本文主要介绍如何在springboot项目中使用feign来访问cnode中文公共api接口
一、fein简介
Feign使得 Java HTTP 客户端编写更方便。Feign 灵感来源于Retrofit、JAXRS-2.0和WebSocket。Feign最初是为了降低统一绑
定Denominator到HTTP API的复杂度，不区分是否支持Restful。Feign旨在通过最少的资源和代码来实现和HTTP API的连接。通过可
定制的解码器和错误处理，可以编写任意的HTTP API。
github:https://github.com/OpenFeign/feign
二、feign使用步骤
1、增加pom依赖
<dependency> <groupId>io.github.openfeign</groupId> <artifactId>feign-core</artifactId> <version>9.5.0</version> </dependency> <dependency> <groupId>io.github.openfeign</groupId> <artifactId>feign-slf4j</artifactId> <version>9.5.0</version> </dependency> <dependency> <groupId>io.github.openfeign</groupId> <artifactId>feign-hystrix</artifactId> <version>9.5.0</version> </dependency> <dependency> <groupId>io.github.openfeign</groupId> <artifactId>feign-jackson</artifactId> <version>9.5.0</version> </dependency>
2、application.properties增加基础url
application.cnode.url=https://cnodejs.org
3、写访问api的接口
@Headers("Content-Type:application/json") public interface NodeClient { @RequestLine("GET /api/v1/topics?page={page}&tab={tab}&limit={limit}&mdrender={mdrender}") CnodeTopicsResponse getTopics(@Param("page") int page,@Param("tab") String tab, @Param("limit")int limit,@Param("mdrender") String mdrender); } 4、使用注解，配置NodeClient,并设置等候响应时间
@Configuration public class NodeConfig { @Value("${application.cnode.url}") private String baseUrl; @Bean NodeClient nodeClient() throws InterruptedException { return HystrixFeign.builder() .decoder(new JacksonDecoder()) .encoder(new JacksonEncoder()) .setterFactory((target, method) -> new SetterFactory.Default().create(target, method). andCommandPropertiesDefaults(HystrixCommandProperties.defaultSetter(). withExecutionTimeoutInMilliseconds(10000))) .target(NodeClient.class, this.baseUrl); } } 5、配置controller
@RestController @CrossOrigin public class NodeController { private NodeClient nodeClient; @Autowired public NodeController(final NodeClient nodeClient) { this.nodeClient = nodeClient; } @RequestMapping(value = "/node",method = RequestMethod.GET) public CnodeTopicsResponse get(CnodeTopicsRequest cnodeTopicsRequest){ return nodeClient.getTopics(cnodeTopicsRequest.getPage(), cnodeTopicsRequest.getTab(), cnodeTopicsRequest.getLimit(), cnodeTopicsRequest.getMdrender()); } }
6、其中CnodeTopicsRequest和CnodeTopicsResponse如下
public class CnodeTopicsRequest { private Integer page; private String tab; private Integer limit; private String mdrender; public Integer getPage() { return page; } public void setPage(Integer page) { this.page = page; } public Integer getLimit() { return limit; } public void setLimit(Integer limit) { this.limit = limit; } public String getTab() { return tab; } public void setTab(String tab) { this.tab = tab; } public String getMdrender() { return mdrender; } public void setMdrender(String mdrender) { this.mdrender = mdrender; } } public class CnodeTopicsResponse { private boolean success; private List<CnodeArticle> data; public boolean isSuccess() { return success; } public void setSuccess(boolean success) { this.success = success; } public List<CnodeArticle> getData() { return data; } public void setData(List<CnodeArticle> data) { this.data = data; } } 6、然后启动application，访问链接： http://localhost:8080/node?page=1&limit=100&tab=&mdrender=false
