本文主要是介绍Java封装Azkaban相关API,希望对大家解决编程问题提供一定的参考价值,需要的开发者们随着小编来一起学习吧!
Java封装Azkaban相关API
版本说明:
azkaban:3.43.0
jdk:1.8
项目地址:https://github.com/shirukai/azkaban-java-api.git
1 前言
之前在项目开发记录中,写到过两篇文章《利用AOP对Azkaban进行登录控制》和 《Java调用Azkaban相关服务》,记录了在开发过程中使用spring的aop对azkaban进行了登录控制,以及使用Java请求azkaban相关的服务。总的来说,能够完成基本的需求,但是还是存在一些问题,比如:
- 深度依赖Spring,利用AOP切面进行的登录控制以及RestTemplate的HTTP请求
- Azkaban本身REST API缺陷,响应风格不统一,导致在之前的Java调用Azakban相关服务时候,请求响应统一被当做字符串处理,后期根据需要单独处理,不友好。
- 登录控制不精确
为解决如上问题,进行了代码重构。对于Azkaban API的请求脱离Spring的RestTemplate使用http-client的fluent,统一了请求响应,使用动态代理替换之前Spring的AOP,使用构建器使封装的Azkaban API支持可插拔,可以脱离Spring使用也可以整合Spring0。
2 统一Azkaban响应
这里为什么要统一Azkaban响应呢?我们先看一下官网关于API的说明文档。
上图截了一个登录响应描述的图,看这个描述,参数是error,描述如果登录失败会返回错误信息,参数session.id 如果登录成功返回session.id。响应内容不定,还有条件语句,有错误也不报个错误码,也没有个状态描述。如果单纯是这样的逻辑就算了,看如下的官网给的简单实例
{"status" : "success","session.id" : "c001aba5-a90f-4daf-8f11-62330d034c0a"
}
what?怎么还有个status?意义何在,响应成功,我就给你返回一个"status":“success”,失败了,直接返回"error":“info”,难道不应该返回一个"status":"error"吗?对于其它的接口,响应也有不同的呈现,难道对响应的处理逻辑还要一个API一个嘛。所以这里为了解决响应不统一的问题,对Azkaban的响应结果进行了一层封装。
2.1 创建响应实体类
如下所示为响应实体类,其中BaseResponse为响应基类。
BaseResponse内容如下,其中为了映射Azkaban的响应,既包含了"status"又包含了"error",最后通过correction会更正信息到"status",所以我们可以统一对"status"进行判断是否执行成功。内容如下:
package com.azkaban.response;import java.util.Objects;/*** Created by shirukai on 2019-06-01 15:03*/
public class BaseResponse {public static final String SUCCESS = "success";public static final String ERROR = "error";/*** 响应状态*/private String status;/*** 错误类型(单纯为了映射Azkaban)*/private String error;/*** 详细信息*/private String message;public String getStatus() {return status;}public void setStatus(String status) {this.status = status;}public String getError() {return error;}public void setError(String error) {this.error = error;}public String getMessage() {return message;}public void setMessage(String message) {this.message = message;}/*** 更正信息*/public void correction() {if (!ERROR.equals(this.status) && Objects.isNull(this.error)) {this.status = SUCCESS;} else {this.status = ERROR;if (Objects.isNull(this.error)) {this.error = this.message;} else if (Objects.isNull(this.message)) {this.message = this.error;}}}
}
2.2 响应处理器
为了统一响应,这里使用响应处理器,对Azkaban响应进行统一处理,内容如下:
package com.azkaban.response;import com.alibaba.fastjson.JSONObject;
import org.apache.http.HttpEntity;
import org.apache.http.client.fluent.Request;
import org.apache.http.client.fluent.Response;
import org.apache.http.util.EntityUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;import java.util.Objects;/*** Created by shirukai on 2019-06-01 14:58* 响应处理器*/
public class ResponseHandler {private static Logger log = LoggerFactory.getLogger(ResponseHandler.class);public static <T extends BaseResponse> T handle(Request request, Class<T> tClass) {T response = null;try {Response res = request.execute();HttpEntity entity = res.returnResponse().getEntity();response = handle(entity, tClass);} catch (Exception e) {try {response = tClass.newInstance();response.setStatus(T.ERROR);response.setError(e.getMessage());response.correction();} catch (Exception ea) {log.warn(ea.getMessage());}}return response;}public static BaseResponse handle(Request request) {return handle(request, BaseResponse.class);}public static BaseResponse handle(String content) {return handle(content, BaseResponse.class);}public static <T extends BaseResponse> T handle(HttpEntity entity, Class<T> tClass) {T response = null;try {String content = EntityUtils.toString(entity);response = handle(content, tClass);} catch (Exception e) {log.warn(e.getMessage());}return response;}public static <T extends BaseResponse> T handle(String content, Class<T> tClass) {T response = null;try {response = JSONObject.parseObject(content, tClass);if (Objects.nonNull(response.getError())) {response.setStatus(T.ERROR);}response.correction();} catch (Exception e) {try {response = tClass.newInstance();response.setStatus(T.ERROR);response.setError(content);response.correction();} catch (Exception ea) {log.warn(ea.getMessage());}}return response;}
}
3 API 接口及实现
这里整理了常用的14种常见的Azkaban的API,在使用Java实现之前,使用Postman测试过,并生成了一份postman的接口文档,可以访问https://documenter.getpostman.com/view/2759292/S1TbUaeU查看。
3.1 创建API接口类
在com.azkaban.api包下创建AzkabanApi接口类,提供Azkaban相对应API的接口,内容如下所示:
package com.azkaban.api;import com.azkaban.response.*;/*** Created by shirukai on 2019-06-01 20:12* azkaban api 接口*/
public interface AzkabanApi {/*** 创建项目 API** @param name 项目名称* @param desc 项目描述* @return BaseResponse*/BaseResponse createProject(String name, String desc);/*** 删除项目 API** @param name 项目名称* @return BaseResponse*/BaseResponse deleteProject(String name);/*** 上传Zip API** @param filePath zip文件路径* @param projectName 项目名称* @return ProjectZipResponse*/ProjectZipResponse uploadProjectZip(String filePath, String projectName);/*** 查询项目Flows** @param projectName 项目名称* @return FetchFlowsResponse*/FetchFlowsResponse fetchProjectFlows(String projectName);/*** 执行flow** @param projectName 项目名称* @param flowName flow名称* @return ExecuteFlowResponse*/ExecuteFlowResponse executeFlow(String projectName, String flowName);/*** 取消执行flow** @param execId 执行ID* @return BaseResponse*/BaseResponse cancelFlow(String execId);/*** 查询执行Flow信息** @param execId 执行ID* @return FetchExecFlowResponse*/FetchExecFlowResponse fetchExecFlow(String execId);/*** 查询执行Job的日志** @param execId 执行ID* @param jobId JobID* @param offset 起始位置* @param length 长度* @return FetchExecJobLogs*/FetchExecJobLogs fetchExecJobLogs(String execId, String jobId, int offset, int length);/*** 查询Flow的执行记录** @param projectName 项目名称* @param flowName flow名称* @param start 开始位置* @param length 查询条数* @return FetchFlowExecutionsResponse*/FetchFlowExecutionsResponse fetchFlowExecutions(String projectName, String flowName, int start, int length);/*** 查询所有项目** @return FetchAllProjectsResponse*/FetchAllProjectsResponse fetchAllProjects();/*** 设置定时任务** @param projectName 项目名称* @param flowName Flow名称* @param cronExpression cron表达式* @return ScheduleCronFlowResponse*/ScheduleCronFlowResponse scheduleCronFlow(String projectName, String flowName, String cronExpression);/*** 查询定时任务** @param projectId 项目ID* @param flowId Flow ID* @return FetchScheduleResponse*/FetchScheduleResponse fetchSchedule(String projectId, String flowId);/*** 移除定时任务** @param scheduleId schedule ID* @return BaseResponse*/BaseResponse removeSchedule(String scheduleId);
}
3.2 创建接口实现类
接口有了,接下来就是实现接口,创建AzkabanApiImpl实现类,其中请求主要使用了http-client的fluent,内容如下:
package com.azkaban.api;import com.azkaban.response.*;
import org.apache.commons.lang3.StringUtils;
import org.apache.http.HttpEntity;
import org.apache.http.client.fluent.Form;
import org.apache.http.client.fluent.Request;
import org.apache.http.client.fluent.Response;
import org.apache.http.entity.mime.MultipartEntityBuilder;
import org.apache.http.util.EntityUtils;import java.io.File;
import java.io.IOException;
import java.text.MessageFormat;/*** Created by shirukai on 2019-05-31 16:46* Azkaban 操作相关API实现类*/
public class AzkabanApiImpl implements AzkabanApi {private String username;private String password;private String uri;private String sessionId = "b1d4f665-f4b9-4e7d-b83a-b928b41cc323";private static final String DELETE_PROJECT = "{0}/manager?delete=true&project={1}&session.id={2}";private static final String FETCH_PROJECT_FLOWS = "{0}/manager?ajax=fetchprojectflows&session.id={1}&project={2}";private static final String EXECUTE_FLOW = "{0}/executor?ajax=executeFlow&session.id={1}&project={2}&flow={3}";private static final String CANCEL_FLOW = "{0}/executor?ajax=cancelFlow&session.id={1}&execid={2}";private static final String FETCH_EXEC_FLOW = "{0}/executor?ajax=fetchexecflow&session.id={1}&execid={2}";private static final String FETCH_EXEC_JOB_LOGS = "{0}/executor?ajax=fetchExecJobLogs&session.id={1}&execid={2}" +"&jobId={3}&offset={4}&length={5}";private static final String FETCH_FLOW_EXECUTIONS = "{0}/manager?ajax=fetchFlowExecutions&session.id={1}" +"&project={2}&flow={3}&start={4}&length={5}";private static final String FETCH_ALL_PROJECTS = "{0}/index?ajax=fetchuserprojects&session.id={1}";private static final String SCHEDULE_CRON_FLOW = "{0}/schedule?ajax=scheduleCronFlow&session.id={1}&" +"projectName={2}&flow={3}&cronExpression={4}";private static final String FETCH_SCHEDULE = "{0}/schedule?ajax=fetchSchedule&session.id={1}&projectId={2}&flowId={3}";public AzkabanApiImpl(String uri, String username, String password) {this.uri = uri;this.username = username;this.password = password;}/*** 登录 API** @return LoginResponse*/public LoginResponse login() throws IOException {Response res = Request.Post(uri).bodyForm(Form.form().add("action", "login").add("username", username).add("password", password).build()).execute();HttpEntity entity = res.returnResponse().getEntity();String content = EntityUtils.toString(entity).replace("session.id", "sessionId");LoginResponse response = ResponseHandler.handle(content, LoginResponse.class);if (StringUtils.isNotEmpty(response.getSessionId())) {this.sessionId = response.getSessionId();}return response;}@Overridepublic BaseResponse createProject(String name, String desc) {Request res = Request.Post(uri + "/manager").bodyForm(Form.form().add("session.id", sessionId).add("action", "create").add("name", name).add("description", desc).build());return ResponseHandler.handle(res);}@Overridepublic BaseResponse deleteProject(String name) {Request res = Request.Get(MessageFormat.format(DELETE_PROJECT, uri, name, sessionId));return ResponseHandler.handle(res);}@Overridepublic ProjectZipResponse uploadProjectZip(String filePath, String projectName) {HttpEntity entity = MultipartEntityBuilder.create().addBinaryBody("file", new File(filePath)).addTextBody("session.id", sessionId).addTextBody("ajax", "upload").addTextBody("project", projectName).build();Request res = Request.Post(uri + "/manager").body(entity);return ResponseHandler.handle(res, ProjectZipResponse.class);}@Overridepublic FetchFlowsResponse fetchProjectFlows(String projectName) {Request res = Request.Get(MessageFormat.format(FETCH_PROJECT_FLOWS, uri, sessionId, projectName));return ResponseHandler.handle(res, FetchFlowsResponse.class);}@Overridepublic ExecuteFlowResponse executeFlow(String projectName, String flowName) {Request res = Request.Post(MessageFormat.format(EXECUTE_FLOW, uri, sessionId, projectName, flowName));return ResponseHandler.handle(res, ExecuteFlowResponse.class);}@Overridepublic BaseResponse cancelFlow(String execId) {Request res = Request.Post(MessageFormat.format(CANCEL_FLOW, uri, sessionId, execId));return ResponseHandler.handle(res);}@Overridepublic FetchExecFlowResponse fetchExecFlow(String execId) {Request res = Request.Get(MessageFormat.format(FETCH_EXEC_FLOW, uri, sessionId, execId));return ResponseHandler.handle(res, FetchExecFlowResponse.class);}@Overridepublic FetchExecJobLogs fetchExecJobLogs(String execId, String jobId, int offset, int length) {Request res = Request.Get(MessageFormat.format(FETCH_EXEC_JOB_LOGS, uri, sessionId, execId, jobId, String.valueOf(offset),String.valueOf(length)));return ResponseHandler.handle(res, FetchExecJobLogs.class);}@Overridepublic FetchFlowExecutionsResponse fetchFlowExecutions(String projectName,String flowName,int start,int length) {Request res = Request.Get(MessageFormat.format(FETCH_FLOW_EXECUTIONS, uri, sessionId, projectName, flowName,String.valueOf(start), String.valueOf(length)));return ResponseHandler.handle(res, FetchFlowExecutionsResponse.class);}@Overridepublic FetchAllProjectsResponse fetchAllProjects() {Request res = Request.Get(MessageFormat.format(FETCH_ALL_PROJECTS, sessionId));return ResponseHandler.handle(res, FetchAllProjectsResponse.class);}@Overridepublic ScheduleCronFlowResponse scheduleCronFlow(String projectName, String flowName, String cronExpression) {Request res = Request.Post(MessageFormat.format(SCHEDULE_CRON_FLOW, uri, sessionId, projectName, flowName, cronExpression));return ResponseHandler.handle(res, ScheduleCronFlowResponse.class);}@Overridepublic FetchScheduleResponse fetchSchedule(String projectId, String flowId) {Request res = Request.Get(MessageFormat.format(FETCH_SCHEDULE, uri, sessionId, projectId, flowId));return ResponseHandler.handle(res, FetchScheduleResponse.class);}@Overridepublic BaseResponse removeSchedule(String scheduleId) {Request res = Request.Post(uri + "/schedule").bodyForm(Form.form().add("session.id", sessionId).add("action", "removeSched").add("scheduleId", scheduleId).build());return ResponseHandler.handle(res);}
}
4 利用动态代理实现登录控制
思想与之前的AOP一样,在代理方法执行完成后,判断执行结果是否异常,如果异常,调用login方法,进行Azkaban登录,然后重新执行代理方法。
4.1 创建ApiInvocationHandler
ApiInvocationHander继承java.lang.reflect.InvocationHandler,重写invoke()方法,是动态代理的调用处理器。其中主要实现了三个功能,一个是代理AzkabanApiImpl提供的方法,二是判断执行结果是否异常,如果异常进行登录,三是进行统一的异常处理。代码如下:
package com.azkaban.proxy;import com.azkaban.api.AzkabanApiImpl;
import com.azkaban.response.BaseResponse;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;import java.lang.reflect.Field;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;
import java.util.Objects;/*** Created by shirukai on 2019-06-01 20:17* API 动态代理处理类*/
public class ApiInvocationHandler implements InvocationHandler {/*** api 接口实现类实例*/private AzkabanApiImpl azkabanApi;/*** 重试次数*/private static final Integer RETRY = 2;/*** object默认方法*/private List<String> defaultMethods;private static Logger log = LoggerFactory.getLogger(ApiInvocationHandler.class);ApiInvocationHandler(AzkabanApiImpl azkabanApi) {this.azkabanApi = azkabanApi;this.defaultMethods = new ArrayList<>(16);for (Method method : Object.class.getMethods()) {this.defaultMethods.add(method.getName());}}/*** 判断是否为默认方法** @param methodName 方面名称* @return boolean*/private boolean isDefault(String methodName) {return this.defaultMethods.contains(methodName);}/*** 重写动态代理invoke方法** @param proxy 代理实例* @param method 方法* @param args 参数* @return 执行结果*/@Overridepublic Object invoke(Object proxy, Method method, Object[] args) {Object result = null;int tryTime = 1;try {while (tryTime <= RETRY) {// 指定代理方法result = method.invoke(azkabanApi, args);// 判断是否执行成功if (Objects.nonNull(result) && !this.isDefault(method.getName())) {Class superClass = result.getClass().getSuperclass();if (Object.class.equals(superClass)) {superClass = result.getClass();}Field field = superClass.getDeclaredField("status");field.setAccessible(true);if (BaseResponse.SUCCESS.equals(field.get(result))) {log.info("Execute the azkaban's API {} successfully.", method.getName());return result;}azkabanApi.login();}tryTime++;}} catch (Exception e) {// 如果返回结果为null,捕获异常并实重新生成结果实例,设置异常信息if (Objects.isNull(result)) {Class returnType = method.getReturnType();try {Object response = returnType.newInstance();if (response instanceof BaseResponse) {BaseResponse baseResponse = (BaseResponse) response;baseResponse.setStatus(BaseResponse.ERROR);if (e instanceof InvocationTargetException) {baseResponse.setMessage(((InvocationTargetException) e).getTargetException().getMessage());} else {baseResponse.setMessage(e.getMessage());}baseResponse.correction();result = response;}} catch (InstantiationException | IllegalAccessException ex) {ex.printStackTrace();}}}return result;}}
4.2 创建AzkabanApiProxyBuilder
AzkabanApiProxyBuilder是动态代理的构建器,通过构建器能够构建出代理的AzkabanApi实例。构建器需要传入azkaban的服务地址、用户名、密码。代码如下:
package com.azkaban.proxy;import com.azkaban.api.AzkabanApi;
import com.azkaban.api.AzkabanApiImpl;import java.lang.reflect.Proxy;/*** Created by shirukai on 2019-06-01 22:26* azkaban api Builder*/
public class AzkabanApiProxyBuilder {private String uri;private String username;private String password;private AzkabanApiProxyBuilder() {}public static AzkabanApiProxyBuilder create() {return new AzkabanApiProxyBuilder();}public AzkabanApiProxyBuilder setUri(String uri) {this.uri = uri;return this;}public AzkabanApiProxyBuilder setUsername(String username) {this.username = username;return this;}public AzkabanApiProxyBuilder setPassword(String password) {this.password = password;return this;}public AzkabanApi build() {AzkabanApiImpl impl = new AzkabanApiImpl(this.uri, this.username, this.password);ApiInvocationHandler handler = new ApiInvocationHandler(impl);return (AzkabanApi) Proxy.newProxyInstance(impl.getClass().getClassLoader(),impl.getClass().getInterfaces(),handler);}}
5 两种方式调用API
5.1 普通方式调用
无论在什么时候使用,只要使用代理构建器构建出AzkabanApi实例即可。如下代码所示:
@Testpublic void builder() {AzkabanApi apis = AzkabanApiProxyBuilder.create().setUri("http://localhost:8666").setUsername("azkaban").setPassword("azkaban").build();}
5.2 整合Spring
通过AzkabanApiConfig类,创建Bean注册到Spring里,代码如下所示:
package com.azkaban.config;import com.azkaban.api.AzkabanApi;
import com.azkaban.proxy.AzkabanApiProxyBuilder;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;/*** Created by shirukai on 2019-06-03 11:05* 配置API,创建Bean,并注入Spring*/
@Configuration
public class AzkabanApiConfig {@Value("${azkaban.url}")private String uri;@Value("${azkaban.username}")private String username;@Value("${azkaban.password}")private String password;@Beanpublic AzkabanApi azkabanApi() {return AzkabanApiProxyBuilder.create().setUri(uri).setUsername(username).setPassword(password).build();}
}
调用
@Autowiredprivate AzkabanApi azkabanApi;
6 总结
之前写过两篇关于Azkaban的文章,都是关于使用Java调用Azkaban的API。其中有同学问具体代码,这次把重构后的代码提交到了github上了,项目地址:https://github.com/shirukai/azkaban-java-api.git。
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