springboot bug实例5
2019-10-24 本文已影响0人
凉风拂面秋挽月
今天在阿里云通过docker部署了redis数据库，通过本地的客户端
Redis Desktop Manager连接到远程数据库也成功了，如下图：
image.png
在验证springboot整合redis的时候却遇到了意想不到的bug。
springboot redis bug
通过在pom中引入spring-boot-starter-data-redis
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>
在通过测试类验证redis相关操作的时候(testRedis01)，出现了bug。
测试类：
public class SpringBoot05cacheApplicationTests {
@Autowired
EmployeeMapper employeeMapper;
@Autowired
StringRedisTemplate stringRedisTemplate;//操作k-v都是字符串
@Autowired
RedisTemplate<Object, Object> redisTemplate;//操作k-v都是对象
@Test
public void testRedis01() {
stringRedisTemplate.opsForValue().append("ms", "hello");
}
@Test
public void contextLoads() {
Employee emp = employeeMapper.getEmpById(1);
System.out.println(emp);
}
点击运行testRedis01，控制台报错信息如下：
java.lang.IllegalStateException: Failed to load ApplicationContext
at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:125)
at org.springframework.test.context.support.DefaultTestContext.getApplicationContext(DefaultTestContext.java:108)
at org.springframework.test.context.web.ServletTestExecutionListener.setUpRequestContextIfNecessary(ServletTestExecutionListener.java:190)
at org.springframework.test.context.web.ServletTestExecutionListener.prepareTestInstance(ServletTestExecutionListener.java:132)
at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:246)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.createTest(SpringJUnit4ClassRunner.java:227)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner$1.runReflectiveCall(SpringJUnit4ClassRunner.java:289)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.methodBlock(SpringJUnit4ClassRunner.java:291)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:246)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:97)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:190)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:538)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:760)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:460)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:206)
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'lettuceClientResources' defined in class path resource [org/springframework/boot/autoconfigure/data/redis/LettuceConnectionConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [io.lettuce.core.resource.DefaultClientResources]: Factory method 'lettuceClientResources' threw exception; nested exception is java.lang.NoClassDefFoundError: io/netty/util/Timer
at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:627)
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:456)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1288)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1127)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:538)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:498)
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:846)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:863)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:546)
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:775)
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:316)
at org.springframework.boot.test.context.SpringBootContextLoader.loadContext(SpringBootContextLoader.java:127)
at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContextInternal(DefaultCacheAwareContextLoaderDelegate.java:99)
at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:117)
... 25 more
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [io.lettuce.core.resource.DefaultClientResources]: Factory method 'lettuceClientResources' threw exception; nested exception is java.lang.NoClassDefFoundError: io/netty/util/Timer
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185)
at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:622)
... 43 more
Caused by: java.lang.NoClassDefFoundError: io/netty/util/Timer
at org.springframework.boot.autoconfigure.data.redis.LettuceConnectionConfiguration.lettuceClientResources(LettuceConnectionConfiguration.java:67)
at org.springframework.boot.autoconfigure.data.redis.LettuceConnectionConfiguration$$EnhancerBySpringCGLIB$$d790c980.CGLIB$lettuceClientResources$0(<generated>)
at org.springframework.boot.autoconfigure.data.redis.LettuceConnectionConfiguration$$EnhancerBySpringCGLIB$$d790c980$$FastClassBySpringCGLIB$$6c9238ec.invoke(<generated>)
at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:244)
at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:363)
at org.springframework.boot.autoconfigure.data.redis.LettuceConnectionConfiguration$$EnhancerBySpringCGLIB$$d790c980.lettuceClientResources(<generated>)
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:498)
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154)
... 44 more
Caused by: java.lang.ClassNotFoundException: io.netty.util.Timer
at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
... 55 more
image.png
第一行Failed to load ApplicationContext？？我tm一脸问号，说明一下，这个测试类在验证第二个方法的时候是通过的，验证springboot整合mybatis的相关操作。
在我有点不相信的时候，运行第二个测试方法，居然出现同样的错误，问题瞬间严重了，因为一个环境的引入，导致正常运行的方法也报错，而且是由于配置文件出错。
在往下看
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'lettuceClientResources' defined in class path resource [org/springframework/boot/autoconfigure/data/redis/LettuceConnectionConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [io.lettuce.core.resource.DefaultClientResources]: Factory method 'lettuceClientResources' threw exception; nested exception is java.lang.NoClassDefFoundError: io/netty/util/Timer
根据描述，猜测应该是springboot的redis环境依赖netty，而springboot并没有把netty引入进来，在网上的一篇博客里也验证了我的想法。
image.png
那么我们去导netty
<dependency>
<groupId>io.netty</groupId>
<artifactId>netty-all</artifactId>
</dependency>
问题应该解决了吧？但事情没这么简单，woc，当netty引入环境后，报错内容变了
如下：
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'lettuceClientResources' defined in class path resource [org/springframework/boot/autoconfigure/data/redis/LettuceConnectionConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [io.lettuce.core.resource.DefaultClientResources]: Factory method 'lettuceClientResources' threw exception; nested exception is java.lang.NoClassDefFoundError: reactor/core/scheduler/Schedulers
完了，报错遇到了未知问题，在maven中，reactor似乎与jvm有关，根据NoClassDefFoundError，那么一定是哪里少了什么。
在springboot的1.5.9版本中，即不需要引入netty，也不需要报这种错，那springboot在2.0之后干了什么。。。
问题解决
在尝试重新创建一个快速的springboot的时候，我注意到，关于redis的选项，居然有两个。
image.png
试一试吧，在添加两个引用后，发现在新建项目的pom文件中，出现了那个reator！
还附赠了一个reactive！
在此运行，还是报错，报错信息是最开始的那一种，没事，我们在引入netty，问题解决！
也就是说，在springboot2.0之后，如果你想整合redis，那么你的pom文件应该长下面这样。。
<dependency>
<groupId>io.netty</groupId>
<artifactId>netty-all</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-redis-reactive</artifactId>
</dependency>
<dependency>
<groupId>io.projectreactor</groupId>
<artifactId>reactor-test</artifactId>
<scope>test</scope>
</dependency>
收工了。。
