spring openfeign

pom

<?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>4.0.0</modelVersion>

    <groupId>dr.cqr</groupId>
    <artifactId>demor</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
        <java.version>1.8</java.version>
    </properties>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.13.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.mybatis/mybatis -->

        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>


        <!-- https://mvnrepository.com/artifact/org.springframework.cloud/spring-cloud-starter-openfeign -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
            <version>2.2.2.RELEASE</version>
        </dependency>
    </dependencies>
    <dependencyManagement>

    </dependencyManagement>

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

APPApplication

package dr.cqr;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.openfeign.EnableFeignClients;
import org.springframework.web.bind.annotation.RestController;

@SpringBootApplication
@RestController
// 它告诉 Spring 容器需要启用 Feign 客户端的功能，
// 并且会扫描项目中的 Feign 客户端接口，将其注册为 Spring Bean，
// 以便后续在项目中可以自动装配和使用这些 Feign 客户端。
// Feign默认情况下是启用重试机制的,会自动重新发送请求，最多尝试5次‌
@EnableFeignClients
public class APPApplication {
    public static void main(String[] args) {
        SpringApplication.run(APPApplication.class, args);
        System.out.println("################### 启动成功 ##################");
    }
}

feign

package dr.cqr.feign;

import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;

@FeignClient(name="test-name", url="http://192.168.1.2:8090", configuration = TestErrorDecoder.class)
public interface TestClient {

    @GetMapping("/api/qing")
    Object getQing(@RequestParam(required = false, name="name") String name);
}

Controller

package dr.cqr.controller;

import dr.cqr.feign.TestClient;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.Optional;

@RestController
@RequestMapping("/test")
public class Test {
    @Autowired
    private TestClient testClient;

    @GetMapping("/t")
    public String tt () {
        Object o = testClient.getQing(null);

        System.out.println(o);

        return "ok";
    }
}

package dr.cqr.feign;

import feign.FeignException;
import feign.Response;
import feign.codec.ErrorDecoder;

public class TestErrorDecoder implements ErrorDecoder {

    @Override
    public Exception decode(String methodKey, Response response) {

        System.out.println("methodKey " + methodKey);
        // 根据响应状态码和响应内容判断异常类型，并返回对应的自定义异常
        if (response.status() == 404) {
            System.out.println("11");
        } else if (response.status() == 500) {
            System.out.println("22");
        }

        // 返回默认异常
        return FeignException.errorStatus(methodKey, response);
    }
}