sc-gateway 入门
本文中sc-gateway，指的是spring-cloud-gateway
1.这是一个基于Spring技术栈构建的API网关，涉及到：Spring5、Spring Boot 2、Reactor等，目标是为项目提供简单高效的API路由，以及强大的扩展能力：安全、监控、弹性计算等
2.官方架构图如下，可见请求到来后，由Handler Mapping决定请求对应的真实目标，然后交给Web Handler，由一系列过滤器(filter)执行链式处理，从红色箭头和注释可以发现，请求前后都有过滤器在运行：
1.启动nacos
- 启动
startup.sh -m standalone- 浏览器登录nacos，地址是http://localhost:8848/nacos，账号和密码都是nacos
2.在父工程中添加以下依赖
- 本教程的父工程为rrs-人人书平台
<properties>
<maven.compiler.source>8</maven.compiler.source>
<maven.compiler.target>8</maven.compiler.target>
<java.version>1.8</java.version>
<spring-cloud.version>2020.0.1</spring-cloud.version>
<spring-cloud-alibaba.version>2021.1</spring-cloud-alibaba.version>
</properties>
<packaging>pom</packaging>
<description>Demo project for Spring Cloud </description>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-alibaba-dependencies</artifactId>
<version>${spring-cloud-alibaba.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
<dependency>
<groupId>com.squareup.okhttp3</groupId>
<artifactId>okhttp</artifactId>
<version>3.14.9</version>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-classic</artifactId>
<version>1.1.7</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.16.16</version>
</dependency>
</dependencies>
</dependencyManagement>3 创建名为common的子工程
public interface Constants {
String HELLO_PREFIX = "Hello World";
}
```
- 在common工程中添加一个类，用于其他工程使用
### 4. 创建web应用，作为服务提供方
- hello是个普通的springboot应用，会在nacos进行注册
```xml
<dependencies>
<dependency>
<groupId>com.bolingcavalry</groupId>
<artifactId>common</artifactId>
<version>${project.version}</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!--nacos:用于服务注册与发现-->
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
</dependency>
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<!-- 如果父工程不是springboot，就要用以下方式使用插件，才能生成正常的jar -->
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<mainClass>com.bolingcavalry.provider.ProviderApplication</mainClass>
</configuration>
<executions>
<execution>
<goals>
<goal>repackage</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
```
- yml
```yml
server:
#服务端口
port: 8082
spring:
application:
name: rrs-hello
cloud:
nacos:
discovery:
# nacos服务地址
server-addr: 127.0.0.1:8848
```
- 启动类
```java
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
@SpringBootApplication
public class ProviderApplication {
public static void main(String[] args) {
SpringApplication.run(ProviderApplication.class, args);
}
}- hello中添加控制器
import com.bolingcavalry.common.Constants;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import java.text.SimpleDateFormat;
import java.util.Date;
@RestController
@RequestMapping("/hello")
public class Hello {
private String dateStr(){
return new SimpleDateFormat("yyyy-MM-dd hh:mm:ss").format(new Date());
}
/**
* 返回字符串类型
* @return
*/
@GetMapping("/str")
public String helloStr() {
return Constants.HELLO_PREFIX + ", " + dateStr();
}
}
```
### 5 创建网关工程
- 新增名为sc-gateway的子工程
```xml
<dependencies>
<dependency>
<groupId>com.bolingcavalry</groupId>
<artifactId>common</artifactId>
<version>${project.version}</version>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-gateway</artifactId>
</dependency>
<dependency>
<groupId>io.projectreactor</groupId>
<artifactId>reactor-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
```
- yml
```yml
server:
#服务端口
port: 8081
spring:
application:
name: sc-gateway
cloud:
gateway:
routes:
- id: path_route
# 匹配成功后，会被转发到8082端口，至于端口后面的path，会直接使用原始请求的
# 例如http://127.0.0.1:8081/hello/str，会被转发到http://127.0.0.1:8082/hello/str
uri: http://127.0.0.1:8082
predicates:
# 根据请求路径中带有"/hello/"，就算匹配成功
- Path=/hello/**
- 启动类
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class HelloGatewayApplication {
public static void main(String[] args) {
SpringApplication.run(HelloGatewayApplication.class,args);
}
}6 实验
- 启动sc-gateway工程
- 启动hello服务
- 浏览器访问8081:/hello/str,会被转发到8082:/hello/str
本文仅仅是启动网关，用默认的路由配置方式实现了路由转发。
下文将会使用，lb负载均衡更，nacos配置，代码配置来实现路由。
