OpenFeign根据服务名动态调用服务

本文作为springboot注解Aspect文章的补充，切面拦截方法，将方法所有信息及服务名称持久化到数据库。
审批的时候，从数据库获取服务名称动态调用服务。

实体类

示例中的响应实体类

@Getter
@Setter
public class Response<T> {

    private String code;
    private String msg;
    private String description;
    private T data;
}

示例中的方法参数实体类

@Getter
@Setter
public class ProcessCheckDTO {

	private ProcessCheckModel processCheckModel;
	
	private MethodInfo methodInfo;
}

@Setter
@Getter
public class ProcessCheckModel {
	
	/**
	 * 0-审批通过 1-审批拒绝
	 */
	private String checkType;
	
	/**
	 * 审批拒绝原因
	 */
	private String reason;
}

拦截的方法实体类

@Getter
@Setter
public class MethodInfo {
	
	//，项目名称
	private String appName;

	//bean的目标类全限定名
	private String targetClassName;
	
	//拦截到的service方法名
	private String methodName;
	
	//拦截到的service入参类型，包含泛型信息
	private String paramTypes;
	
	//拦截到的service入参值
	private String paramArgs;
	
}

下面的才是最重要的

先写一个FeignCient接口

/**
 * 接口上不需要任何注解
 */
public interface ProcessClientApi {

	@PostMapping(value = "/processCheck", consumes = MediaType.APPLICATION_JSON_VALUE)
	public Response<?> process(@RequestBody ProcessCheckDTO processCheckDTO);
}

再写一个Bean用来动态获取ProcessClientApi

import java.util.HashMap;
import java.util.Map;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.openfeign.FeignClientBuilder;
import org.springframework.context.ApplicationContext;
import org.springframework.stereotype.Component;

@Component
public class DynamicProcessFeign {
	
	//缓存feignClient，提高客户端性能
	private static volatile Map<String, ProcessClientApi> processMap = new HashMap<>();

	private FeignClientBuilder feignClientBuilder;
	
	public DynamicProcessFeign(@Autowired ApplicationContext appContext) {
        this.feignClientBuilder = new FeignClientBuilder(appContext);
    }
	
	public ProcessClientApi getFeignClient(String seviceName) {
		ProcessClientApi api = processMap.get(seviceName);
		if (api != null) {
			return api;
		}
		synchronized (DynamicProcessFeign.class) {
			api = processMap.get(seviceName);
			if (api != null) {
				return api;
			}
			api = this.feignClientBuilder.forType(ProcessClientApi.class, seviceName).build();
			processMap.put(seviceName, api);
		}
        return api;
    }
}

使用

private void process(ProcessRecordExecuteVO vo) {
		ProcessCheckDTO processCheckDTO = new ProcessCheckDTO();
		ProcessCheckModel processCheckModel = new ProcessCheckModel();
		processCheckModel.setCheckType(vo.getAccept());
		processCheckModel.setReason(vo.getReason());
		processCheckDTO.setProcessCheckModel(processCheckModel);
		ProcessMethodInfo processMethodInfo = processMethodInfoMapper.selectById(vo.getBatchId());
		if (processMethodInfo == null) {
			throw new BizException("未找到数据");
		}
		MethodInfo methodInfo = new MethodInfo();
		methodInfo.setAppName(processMethodInfo.getAppName());
		methodInfo.setTargetClassName(processMethodInfo.getTargetClassName());
		methodInfo.setMethodName(processMethodInfo.getMethodName());
		methodInfo.setParamTypes(processMethodInfo.getParamTypes());
		methodInfo.setParamArgs(processMethodInfo.getParamArgs());
		processCheckDTO.setMethodInfo(methodInfo);
		
		/*
		 * 下面的两行代码是动态调用服务的用法
		 */
		
		//传入服务名称获取对应的FeignClient
		ProcessClientApi processClientApi = dynamicProcessFeign.getFeignClient(methodInfo.getAppName());
		//通过OpenFeign调用远程服务
		processClientApi.process(processCheckDTO);
	}