WebFlux REST API 全局异常处理 Error Handling

2-x-spring-boot-webflux-handling-errors/pom.xml

@@ -0,0 +1,51 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<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>
+
+  <groupId>springboot</groupId>
+  <artifactId>2-x-spring-boot-webflux-handling-errors</artifactId>
+  <version>0.0.1-SNAPSHOT</version>
+  <name>2-x-spring-boot-webflux-handling-errors</name>
+
+  <parent>
+    <groupId>org.springframework.boot</groupId>
+    <artifactId>spring-boot-starter-parent</artifactId>
+    <version>2.1.3.RELEASE</version>
+    <relativePath/> <!-- lookup parent from repository -->
+  </parent>
+
+  <properties>
+    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
+    <java.version>1.8</java.version>
+  </properties>
+
+  <dependencies>
+    <dependency>
+      <groupId>org.springframework.boot</groupId>
+      <artifactId>spring-boot-starter-webflux</artifactId>
+    </dependency>
+
+    <dependency>
+      <groupId>org.springframework.boot</groupId>
+      <artifactId>spring-boot-starter-test</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>io.projectreactor</groupId>
+      <artifactId>reactor-test</artifactId>
+      <scope>test</scope>
+    </dependency>
+  </dependencies>
+
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-maven-plugin</artifactId>
+      </plugin>
+    </plugins>
+  </build>
+
+</project>

2-x-spring-boot-webflux-handling-errors/src/main/java/org/spring/springboot/Application.java

@@ -0,0 +1,20 @@
+package org.spring.springboot;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+/**
+ * Spring Boot 应用启动类
+ *
+ */
+// Spring Boot 应用的标识
+@SpringBootApplication
+public class Application {
+
+    public static void main(String[] args) {
+        // 程序启动入口
+        // 启动嵌入式的 Tomcat 并初始化 Spring 环境及其各 Spring 组件
+        SpringApplication.run(Application.class,args);
+
+    }
+}

2-x-spring-boot-webflux-handling-errors/src/main/java/org/spring/springboot/error/GlobalErrorAttributes.java

@@ -0,0 +1,32 @@
+package org.spring.springboot.error;
+
+import org.springframework.boot.web.reactive.error.DefaultErrorAttributes;
+import org.springframework.stereotype.Component;
+import org.springframework.web.reactive.function.server.ServerRequest;
+
+import java.util.Map;
+
+@Component
+public class GlobalErrorAttributes extends DefaultErrorAttributes {
+    
+    @Override
+    public Map<String, Object> getErrorAttributes(ServerRequest request, boolean includeStackTrace) {
+        Map<String, Object> map = super.getErrorAttributes(request, includeStackTrace);
+    
+        if (getError(request) instanceof GlobalException) {
+            GlobalException ex = (GlobalException) getError(request);
+            map.put("exception", ex.getClass().getSimpleName());
+            map.put("message", ex.getMessage());
+            map.put("status", ex.getStatus().value());
+            map.put("error", ex.getStatus().getReasonPhrase());
+            
+            return map;
+        }
+    
+        map.put("exception", "SystemException");
+        map.put("message", "System Error , Check logs!");
+        map.put("status", "500");
+        map.put("error", " System Error ");
+        return map;
+    }
+}

2-x-spring-boot-webflux-handling-errors/src/main/java/org/spring/springboot/error/GlobalErrorWebExceptionHandler.java

@@ -0,0 +1,47 @@
+package org.spring.springboot.error;
+
+import org.springframework.boot.autoconfigure.web.ResourceProperties;
+import org.springframework.boot.autoconfigure.web.reactive.error.AbstractErrorWebExceptionHandler;
+import org.springframework.boot.web.reactive.error.ErrorAttributes;
+import org.springframework.context.ApplicationContext;
+import org.springframework.core.annotation.Order;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
+import org.springframework.http.codec.ServerCodecConfigurer;
+import org.springframework.stereotype.Component;
+import org.springframework.web.reactive.function.BodyInserters;
+import org.springframework.web.reactive.function.server.RequestPredicates;
+import org.springframework.web.reactive.function.server.RouterFunction;
+import org.springframework.web.reactive.function.server.RouterFunctions;
+import org.springframework.web.reactive.function.server.ServerRequest;
+import org.springframework.web.reactive.function.server.ServerResponse;
+import reactor.core.publisher.Mono;
+
+import java.util.Map;
+
+@Component
+@Order(-2)
+public class GlobalErrorWebExceptionHandler extends AbstractErrorWebExceptionHandler {
+
+    public GlobalErrorWebExceptionHandler(GlobalErrorAttributes g, ApplicationContext applicationContext,
+            ServerCodecConfigurer serverCodecConfigurer) {
+        super(g, new ResourceProperties(), applicationContext);
+        super.setMessageWriters(serverCodecConfigurer.getWriters());
+        super.setMessageReaders(serverCodecConfigurer.getReaders());
+    }
+
+    @Override
+    protected RouterFunction<ServerResponse> getRoutingFunction(final ErrorAttributes errorAttributes) {
+        return RouterFunctions.route(RequestPredicates.all(), this::renderErrorResponse);
+    }
+
+    private Mono<ServerResponse> renderErrorResponse(final ServerRequest request) {
+
+        final Map<String, Object> errorPropertiesMap = getErrorAttributes(request, false);
+
+        return ServerResponse.status(HttpStatus.BAD_REQUEST)
+            .contentType(MediaType.APPLICATION_JSON_UTF8)
+            .body(BodyInserters.fromObject(errorPropertiesMap));
+    }
+
+}

2-x-spring-boot-webflux-handling-errors/src/main/java/org/spring/springboot/error/GlobalException.java

@@ -0,0 +1,15 @@
+package org.spring.springboot.error;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.web.server.ResponseStatusException;
+
+public class GlobalException extends ResponseStatusException {
+    
+    public GlobalException(HttpStatus status, String message) {
+        super(status, message);
+    }
+    
+    public GlobalException(HttpStatus status, String message, Throwable e) {
+        super(status, message, e);
+    }
+}

2-x-spring-boot-webflux-handling-errors/src/main/java/org/spring/springboot/handler/CityHandler.java

@@ -0,0 +1,27 @@
+package org.spring.springboot.handler;
+
+import org.spring.springboot.error.GlobalException;
+import org.springframework.http.HttpStatus;
+import org.springframework.stereotype.Component;
+import org.springframework.web.reactive.function.server.ServerRequest;
+import org.springframework.web.reactive.function.server.ServerResponse;
+import reactor.core.publisher.Mono;
+
+import java.util.Optional;
+
+@Component
+public class CityHandler {
+    
+    public Mono<ServerResponse> helloCity(ServerRequest request) {
+        return ServerResponse.ok().body(sayHelloCity(request), String.class);
+    }
+    
+    private Mono<String> sayHelloCity(ServerRequest request) {
+        Optional<String> cityParamOptional = request.queryParam("city");
+        if (!cityParamOptional.isPresent()) {
+            throw new GlobalException(HttpStatus.INTERNAL_SERVER_ERROR, "request param city is ERROR");
+        }
+        
+        return Mono.just("Hello," + cityParamOptional.get());
+    }
+}

2-x-spring-boot-webflux-handling-errors/src/main/java/org/spring/springboot/router/CityRouter.java

@@ -0,0 +1,20 @@
+package org.spring.springboot.router;
+
+import org.spring.springboot.handler.CityHandler;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.http.MediaType;
+import org.springframework.web.reactive.function.server.RequestPredicates;
+import org.springframework.web.reactive.function.server.RouterFunction;
+import org.springframework.web.reactive.function.server.RouterFunctions;
+import org.springframework.web.reactive.function.server.ServerResponse;
+
+@Configuration
+public class CityRouter {
+    
+    @Bean
+    public RouterFunction<ServerResponse> routeCity(CityHandler cityHandler) {
+        return RouterFunctions.route(RequestPredicates.GET("/hello").and(RequestPredicates.accept(MediaType.TEXT_PLAIN)), cityHandler::helloCity);
+    }
+    
+}

pom.xml

@@ -9,6 +9,8 @@
 	<packaging>pom</packaging>
 
 	<modules>
+		<!-- WebFlux 异常处理 -->
+		<module>2-x-spring-boot-webflux-handling-errors</module>
 
 		<!-- 第 1 章《Spring Boot 入门》 -->
 		<module>chapter-1-spring-boot-quickstart</module>