国产av日韩一区二区三区精品,成人性爱视频在线观看,国产,欧美,日韩,一区,www.成色av久久成人,2222eeee成人天堂

Table of Contents
What's Included in the JDK?
Why Do Developers Need the JDK?
How to Check if You Have the JDK Installed
Choosing the Right JDK Version
Home Java javaTutorial What is the JDK?

What is the JDK?

Jun 25, 2025 pm 04:05 PM
java jdk

JDK (Java Development Kit) is a software development environment for developing Java applications and applets, and includes tools and libraries required to compile, debug and run Java programs. Its core components include Java compiler (javac), Java runtime environment (JRE), Java interpreter (java), debugger (jdb), document generation tools (javadoc) and packaging tools (such as jar and jmod). Developers need JDK to write, compile Java code and develop with the help of IDE; without JDK, Java applications cannot be built or modified. You can check whether the installation and version information by entering javac -version and java -version in the terminal. When choosing a JDK version, you should consider project requirements, such as long-term support versions (Java 8, 11, 17) or new feature versions, and pay attention to the licensing differences between different vendors (such as Oracle, OpenJDK, Adoptium).

What is the JDK?

JDK stands for Java Development Kit. It's a software development environment used for developing Java applications and apples. If you're working with Java, you can't do much without it — it includes the tools, executables, and binaries that allow you to compile, debug, and run Java programs.

What's Included in the JDK?

The JDK isn't just one thing — it's a collection of several important components:

  • Java Compiler (javac) : Turns your Java code into bytecode.
  • Java Runtime Environment (JRE) : Contains the Java Virtual Machine (JVM) and class libraries needed to run compiled Java programs.
  • Java Interpreter (java) : Executes the compiled Java bytecode.
  • Debugger (jdb) : Helps you find and fix bugs in your code.
  • Java Documentation Tool (javadoc) : Generates API documentation from source code comments.
  • Packaging Tools : Like jar and jmod , which help bundle and manage modules.

So when you install the JDK, you get everything you need to start writing, compiling, and running Java code right away.

Why Do Developers Need the JDK?

If you're building Java applications from scratch, the JDK is essential. Here's why:

  • You can write and compile Java code into .class files that the JVM understands.
  • It gives you access to development tools like profilers, monitoring utilities, and more.
  • Most IDEs (like IntelliJ IDEA or Eclipse) require the JDK to be installed so they know where to find the compiler and libraries.

Without the JDK, you could still run Java apps using just the JRE, but you wouldn't be able to build or modify them.

How to Check if You Have the JDK Installed

You don't always have to download and install the JDK manually — sometimes it comes bundled with other tools or IDEs. But to confirm what version you have (or if you have it at all), open up your terminal or command prompt and type:

 javac -version

This will tell you whether the Java compiler is available and which version you're using. If it's not found, you'll need to download and set it up yourself.

Also, check:

 java -version

That shows you the runtime version, which should match your JDK version unless you have multiple versions installed.

Choosing the Right JDK Version

There are different versions of the JDK, and some are better suited for certain projects than others. For example:

  • Long-term support (LTS) versions like Java 8, 11, or 17 are good for production environments.
  • Newer versions offer modern features but may not be supported as long.
  • Different vendors (like Oracle, OpenJDK, Adoptium) offer their own builds — some are free for commercial use, others aren't.

It's worth checking what your project or team requires before downloading one.

Basically that's it.

The above is the detailed content of What is the JDK?. For more information, please follow other related articles on the PHP Chinese website!

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undress AI Tool

Undress AI Tool

Undress images for free

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

Hot Topics

PHP Tutorial
1502
276
How to handle transactions in Java with JDBC? How to handle transactions in Java with JDBC? Aug 02, 2025 pm 12:29 PM

To correctly handle JDBC transactions, you must first turn off the automatic commit mode, then perform multiple operations, and finally commit or rollback according to the results; 1. Call conn.setAutoCommit(false) to start the transaction; 2. Execute multiple SQL operations, such as INSERT and UPDATE; 3. Call conn.commit() if all operations are successful, and call conn.rollback() if an exception occurs to ensure data consistency; at the same time, try-with-resources should be used to manage resources, properly handle exceptions and close connections to avoid connection leakage; in addition, it is recommended to use connection pools and set save points to achieve partial rollback, and keep transactions as short as possible to improve performance.

How to work with Calendar in Java? How to work with Calendar in Java? Aug 02, 2025 am 02:38 AM

Use classes in the java.time package to replace the old Date and Calendar classes; 2. Get the current date and time through LocalDate, LocalDateTime and LocalTime; 3. Create a specific date and time using the of() method; 4. Use the plus/minus method to immutably increase and decrease the time; 5. Use ZonedDateTime and ZoneId to process the time zone; 6. Format and parse date strings through DateTimeFormatter; 7. Use Instant to be compatible with the old date types when necessary; date processing in modern Java should give priority to using java.timeAPI, which provides clear, immutable and linear

Comparing Java Frameworks: Spring Boot vs Quarkus vs Micronaut Comparing Java Frameworks: Spring Boot vs Quarkus vs Micronaut Aug 04, 2025 pm 12:48 PM

Pre-formanceTartuptimeMoryusage, Quarkusandmicronautleadduetocompile-Timeprocessingandgraalvsupport, Withquarkusoftenperforminglightbetterine ServerLess scenarios.2.Thyvelopecosyste,

Understanding Network Ports and Firewalls Understanding Network Ports and Firewalls Aug 01, 2025 am 06:40 AM

Networkportsandfirewallsworktogethertoenablecommunicationwhileensuringsecurity.1.Networkportsarevirtualendpointsnumbered0–65535,withwell-knownportslike80(HTTP),443(HTTPS),22(SSH),and25(SMTP)identifyingspecificservices.2.PortsoperateoverTCP(reliable,c

How does garbage collection work in Java? How does garbage collection work in Java? Aug 02, 2025 pm 01:55 PM

Java's garbage collection (GC) is a mechanism that automatically manages memory, which reduces the risk of memory leakage by reclaiming unreachable objects. 1.GC judges the accessibility of the object from the root object (such as stack variables, active threads, static fields, etc.), and unreachable objects are marked as garbage. 2. Based on the mark-clearing algorithm, mark all reachable objects and clear unmarked objects. 3. Adopt a generational collection strategy: the new generation (Eden, S0, S1) frequently executes MinorGC; the elderly performs less but takes longer to perform MajorGC; Metaspace stores class metadata. 4. JVM provides a variety of GC devices: SerialGC is suitable for small applications; ParallelGC improves throughput; CMS reduces

Using HTML `input` Types for User Data Using HTML `input` Types for User Data Aug 03, 2025 am 11:07 AM

Choosing the right HTMLinput type can improve data accuracy, enhance user experience, and improve usability. 1. Select the corresponding input types according to the data type, such as text, email, tel, number and date, which can automatically checksum and adapt to the keyboard; 2. Use HTML5 to add new types such as url, color, range and search, which can provide a more intuitive interaction method; 3. Use placeholder and required attributes to improve the efficiency and accuracy of form filling, but it should be noted that placeholder cannot replace label.

go by example http middleware logging example go by example http middleware logging example Aug 03, 2025 am 11:35 AM

HTTP log middleware in Go can record request methods, paths, client IP and time-consuming. 1. Use http.HandlerFunc to wrap the processor, 2. Record the start time and end time before and after calling next.ServeHTTP, 3. Get the real client IP through r.RemoteAddr and X-Forwarded-For headers, 4. Use log.Printf to output request logs, 5. Apply the middleware to ServeMux to implement global logging. The complete sample code has been verified to run and is suitable for starting a small and medium-sized project. The extension suggestions include capturing status codes, supporting JSON logs and request ID tracking.

Comparing Java Build Tools: Maven vs. Gradle Comparing Java Build Tools: Maven vs. Gradle Aug 03, 2025 pm 01:36 PM

Gradleisthebetterchoiceformostnewprojectsduetoitssuperiorflexibility,performance,andmoderntoolingsupport.1.Gradle’sGroovy/KotlinDSLismoreconciseandexpressivethanMaven’sverboseXML.2.GradleoutperformsMaveninbuildspeedwithincrementalcompilation,buildcac

See all articles