Runtime load(String) in Java

load(String): This method is available in the java.lang.Runtime class of Java.

Syntax:

void java.lang.Runtime.load(String filename)

This method takes one argument. This method loads the native library specified by the filename argument.

The filename argument must be an absolute path name.

Parameters: One parameter is required for this method.

filename: the file to load.

Throws:

1. SecurityException - if a security manager exists and its checkLink method doesn't allow loading of the specified dynamic library.

2. UnsatisfiedLinkError - if either the filename is not an absolute path name, the native library is not statically linked with the VM or the library cannot be mapped to a native library image by the host system.

3. NullPointerException - if filename is null.

Approach 1: When no exception

Java

package com.Runtime;

public class Runtimeload {
    public static void main(String[] args) {

        Runtime runtime = Runtime.getRuntime();

        String filename = "C:/Windows/System32/crypt32.dll";
        runtime.load(filename);
        System.out.println("Successfully loads");

    }
}

Output:

Successfully loads

Approach 2: UnsatisfiedLinkError

Java

package com.Runtime;

public class Runtimeload {
    public static void main(String[] args) {

        Runtime runtime = Runtime.getRuntime();

        String filename = "C:\\Program Files\\Notepad++\\notepad.exe";
        runtime.load(filename);
        System.out.println("Successfully loads");

    }
}

Output:

Exception in thread "main" java.lang.UnsatisfiedLinkError: Can't load library: C:\Program Files\Notepad++\notepad.exe
	at java.base/java.lang.ClassLoader.loadLibrary(ClassLoader.java:2411)
	at java.base/java.lang.Runtime.load0(Runtime.java:747)
	at java.base/java.lang.Runtime.load(Runtime.java:734)
	at com.Runtime.Runtimeload.main(Runtimeload.java:9)

Approach 3: NullPointerException

Java

package com.Runtime;

public class Runtimeload {
    public static void main(String[] args) {

        Runtime runtime = Runtime.getRuntime();

        String filename =null;
        runtime.load(filename);
        System.out.println("Successfully loads");

    }
}

Output:

Exception in thread "main" java.lang.NullPointerException
	at java.base/java.io.File.<init>(File.java:279)
	at java.base/java.lang.Runtime.load0(Runtime.java:742)
	at java.base/java.lang.Runtime.load(Runtime.java:734)
	at com.Runtime.Runtimeload.main(Runtimeload.java:9)

Some other methods of Runtime

addShutdownHook(Thread): This method registers a new virtual machine shutdown hook.

availableProcessors(): This method returns the number of processors available to the Java virtual machine.

exec(String): This method executes the specified string command in a separate process.

exec(String[]): This method executes the specified command and arguments in a separate process.

exec(String, String[]): This method executes the specified string command in a separate process with the specified environment.

exec(String[], String[]): This method executes the specified command and arguments in a separate process with the specified environment.

exec(String, String[], File): This method executes the specified string command in a separate process with the specified environment and working directory.

exec(String[], String[], File): This method executes the specified command and arguments in a separate process with the specified environment and working directory.

gc(): This method runs the garbage collector in the Java Virtual Machine.

Runtime.getRuntime(): This method returns the runtime object associated with the current Java application.

halt(int): This method forcibly terminates the currently running Java virtual machine.

load(String): This method loads the native library specified by the filename argument.

loadLibrary(String): This method loads the native library specified by the libname argument.

maxMemory(): This method returns the maximum amount of memory that the Java virtual machine will attempt to use.

removeShutdownHook(Thread): This method De-registers a previously registered virtual machine shutdown hook.

runFinalization(): This method runs the finalization methods of any objects pending finalization.

version(): This method returns the version of the Java Runtime Environment as a Version.

exit(int): This method terminates the currently running Java virtual machine by initiating its shutdown sequence. This method never returns normally.

freeMemory(): This method returns the amount of free memory in the Java Virtual Machine.

totalMemory(): This method returns the total amount of memory in the Java virtual machine.