Resolving the “Access Restriction” Error for BASE64Encoder in Eclipse

When using sun.misc.BASE64Encoder or sun.misc.BASE64Decoder in your project, Eclipse might show the following error:

Access restriction: The type BASE64Decoder is not accessible due to restriction on required library xxx.jar

This error occurs because sun.misc classes are part of non-public APIs that are discouraged for use in production. Eclipse flags this as a configuration issue by default.

Root Cause

• sun.misc classes are internal, non-public APIs provided by the JDK. Using these classes is discouraged as they are not guaranteed to be available in future Java versions.
• Eclipse enforces these restrictions by default and prevents you from using them.

Solution

Option 1: Change Eclipse Compiler Settings

1. Navigate to Preferences:

   • Go to Window → Preferences → Java → Compiler → Errors/Warnings.

2. Adjust Settings:

   • Locate “Deprecated and restricted API”.
   • Change the setting to Warning or Ignore.
   • Locate “Forbidden and Discouraged References”.
   • Change the setting to Warning or Ignore.

3. Apply Changes:

   • Click Apply and OK.
   • Clean and rebuild your project.

Option 2: Use an Alternative Base64 Encoder

Instead of using sun.misc.BASE64Encoder, switch to a more robust and modern library like Apache Commons Codec or Java 8’s built-in Base64 API.

Using Java 8’s Base64 API

import java.util.Base64;

public class Base64Example {
    public static void main(String[] args) {
        String originalInput = "Hello, World!";
        
        // Encoding
        String encodedString = Base64.getEncoder().encodeToString(originalInput.getBytes());
        System.out.println("Encoded: " + encodedString);

        // Decoding
        byte[] decodedBytes = Base64.getDecoder().decode(encodedString);
        String decodedString = new String(decodedBytes);
        System.out.println("Decoded: " + decodedString);
    }
}

Using Apache Commons Codec

1. Add Dependency:

   • Add Apache Commons Codec to your project.
   • For Maven:

     <dependency>
         <groupId>commons-codec</groupId>
         <artifactId>commons-codec</artifactId>
         <version>1.15</version>
     </dependency>
     

2. Code Example:

   import org.apache.commons.codec.binary.Base64;
   
   public class Base64Example {
       public static void main(String[] args) {
           String originalInput = "Hello, World!";
           
           // Encoding
           String encodedString = Base64.encodeBase64String(originalInput.getBytes());
           System.out.println("Encoded: " + encodedString);
   
           // Decoding
           byte[] decodedBytes = Base64.decodeBase64(encodedString);
           String decodedString = new String(decodedBytes);
           System.out.println("Decoded: " + decodedString);
       }
   }
   

Why Avoid sun.misc.BASE64Encoder?

1. Not Standard:

   • sun.misc.BASE64Encoder is part of JDK internal APIs, and its usage is not recommended.

2. Future Compatibility:

   • These classes might not be available in future versions of Java.

3. Better Alternatives:

   • Java 8’s Base64 API and Apache Commons Codec are standard, widely used, and reliable.

Conclusion

While adjusting Eclipse settings can bypass the error, it’s better to use a modern, standard library for Base64 encoding and decoding. Java 8’s built-in Base64 API or Apache Commons Codec are excellent choices for robust and future-proof implementations.

Would you like more examples or assistance with integrating these libraries? 😊

Ahmad Gohar

With over 18 years of experience in software architecture, Java technologies, and leadership, I specialize in crafting scalable, future-proof solutions for global organizations. Whether it’s transforming legacy systems, building cutting-edge cloud-native applications, or mentoring teams to excel, I’m committed to delivering value-driven results.

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