一、Feign的使用（客户端调用 json/xml格式的接口）
1.服务端接口编写
org.springframework.boot spring-boot-starter-parent 2.0.2.RELEASE org.springframework.boot spring-boot-starter-web com.fasterxml.jackson.jaxrs jackson-jaxrs-xml-provider 2.9.0
@RequestMapping(value = "/hello", method = RequestMethod.GET) public String hello() { return "hello world"; } @RequestMapping(value = "/person/create", method = RequestMethod.POST, produces = MediaType.APPLICATION_JSON_VALUE, consumes = MediaType.APPLICATION_JSON_VALUE) public String createPerson(@RequestBody Person person) { System.out.println(person.getName() + "~~~~~~~" +person.getAge()); return "success, id:" + person.getId(); } @RequestMapping(value = "/createXmlPerson/create", method = RequestMethod.POST, produces = MediaType.APPLICATION_XML_VALUE, consumes = MediaType.APPLICATION_XML_VALUE) public String createXmlPerson(@RequestBody Person person) { System.out.println(person.getName() + "~~~~~~~" +person.getAge()); return " success "; } 2.客户端编写
（1）导入jar包
io.github.openfeign feign-core 9.5.0 io.github.openfeign feign-gson 9.5.0 io.github.openfeign feign-jaxb 9.5.0 org.projectlombok lombok 1.16.20 javax.xml.bind jaxb-api 2.3.0 org.apache.httpcomponents httpclient 4.5.5
（2）编写客户端测试代码
public interface ClientInterface { @RequestLine("GET /hello") public String hello(); @RequestLine("GET /person/{id}") public Person getPerson(@Param("id") Integer id); @RequestLine("POST /person/create") @Headers("Content-Type: application/json") public String createPerson(Person person); @RequestLine("POST /createXmlPerson/create") @Headers("Content-Type: application/xml") public Result createXmlPerson(Person person);} public static void main(String[] args) { //hello ClientInterface helloClient = Feign.builder().target(ClientInterface.class, "http://localhost:8080"); String hello = helloClient.hello(); System.out.println(hello); //json 创建 Person ClientInterface creatPersonInter = Feign.builder() .encoder(new GsonEncoder()) .target(ClientInterface.class, "http://localhost:8080"); Person person = new Person(); person.setAge(18); person.setId(1); person.setName("admin"); String result = creatPersonInter.createPerson(person); System.out.println("result:" + result); //xml 创建 Person JAXBContextFactory jaxbContextFactory = new JAXBContextFactory.Builder().build(); ClientInterface xmlClient = Feign.builder().encoder(new JAXBEncoder(jaxbContextFactory)) .decoder(new JAXBDecoder(jaxbContextFactory)) .target(ClientInterface.class, "http://localhost:8080/"); Person person1 = new Person(); person1.setAge(18); person1.setId(1); person1.setName("admin"); Result result2 = xmlClient.createXmlPerson(person1); System.out.println("result:"+result2.getMessage()); }
二、自定义Feign客户端
1.编写myClient
import feign.Client;import feign.Request;import feign.Response;import org.apache.http.HttpResponse;import org.apache.http.client.methods.HttpRequestBase;import org.apache.http.impl.client.CloseableHttpClient;import org.apache.http.impl.client.HttpClients;import org.apache.http.util.EntityUtils;import java.io.IOException;import java.net.URI;import java.net.URISyntaxException;import java.util.Collection;import java.util.HashMap;public class MyClient implements Client { @Override public Response execute(Request request, Request.Options options) throws IOException { try { System.out.println("自定义的client"); //创建一个默认的客户端 CloseableHttpClient httpClient = HttpClients.createDefault(); //获取调用的http方法 final String method = request.method(); //创建一个HttpClient 的 HttpRequest HttpRequestBase httpRequestBase = new HttpRequestBase() { @Override public String getMethod() { return method; } }; //设置请求地址 httpRequestBase.setURI(new URI(request.url())); //执行请求，获取响应 HttpResponse httpResponse = httpClient.execute(httpRequestBase); //获取响应的内容 byte[] body = EntityUtils.toByteArray(httpResponse.getEntity()); //将HttpClient d的响应对象转换为Feign的Response Response response = Response.builder() .body(body) .headers(new HashMap >()) .status(httpResponse.getStatusLine().getStatusCode()) .build(); return response; } catch (URISyntaxException e) { e.printStackTrace(); } return null; }} 2.编写MyClientTest测试
public static void main(String[] args) { ClientInterface clientInterface = Feign.builder() .client(new MyClient()) .target(ClientInterface.class, "http://localhost:8080"); String hello = clientInterface.hello(); System.out.println(hello); }