还有哪些网站可以做淘宝活动,重庆网站推广解决方案,江阴市住房和城乡建设局网站,wordpress能做app吗前言 习惯了Spring全家桶#xff0c;对spring的容器爱不释手。使用dropwizard#xff0c;看起来确实很轻#xff0c;然而#xff0c;真正使用的时候不得不面临一个问题。我们不可能一个resource就能把所有的业务逻辑囊括#xff01;那么#xff0c;必然就要有负责处理逻辑… 前言 习惯了Spring全家桶对spring的容器爱不释手。使用dropwizard看起来确实很轻然而真正使用的时候不得不面临一个问题。我们不可能一个resource就能把所有的业务逻辑囊括那么必然就要有负责处理逻辑的代码有要提取的公共的代码要做面向接口开发等等。按照简单的用法Java Bean就自己new只要通过Jersey提供的web能力发出去就好。这样写下来到处都需要new难以测试等等。目前我最care的是每个request过来都要new一堆重复的对象垃圾回收频繁。写个单例不就解决了是的当然要想到单例然后发现几乎所有的类都是设计成单例的。然后一堆单例的代码写的死。这就是样板代码。于是想到提取工具类算了不如用Dagger好了。 什么是Dagger Dagger是Java里开源的DI框架中最火的之一主要用在Android领域很多特性也多针对Android开发的。因为Android开发对省电性能之类的要求比较高因此抛弃了反射直接在编译级别生成工厂。详细学习测试Dagger2之helloworld原理探究 Demo Source https://github.com/Ryan-Miao/l4dropwizard structure .
├── pom.xml
├── readme.md
└── src└── main├── java│ └── com│ └── test│ ├── HelloWorldApplication.java│ ├── bundles│ │ └── ConnectivityBundle.java│ ├── configuration│ │ ├── HelloWorldConfiguration.java│ │ └── modules│ │ ├── ConnectAndReadConfig.java│ │ └── GithubApiConfig.java│ └── domain│ ├── connect│ │ ├── FeignClientBuilder.java│ │ ├── GithubClient.java│ │ └── GithubConnector.java│ ├── entiry│ │ ├── GithubUser.java│ │ └── Saying.java│ ├── exception│ │ └── UpstreamException.java│ ├── health│ │ └── TemplateHealthCheck.java│ ├── ioc│ │ ├── component│ │ │ └── GithubComponent.java│ │ └── module│ │ ├── ConfigurationModule.java│ │ ├── ConnectorModule.java│ │ └── ServiceModule.java│ ├── resource│ │ ├── GithubResource.java│ │ └── HelloWorldResource.java│ └── service│ ├── IGithubService.java│ └── impl│ └── GithubService.java└── resources└── config└── dev.yml 本文基于之前的dropwizard入门演进. 添加dagger依赖 在properties结点下新增 dagger.verion2.12/dagger.verion 在dependencies下新增
dependencygroupIdcom.google.dagger/groupIdartifactIddagger/artifactIdversion${dagger.verion}/version
/dependency 在build.plugins下新增plugin plugingroupIdorg.apache.maven.plugins/groupIdartifactIdmaven-compiler-plugin/artifactIdversion3.6.1/versionconfigurationsource${java.version}/sourcetarget${java.version}/targetencodingUTF-8/encodingannotationProcessorPathspathgroupIdcom.google.dagger/groupIdartifactIddagger-compiler/artifactIdversion${dagger.verion}/version/path/annotationProcessorPaths/configuration
/plugin 在IDEA设置中找到BuildCompilerAnnotation Processors, 选择Enable annotation processing. 创建一个Component 下面创建Component用来包容Resource类对外提供Resource类。新建com.test.domain.ioc.component.GithubComponent package com.test.domain.ioc.component;import com.test.domain.ioc.module.ServiceModule;
import com.test.domain.resource.GithubResource;
import dagger.Component;import javax.inject.Singleton;/*** Created by Ryan Miao on 10/26/17.*/
Singleton
Component(modules {ServiceModule.class})
public interface GithubComponent {GithubResource gitHubResource();
} 显然这个GithubResource需要注入一个service于是声明一个ServiceModule, 创建com.test.domain.ioc.module.ServiceModule package com.test.domain.ioc.module;import com.test.domain.service.IGithubService;
import com.test.domain.service.impl.GithubService;
import dagger.Module;
import dagger.Provides;import javax.inject.Singleton;/*** Created by Ryan Miao on 10/26/17.*/
Module(includes ConnectorModule.class)
public class ServiceModule {SingletonProvidespublic IGithubService githubService(GithubService service) {return service;}
} ServiceModule用来提供service注入service接着依赖connector层新建com.test.domain.ioc.module.ConnectorModule package com.test.domain.ioc.module;import com.test.domain.connect.FeignClientBuilder;
import dagger.Module;
import dagger.Provides;import javax.inject.Singleton;/*** Created by Ryan Miao on 10/26/17.*/
Module(includes ConfigurationModule.class)
public class ConnectorModule {ProvidesSingletonpublic FeignClientBuilder feignClientBuilder(){return new FeignClientBuilder();}} 在connecttor层中需要调用GlobalConfiguration的配置项所以单独把配置提出来引入。新增com.test.domain.ioc.module.ConfigurationModule package com.test.domain.ioc.module;import com.test.configuration.HelloWorldConfiguration;
import dagger.Module;
import dagger.Provides;import javax.inject.Singleton;/*** Created by Ryan Miao on 11/20/17.*/
Module
public class ConfigurationModule {private final HelloWorldConfiguration configuration;public ConfigurationModule(HelloWorldConfiguration configuration) {this.configuration configuration;}ProvidesSingletonpublic HelloWorldConfiguration helloWorldConfiguration(){return configuration;}
} 这是依赖的最底层我们通过手动构造函数的方式注入configuration这样可以在dropwizard启动时生成module并且得到configuration。 引入我们的Component 这时候build一下dagger就会自动生成我们的工厂。 mvn clean install 然后在IDEA里的maven plugin里右键reimport。防止IDEA不认识dagger自动生成的类。dagger自动生成的类位于target/generated-sources/annotations. 点击刷新按钮刷新下maven依赖。 然后在com.test.HelloWorldApplication中,新增 private void registerResources(HelloWorldConfiguration configuration, Environment environment) {GithubComponent component DaggerGithubComponent.builder().configurationModule(new ConfigurationModule(configuration)).build();environment.jersey().register(component.gitHubResource());
} DaggerGithubComponent要在maven install之后dagger生成的。完整启动类如下 public class HelloWorldApplication extends ApplicationHelloWorldConfiguration {public static void main(String[] args) throws Exception {new HelloWorldApplication().run(args);}Overridepublic String getName() {return hello-world;}Overridepublic void initialize(BootstrapHelloWorldConfiguration bootstrap) {bootstrap.addBundle(new ConnectivityBundle());}Overridepublic void run(HelloWorldConfiguration configuration, Environment environment) throws Exception {final HelloWorldResource resource new HelloWorldResource(configuration.getTemplate(),configuration.getDefaultName());final TemplateHealthCheck healthCheck new TemplateHealthCheck(configuration.getTemplate());environment.healthChecks().register(template, healthCheck);environment.jersey().register(resource);environment.jersey().register(healthCheck);registerResources(configuration, environment);}private void registerResources(HelloWorldConfiguration configuration, Environment environment) {GithubComponent component DaggerGithubComponent.builder().configurationModule(new ConfigurationModule(configuration)).build();environment.jersey().register(component.gitHubResource());}
} 当然我们的Resource也要改成Inject模式 public class GithubResource {private IGithubService service;Injectpublic GithubResource(IGithubService service) {this.service service;}GETTimedPath(/users/{username})public GithubUser getUserProfile(PathParam(username) final String username) {return service.getUserProfile(username);}} 启动运行。一切OK。以后就可以在需要注入的类的构造器上声明Inject, 或者在module里Provide就可以实现构造解耦。测试不要太方便. 唯有不断学习方能改变 -- Ryan Miao
