Jetty Integration

This page describes Jetty-specific configuration and behavior.

How It Works

When Jetty is the embedded server, the starter installs a custom RequestLog on the Jetty Server. Jetty invokes the RequestLog after each request completes, and the starter emits the access event through the configured appenders.

Using Jetty

Replace Spring Boot's default Tomcat with Jetty:

Gradle (Kotlin)

implementation("org.springframework.boot:spring-boot-starter-webmvc") {
    exclude(group = "org.springframework.boot", module = "spring-boot-starter-tomcat")
}
implementation("org.springframework.boot:spring-boot-starter-jetty")
implementation("io.github.seijikohara:logback-access-spring-boot-starter:VERSION")

Gradle (Groovy)

implementation('org.springframework.boot:spring-boot-starter-webmvc') {
    exclude group: 'org.springframework.boot', module: 'spring-boot-starter-tomcat'
}
implementation 'org.springframework.boot:spring-boot-starter-jetty'
implementation 'io.github.seijikohara:logback-access-spring-boot-starter:VERSION'

Maven

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-webmvc</artifactId>
    <exclusions>
        <exclusion>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
        </exclusion>
    </exclusions>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-jetty</artifactId>
</dependency>
<dependency>
    <groupId>io.github.seijikohara</groupId>
    <artifactId>logback-access-spring-boot-starter</artifactId>
    <version>VERSION</version>
</dependency>

Jetty 12 Compatibility

This library targets Jetty 12, the version bundled with Spring Boot 4.

Pattern Variables

For the full pattern variable reference, see Getting Started — Pattern Variables.

Jetty-specific behavior:

• Cookies (%{name}c): the starter reads cookies via Jetty's Request.getCookies().
• Request attributes (%{name}r): standard servlet attributes are exposed; Tomcat-specific AccessLog attributes (e.g., org.apache.catalina.AccessLog.RemoteAddr) are not available.
• Remote host (%h): always renders the IP address. Jetty does not perform reverse DNS lookups.
• Request parameters: always exposed as an empty map to avoid consuming the request body.

Known Limitations

Remote Host Resolution

Jetty does not perform reverse DNS lookups. %h always renders an IP address.

Request Parameters

The starter exposes requestParameterMap as an empty map. Calling getParameter* on a Jetty Request would consume the body for application/x-www-form-urlencoded requests, so the starter deliberately skips this path.

TeeFilter

Not supported on Jetty 12

The Jetty 12 RequestLog API operates at the core server level, below the Servlet container. TeeFilter writes its captured buffers as Servlet request attributes, which the Jetty RequestLog cannot read. See Advanced Topics — TeeFilter for TeeFilter usage on Tomcat.

Local Port Strategy

Choose which port the %p variable reports:

logback:
  access:
    local-port-strategy: server  # or 'local'

• server: the port the client addressed (typically derived from the Host header or forwarded headers).
• local: the port of the local interface that accepted the connection.

Behind a Reverse Proxy

Configure Jetty to honor forwarded headers:

server:
  forward-headers-strategy: native

Or, to use Spring's ForwardedHeaderFilter instead:

server:
  forward-headers-strategy: framework

Spring Security Integration

When Spring Security is on the classpath (Servlet only), the starter writes the authenticated username to %u. See Advanced Topics — Spring Security Integration for details. On reactive applications (Spring WebFlux on Jetty), %u always renders as -.

Example Configuration

A production-style configuration for Jetty that writes to a rolling file and excludes operational endpoints:

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <appender name="file" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <file>logs/access.log</file>
        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
            <fileNamePattern>logs/access.%d{yyyy-MM-dd}.log.gz</fileNamePattern>
            <maxHistory>30</maxHistory>
        </rollingPolicy>
        <encoder>
            <pattern>%h %l %u [%t] "%r" %s %b "%{Referer}i" "%{User-Agent}i" %D</pattern>
        </encoder>
    </appender>

    <appender-ref ref="file"/>
</configuration>

Application properties:

logback:
  access:
    filter:
      exclude-url-patterns:
        - /actuator/.*
        - /health

See Also

• Configuration Reference — Full property reference and XML configuration.
• Advanced Topics — TeeFilter, URL filtering, JSON logging, and Spring Security.