Why Compare?

Cloudhopper was the de facto Java SMPP library for over a decade. However, it was abandoned in 2015 and hasn't received updates since. As Java has evolved significantly (Java 8 → Java 21), developers need a modern alternative that leverages current language features and best practices.

smpp-core is a clean-room implementation built from the ground up with Java 21, designed to be the actively maintained successor to Cloudhopper.

Feature Comparison

Feature	smpp-core	Cloudhopper
Java Version	Java 21 LTS	Java 8
Last Updated	2025 (Active)	2015 (Abandoned)
Maintenance Status	✓ Actively Maintained	✗ Abandoned
Virtual Threads	✓ Native Support	✗ Not Available
PDU Design	Immutable Records	Mutable Objects
Thread Safety	✓ Built-in (Immutable)	✗ Manual Synchronization
Pattern Matching	✓ Sealed Classes	✗ instanceof Chains
Auto-Reconnect	✓ Built-in	✗ Manual Implementation
TLS/SSL Support	✓ Full Support	Limited
Request Windowing	✓ Built-in	✓ Available
Netty Transport	Netty 4.1.x (Current)	Netty 3.x (EOL)
SMPP 3.4 Compliance	✓ Full	✓ Full
Maven Central	✓ Available	✓ Available
Documentation	✓ Modern & Active	Outdated
License	Apache 2.0	Apache 2.0

Code Comparison

Creating a PDU - Cloudhopper (Mutable)

// Cloudhopper - mutable, not thread-safe
SubmitSm submit = new SubmitSm();
submit.setSourceAddress(new Address((byte)0x01, (byte)0x01, "12345"));
submit.setDestAddress(new Address((byte)0x01, (byte)0x01, "67890"));
submit.setShortMessage(CharsetUtil.encode("Hello", CharsetUtil.CHARSET_GSM));
submit.setRegisteredDelivery((byte)0x01);

Creating a PDU - smpp-core (Immutable)

// smpp-core - immutable, thread-safe by design
SubmitSm submit = SubmitSm.builder()
    .sourceAddress(new Address(TON.INTERNATIONAL, NPI.ISDN, "12345"))
    .destAddress(new Address(TON.INTERNATIONAL, NPI.ISDN, "67890"))
    .shortMessage("Hello", SmppCharset.GSM)
    .registeredDelivery(RegisteredDelivery.SMSC_RECEIPT_REQUESTED)
    .build();

Performance

smpp-core leverages Java 21's virtual threads for handling concurrent connections efficiently. This allows thousands of concurrent sessions without the overhead of platform threads.

Metric	smpp-core	Cloudhopper
Threading Model	Virtual Threads	Platform Threads
Memory per Connection	~1KB (virtual thread)	~1MB (platform thread)
Max Concurrent Sessions	Millions	Thousands
Buffer Handling	Zero-copy (Netty 4)	Copy-based (Netty 3)

Migration Guide

Migrating from Cloudhopper to smpp-core is straightforward:

Update your dependency - Replace Cloudhopper with smpp-core in your pom.xml
Update imports - Change from com.cloudhopper.smpp.* to io.smppgateway.smpp.*
Refactor PDU creation - Use immutable builders instead of setters
Update session handling - Leverage the cleaner callback interfaces

Dependency Change

<!-- Remove Cloudhopper -->
<dependency>
    <groupId>com.cloudhopper</groupId>
    <artifactId>ch-smpp</artifactId>
</dependency>

<!-- Add smpp-core -->
<dependency>
    <groupId>io.smppgateway</groupId>
    <artifactId>smpp-core</artifactId>
    <version>1.0.2</version>
</dependency>

The Verdict

If you're starting a new project or maintaining an existing SMPP application, smpp-core is the clear choice. It's actively maintained, built with modern Java, and designed for today's high-performance requirements.

Get Started with smpp-core