springCloud 的 hystrix（熔断器）的简单入门

时间：2019-08-30 17:14:53 阅读：107 评论：0 收藏：0 [点我收藏+]

标签：相互 password ret 返回JSON数据主机 reg pil 自动 classpath

1..... pom.xml 依赖 jar

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <project xmlns="http://maven.apache.org/POM/4.0.0"
 3          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 4          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 5     <parent>
 6         <artifactId>spring-cloud-parent</artifactId>
 7         <groupId>com.wsc</groupId>
 8         <version>1.0-SNAPSHOT</version>
 9         <relativePath>../springCloud/spring-cloud-parent/pom.xml</relativePath>
10     </parent>
11     <modelVersion>4.0.0</modelVersion>
12 
13     <artifactId>hystrix-8001</artifactId>
14 
15 
16     <properties>
17         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
18         <maven.compiler.source>1.8</maven.compiler.source>
19         <maven.compiler.target>1.8</maven.compiler.target>
20     </properties>
21     <dependencies>
22         <dependency>
23             <groupId>com.wsc</groupId>
24             <artifactId>common</artifactId>
25             <version>1.0-SNAPSHOT</version>
26         </dependency>
27         <!--添加hystirx依赖-->
28         <dependency>
29             <groupId>org.springframework.cloud</groupId>
30             <artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
31         </dependency>
32         <!--服务提供者注册进服务中心-->
33         <dependency>
34             <groupId>org.springframework.cloud</groupId>
35             <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
36         </dependency>
37         <!--springboot web启动器-->
38         <dependency>
39             <groupId>org.springframework.boot</groupId>
40             <artifactId>spring-boot-starter-web</artifactId>
41         </dependency>
42 
43         <!--导入 mybatis 启动器-->
44         <dependency>
45             <groupId>org.mybatis.spring.boot</groupId>
46             <artifactId>mybatis-spring-boot-starter</artifactId>
47         </dependency>
48         <dependency>
49             <groupId>org.springframework.boot</groupId>
50             <artifactId>spring-boot-starter-test</artifactId>
51         </dependency>
52         <dependency>
53             <groupId>junit</groupId>
54             <artifactId>junit</artifactId>
55         </dependency>
56         <dependency>
57             <groupId>mysql</groupId>
58             <artifactId>mysql-connector-java</artifactId>
59             <version>8.0.13</version>
60         </dependency>
61         <dependency>
62             <groupId>com.alibaba</groupId>
63             <artifactId>druid</artifactId>
64         </dependency>
65     </dependencies>
66 </project>

pom.xml

2..... hystrix-8001 包

resources / mybatis / mapper / ProductMapper.xml 配置映射文件

 1 <?xml version="1.0" encoding="UTF-8" ?>
 2 <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
 3         "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
 4 <mapper namespace="com.wsc.core.mapper.ProductMapper">
 5     <select id="findAll" resultType="Product">
 6         select * from product;
 7     </select>
 8 
 9     <select id="findById" resultType="Product" parameterType="Long">
10         select * from product where pid=#{pid};
11     </select>
12 
13     <insert id="add"    parameterType="Product" >
14         insert into product values (null,#{product_name},#{db_source});
15     </insert>
16 </mapper>

ProductMapper.xml

resources / mybatis / mybatis.cfg.xml 配置开启驼峰命名

 1 <?xml version="1.0" encoding="UTF-8" ?>
 2 <!DOCTYPE configuration
 3         PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
 4         "http://mybatis.org/dtd/mybatis-3-config.dtd">
 5 <configuration>
 6     <settings>
 7         <!--开启驼峰命名-->
 8         <setting name="mapUnderscoreToCamelCase" value="true"/>
 9     </settings>
10 </configuration>

mybatis.cfg.xml

resources / application.yml 数据库扫描文件注册客户端

server:
  port: 8001
mybatis:
  config-location: classpath:mybatis/mybatis.cfg.xml #mybatis 配置文件路径
  type-aliases-package: com.wsc.core.pojo # entity别名类所在包
  mapper-locations: mybatis/mapper/*.xml    # mapper映射文件
spring:
  application:
    name: microserver-product #这个很重要，这在以后的服务与服务之间相互调用一般都是根据这个name
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://127.0.0.1:3306/springcloud_db01?serverTimezone=GMT%2B8
    password: wsc
    username: root
    dbcp2:
      min-idle: 5                         # 数据库连接池的最小维持连接数
      initial-size: 5                     # 初始化连接数
      max-total: 5                        # 最大连接数
      max-wait-millis: 150                                    # 等待连接获取的最大超时时间

eureka:
  client:
    register-with-eureka: true             #服务注册开关
    fetch-registry: true                  #服务发现开关
    service-url:
      defaultZone: http://eureka6001.com:6001/eureka/, http://eureka6002.com:6002/eureka/    # http://localhost:6001/eureka # 1 显示主机名
      instance:
        instanceId: ${spring.application.name}:${server.port}-hystrix   #  2   指定实例ID 不显示主机名
        preferipAddress: true

service / ProductService

 1 package com.wsc.core.service;
 2 
 3 import com.wsc.core.pojo.Product;
 4 
 5 import java.util.List;
 6 
 7 public interface ProductService {
 8     public List<Product> findAll();
 9 
10     public Product findById(Long id);
11 
12     public Boolean add(Product product);
13 }

ProductService

service /impl / ProductServiceImpl

 1 package com.wsc.core.service.impl;
 2 
 3 import com.wsc.core.mapper.ProductMapper;
 4 import com.wsc.core.pojo.Product;
 5 import com.wsc.core.service.ProductService;
 6 import org.springframework.beans.factory.annotation.Autowired;
 7 import org.springframework.stereotype.Service;
 8 
 9 import java.util.List;
10 
11 /**
12  * @version 1.0
13  * @ClassName ProductServiceImpl
14  * @Description TODO
15  * @Author WSC
16  * @Date 2019/8/27 10:53
17  **/
18 @Service
19 public class ProductServiceImpl implements ProductService {
20     @Autowired
21     private ProductMapper productMapper;
22     @Override
23     public List<Product> findAll() {
24         return productMapper.findAll();
25     }
26 
27     @Override
28     public Product findById(Long id) {
29         return productMapper.findById(id);
30     }
31 
32     @Override
33     public Boolean add(Product product) {
34         return productMapper.add(product);
35     }
36 }

ProductServiceImpl

mapper / ProductMapper

 1 package com.wsc.core.mapper;
 2 
 3 import com.wsc.core.pojo.Product;
 4 
 5 import java.util.List;
 6 
 7 public interface ProductMapper {
 8     public List<Product> findAll();
 9 
10     public Product findById(Long id);
11 
12     public Boolean add(Product product);
13 }

ProductMapper

controller / ProductController

 1 package com.wsc.core.controller;
 2 
 3 import com.netflix.hystrix.contrib.javanica.annotation.HystrixCommand;
 4 import com.wsc.core.pojo.Product;
 5 import com.wsc.core.service.ProductService;
 6 import org.springframework.beans.factory.annotation.Autowired;
 7 import org.springframework.web.bind.annotation.*;
 8 
 9 import java.util.List;
10 
11 /**
12  * @version 1.0
13  * @ClassName ProductController
14  * @Description TODO
15  * @Author WSC
16  * @Date 2019/8/27 11:06
17  **/
18 @RestController //返回json数据
19 public class ProductController {
20     @Autowired
21     private ProductService productService;
22     //查询全部
23     @RequestMapping(value ="/product/get/list",method = RequestMethod.GET)
24     public List<Product> getAll(){
25         return productService.findAll();
26     }
27 
28 //查询id
29 //get 方法出现异常  则会调用  hystrixGet方法进行处理
30     @HystrixCommand(fallbackMethod = "getFallBack")
31     @RequestMapping(value = "/product/get/{pid}",method = RequestMethod.GET)
32     public Product getById(@PathVariable("pid")Long pid){
33         Product productServiceById = productService.findById(pid);
34         // 模拟异常
35         if(productServiceById==null){
36             throw new RuntimeException("pid"+pid+"无效");
37         }
38         return productServiceById;
39     }
40     // 当get方法 出现异常的时候 会调用此方法  注意方法的返回值 参数列表  要与原方法一致
41     public Product getFallBack(@PathVariable("pid")Long pid){
42         return new Product(pid,"pid" +pid+ "无效--@HystrixCommand","无效的数据库");
43 
44     }
45 //添加
46     @RequestMapping(value ="/product/get/add",method = RequestMethod.POST)
47     public boolean add(@RequestBody Product product){
48         return productService.add(product);
49     }
50 }

Start_8001_hystrix

 1 package com.wsc.core;
 2 
 3 import org.mybatis.spring.annotation.MapperScan;
 4 import org.springframework.boot.SpringApplication;
 5 import org.springframework.boot.autoconfigure.SpringBootApplication;
 6 import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
 7 import org.springframework.cloud.netflix.hystrix.EnableHystrix;
 8 
 9 /**
10  * @version 1.0
11  * @ClassName Start
12  * @Description TODO
13  * @Author WSC
14  * @Date 2019/8/27 10:54
15  **/
16 @EnableHystrix  //开启Hystrix  熔断机制的支持
17 @EnableEurekaClient //  本服务启动后 自动注册进Eureka中心
18 @MapperScan("com.wsc.core.mapper") //mapper扫描包 类 ProductMapper
19 @SpringBootApplication
20 public class Start_8001_hystrix {
21     public static void main(String[] args) {
22         SpringApplication.run(Start_8001_hystrix.class,args);
23     }
24 }

Start_8001_hystrix

测试地址输入：

http://eureka6002.com:6002/  6002注册中心
http://eureka6001.com:6001/  6001注册中心
http://localhost:8001/product/get/1 有效 pid
http://localhost:8001/product/get/-1 无效 pid

无效地址 -1

技术图片