本指南介绍如何在项目中加入基于 KSP 的注解处理器、如何使用 KSP API 创建自己的处理器，以及在哪里找到生成的代码。
为项目加入基于 KSP 的处理器
要使用外部处理器，请在 build.gradle(.kts) 的 plugins {} 块加入 KSP。如果仅某个模块需要处理器，就修改该模块的构建文件。
Kotlin DSL
// build.gradle.kts
plugins {
kotlin("jvm") version "%kotlinVersion%"
id("com.google.devtools.ksp") version "%kspVersion%"
}Groovy DSL
// build.gradle
plugins {
id 'org.jetbrains.kotlin.jvm' version '%kotlinVersion%'
id 'com.google.devtools.ksp' version '%kspVersion%'
}最新 KSP 版本见 GitHub Releases。源文中的 %kotlinVersion% 和 %kspVersion% 是网站构建变量；2026-10-03 的官方页面显示 Kotlin 2.4.20、KSP 2.3.10。
在顶层 dependencies {} 块加入需要的处理器。下面使用 Moshi，其他处理器的配置方式相同。
// build.gradle.kts
dependencies {
ksp("com.squareup.moshi:moshi-kotlin-codegen:1.15.2")
}// build.gradle
dependencies {
ksp 'com.squareup.moshi:moshi-kotlin-codegen:1.15.2'
}ksp(...) 只处理应用源码。测试源码应使用 kspTest(...)。ksp(...) 仅适用于单平台项目；Kotlin Multiplatform 各目标与编译单元的配置见 KSP 与 Kotlin Multiplatform。
创建自己的处理器
接下来创建一个生成 helloWorld() 函数的简单注解处理器。它的实际用途有限，但可以演示处理器与注解的基本工作方式。
将 KSP 加入项目
在 IntelliJ IDEA 中依次选择 File → New → Project，在左侧选择 Kotlin，构建系统选择 Gradle，然后点击 Create。
在项目的 build.gradle(.kts) 中加入 KSP 插件：
// build.gradle.kts
plugins {
kotlin("jvm") version "%kotlinVersion%"
id("com.google.devtools.ksp") version "%kspVersion%" apply false
} // build.gradle
plugins {
id 'org.jetbrains.kotlin.jvm' version '%kotlinVersion%'
id 'com.google.devtools.ksp' version '%kspVersion%' apply false
}创建注解
在项目根目录创建模块：选择 File → New → Module，左侧选择 Kotlin，名称填写 annotations，构建系统选择 Gradle，点击 Create。
在模块中创建 HelloWorldAnnotation.kt，声明 HelloWorldAnnotation 注解：
// annotations/src/main/kotlin/com/example/annotations/HelloWorldAnnotation.kt
package com.example.annotations
annotation class HelloWorldAnnotation创建并注册处理器
在项目根目录创建另一个名为 processor 的模块。在其构建文件中加入 KSP API 和刚声明的注解依赖：
// processor/build.gradle.kts
plugins {
kotlin("jvm")
}
dependencies {
implementation(project(":annotations"))
implementation("com.google.devtools.ksp:symbol-processing-api:2.3.6")
} // processor/build.gradle
plugins {
id 'org.jetbrains.kotlin.jvm'
}
dependencies {
implementation project ':annotations'
implementation 'com.google.devtools.ksp:symbol-processing-api:2.3.6'
}在 processor 模块创建 HelloWorldProcessor.kt，写入以下代码：
// processor/src/main/kotlin/HelloWorldProcessor.kt
class HelloWorldProcessor(val codeGenerator: CodeGenerator) : SymbolProcessor {
// 1️⃣ process() function
override fun process(resolver: Resolver): List<KSAnnotated> {
resolver
.getSymbolsWithAnnotation("com.example.annotations.HelloWorldAnnotation")
.filter { it.validate() }
.filterIsInstance<KSFunctionDeclaration>()
.forEach { it.accept(HelloWorldVisitor(), Unit) }
return emptyList()
}
// 2️⃣ Visitor
inner class HelloWorldVisitor : KSVisitorVoid() {
override fun visitFunctionDeclaration(function: KSFunctionDeclaration, data: Unit) {
createNewFileFrom(function).use { file ->
file.write(
"""
fun helloWorld(): Unit {
println("Hello world from function generated by KSP")
}
""".trimIndent()
)
}
}
}
// 3️⃣ createNewFileFrom() function
private fun createNewFileFrom(function: KSFunctionDeclaration): OutputStream {
return codeGenerator.createNewFile(
dependencies = createDependencyOn(function),
packageName = "",
fileName = "GeneratedHelloWorld"
)
}
// 3️⃣ createDependencyOn() function
private fun createDependencyOn(function: KSFunctionDeclaration): Dependencies {
return Dependencies(aggregating = false, function.containingFile!!)
}
}
// Utility function for writing string to OutputStream
fun OutputStream.write(string: String): Unit {
this.write(string.toByteArray())
}加入 IDE 建议的导入语句。Resolver 和 Dependencies 必须来自 com.google.devtools.ksp.processing。也可以将下面的导入语句复制到文件顶部：
// processor/src/main/kotlin/HelloWorldProcessor.kt
import com.google.devtools.ksp.processing.CodeGenerator
import com.google.devtools.ksp.processing.Dependencies
import com.google.devtools.ksp.processing.Resolver
import com.google.devtools.ksp.processing.SymbolProcessor
import com.google.devtools.ksp.symbol.KSAnnotated
import com.google.devtools.ksp.symbol.KSFunctionDeclaration
import com.google.devtools.ksp.symbol.KSVisitorVoid
import com.google.devtools.ksp.validate
import java.io.OutputStream代码分为三个部分。
process()包含处理器的主要逻辑：查找所有带有HelloWorldAnnotation的符号，为每个符号调用HelloWorldVisitor。它返回尚未处理、需要在后续轮次继续处理的符号列表；本例可以返回emptyList()。详情见多轮处理。- 处理器通过访问者遍历 KSP 所提供的 Kotlin 抽象语法树（AST）视图。这里
HelloWorldVisitor就是访问者。注解仅用于函数，因此只重写visitFunctionDeclaration()。KSVisitorVoid是 KSP 提供的可重写访问者之一，也可以实现KSVisitor<D, R>接口来创建访问者。 createNewFileFrom()创建生成代码的文件；createDependencyOn()让输出文件依赖使用注解的源文件。KSP 如何创建和管理文件，见CodeGenerator接口源码。
接着创建 HelloWorldProcessorProvider.kt，声明继承 SymbolProcessorProvider 的提供者类：
// processor/src/main/kotlin/HelloWorldProcessorProvider.kt
import com.google.devtools.ksp.processing.SymbolProcessor
import com.google.devtools.ksp.processing.SymbolProcessorEnvironment
import com.google.devtools.ksp.processing.SymbolProcessorProvider
class HelloWorldProcessorProvider : SymbolProcessorProvider {
override fun create(environment: SymbolProcessorEnvironment): SymbolProcessor {
return HelloWorldProcessor(environment.codeGenerator)
}
}注册提供者：在 resources/META-INF/services 目录创建名为 com.google.devtools.ksp.processing.SymbolProcessorProvider 的文件，写入提供者的完全限定名：
## processor/src/main/resources/META-INF/services/com.google.devtools.ksp.processing.SymbolProcessorProvider
HelloWorldProcessorProvider使用处理器
现在创建调用方模块，让处理器根据带注解的元素生成代码。
在项目根目录创建 app 模块。在它的构建文件的 plugins {} 中加入 KSP 插件，在 dependencies {} 中加入处理器和注解，例如：
// app/build.gradle.kts
plugins {
kotlin("jvm")
id("com.google.devtools.ksp")
}
dependencies {
implementation(project(":annotations"))
ksp(project(":processor"))
} // app/build.gradle
plugins {
id 'com.google.devtools.ksp'
}
dependencies {
implementation project (':annotations')
ksp project (':processor')
}在项目级 settings.gradle(.kts) 中确认所有子模块已经自动加入：
// settings.gradle.kts
include("annotations")
include("app")
include("processor") // settings.gradle
include 'processor'
include 'annotations'
include 'app'在 app 模块创建 Main.kt 并加入以下代码：
// app/src/main/kotlin/Main.kt
import com.example.annotations.HelloWorldAnnotation
@HelloWorldAnnotation
fun main() {
helloWorld()
}main() 调用了尚不存在的 helloWorld()；此时 IDE 会提示未定义引用，这是预期行为。构建并运行项目时，KSP 才会生成这个函数。
运行程序后，控制台应显示：
Hello world from function generated by KSPKSP 在 GeneratedHelloWorld.kt 中生成代码，文件位置为：
app/build/generated/ksp/main/kotlin/GeneratedHelloWorld.kt查看项目结构
最终项目结构如下；你可能还有其他文件或目录。
.
├── app
│ ├── build.gradle.kts
│ └── src
│ └── main
│ └── kotlin
│ └── Main.kt
├── annotations
│ ├── build.gradle.kts
│ └── src
│ └── main
│ └── kotlin
| └── com
| └── example
| └── annotations
| └── HelloWorldAnnotation.kt
├── processor
│ ├── build.gradle.kts
│ └── src
│ └── main
│ ├── kotlin
│ │ ├── HelloWorldProcessor.kt
│ │ └── HelloWorldProcessorProvider.kt
│ └── resources/META-INF/services
| └── com.google.devtools.ksp.processing.SymbolProcessorProvider
├── build.gradle.kts
└── settings.gradle.kts下一步
原文：Getting started with KSP，JetBrains / Kotlin 文档贡献者。文档源文件来自 kotlin-web-site。本文件将说明文字译为中文，保留源文件的代码与构建变量；完整许可证见完整许可。依据 Apache License 2.0修改与分发。配图仅保留原文链接
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