadoc (generates HTML documentation from code comments).

Packaging tools: jar (packaged as JAR files), moditect (Java 9+ modular support).

Modular system (Java 9+)

Define modules through module-info.java to resolve class path dependency conflicts.

JAVA JDK official features

Cross-platform development

The same bytecode can be run on Windows, Linux, macOS and other systems (requires corresponding JVM).

Supports local interface (JNI), allowing calling C/C++ code.

Concurrent programming support

Provides Thread class, Runnable interface, and ExecutorService (thread pool management).

Supports synchronization mechanism (synchronized, ReentrantLock) and asynchronous programming (CompletableFuture).

Security enhancements

The encryption library (javax.crypto) supports AES, RSA and other algorithms.

The sandbox mechanism (SecurityManager) limits code permissions.

The certificate management tool keytool generates a keystore (Keystore).

Performance optimization tools

JIT compilation dynamically converts hot code into machine code.

AOT compilation (Java 11+) compiles bytecode into native code ahead of time.

GC log analysis (-Xlog:gc*) optimizes heap memory configuration.

JAVA JDK installation tutorial

​ ​ 1. First download the JAVA JDK official software package from this site. After the download is completed, you will get a compressed package in zip format. After decompression is completed, we double-click to run the exe file and enter the installation wizard interface, as shown in the figure below. Click Next to continue the installation.

​ ​ 2. Enter the JAVA JDK software installation location selection interface. You can install it to the C drive by default or click Change to select the appropriate installation location, and then click Next.

3. Enter the JAVA JDK software target folder interface. You can install it by default or click to change it, and then click Next

​​ 4. JAVA JDK is being installed, as shown in the picture below, we need to wait for the installation progress bar to be completed. But don't worry, the installation speed is very fast and it only takes a short time to complete the installation.

5. After the JAVA JDK software installation is completed, the interface in the picture below appears, indicating that the software has been successfully installed on your computer. We can close the installation interface by clicking the close option at the top of the interface.

Installation summary: After downloading Java (JDK) from this site, run the exe file and enter the installation wizard. Follow the prompts to install. You can choose the default installation location or a customized installation location. It is recommended that you use the default location for the target folder to facilitate finding files later. After waiting for a while, the installation will be completed.

JAVA JDK update log

JEP 339: EdDSA digital signature algorithm

JEP 360: Sealed Class (Preview)

JEP 371: Hidden Classes

JEP 372: Remove Nashorn JavaScript engine

JEP 373: Reimplementation of Legacy DatagramSocket API

JEP 374: Reimplementation of DatagramSocket API

JEP 375: Instance Pattern Matching (Second Preview)

JEP 377: ZGC: A scalable low-latency garbage collector

JEP 378: Text blocks

JEP 379: Low pause time garbage collector

JEP 381: Remove Solaris and SPARC ports

JEP 383: External Memory Access API (Second Built-in)

JEP 384: Records (Second Preview)

JEP 385: Deprecated RMI activation removal