Fegin

public static void main(String[] args) throws IOException {        //1.打开浏览器        CloseableHttpClient httpClient = HttpClients.createDefault();        //2.声明get请求        HttpGet httpGet = new HttpGet("http://www.baidu.com/s?wd=java");        //3.发送请求        CloseableHttpResponse response = httpClient.execute(httpGet);        //4.判断状态码        if(response.getStatusLine().getStatusCode()==200){            HttpEntity entity = response.getEntity();           //使用工具类EntityUtils，从响应中取出实体表示的内容并转换成字符串            String string = EntityUtils.toString(entity, "utf-8");            System.out.println(string);        }        //5.关闭资源        response.close();        httpClient.close();    }

public static void main(String[] args) throws IOException {        //1.打开浏览器        CloseableHttpClient httpClient = HttpClients.createDefault();        //2.声明get请求        HttpPost httpPost = new HttpPost("https://www.oschina.net/");        //3.开源中国为了安全，防止恶意攻击，在post请求中都限制了浏览器才能访问        httpPost.addHeader("User-Agent","Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.106 Safari/537.36");        //4.判断状态码        List<NameValuePair> parameters = new ArrayList<NameValuePair>(0);        parameters.add(new BasicNameValuePair("scope", "project"));        parameters.add(new BasicNameValuePair("q", "java"));
        UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(parameters,"UTF-8");
        httpPost.setEntity(formEntity);
        //5.发送请求        CloseableHttpResponse response = httpClient.execute(httpPost);
        if(response.getStatusLine().getStatusCode()==200){            HttpEntity entity = response.getEntity();            String string = EntityUtils.toString(entity, "utf-8");            System.out.println(string);        }        //6.关闭资源        response.close();        httpClient.close();    }

public void doHttpGetTest() throws UnsupportedEncodingException {    // -------------------------------> 获取Rest客户端实例    RestTemplate restTemplate = new RestTemplate();        // -------------------------------> 解决(响应数据可能)中文乱码 的问题    List<HttpMessageConverter<?>> converterList = restTemplate.getMessageConverters();    converterList.remove(1); // 移除原来的转换器    // 设置字符编码为utf-8    HttpMessageConverter<?> converter = new StringHttpMessageConverter(StandardCharsets.UTF_8);    converterList.add(1, converter); // 添加新的转换器(注:convert顺序错误会导致失败)    restTemplate.setMessageConverters(converterList);        // -------------------------------> (选择性设置)请求头信息    // HttpHeaders实现了MultiValueMap接口    HttpHeaders httpHeaders = new HttpHeaders();    // 给请求header中添加一些数据    httpHeaders.add("Java 学习部落", "这是一个学习技术的公众号!");        // -------------------------------> 注:GET请求 创建HttpEntity时,请求体传入null即可    // 请求体的类型任选即可;只要保证 请求体 的类型与HttpEntity类的泛型保持一致即可    String httpBody = null;    HttpEntity<String> httpEntity = new HttpEntity<String>(httpBody, httpHeaders);        // -------------------------------> URI    StringBuffer paramsURL = new StringBuffer("http://127.0.0.1:8080/restTemplate/doHttpGet");    // 字符数据最好encoding一下;这样一来，某些特殊字符才能传过去(如:flag的参数值就是“&”,不encoding的话,传不过去)    paramsURL.append("?flag=" + URLEncoder.encode("&", "utf-8"));    URI uri = URI.create(paramsURL.toString());        //  -------------------------------> 执行请求并返回结果    // 此处的泛型  对应 响应体数据   类型;    // 即:这里指定响应体的数据装配为String    ResponseEntity<String> response =         restTemplate.exchange(uri, HttpMethod.GET, httpEntity, String.class);        // -------------------------------> 响应信息    //响应码,如:401、302、404、500、200等    System.err.println(response.getStatusCodeValue());    Gson gson = new Gson();    // 响应头    System.err.println(gson.toJson(response.getHeaders()));    // 响应体    if(response.hasBody()) {      System.err.println(response.getBody());    }      }

public void doHttpPostTest() throws UnsupportedEncodingException {  // 获取Rest客户端实例  RestTemplate restTemplate = new RestTemplate();    //  解决(响应数据可能)中文乱码 的问题  List<HttpMessageConverter<?>> converterList         = restTemplate.getMessageConverters();  converterList.remove(1); // 移除原来的转换器  // 设置字符编码为utf-8  HttpMessageConverter<?> converter         = new StringHttpMessageConverter(StandardCharsets.UTF_8);  // 添加新的转换器(注:convert顺序错误会导致失败)  converterList.add(1, converter);   restTemplate.setMessageConverters(converterList);    // (选择性设置)请求头信息  // HttpHeaders实现了MultiValueMap接口  HttpHeaders httpHeaders = new HttpHeaders();  // 设置contentType  httpHeaders.setContentType(MediaType.APPLICATION_JSON_UTF8);  // 给请求header中添加一些数据  httpHeaders.add("Java 学习部落", "这是一个学习java的公众号 !");    // 将请求头、请求体数据，放入HttpEntity中  // 请求体的类型任选即可;只要保证 请求体 的类型与HttpEntity类的泛型保持一致即可  // 这里手写了一个json串作为请求体 数据 (实际开发时,可使用fastjson、gson等工具将数据转化为json串)  String httpBody = "{\"motto\":\"java真强大啊 ！\"}";  HttpEntity<String> httpEntity             = new HttpEntity<String>(httpBody, httpHeaders);   // URI  StringBuffer paramsURL         = new StringBuffer("http://127.0.0.1:8080/restTemplate/doHttpPost");  // 字符数据最好encoding一下;这样一来，某些特殊字符才能传过去(如:flag的参数值就是“&”,不encoding的话,传不过去)  paramsURL.append("?flag=" + URLEncoder.encode("&", "utf-8"));  URI uri = URI.create(paramsURL.toString());    // 执行请求并返回结果  // 此处的泛型  对应 响应体数据   类型;即:这里指定响应体的数据装配为String  ResponseEntity<String> response =       restTemplate.exchange(uri, HttpMethod.POST, httpEntity, String.class);    //  响应信息  //响应码,如:401、302、404、500、200等  System.err.println(response.getStatusCodeValue());  Gson gson = new Gson();  // 响应头  System.err.println(gson.toJson(response.getHeaders()));  // 响应体  if(response.hasBody()) {    System.err.println(response.getBody());  }}

<dependency>
    <groupId>com.netflix.feign</groupId>
    <artifactId>feign-core</artifactId>
</dependency>
<dependency>
    <groupId>io.github.openfeign</groupId>
    <artifactId>feign-core</artifactId>
</dependency>

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-feign</artifactId>
</dependency>

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-openfeign</artifactId>
</dependency>

public interface GitHub {
  @RequestLine("GET /repos/{owner}/{repo}/contributors")  List<Contributor> contributors(@Param("owner") String owner, @Param("repo") String repository);
  class Contributor {    String login;    int contributions;  }}
public class MyApp {  public static void main(String[] args) {    GitHub github = Feign.builder()                         .decoder(new GsonDecoder())                         .target(GitHub.class, "https://api.github.com");
    /* The owner and repository parameters will be used to expand the owner and repo expressions     * defined in the RequestLine.     *     * the resulting uri will be https://api.github.com/repos/OpenFeign/feign/contributors     */    github.contributors("OpenFeign", "feign");  }}

        <dependency>            <groupId>org.springframework.cloud</groupId>            <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>        </dependency>        <dependency>            <groupId>org.springframework.cloud</groupId>            <artifactId>spring-cloud-starter-openfeign</artifactId>        </dependency>

package com.javaer.study.openfeginclient;
import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;import org.springframework.cloud.netflix.eureka.EnableEurekaClient;import org.springframework.cloud.openfeign.EnableFeignClients;
/** * @Author 公众号【Java学习部落】 * * 关注公众号获取4000G精品视频资源 * * 更有更多学习Java后端、中间件，大数据、微服务、分布式、大数据等学习干货 **/@SpringBootApplication@EnableFeignClients@EnableEurekaClientpublic class OpenfeginclientApplication {
    public static void main(String[] args) {        SpringApplication.run(OpenfeginclientApplication.class, args);    }
}

server:  port: 8888spring:  application:    name: spring-cloud-feign-openClienteureka:  client:    service-url:      defaultZone: http://localhost:8761/eureka/

package com.javaer.study.openfeginclient;
import org.springframework.cloud.openfeign.FeignClient;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestMethod;import org.springframework.web.bind.annotation.RequestParam;
/** * 一个可以调用的客户端 * * @author topJavaer * 公众号：【Java学习部落】 * @create 2020 11 10 * @Version 1.0.0 *///@FeignClient 即是指定客户端信息注解，务必声明在接口上面，url手动指定了客户端的接口地址@FeignClient(name = "github-client", url = "https://api.github.com")public interface GitHubApiClient {    @RequestMapping(value = "/search/repositories", method = RequestMethod.GET)    String searchRepositories(@RequestParam("q") String queryStr);}

package com.javaer.study.openfeginclient;
import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestParam;import org.springframework.web.bind.annotation.RestController;
import javax.annotation.Resource;
/** * 测试类 * * @author topJavaer * 公众号：【Java学习部落】 * @create 2020 11 10 * @Version 1.0.0 */
@RestControllerpublic class GitHubApiTest {    @Resource    private GitHubApiClient gitHubApiClient;
    @RequestMapping("/search/github/repository")    public String searchGithubRepositoryByName(@RequestParam("name") String repositoryName) {        return gitHubApiClient.searchRepositories(repositoryName);    }}

package org.springframework.cloud.netflix.feign; import java.lang.annotation.Documented; import java.lang.annotation.ElementType; import java.lang.annotation.Retention; import java.lang.annotation.RetentionPolicy; import java.lang.annotation.Target; import org.springframework.core.annotation.AliasFor; 
@Target(ElementType.TYPE) @Retention(RetentionPolicy.RUNTIME) @Documented public @interface FeignClient {   @AliasFor("name") String value() default "";   @Deprecated String serviceId() default "";  @AliasFor("value")   String name() default "";   String qualifier() default "";   String url() default "";   boolean decode404() default false;   Class<?>[] configuration() default {};   Class<?> fallback() default void.class;   Class<?> fallbackFactory() default void.class;   String path() default "";   boolean primary() default true; }

      # 开启GZIP压缩配置      #请求GZIP压缩      feign.compression.request.enable=true                       #响应GIZP压缩      feign.compression.response.enable=true                    #压缩支持的mime type      feign.compression.request.mime-types=text/xml,application/xml.application/json                        feign.compression.request.min-request-size=1024               #压缩数据大小的最小值

NONE 表示不输出日志。
BASIC 表示只输出请求方法的 URL 和响应的状态码以及执行的时间。
HEADERS 将 BASIC 信息和请求头信息输出。
FULL 会输出全部完整的请求信息。

logging:  level:    com.javaer.study: debug
feign:  client:    config:      # 要调用服务的名称      java-master:        loggerLevel: full

### Ribbon 配置ribbon:  # 连接超时  ConnectTimeout: 2000  # 响应超时  ReadTimeout: 5000

### Feign 配置feign:  # 开启断路器（熔断器）  hystrix:    enabled: true

### Hystrix 配置hystrix:  # 这样将会自动配置一个 Hystrix 并发策略插件的 hook，这个 hook 会将 SecurityContext 从主线程传输到 Hystrix 的命令。  # 因为 Hystrix 不允许注册多个 Hystrix 策略，所以可以声明 HystrixConcurrencyStrategy  # 为一个 Spring bean 来实现扩展。Spring Cloud 会在 Spring 的上下文中查找你的实现，并将其包装在自己的插件中。  shareSecurityContext: true  command:    default:      circuitBreaker:        # 当在配置时间窗口内达到此数量的失败后，进行短路。默认20个        requestVolumeThreshold: 1        # 触发短路的时间值，当该值设为5000时，则当触发 circuit break 后的5000毫秒内都会拒绝request        # 也就是5000毫秒后才会关闭circuit。默认5000        sleepWindowInMilliseconds: 15000        # 强制打开熔断器，如果打开这个开关，那么拒绝所有request，默认false        forceOpen: false        # 强制关闭熔断器 如果这个开关打开，circuit将一直关闭且忽略，默认false        forceClosed: false      execution:        isolation:          thread:            # 熔断器超时时间，默认：1000/毫秒            timeoutInMilliseconds: 5000

#断路器的超时时长需要大于Ribbon的超时时间，不然不会触发重试hystrix.command.default.execution.isolation.thread.timeoutInMilliseconds=10000
#请求连接超时时间fegin-service.ribbon.ConnectTimeout=500#请求处理的超时时间fegin-service.ribbon.ReadTimeout=1000#对所有请求都进行重试(是否所有操作都重试，若false则仅get请求重试)fegin-service.ribbon.OkToRetryOnAllOperations=true#对当前实例的重试次数fegin-service.ribbon.MaxAutoRetries=1#切换实例的重试次数fegin-service.ribbon.MaxAutoRetriesNextServer=2