第三篇 服务提供者和服务消费者

一、服务提供者和服务消费者概念

服务提供者：服务的被调用方（即：为其他服务提供服务的服务）
服务消费者： 服务的调用方（即： 依赖其他服务的服务）

二、编写一个服务提供者 (自动生成框架：http://start.spring.io/)

生成服务提供者框架将项目导入IDE

配置maven仓库

修改Maven原有的settings文件：

• 配置本地仓库路径:

<localRepository>E:\JAVA\apache-maven-3.3.9\conf\localRepository>

• 配置阿里云的镜像

<mirror>
  <id>nexus-aliyunid>
  <mirrorOf>centralmirrorOf>
  <name>Nexus aliyunname>
  <url>http://maven.aliyun.com/nexus/content/groups/publicurl>
mirror>

代码

Controller:

package cn.com.yeexun.cloud.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;
import cn.com.yeexun.cloud.dao.UserDao;
import cn.com.yeexun.cloud.entity.User;

@RestController
public class UserController {

  @Autowired
  private UserDao userDao;

  @GetMapping("/simple/{id}")
  public User findById(@PathVariable Long id)
  {
    return userDao.findOne(id);
  }
}

Dao:

package cn.com.yeexun.cloud.dao;

import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;
import cn.com.yeexun.cloud.entity.User;

@Repository
public interface UserDao extends JpaRepository {
}

Entity:

package cn.com.yeexun.cloud.entity;

import java.math.BigDecimal;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

@Entity
public class User {
    @Id 
    @GeneratedValue(strategy = GenerationType.AUTO)
    private long id;
    
    @Column
    private String username;
    
    @Column
    private String name;
    
    @Column
    private Short age;
    
    @Column
    private BigDecimal balance;
    
    public long getId() {
        return id;
    }
    public void setId(long id) {
        this.id = id;
    }
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public Short getAge() {
        return age;
    }
    public void setAge(Short age) {
        this.age = age;
    }
    public BigDecimal getBalance() {
        return balance;
    }
    public void setBalance(BigDecimal balance) {
        this.balance = balance;
    }
}

Apllication启动类：

package cn.com.yeexun.cloud;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class MicoroserviceSimpleProviderUserApplication {

    public static void main(String[] args) {
     SpringApplication.run(MicoroserviceSimpleProviderUserApplication.class, args);
    }
}

application.yml:

server:
  port: 7900

spring:
  jpa:
    generate-ddl: false #启动时是否生成ddl语句
    show-sql: true
    hibernate:
      ddl-auto: none  #启动时不做ddl语句处理
  datasource:
    platform: h2
    schema: classpath:schema.sql
    data: classpath:data.sql

logging:
  level:
    root: INFO
    org.hibernate:  INFO
    org.hibernate.type.descriptor.sql.BasicBinder: TRACE
    org.hibernate.type.descriptor.sql.BasicExtractor: TRACE
    cn.com: DEBUG

data.sql:

insert into user(id, username, name, age, balance) values(1, 'user1', '张一', 20, 100.00);
insert into user(id, username, name, age, balance) values(2, 'user2', '王二', 22, 101.00);
insert into user(id, username, name, age, balance) values(3, 'user3', '李三', 23, 102.00);
insert into user(id, username, name, age, balance) values(4, 'user4', '马四', 24, 103.00);

schema.sql:

drop table user if exists;
create table user(
    id bigint generated by default as identity, 
    username varchar(40),
    name varchar(20),
    age int(3),
    balance decimal(10,2),
    primary key(id) 
);

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>4.0.0modelVersion>

    <groupId>cn.com.yeexun.cloudgroupId>
    <artifactId>micoroservice-simple-provider-userartifactId>
    <version>0.0.1-SNAPSHOTversion>
    <packaging>jarpackaging>

    <name>micoroservice-simple-provider-username>
    <description>Demo project for Spring Bootdescription>

    <parent>
        <groupId>org.springframework.bootgroupId>
        <artifactId>spring-boot-starter-parentartifactId>
        <version>1.5.10.RELEASEversion>
        <relativePath/> 
    parent>

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

    <dependencies>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-data-jpaartifactId>
        dependency>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-webartifactId>
        dependency>

        <dependency>
            <groupId>com.h2databasegroupId>
            <artifactId>h2artifactId>
            <scope>runtimescope>
        dependency>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-testartifactId>
            <scope>testscope>
        dependency>
    dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.bootgroupId>
                <artifactId>spring-boot-maven-pluginartifactId>
            plugin>
        plugins>
    build>
project>

可以成功访问，并且返回数据

三、编写一个服务消费者

生成服务消费者框架(自动生成框架：http://start.spring.io/)

将项目导入IDE

配置maven仓库

    同上，修改过maven的库文件settins.xml,则这块就不用修改了

代码

Controller:

package cn.com.yeexun.cloud.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;
import cn.com.yeexun.cloud.entity.User;

@RestController
public class MovieController {

  @Autowired
  private RestTemplate restTemplate;

  @GetMapping("/movie/{id}")
  public User findById(@PathVariable Long id)
  {
    return this.restTemplate.getForObject("http://localhost:7900/simple/" + id, User.class);
  }
}

entity:

package cn.com.yeexun.cloud.entity;

import java.math.BigDecimal;

public class User {

  private long id;
  private String username;
  private String name;
  private Short age;
  private BigDecimal balance;

  public long getId() {
    return id;
  }
  public void setId(long id) {
    this.id = id;
  }
  public String getUsername() {
    return username;
  }
  public void setUsername(String username) {
    this.username = username;
  }
  public String getName() {
    return name;
  }
  public void setName(String name) {
    this.name = name;
  }
  public Short getAge() {
    return age;
  }
  public void setAge(Short age) {
    this.age = age;
  }
  public BigDecimal getBalance() {
    return balance;
  }
  public void setBalance(BigDecimal balance) {
    this.balance = balance;
  }
}

application:

package cn.com.yeexun.cloud;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;

@SpringBootApplication
public class MicoroserviceSimpleComsumerMovieApplication {

  @Bean
  public RestTemplate restTemplate()
  {
    return new RestTemplate();
  }

  public static void main(String[] args) {
    SpringApplication.run(
                  MicoroserviceSimpleComsumerMovieApplication.class, args);
  }
}

application.yml:

server:
  port: 7091

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>4.0.0modelVersion>

  <groupId>cn.com.yeexun.cloudgroupId>

  <artifactId>micoroservice-simple-comsumer-movieartifactId>

  <version>0.0.1-SNAPSHOTversion>

  <packaging>jarpackaging>

  <name>micoroservice-simple-comsumer-moviename>

  <description>Demo project for Spring Bootdescription>

  <parent>
    <groupId>org.springframework.bootgroupId>
    <artifactId>spring-boot-starter-parentartifactId>
    <version>1.5.10.RELEASEversion>
    <relativePath/> 
  parent>

  <properties>
    <project.build.sourceEncoding>UTF-8project.build.sourceEncoding>
    <project.reporting.outputEncoding>UTF8
      project.reporting.outputEncoding>
    <java.version>1.8java.version>
  properties>

  <dependencies>
    <dependency>
      <groupId>org.springframework.bootgroupId>
      <artifactId>spring-boot-starter-webartifactId>
    dependency>

    <dependency>
      <groupId>org.springframework.bootgroupId>
      <artifactId>spring-boot-starter-testartifactId>
      <scope>testscope>
    dependency>
  dependencies>

  <build>
    <plugins>
     <plugin>
      <groupId>org.springframework.bootgroupId>
      <artifactId>spring-boot-maven-pluginartifactId>
      plugin>
    plugins>
   build>
project>

访问成功