compile

name	compile
description	Build SkyWalking OAP server, run javadoc checks, and verify checkstyle. Use to validate changes before submitting a PR.
argument-hint	[all|backend|javadoc|checkstyle|module-name]

Compile & Verify

Build the project and run static checks matching CI.

Prerequisites

• JDK 11, 17, or 21 (LTS versions)
• Maven 3.6+ (use ./mvnw wrapper)

Maven profiles

• backend (default): Builds OAP server modules
• ui (default): Builds web application
• dist (default): Creates distribution packages
• all: Builds everything including submodule initialization

Commands by argument

all or no argument — full CI build

./mvnw clean flatten:flatten install javadoc:javadoc -B -q -Pall \
  -Dmaven.test.skip \
  -Dcheckstyle.skip \
  -Dgpg.skip

backend — backend only (faster)

./mvnw clean flatten:flatten package -Pbackend,dist -Dmaven.test.skip

javadoc — javadoc check only

Javadoc requires delombok output, so install must run first:

./mvnw clean flatten:flatten install javadoc:javadoc -B -q -Pall \
  -Dmaven.test.skip \
  -Dcheckstyle.skip \
  -Dgpg.skip

Running javadoc:javadoc alone without install will miss errors because ${delombok.output.dir} won't be populated.

checkstyle — checkstyle only

./mvnw -B -q clean flatten:flatten checkstyle:check

Module name — single module build

./mvnw clean flatten:flatten package -pl oap-server/analyzer/<module-name> -Dmaven.test.skip

Reading javadoc output

Maven prefixes all javadoc output with [ERROR], but the actual severity is in the message after the line number. Only lines containing error: fail the build; lines with warning: do not.

[ERROR] Foo.java:42: error: bad use of '>'        ← ACTUAL ERROR (must fix)
[ERROR] Foo.java:50: warning: no @param for <T>   ← WARNING (does not fail build)

Common javadoc errors

Error	Cause	Fix
bad use of '>'	Bare > in javadoc HTML (e.g., -> in <pre> blocks)	Use {@code ->} or -&gt;
heading out of sequence	Heading level skips the expected hierarchy	See heading rules below
reference not found	{@link Foo#bar()} with wrong signature	Match exact parameter types: {@link Foo#bar(ArgType)}

Javadoc heading rules (JDK 13+)

Strict heading validation was introduced in JDK 13. JDK 11 does not enforce it, but JDK 17/21/25 do. Write headings correctly for forward compatibility:

Javadoc location	Start heading at
Class, interface, enum, package, module	<h2>
Constructor, method, field	<h4>
Standalone HTML files (doc-files/)	<h1>

The generated javadoc page uses <h1> for the class name and <h3> for member sections (Methods, Fields, etc.), so class-level subsections must use <h2> and method-level subsections must use <h4> to maintain proper nesting.

CI reference

CI uses JDK 11 on Linux. The dist-tar job runs:

./mvnw clean flatten:flatten install javadoc:javadoc -B -q -Pall \
  -Dmaven.test.skip \
  -Dcheckstyle.skip \
  -Dgpg.skip

The code-style job runs:

./mvnw -B -q clean flatten:flatten checkstyle:check