Loading Native Libraries

This section provides a tutorial example on how to load native libraries (DLL files on Windows systems) with loadLibrary() and load() methods.

The JVM instance also allows you to load native libraries into the system to support native methods by using loadLibrary() and load() methods:

Here is tutorial example program testing loadLibrary() and load() methods:

/* RuntimeLoadLibrary.java
 * Copyright (c) HerongYang.com. All Rights Reserved.
class RuntimeLoadLibrary {
   public static void main(String[] a) {
      java.io.PrintStream out = System.out;
      Runtime rt = Runtime.getRuntime();

      try {
         out.println("Loading a native library...");
         // rt.loadLibrary("msvcr71"); // c:/local/jdk/bin/msvcr71.dll
         rt.loadLibrary("java");       // c:/local/jdk/bin/java.dll

         out.println("Loading a native code...");
      } catch (Exception e) {

When executed with JVM in JDK, I got this result, assuming that java.dll and java.exe are exists in folder: \local\jdk\bin:

herong> java RuntimeLoadLibrary

Loading a native library...
Loading a native code...

The test result tells me that:

I don't have any example programs for calling native methods provided in native libraries yet.

Table of Contents

 About This Book

 JVM (Java Virtual Machine) Specification

 Java HotSpot VM - JVM by Oracle/Sun

java.lang.Runtime Class - The JVM Instance

 What Is Runtime?

 Printing Runtime Basic Information

 Running the Garbage Collector Explicitly

 Shutting Down or Terminating the JVM Instance

 Executing System Commands

Loading Native Libraries

 java.lang.System Class - The Operating System

 ClassLoader Class - Class Loaders

 Class Class - Class Reflections

 JVM Runtime Data Areas

 JVM Stack, Frame and Stack Overflow

 Thread Testing Program and Result

 CPU Impact of Multi-Thread Applications

 I/O Impact of Multi-Thread Applications

 CDS (Class Data Sharing)

 Micro Benchmark Runner and JVM Options

 Micro Benchmark Tests on "int" Operations

 Micro Benchmark Tests on "long" Operations

 Micro Benchmark Tests in JIT Compilation Mode

 Micro Benchmark Tests on "float" and "double" Operations

 OpenJ9 by Eclipse Foundation

 JRockit JVM 28.2.7 by Oracle Corporation

 Archived Tutorials


 Full Version in PDF/EPUB