IDEA从零搭建SpringCloud Alibaba完整工程

环境：IDEA 2022+/JDK8/Maven3.6+、提前装好 Nacos（单机启动备用）

一、第一步：创建顶层父工程 cloud-parent

1. 新建项目

1、IDEA 首页 → New Project

2、左侧选择 Maven，不要勾选 Archetype，直接 Next

3、填写坐标：

GroupId：com.cloud

ArtifactId：cloud-parent

Version：1.0-SNAPSHOT

4、项目名称：cloud-parent，选择本地存放路径 → Finish

2. 修改父工程 pom.xml

<?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>com.cloud</groupId>
    <artifactId>cloud-parent</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>pom</packaging>
    <name>cloud-parent</name>
    <description>SpringCloud父工程统一依赖管理</description>

    <!-- 子模块 -->
    <modules>
        <module>cloud-common</module>
        <module>cloud-user-service</module>
        <module>cloud-order-service</module>
        <module>cloud-nacos-gateway</module>
    </modules>

    <!-- 版本锁定 -->
    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
        <spring.boot.version>2.7.15</spring.boot.version>
        <spring.cloud.alibaba.version>2021.0.1.0</spring.cloud.alibaba.version>
        <spring.cloud.version>2021.0.1</spring.cloud.version>
    </properties>

    <!-- 统一依赖管理，子模块无需写版本 -->
    <dependencyManagement>
        <dependencies>
            <!-- SpringBoot统一父依赖 -->
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>${spring.boot.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <!-- SpringCloud 核心依赖 -->
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring.cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <!-- SpringCloud Alibaba 全套 -->
            <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>
        </dependencies>
    </dependencyManagement>

    <!-- 公共依赖所有子模块继承 -->
    <dependencies>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
    </dependencies>

    <!-- 仓库配置 -->
    <repositories>
        <repository>
            <id>aliyunmaven</id>
            <url>https://maven.aliyun.com/repository/public</url>
            <releases>
                <enabled>true</enabled>
            </releases>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </repository>
    </repositories>

</project>

3. Maven 刷新

右侧 Maven 面板 → 刷新按钮，无报错继续。

二、第二步：创建公共模块 cloud-common（底层依赖包）

1. 在父工程下新建 Module

1、左侧右键 cloud-parent → New → Module

2、选择 Maven，无骨架 Next

3、ArtifactId：cloud-common，GroupId、Version 继承父工程，Next

4、模块名称 cloud-common，存放目录自动在 cloud-parent 内 → Finish

2. 配置 cloud-common pom.xml

<?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">
    <parent>
        <artifactId>cloud-parent</artifactId>
        <groupId>com.cloud</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>cloud-common</artifactId>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
    </dependencies>

</project>

3. 编写统一返回类 Result

1、打开 cloud-common/src/main/java

2、新建包 com.cloud.common.result

3、创建 Result.java

package com.cloud.common.result;

import lombok.Data;

@Data
public class Result<T> {
    private Integer code;
    private String msg;
    private T data;

    public static <T> Result<T> success(T data) {
        Result<T> r = new Result<>();
        r.setCode(200);
        r.setMsg("操作成功");
        r.setData(data);
        return r;
    }

    public static <T> Result<T> fail(Integer code, String msg) {
        Result<T> r = new Result<>();
        r.setCode(code);
        r.setMsg(msg);
        return r;
    }
}

三、第三步：创建生产者 cloud-user-service

1. 父工程右键新建 Module

右键 cloud-parent → New → Module → Maven

ArtifactId：cloud-user-service → Finish

2. 修改 pom.xml

• parent 自动继承 cloud-parent
• 添加依赖：web、nacos 发现、feign、cloud-common

<?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">
    <parent>
        <artifactId>cloud-parent</artifactId>
        <groupId>com.cloud</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>cloud-user-service</artifactId>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>
        <!-- 缺少这个就会报你当前的错！ -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-loadbalancer</artifactId>
        </dependency>
        <dependency>
            <groupId>com.cloud</groupId>
            <artifactId>cloud-common</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
    </dependencies>

</project>

刷新 Maven

3. 配置 yml 文件

• user 模块 resources 右键 New → YAML Configuration File → application.yml

  server:
    port: 8081
  spring:
    application:
      name: user-service
    cloud:
      nacos:
        discovery:
          server-addr: 127.0.0.1:8848

  4. 创建启动类 + Controller

• 包：com.cloud
  新建 UserApplication 启动类，添加 @SpringBootApplication @EnableDiscoveryClient

package com.cloud;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;

@SpringBootApplication
@EnableDiscoveryClient
public class UserApplication {
    public static void main(String[] args) {
        SpringApplication.run(UserApplication.class,args);
    }
}

新建 controller 包，UserController，编写测试接口
*

package com.cloud.controller;

import com.cloud.common.result.Result;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/user")
public class UserController {
    @GetMapping("/get/{id}")
    public Result<String> getUser(@PathVariable Long id) {
        return Result.success("用户信息：" + id);
    }
}

四、第四步：创建消费者 cloud-order-service

1. 父工程新建 Module cloud-order-service

流程同上 user-service

2. pom.xml 依赖和 user 完全一致

<?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">
    <parent>
        <artifactId>cloud-parent</artifactId>
        <groupId>com.cloud</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>cloud-order-service</artifactId>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>
        <!-- 缺少这个就会报你当前的错！ -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-loadbalancer</artifactId>
        </dependency>
        <dependency>
            <groupId>com.cloud</groupId>
            <artifactId>cloud-common</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
    </dependencies>
</project>

3. application.yml

server:
  port: 8082
spring:
  application:
    name: order-service
  cloud:
    nacos:
      discovery:
        server-addr: 127.0.0.1:8848

4. 启动类

package com.cloud.order;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.openfeign.EnableFeignClients;

@SpringBootApplication
@EnableDiscoveryClient
@EnableFeignClients
public class OrderApplication {
    public static void main(String[] args) {
        SpringApplication.run(OrderApplication.class,args);
    }
}

5. Feign 远程调用接口

• 新建包 com.cloud.order.feign → UserFeign

package com.cloud.order.feign;

import com.cloud.common.result.Result;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;

@FeignClient("user-service")////对应生产者服务名
public interface UserFeign {
    @GetMapping("/user/get/{id}")
    Result<String> getUser(@PathVariable("id") Long id);
}

6. OrderController

• 注入 UserFeign，编写创建订单接口

package com.cloud.order.controller;

import com.cloud.common.result.Result;
import com.cloud.order.feign.UserFeign;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.annotation.Resource;

@RestController
@RequestMapping("/order")
public class OrderController {
    @Resource
    private UserFeign userFeign;

    @GetMapping("/create/{uid}")
    public Result<String> createOrder(@PathVariable Long uid) {
        Result<String> user = userFeign.getUser(uid);
        return Result.success("创建订单成功，关联用户：" + user.getData());
    }
}

五、第五步：创建网关 cloud-nacos-gateway

1. 父工程新建 Module cloud-nacos-gateway

2. pom.xml 依赖（注意：不能引入 web！冲突）

<?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">
    <parent>
        <artifactId>cloud-parent</artifactId>
        <groupId>com.cloud</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>cloud-nacos-gateway</artifactId>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-gateway</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-loadbalancer</artifactId>
        </dependency>
        <dependency>
            <groupId>com.cloud</groupId>
            <artifactId>cloud-common</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
    </dependencies>

</project>

3. application.yml 路由配置

server:
  port: 80
spring:
  application:
    name: gateway
  cloud:
    nacos:
      discovery:
        server-addr: 127.0.0.1:8848
    gateway:
      routes:
        - id: user-route
          uri: lb://user-service
          predicates:
            - Path=/user/**
        - id: order-route
          uri: lb://order-service
          predicates:
            - Path=/order/**

4. 网关启动类 GatewayApplication

package com.cloud.gateway;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;

@SpringBootApplication
@EnableDiscoveryClient
public class GatewayApplication {
    public static void main(String[] args) {
        SpringApplication.run(GatewayApplication.class,args);
    }
}

刷新 Maven，此时左侧完整工程结构全部出现。
*

六、IDEA 关键配置（必做，否则报错）

1. JDK 统一配置

• File → Project Structure
  • Project：SDK 选 JDK8，language level 8
  • Modules：所有模块 language level 统一 8
• File → Settings → Build,Execution,Deployment → Build Tools → Maven
  • Maven home path：本地 maven
  • Runner → JRE：选择 JDK8

2. Lombok 开启注解支持（否则找不到 get/set）

Settings → Build → Compiler → Annotation Processors

勾选：Enable annotation processing → Apply

3. Maven 阿里云镜像加速（避免依赖下载失败）

打开 maven 安装目录 conf/settings.xml，添加镜像

<mirror>
    <id>aliyunmaven</id>
    <mirrorOf>*</mirrorOf>
    <url>https://maven.aliyun.com/repository/public</url>
</mirror>

七、启动与测试完整流程

前置：启动 Nacos

进入 nacos bin 目录，windows 执行 startup.cmd -m standalone

访问 http://localhost:8848/nacos 账号密码 nacos/nacos

IDEA 启动顺序

cloud-user-service（8081）

运行 UserApplication main 方法

cloud-order-service（8082）

运行 OrderApplication

cloud-nacos-gateway（80）

运行 GatewayApplication

测试地址（全部走网关 80 端口）

查询用户：http://localhost/user/get/1

创建订单：http://localhost/order/create/1

如果上面有报错，分开分步测试验证，方便问题

测试 1：绕过网关，直接访问生产者，验证生产者正常

访问：http://localhost:8081/user/get/1

返回正常数据 → user 服务没问题

404 / 报错 → user 服务本身异常，先修好

测试 2：绕过网关，直接访问消费者，验证 Feign 调用

访问：http://localhost:8082/order/create/1

503 → Feign 找不到 user 服务，聚焦 nacos 注册、loadbalancer 依赖

正常返回 → 问题只在网关路由配置

测试 3：走网关访问

http://localhost/user/get/1

http://localhost/order/create/1

只有前两步正常，网关才会正常转发

订单测试：