GzipHandler.setCompressionLevel() method not available in latest release

Issue

Jetty version : 11.0.15

Java version : 17

I am trying to update my Spring boot project to 3.1.0. I need GZip compression for reduce response data size. For that I use spring-boot-starter-jetty instead of tomcat server. It download jettry version 11.0.15.

GZip config file

import org.eclipse.jetty.server.Server;
import org.eclipse.jetty.server.handler.HandlerCollection;
import org.eclipse.jetty.server.handler.gzip.GzipHandler;
import org.eclipse.jetty.util.thread.QueuedThreadPool;
import org.springframework.boot.web.embedded.jetty.JettyServletWebServerFactory;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import java.io.IOException;
import java.util.zip.Deflater;

@Configuration
public class GZipConfig {

    @Bean
    public JettyServletWebServerFactory jettyServletWebServerFactory() throws IOException {
        JettyServletWebServerFactory factory = new JettyServletWebServerFactory();
        factory.addServerCustomizers((Server server) -> {
            GzipHandler gzipHandler = new GzipHandler();
            gzipHandler.setInflateBufferSize(1);
            gzipHandler.setHandler(server.getHandler());
            gzipHandler.setIncludedMethods("GET", "POST", "DELETE", "PUT");
            gzipHandler.setCompressionLevel(Deflater.BEST_SPEED);

            HandlerCollection handlerCollection = new HandlerCollection(gzipHandler);
            server.setHandler(handlerCollection);
        });

        QueuedThreadPool threadPool = new QueuedThreadPool();
        threadPool.setMinThreads(10);
        threadPool.setMaxThreads(200);
        threadPool.setIdleTimeout(600000);
        factory.setThreadPool(threadPool);

        return factory;
    }

}

Versions before jetty 9.x has GzipHandler.setCompressionLevel() method to set compression level. But it is not available since jetty 10.x.

How I set compression level in latest jettry server versions.

Solution

The GzipHandler now uses an InflaterPool and DeflaterPool, so you will need to configure this pool instead of using a gzipHandler.setCompressionLevel() method.

Instead use something like this

gzipHandler.setDeflaterPool(new DeflaterPool(CompressionPool.DEFAULT_CAPACITY, Deflater.BEST_SPEED, true));

You could also just create the DeflaterPool and add it as a bean on the server and it will be shared by any components which also need the pool, and it will be automatically detected by the GzipHandler without using setDeflaterPool() explictly.

Answered By - Lachlan