[bigdata-111] spring-cloud-07 api网关服务

1. api网关

后面有很多服务，对外用api网管统一提供访问。如果一个用户访问api网关，那么，api网关就会将这些调用转发到后面的诸多服务，然后获取服务结果再返回。而后端的服务都是配置出来的。

2. 参考文献

https://github.com/dyc87112/SpringCloudBook/tree/master/api-gateway

3. 源码目录结构

.
├── pom.xml
├── src
│ ? ├── main
│ ? │ ? ├── java
│ ? │ ? │ ? └── com
│ ? │ ? │ ? ? ? └── brian
│ ? │ ? │ ? ? ? ? ? └── demo
│ ? │ ? │ ? ? ? ? ? ? ? └── apigateway
│ ? │ ? │ ? ? ? ? ? ? ? ? ? └── App.java
│ ? │ ? └── resources
│ ? │ ? ? ? └── application.properties

4. pom.xml

<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>com.brian.demo</groupId>
	<artifactId>apigateway</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

	<name>apigateway</name>
	<url>http://maven.apache.org</url>

	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>1.3.7.RELEASE</version>
		<relativePath /> <!-- lookup parent from repository -->
	</parent>

	<repositories>
		<repository>
			<id>my-nexus-central</id>
			<name>my local nexus</name>
			<url>http://localhost:8081/nexus/content/repositories/central/</url>
			<releases>
				<enabled>true</enabled>
				<updatePolicy>never</updatePolicy>
			</releases>
		</repository>
	</repositories>

	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		<java.version>1.8</java.version>
	</properties>

	<dependencies>
		<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-starter-zuul</artifactId>
		</dependency>

		<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-starter-eureka</artifactId>
		</dependency>

		<dependency>
			<groupId>junit</groupId>
			<artifactId>junit</artifactId>
			<version>3.8.1</version>
			<scope>test</scope>
		</dependency>
	</dependencies>

	<dependencyManagement>
		<dependencies>
			<dependency>
				<groupId>org.springframework.cloud</groupId>
				<artifactId>spring-cloud-dependencies</artifactId>
				<version>Brixton.SR5</version>
				<type>pom</type>
				<scope>import</scope>
			</dependency>
		</dependencies>
	</dependencyManagement>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>

</project>

5. App.java

package com.brian.demo.apigateway;

import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.cloud.client.SpringCloudApplication;
import org.springframework.cloud.netflix.zuul.EnableZuulProxy;
import org.springframework.cloud.netflix.zuul.filters.discovery.PatternServiceRouteMapper;
import org.springframework.context.annotation.Bean;

@EnableZuulProxy
@SpringCloudApplication
public class App {
	
	@Bean
	public PatternServiceRouteMapper serviceRouteMapper() {
		return new PatternServiceRouteMapper("(?<name>^.+)-(?<version>v.+$)","${version}/${name}");
	}

	public static void main(String[] args) {
		new SpringApplicationBuilder(App.class).web(true).run(args);
	}
}

6. application.properites

spring.application.name=api-gateway
server.port=5555
eureka.client.serviceUrl.defaultZone=http://localhost:1111/eureka/,http://localhost:1111/eureka/
zuul.routes.api-a.path=/api/a/**
zuul.routes.api-a.serviceId=hello-service
zuul.AccessFilter.pre.disable=true

7. 编译打包

mvn clean package

8. 运行

java -jar target/apigateway-0.0.1-SNAPSHOT.jar

9. 查看

根据配置，如果访问http://localhost:5555/api/a/*，那么，api网关会将这个路由转发到HELLO-SERVICE这里，因此，访问http://localhost:5555/api/a/hello，能看到一个字符串。