Java ClassLoader getSystemResource() Method



Description

The Java ClassLoader getSystemResource() method find a resource of the specified name from the search path used to load classes.

Declaration

Following is the declaration for java.lang.ClassLoader.getSystemResource() method

public static URL getSystemResource(String name)

Parameters

name − This is the resource name.

Return Value

This method returns a URL object for reading the resource, or null if the resource could not be found.

Exception

NA

Getting Resource from a Class Path Example

The following example shows the usage of java.lang.ClassLoader.getSystemResource() method. In this program, we've retrieved class of a ClassLoaderDemo. Then using getClassLoader(), we get the required ClassLoader and printed class loader class using getClass(). Now considering file.txt being in classpath of the java program, we've retrieved URL of the file using getSystemResource() method and printed the same.

package com.tutorialspoint;

import java.net.URL;

public class ClassLoaderDemo {

   public static void main(String[] args) throws Exception {
     
      Class cls = Class.forName("com.tutorialspoint.ClassLoaderDemo");

      // returns the ClassLoader object associated with this Class
      ClassLoader cLoader = cls.getClassLoader();
    
      System.out.println(cLoader.getClass());
    
      // finds resource
      URL url = cLoader.getSystemResource("file.txt");
      System.out.println("Value = " + url);
   }
} 

Output

Let us compile and run the above program, this will produce the following result −

class jdk.internal.loader.ClassLoaders$AppClassLoader
Value = file:/C:/Users/Tutorialspoint/eclipse-workspace/Tutorialspoint/lib/file.txt

Checking Resource from a Class Path Example

The following example shows the usage of java.lang.ClassLoader.getSystemResource() method. In this program, we've retrieved class of a ClassLoaderDemo. Then using getClassLoader(), we get the required ClassLoader and printed class loader class using getClass(). Now considering a.txt not being in the class path, we've retrieved URL of the file using getSystemResource() method as null and printed the same.

package com.tutorialspoint;

import java.net.URL;

public class ClassLoaderDemo {

   public static void main(String[] args) throws Exception {
     
      Class cls = Class.forName("com.tutorialspoint.ClassLoaderDemo");

      // returns the ClassLoader object associated with this Class
      ClassLoader cLoader = cls.getClassLoader();
    
      System.out.println(cLoader.getClass());

      // finds resource
      URL url = cLoader.getSystemResource("newfolder/a.txt");
      System.out.println("Value = " + url);  
   }
} 

Output

Let us compile and run the above program, this will produce the following result −

class jdk.internal.loader.ClassLoaders$AppClassLoader
Value = null
java_lang_classloader.htm
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