Kotlin无法在Class中创建使用@Configuration @EnableWebMvc注释的@Autowired字段

Question

Autowired字段是null在初始化项目时:

package com.lynas.config

import org.springframework.stereotype.Component
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter
import javax.servlet.http.HttpServletRequest
import javax.servlet.http.HttpServletResponse


@Component
open class InterceptorConfig : HandlerInterceptorAdapter() {

    override fun preHandle(request: HttpServletRequest, response: HttpServletResponse, handler: Any?): Boolean {

        return true
    }
}



package com.lynas.config

import org.springframework.beans.factory.annotation.Autowired
import org.springframework.context.annotation.ComponentScan
import org.springframework.context.annotation.Configuration
import org.springframework.web.servlet.config.annotation.EnableWebMvc
import org.springframework.web.servlet.config.annotation.InterceptorRegistry
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter

@Configuration
@EnableWebMvc
@ComponentScan("com.lynas")
open class WebConfig() : WebMvcConfigurerAdapter() {

    // this field show null
    @Autowired
    lateinit var interceptorConfig: InterceptorConfig

    override fun addInterceptors(registry: InterceptorRegistry) {
        registry.addInterceptor(interceptorConfig)
    }

}

lateinit var interceptorConfig: InterceptorConfig是null我运行应用程序时.如何解决这个问题？

完整代码 https://github.com/lynas/kotlinSpringBug

Answer 1

try@field:Autowired lateinit var interceptorConfig或@set:Autowiredwhich 将告诉 kotlin 编译器在字段/setter 上显式添加注释。默认情况下，它将它们放在“property”上，这是 kotlin-only 构造，Java 可能在访问它时遇到问题。请参阅此处的 kotlin 文档