微服务springcloud入门系列二（创建服务提供者）

上篇文章创建好了eurka注册中心，现在来创建服务提供者

首先来看看项目结构：

服务提供者需要从数据库查询记录，数据库名是：db_test，数据库脚本是：

CREATE TABLE `tb_user` (
  `id` INT(11) NOT NULL AUTO_INCREMENT COMMENT 'ID',
  `username` VARCHAR(50) NOT NULL COMMENT '用户名',
  `age` INT(11) NOT NULL COMMENT '年龄',
  `ctm` VARCHAR(50) NOT NULL COMMENT '创建时间',
  PRIMARY KEY (`id`)
) ENGINE=INNODB DEFAULT CHARSET=utf8
INSERT INTO `db_test`.`tb_user` (`username`, `age`, `ctm`) VALUES('张三', '18', NOW()) ;
INSERT INTO `db_test`.`tb_user` (`username`, `age`, `ctm`) VALUES('李四', '20', NOW()) ;
INSERT INTO `db_test`.`tb_user` (`username`, `age`, `ctm`) VALUES('王五', '19', NOW()) ;

服务提供者的pom文件：

<?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>springcloud-parent</artifactId>
        <groupId>com.xiami</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>user-service</artifactId>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
    </dependencies>

</project>

属性配置文件application.properties：

server.port=8080
spring.application.name=user-service
eureka.client.service-url.defaultZone=http://localhost:8888/eureka

spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/db_test?characterEncoding=utf-8&serverTimezone=GMT%2B8
spring.datasource.username=root
spring.datasource.password=root

服务启动文件UserServiceApplication.java：

package com.xiami.user;

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

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

User.java文件：

package com.xiami.user.entity;

public class User {
    private int id;
    private String username;
    private int age;
    private String ctm;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getCtm() {
        return ctm;
    }

    public void setCtm(String ctm) {
        this.ctm = ctm;
    }
}

UserController.java文件（为了简单起见，这个控制器直接访问数据库，实际开发中很少这样操作的哦！）：

package com.xiami.user.controller;

import com.xiami.user.entity.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.web.bind.annotation.Mapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
@RequestMapping("/user")
public class UserController {

    @Autowired
    private JdbcTemplate jdbcTemplate;

    @RequestMapping("/{id}")
    public User queryById(@PathVariable Long id){
        List<User> list = jdbcTemplate.query("select * from tb_user where id = ?", new Object[]{id}, new BeanPropertyRowMapper(User.class));
        if(list!=null && list.size()>0){
            return list.get(0);
        }else{
            return null;
        }
    }
}

最后就启动UserServiceApplication，再访问localhost:8888，服务提供者已经成功注册到注册中心了：

 再访问localhost:8080/user/2，显示服务提供者启动正常，可以访问数据库了：

微服务springcloud入门系列二（创建服务提供者），大功告成！