草庐IT

java - 在构建时自动更新 Liquibase 的变更日志

coder 2023-05-11 原文

我目前正在开发一个使用 Hibernate 和 Liquibase 的 Spring 项目。我想要实现的是每次构建项目时自动更新 Liquibase 的变更日志。它应该根据我当前的生产数据库和更新的 Hibernate 实体生成差异。

但我遇到的问题是每次清理和重建项目时都会出现以下错误:

liquibase-plugin: Running the 'main' activity...
INFO 6/22/15 11:12 AM: liquibase-hibernate: Reading hibernate configuration hibernate:spring:com.example.name.domain?dialect=org.hibernate.dialect.MySQL5Dialect
INFO 6/22/15 11:12 AM: liquibase-hibernate: Found package com.example.app.domain
INFO 6/22/15 11:12 AM: liquibase-hibernate: Found dialect org.hibernate.dialect.MySQL5Dialect
Unexpected error running Liquibase: Unable to resolve persistence unit root URL

SEVERE 6/22/15 11:12 AM: liquibase: Unable to resolve persistence unit root URL
liquibase.exception.DatabaseException: javax.persistence.PersistenceException: Unable to resolve persistence unit root URL
        at liquibase.integration.commandline.CommandLineUtils.createDatabaseObject(CommandLineUtils.java:69)
        at liquibase.integration.commandline.Main.createReferenceDatabaseFromCommandParams(Main.java:1169)
        at liquibase.integration.commandline.Main.doMigration(Main.java:936)
        at liquibase.integration.commandline.Main.run(Main.java:175)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:497)
        at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:90)
        at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:324)
        at org.codehaus.groovy.runtime.callsite.StaticMetaMethodSite.invoke(StaticMetaMethodSite.java:43)
        at org.codehaus.groovy.runtime.callsite.StaticMetaMethodSite.call(StaticMetaMethodSite.java:88)
        at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:45)
        at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:108)
        at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:116)
        at org.liquibase.gradle.LiquibaseTask.runLiquibase(LiquibaseTask.groovy:97)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:497)
        at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:90)
        at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:324)
        at org.codehaus.groovy.runtime.metaclass.ClosureMetaClass.invokeMethod(ClosureMetaClass.java:382)
        at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1015)
        at org.codehaus.groovy.runtime.callsite.PogoMetaClassSite.callCurrent(PogoMetaClassSite.java:66)
        at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCallCurrent(CallSiteArray.java:49)
        at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callCurrent(AbstractCallSite.java:133)
        at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callCurrent(AbstractCallSite.java:141)
        at org.liquibase.gradle.LiquibaseTask$_liquibaseAction_closure1.doCall(LiquibaseTask.groovy:52)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:497)
        at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:90)
        at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:324)
        at org.codehaus.groovy.runtime.metaclass.ClosureMetaClass.invokeMethod(ClosureMetaClass.java:292)
        at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1015)
        at groovy.lang.Closure.call(Closure.java:423)
        at groovy.lang.Closure.call(Closure.java:439)
        at org.codehaus.groovy.runtime.DefaultGroovyMethods.each(DefaultGroovyMethods.java:1379)
        at org.codehaus.groovy.runtime.DefaultGroovyMethods.each(DefaultGroovyMethods.java:1310)
        at org.codehaus.groovy.runtime.dgm$150.invoke(Unknown Source)
        at org.codehaus.groovy.runtime.callsite.PojoMetaMethodSite$PojoMetaMethodSiteNoUnwrapNoCoerce.invoke(PojoMetaMethodSite.java:271)
        at org.codehaus.groovy.runtime.callsite.PojoMetaMethodSite.call(PojoMetaMethodSite.java:53)
        at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:45)
        at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:108)
        at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:116)
        at org.liquibase.gradle.LiquibaseTask.liquibaseAction(LiquibaseTask.groovy:46)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:497)
        at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:75)
        at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$StandardTaskAction.doExecute(AnnotationProcessingTaskFactory.java:226)
        at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$StandardTaskAction.execute(AnnotationProcessingTaskFactory.java:219)
        at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskFactory$StandardTaskAction.execute(AnnotationProcessingTaskFactory.java:208)
        at org.gradle.api.internal.AbstractTask$TaskActionWrapper.execute(AbstractTask.java:589)
        at org.gradle.api.internal.AbstractTask$TaskActionWrapper.execute(AbstractTask.java:572)
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeAction(ExecuteActionsTaskExecuter.java:80)
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:61)
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.execute(ExecuteActionsTaskExecuter.java:46)
        at org.gradle.api.internal.tasks.execution.PostExecutionAnalysisTaskExecuter.execute(PostExecutionAnalysisTaskExecuter.java:35)
        at org.gradle.api.internal.tasks.execution.SkipUpToDateTaskExecuter.execute(SkipUpToDateTaskExecuter.java:64)
        at org.gradle.api.internal.tasks.execution.ValidatingTaskExecuter.execute(ValidatingTaskExecuter.java:58)
        at org.gradle.api.internal.tasks.execution.SkipEmptySourceFilesTaskExecuter.execute(SkipEmptySourceFilesTaskExecuter.java:42)
        at org.gradle.api.internal.tasks.execution.SkipTaskWithNoActionsExecuter.execute(SkipTaskWithNoActionsExecuter.java:52)
        at org.gradle.api.internal.tasks.execution.SkipOnlyIfTaskExecuter.execute(SkipOnlyIfTaskExecuter.java:53)
        at org.gradle.api.internal.tasks.execution.ExecuteAtMostOnceTaskExecuter.execute(ExecuteAtMostOnceTaskExecuter.java:43)
        at org.gradle.api.internal.AbstractTask.executeWithoutThrowingTaskFailure(AbstractTask.java:310)
        at org.gradle.api.internal.AbstractTask.execute(AbstractTask.java:305)
        at org.gradle.api.internal.TaskInternal$execute$0.call(Unknown Source)
        at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:45)
        at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:108)
        at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:112)
        at build_au43cnsvyw2rwctsxb5mg4cmw$_run_closure4.doCall(/Users/mihajlovic/Documents/repos/Backend/dbmigration/build.gradle:52)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:497)
        at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:90)
        at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:324)
        at org.codehaus.groovy.runtime.metaclass.ClosureMetaClass.invokeMethod(ClosureMetaClass.java:292)
        at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1015)
        at groovy.lang.Closure.call(Closure.java:423)
        at groovy.lang.Closure.call(Closure.java:439)
        at org.gradle.api.internal.AbstractTask$ClosureTaskAction.execute(AbstractTask.java:558)
        at org.gradle.api.internal.AbstractTask$ClosureTaskAction.execute(AbstractTask.java:539)
        at org.gradle.api.internal.tasks.TaskMutator$1.execute(TaskMutator.java:77)
        at org.gradle.api.internal.tasks.TaskMutator$1.execute(TaskMutator.java:73)
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeAction(ExecuteActionsTaskExecuter.java:80)
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:61)
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.execute(ExecuteActionsTaskExecuter.java:46)
        at org.gradle.api.internal.tasks.execution.PostExecutionAnalysisTaskExecuter.execute(PostExecutionAnalysisTaskExecuter.java:35)
        at org.gradle.api.internal.tasks.execution.SkipUpToDateTaskExecuter.execute(SkipUpToDateTaskExecuter.java:64)
        at org.gradle.api.internal.tasks.execution.ValidatingTaskExecuter.execute(ValidatingTaskExecuter.java:58)
        at org.gradle.api.internal.tasks.execution.SkipEmptySourceFilesTaskExecuter.execute(SkipEmptySourceFilesTaskExecuter.java:42)
        at org.gradle.api.internal.tasks.execution.SkipTaskWithNoActionsExecuter.execute(SkipTaskWithNoActionsExecuter.java:52)
        at org.gradle.api.internal.tasks.execution.SkipOnlyIfTaskExecuter.execute(SkipOnlyIfTaskExecuter.java:53)
        at org.gradle.api.internal.tasks.execution.ExecuteAtMostOnceTaskExecuter.execute(ExecuteAtMostOnceTaskExecuter.java:43)
        at org.gradle.api.internal.AbstractTask.executeWithoutThrowingTaskFailure(AbstractTask.java:310)
        at org.gradle.execution.taskgraph.AbstractTaskPlanExecutor$TaskExecutorWorker.executeTask(AbstractTaskPlanExecutor.java:79)
        at org.gradle.execution.taskgraph.AbstractTaskPlanExecutor$TaskExecutorWorker.processTask(AbstractTaskPlanExecutor.java:63)
        at org.gradle.execution.taskgraph.AbstractTaskPlanExecutor$TaskExecutorWorker.run(AbstractTaskPlanExecutor.java:51)
        at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor.process(DefaultTaskPlanExecutor.java:23)
        at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter.execute(DefaultTaskGraphExecuter.java:88)
        at org.gradle.execution.SelectedTaskExecutionAction.execute(SelectedTaskExecutionAction.java:37)
        at org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecuter.java:62)
        at org.gradle.execution.DefaultBuildExecuter.access$200(DefaultBuildExecuter.java:23)
        at org.gradle.execution.DefaultBuildExecuter$2.proceed(DefaultBuildExecuter.java:68)
        at org.gradle.execution.DryRunBuildExecutionAction.execute(DryRunBuildExecutionAction.java:32)
        at org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecuter.java:62)
        at org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecuter.java:55)
        at org.gradle.initialization.DefaultGradleLauncher.doBuildStages(DefaultGradleLauncher.java:149)
        at org.gradle.initialization.DefaultGradleLauncher.doBuild(DefaultGradleLauncher.java:106)
        at org.gradle.initialization.DefaultGradleLauncher.run(DefaultGradleLauncher.java:86)
        at org.gradle.launcher.exec.InProcessBuildActionExecuter$DefaultBuildController.run(InProcessBuildActionExecuter.java:90)
        at org.gradle.tooling.internal.provider.ExecuteBuildActionRunner.run(ExecuteBuildActionRunner.java:28)
        at org.gradle.launcher.exec.ChainingBuildActionRunner.run(ChainingBuildActionRunner.java:35)
        at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:41)
        at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:28)
        at org.gradle.launcher.exec.DaemonUsageSuggestingBuildActionExecuter.execute(DaemonUsageSuggestingBuildActionExecuter.java:50)
        at org.gradle.launcher.exec.DaemonUsageSuggestingBuildActionExecuter.execute(DaemonUsageSuggestingBuildActionExecuter.java:27)
        at org.gradle.launcher.cli.RunBuildAction.run(RunBuildAction.java:40)
        at org.gradle.internal.Actions$RunnableActionAdapter.execute(Actions.java:169)
        at org.gradle.launcher.cli.CommandLineActionFactory$ParseAndBuildAction.execute(CommandLineActionFactory.java:237)
        at org.gradle.launcher.cli.CommandLineActionFactory$ParseAndBuildAction.execute(CommandLineActionFactory.java:210)
        at org.gradle.launcher.cli.JavaRuntimeValidationAction.execute(JavaRuntimeValidationAction.java:35)
        at org.gradle.launcher.cli.JavaRuntimeValidationAction.execute(JavaRuntimeValidationAction.java:24)
        at org.gradle.launcher.cli.CommandLineActionFactory$WithLogging.execute(CommandLineActionFactory.java:206)
        at org.gradle.launcher.cli.CommandLineActionFactory$WithLogging.execute(CommandLineActionFactory.java:169)
        at org.gradle.launcher.cli.ExceptionReportingAction.execute(ExceptionReportingAction.java:33)
        at org.gradle.launcher.cli.ExceptionReportingAction.execute(ExceptionReportingAction.java:22)
        at org.gradle.launcher.Main.doAction(Main.java:33)
        at org.gradle.launcher.bootstrap.EntryPoint.run(EntryPoint.java:45)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:497)
        at org.gradle.launcher.bootstrap.ProcessBootstrap.runNoExit(ProcessBootstrap.java:54)
        at org.gradle.launcher.bootstrap.ProcessBootstrap.run(ProcessBootstrap.java:35)
        at org.gradle.launcher.GradleMain.main(GradleMain.java:23)
Caused by: javax.persistence.PersistenceException: Unable to resolve persistence unit root URL
        at org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager.determineDefaultPersistenceUnitRootUrl(DefaultPersistenceUnitManager.java:580)
        at org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager.preparePersistenceUnitInfos(DefaultPersistenceUnitManager.java:436)
        at liquibase.ext.hibernate.database.HibernateSpringDatabase.buildConfigurationFromScanning(HibernateSpringDatabase.java:227)
        at liquibase.ext.hibernate.database.HibernateSpringDatabase.buildConfiguration(HibernateSpringDatabase.java:55)
        at liquibase.ext.hibernate.database.HibernateDatabase.setConnection(HibernateDatabase.java:45)
        at liquibase.database.DatabaseFactory.findCorrectDatabaseImplementation(DatabaseFactory.java:123)
        at liquibase.database.DatabaseFactory.openDatabase(DatabaseFactory.java:143)
        at liquibase.integration.commandline.CommandLineUtils.createDatabaseObject(CommandLineUtils.java:50)
        ... 140 more
Caused by: java.io.FileNotFoundException: class path resource [] cannot be resolved to URL because it does not exist
        at org.springframework.core.io.ClassPathResource.getURL(ClassPathResource.java:187)
        at org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager.determineDefaultPersistenceUnitRootUrl(DefaultPersistenceUnitManager.java:577)
        ... 147 more

据我了解,问题在于 Liquibase 要求将所有实体类加载到 gradle 的类路径中,但是由于 Java 类刚刚被编译或尚未编译,因此情况并非如此,因此出现错误消息。

我可以通过分两步构建项目来修复此错误:

  1. 首先我执行任务compileJava 来构建实体类。
  2. 一旦完成,我就可以执行正常的 build - 现在没有任何问题了。

但是分两步构建项目是相当乏味的。有没有一种方法可以解决这个问题,只需一步即可构建它?

我的 build.gradle 目前看起来像这样:

buildscript {
    ext {
        springBootVersion = '1.2.3.RELEASE'
    }
    repositories {
        mavenCentral()
        files 'build/classes/main'
    }
    dependencies {
        classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
        classpath("io.spring.gradle:dependency-management-plugin:0.5.0.RELEASE")
        classpath("org.liquibase:liquibase-gradle-plugin:1.1.0")
        classpath("mysql:mysql-connector-java:5.1.35")
        classpath('org.hibernate.javax.persistence:hibernate-jpa-2.1-api:1.0.0.Final')
        classpath('org.liquibase.ext:liquibase-hibernate4:3.5')
        classpath('org.springframework.data:spring-data-jpa:1.8.0.RELEASE')
        classpath files('build/classes/main/')

    }
}

apply plugin: 'org.liquibase.gradle'
apply plugin: 'java'
apply plugin: 'eclipse-wtp'
apply plugin: 'idea'
apply plugin: 'spring-boot'
apply plugin: 'io.spring.dependency-management'
apply plugin: 'war'


war {
    baseName = 'example'
    version = '0.0.1-SNAPSHOT'
}
sourceCompatibility = 1.8
targetCompatibility = 1.8

repositories {
    mavenCentral()

    flatDir {
        dirs 'libs'
    }
}

configurations {
    providedRuntime
}

dependencies {
    compile("org.springframework.boot:spring-boot-starter-data-jpa")
    compile("org.springframework.boot:spring-boot-starter-web")
    compile("org.apache.commons:commons-lang3:3.0")
    compile("mysql:mysql-connector-java:5.1.35")
    compile('org.liquibase:liquibase-core:3.3.5')

    providedRuntime("org.springframework.boot:spring-boot-starter-tomcat")
    testCompile("org.springframework.boot:spring-boot-starter-test")
}

liquibase {
    activities {
        main {
            changeLogFile 'src/main/resources/db/changelog/db.changelog-master.xml'
            url 'jdbc:mysql://localhost:3306/Example'
            username 'root'
            password ''
            referenceDriver 'liquibase.ext.hibernate.database.connection.HibernateDriver'
            referenceUrl 'hibernate:spring:com.example.app.domain?dialect=org.hibernate.dialect.MySQL5Dialect'
        }
    }
    runList = 'main'
}



eclipse {
    classpath {
        containers.remove('org.eclipse.jdt.launching.JRE_CONTAINER')
        containers 'org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-1.7'
    }
}

task wrapper(type: Wrapper) {
    gradleVersion = '2.4'
}

最佳答案

我终于明白了!您可以使用 Exec 类型在命令行中执行命令,随后启动一个新进程。您可以在 the documentation 中找到更多信息.

这是我最终得到的解决方案:

task updateChangeLog(type: Exec) {
    commandLine 'gradle', 'diffChangeLog'
}
updateChangeLog.dependsOn compileJava

这将使用我的 diffChangeLog 任务启动一个新的单独 gradle 进程。

关于java - 在构建时自动更新 Liquibase 的变更日志,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/30972713/

有关java - 在构建时自动更新 Liquibase 的变更日志的更多相关文章

  1. ruby-on-rails - 使用 Ruby on Rails 进行自动化测试 - 最佳实践 - 2

    很好奇,就使用ruby​​onrails自动化单元测试而言,你们正在做什么?您是否创建了一个脚本来在cron中运行rake作业并将结果邮寄给您?git中的预提交Hook?只是手动调用?我完全理解测试,但想知道在错误发生之前捕获错误的最佳实践是什么。让我们理所当然地认为测试本身是完美无缺的,并且可以正常工作。下一步是什么以确保他们在正确的时间将可能有害的结果传达给您? 最佳答案 不确定您到底想听什么,但是有几个级别的自动代码库控制:在处理某项功能时,您可以使用类似autotest的内容获得关于哪些有效,哪些无效的即时反馈。要确保您的提

  2. ruby-on-rails - 如何验证 update_all 是否实际在 Rails 中更新 - 2

    给定这段代码defcreate@upgrades=User.update_all(["role=?","upgraded"],:id=>params[:upgrade])redirect_toadmin_upgrades_path,:notice=>"Successfullyupgradeduser."end我如何在该操作中实际验证它们是否已保存或未重定向到适当的页面和消息? 最佳答案 在Rails3中,update_all不返回任何有意义的信息,除了已更新的记录数(这可能取决于您的DBMS是否返回该信息)。http://ar.ru

  3. ruby-on-rails - 使用 rails 4 设计而不更新用户 - 2

    我将应用程序升级到Rails4,一切正常。我可以登录并转到我的编辑页面。也更新了观点。使用标准View时,用户会更新。但是当我添加例如字段:name时,它​​不会在表单中更新。使用devise3.1.1和gem'protected_attributes'我需要在设备或数据库上运行某种更新命令吗?我也搜索过这个地方,找到了许多不同的解决方案,但没有一个会更新我的用户字段。我没有添加任何自定义字段。 最佳答案 如果您想允许额外的参数,您可以在ApplicationController中使用beforefilter,因为Rails4将参数

  4. java - 等价于 Java 中的 Ruby Hash - 2

    我真的很习惯使用Ruby编写以下代码:my_hash={}my_hash['test']=1Java中对应的数据结构是什么? 最佳答案 HashMapmap=newHashMap();map.put("test",1);我假设? 关于java-等价于Java中的RubyHash,我们在StackOverflow上找到一个类似的问题: https://stackoverflow.com/questions/22737685/

  5. ruby - RuntimeError(自动加载常量 Apps 多线程时检测到循环依赖 - 2

    我收到这个错误:RuntimeError(自动加载常量Apps时检测到循环依赖当我使用多线程时。下面是我的代码。为什么会这样?我尝试多线程的原因是因为我正在编写一个HTML抓取应用程序。对Nokogiri::HTML(open())的调用是一个同步阻塞调用,需要1秒才能返回,我有100,000多个页面要访问,所以我试图运行多个线程来解决这个问题。有更好的方法吗?classToolsController0)app.website=array.join(',')putsapp.websiteelseapp.website="NONE"endapp.saveapps=Apps.order("

  6. java - 从 JRuby 调用 Java 类的问题 - 2

    我正在尝试使用boilerpipe来自JRuby。我看过guide从JRuby调用Java,并成功地将它与另一个Java包一起使用,但无法弄清楚为什么同样的东西不能用于boilerpipe。我正在尝试基本上从JRuby中执行与此Java等效的操作:URLurl=newURL("http://www.example.com/some-location/index.html");Stringtext=ArticleExtractor.INSTANCE.getText(url);在JRuby中试过这个:require'java'url=java.net.URL.new("http://www

  7. java - 我的模型类或其他类中应该有逻辑吗 - 2

    我只想对我一直在思考的这个问题有其他意见,例如我有classuser_controller和classuserclassUserattr_accessor:name,:usernameendclassUserController//dosomethingaboutanythingaboutusersend问题是我的User类中是否应该有逻辑user=User.newuser.do_something(user1)oritshouldbeuser_controller=UserController.newuser_controller.do_something(user1,user2)我

  8. java - 什么相当于 ruby​​ 的 rack 或 python 的 Java wsgi? - 2

    什么是ruby​​的rack或python的Java的wsgi?还有一个路由库。 最佳答案 来自Python标准PEP333:Bycontrast,althoughJavahasjustasmanywebapplicationframeworksavailable,Java's"servlet"APImakesitpossibleforapplicationswrittenwithanyJavawebapplicationframeworktoruninanywebserverthatsupportstheservletAPI.ht

  9. ruby - 在 Ruby 中构建长字符串的简洁方法 - 2

    在编写Ruby(客户端脚本)时,我看到了三种构建更长字符串的方法,包括行尾,所有这些对我来说“闻起来”有点难看。有没有更干净、更好的方法?变量递增。ifrender_quote?quote="NowthatthereistheTec-9,acrappyspraygunfromSouthMiami."quote+="ThisgunisadvertisedasthemostpopularguninAmericancrime.Doyoubelievethatshit?"quote+="Itactuallysaysthatinthelittlebookthatcomeswithit:themo

  10. Observability:从零开始创建 Java 微服务并监控它 (二) - 2

    这篇文章是继上一篇文章“Observability:从零开始创建Java微服务并监控它(一)”的续篇。在上一篇文章中,我们讲述了如何创建一个Javaweb应用,并使用Filebeat来收集应用所生成的日志。在今天的文章中,我来详述如何收集应用的指标,使用APM来监控应用并监督web服务的在线情况。源码可以在地址 https://github.com/liu-xiao-guo/java_observability 进行下载。摄入指标指标被视为可以随时更改的时间点值。当前请求的数量可以改变任何毫秒。你可能有1000个请求的峰值,然后一切都回到一个请求。这也意味着这些指标可能不准确,你还想提取最小/

随机推荐