SpringBoot3 WebFlux 拦截器 和 全局异常处理器
SpringBoot3 WebFlux 拦截器 和 全局异常处理器一、拦截器
org.springframework.web.server.CoWebFilter其父类是org.springframework.web.server.WebFilter
webflux 的 拦截器 就像 Servlet 的 Filter 较为原始. 所以Filter咋使用。WebFilter就咋使用。而CoWebFilter是协程环境的Kotlin专用WebFilter，其内部使用mono将Mono转换为了kotlin的挂起函数。
CoWebFilter.kt
abstract class CoWebFilter : WebFilter {
final override fun filter(exchange: ServerWebExchange, chain: WebFilterChain): Mono<Void> {
val context = exchange.attributes as CoroutineContext?
return mono(context ?: Dispatchers.Unconfined) {
filter(exchange, object : CoWebFilterChain {
override suspend fun filter(exchange: ServerWebExchange) {
exchange.attributes = currentCoroutineContext().minusKey(Job.Key)
chain.filter(exchange).awaitSingleOrNull()
}
})}.then()
}
/**
* Process the Web request and (optionally) delegate to the next
* through the given .
* @param exchange the current server exchange
* @param chain provides a way to delegate to the next filter
*/
protected abstract suspend fun filter(exchange: ServerWebExchange, chain: CoWebFilterChain)
companion object {
/**
* Name of the attribute that contains the
* to be passed to the
* .
*/
@JvmField
val COROUTINE_CONTEXT_ATTRIBUTE = CoWebFilter::class.java.getName() + ".context"
}
}
/**
* Kotlin-specific adaption of that allows for coroutines.
*
* @author Arjen Poutsma
* @since 6.0.5
*/
interface CoWebFilterChain {
/**
* Delegate to the next in the chain.
* @param exchange the current server exchange
*/
suspend fun filter(exchange: ServerWebExchange)
}源码分析：
代码非常简单哈，使用CoWebFilter只需要集成并且实现filter方法即可。
放行
放行只需要调用chain.filter(exchange)即可。并且其可以传递CoroutineContext上下文对象，类似于ThreadLocal.
拦截
val defaultMessage = "token is invalid"
exchange.response.apply {
statusCode = HttpStatus.UNAUTHORIZED
headers.contentType = MediaType.APPLICATION_JSON
val result: edu.tyut.spring_boot_ssm.bean.Result<Boolean> = edu.tyut.spring_boot_ssm.bean.Result.failure(message = defaultMessage, data = false)
val resultJson: String = objectMapper.writeValueAsString(result)
val buffer: DataBuffer = bufferFactory().wrap(resultJson.toByteArray(charset = Charsets.UTF_8))
writeWith(Mono.just<DataBuffer>(buffer)).awaitSingleOrNull()
}.setComplete().awaitSingleOrNull()拦截也是比较简单的的直接在filter方法中调用以上方法即可
work
实现了filter方法，还不会生效。必须满足以下两个条件才可以生效
[*]webflux环境
[*]注入bean容器
异常处理器
org.springframework.web.server.CoWebExceptionHandler#CoWebExceptionHandler
这个类是github社区的贡献的。
使用
[*]实现CoWebExceptionHandler
[*]重写coHandle方法
[*]注入容器
[*]提高优先级
案例
GlobalExceptionHandler.kt
@Order(value = -2)
@Component
internal final class GlobalExceptionHandler(
) : CoWebExceptionHandler() {
private final val logger: Logger = LoggerFactory.getLogger(this.javaClass)
override suspend fun coHandle(exchange: ServerWebExchange, ex: Throwable) {
when (ex) {
is WebExchangeBindException -> {
this.handlerBindException(exchange = exchange, ex = ex)
}
else -> {
this.handlerOtherException(exchange = exchange, ex = ex)
}
}
}
}TODO
WebFilter 源码解析
WebExceptionHandler 源码解析
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