我正在使用vert.x-web实施小型服务。我的请求结束处理程序之一（通过CHAR进行了设置）抛出了这个context.request().endHandler()：
NullPointerException为什么此异常不调用我的请求的异常处理程序？为什么不处理？我已将请求的异常处理程序设置为2018-09-02 20:54:35,125 - ERROR [vert.x-eventloop-thread-1] (ContextImpl.java:345) - lambda$wrapTask$2()
Unhandled exception
java.lang.NullPointerException
at (My handler class)
at io.vertx.core.http.impl.HttpServerRequestImpl.handleEnd(HttpServerRequestImpl.java:417)
at io.vertx.core.http.impl.Http1xServerConnection.handleEnd(Http1xServerConnection.java:482)
at io.vertx.core.http.impl.Http1xServerConnection.handleContent(Http1xServerConnection.java:477)
at io.vertx.core.http.impl.Http1xServerConnection.processMessage(Http1xServerConnection.java:458)
at io.vertx.core.http.impl.Http1xServerConnection.handleMessage(Http1xServerConnection.java:144)
at io.vertx.core.http.impl.HttpServerImpl$ServerHandlerWithWebSockets.handleMessage(HttpServerImpl.java:712)
at io.vertx.core.http.impl.HttpServerImpl$ServerHandlerWithWebSockets.handleMessage(HttpServerImpl.java:619)
at io.vertx.core.net.impl.VertxHandler.lambda$channelRead$1(VertxHandler.java:146)
at io.vertx.core.impl.ContextImpl.lambda$wrapTask$2(ContextImpl.java:337)
at io.vertx.core.impl.ContextImpl.executeFromIO(ContextImpl.java:195)
at io.vertx.core.net.impl.VertxHandler.channelRead(VertxHandler.java:144)
（通过context.fail()）。但这似乎没有任何作用。
还有我不知道的另一个异常处理程序吗？
编辑：这是最小的复制代码：
context.request().exceptionHandler()预期的行为：Vertx vertx = Vertx.vertx();
Router router = Router.router(vertx);
router.route().handler(context -> {
context.request()
.exceptionHandler(context::fail)
.endHandler(nothing -> { throw new NullPointerException("null"); })
.handler(buffer -> {});
});
vertx.createHttpServer()
.requestHandler(router::accept)
.listen(8080);
被调用，并且连接因HTTP ERROR 500而关闭。
行为正确：上下文没有失败，连接“挂起”。
答案 0 :(得分：0)
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
...
<packaging>jar</packaging>
<description></description>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
<spring-boot-admin.version>2.0.2</spring-boot-admin.version>
<spring-boot-dependencies.version>2.0.4.RELEASE</spring-boot-dependencies.version>
...
<rat.skip>true</rat.skip>
<log4j-version>2.6.1</log4j-version>
</properties>
<repositories>
...
</repositories>
<dependencyManagement>
<dependencies>
<!-- Necessary dependency for running Spring Boot without starter parent -->
<dependency>
<groupId>org.springframework.data</groupId>
<artifactId>spring-data-releasetrain</artifactId>
<version>Fowler-SR2</version>
<type>pom</type>
<scope>import</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-dependencies</artifactId>
<version>${spring-boot-dependencies.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
...
</dependencies>
</dependencyManagement>
<dependencies>
<dependency>
<groupId>de.codecentric</groupId>
<artifactId>spring-boot-admin-starter-server</artifactId>
<version>${spring-boot-admin.version}</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
...
<!-- TODO The version of this dependency lets Spring Boot fail, but is
necessary tu run the old backend -->
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-api</artifactId>
<version>${log4j-version}</version>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-core</artifactId>
<version>${log4j-version}</version>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-iostreams</artifactId>
<version>${log4j-version}</version>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-1.2-api</artifactId>
<version>${log4j-version}</version>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-jcl</artifactId>
<version>${log4j-version}</version>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-jul</artifactId>
<version>${log4j-version}</version>
</dependency>
<dependency>
<groupId>org.fusesource.jansi</groupId>
<artifactId>jansi</artifactId>
<version>1.13</version>
</dependency>
<dependency>
<groupId>com.google.code.gson</groupId>
<artifactId>gson</artifactId>
</dependency>
...
</dependencies>
<build>
<defaultGoal>verify</defaultGoal>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
<plugin>
...
</plugin>
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<version>2.6</version>
<executions>
<execution>
<id>prepare-config-zip</id>
<phase>prepare-package</phase>
<goals>
<goal>single</goal>
</goals>
<configuration>
<descriptors>
<descriptor>${basedir}/src/main/assembly/config.xml</descriptor>
</descriptors>
<finalName>configs</finalName>
<appendAssemblyId>false</appendAssemblyId>
</configuration>
</execution>
<execution>
<id>prepare-dist-zip</id>
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
<configuration>
<descriptor>src/main/assembly/dist.xml</descriptor>
<finalName>...</finalName>
<appendAssemblyId>false</appendAssemblyId>
</configuration>
</execution>
</executions>
</plugin>
<plugin>
<artifactId>maven-enforcer-plugin</artifactId>
<configuration>
<rules>
<requireJavaVersion>
<version>1.8</version>
</requireJavaVersion>
</rules>
</configuration>
</plugin>
</plugins>
</build>
<profiles>
<profile>
<id>attach-standalone</id>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-shade-plugin</artifactId>
<configuration>
<shadedArtifactAttached>true</shadedArtifactAttached>
<shadedClassifierName>standalone</shadedClassifierName>
</configuration>
</plugin>
</plugins>
</build>
</profile>
<profile>
<id>dont-attach-standalone</id>
<activation>
<activeByDefault>true</activeByDefault>
</activation>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-shade-plugin</artifactId>
<configuration>
<!-- Prevent huge shaded artifacts from being deployed to Artifactory -->
<outputFile>...</outputFile>
</configuration>
</plugin>
</plugins>
</build>
</profile>
</profiles>
适用于exceptionHandler对象。该方法是从HttpServerRequest接口继承的。每当处理HTTP请求而不是用户代码的Vert.x / Netty代码出现问题时，都会调用此回调。
如果您想在实际请求处理之前执行一些代码，我建议您注册一条路由并在处理程序中调用ReadStream：
RoutingContext#next然后，预处理逻辑中的任何故障都将被路由器捕获并正常管理。
答案 1 :(得分：0)
这里需要指出两点：
由响应未明确结束引起的挂起（请参见HttpServerResponse#end()。
要处理在请求处理期间发生的异常，请在路由级别添加故障处理程序（请参见Route#failureHandler()）。根据请求处理异常只会在读取流时捕获异常。
例如：
Router router = Router.router(vertx);
router.route().failureHandler(handler -> handler.response().end());
router.route().handler(routingContext -> routingContext.request().endHandler(handler -> {
throw new NullPointerException("exception here!");
}));
vertx.createHttpServer().requestHandler(router::accept).listen(8085);