开发遇到的问题

NoClassDefFoundError: javax/servlet/jsp/jstl/core/Config：

org.springframework.web.util.NestedServletException: Handler processing failed; nested exception is java.lang.NoClassDefFoundError: javax/servlet/jsp/jstl/core/Config

这种情况检查下是否有这个jar包：

<dependency>
    <groupId>javax.servlet.jsp.jstl</groupId>
    <artifactId>jstl-api</artifactId>
    <version>1.2</version>
</dependency>

该jar的目录结构如下： 

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objc[55613]: Class JavaLaunchHelper is implemented in both /Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/bin/java (0x10a4624c0) and /Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/jre/lib/libinstrument.dylib (0x10b4e14e0). One of the two will be used. Which one is undefined.
SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/Users/chenweiqiang/.m2/repository/org/slf4j/slf4j-log4j12/1.6.1/slf4j-log4j12-1.6.1.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/Users/chenweiqiang/.m2/repository/org/apache/logging/log4j/log4j-slf4j-impl/2.3/log4j-slf4j-impl-2.3.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
Exception in thread "main" java.lang.AbstractMethodError: org.apache.logging.log4j.core.config.ConfigurationFactory.getConfiguration(Lorg/apache/logging/log4j/core/config/ConfigurationSource;)Lorg/apache/logging/log4j/core/config/Configuration;
	at org.apache.logging.log4j.core.config.ConfigurationFactory$Factory.getConfiguration(ConfigurationFactory.java:472)
	at org.apache.logging.log4j.core.config.ConfigurationFactory$Factory.getConfiguration(ConfigurationFactory.java:442)
	at org.apache.logging.log4j.core.config.ConfigurationFactory.getConfiguration(ConfigurationFactory.java:254)
	at org.apache.logging.log4j.core.LoggerContext.reconfigure(LoggerContext.java:425)
	at org.apache.logging.log4j.core.LoggerContext.reconfigure(LoggerContext.java:442)
	at org.apache.logging.log4j.core.LoggerContext.start(LoggerContext.java:138)
	at org.apache.logging.log4j.core.impl.Log4jContextFactory.getContext(Log4jContextFactory.java:207)
	at org.apache.logging.log4j.core.impl.Log4jContextFactory.getContext(Log4jContextFactory.java:41)
	at org.apache.logging.log4j.LogManager.getContext(LogManager.java:160)
	at org.springframework.boot.logging.log4j2.Log4J2LoggingSystem.getLoggerContext(Log4J2LoggingSystem.java:265)
	at org.springframework.boot.logging.log4j2.Log4J2LoggingSystem.beforeInitialize(Log4J2LoggingSystem.java:132)
	at org.springframework.boot.logging.LoggingApplicationListener.onApplicationStartingEvent(LoggingApplicationListener.java:230)
	at org.springframework.boot.logging.LoggingApplicationListener.onApplicationEvent(LoggingApplicationListener.java:209)
	at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:167)
	at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139)
	at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:122)
	at org.springframework.boot.context.event.EventPublishingRunListener.starting(EventPublishingRunListener.java:69)
	at org.springframework.boot.SpringApplicationRunListeners.starting(SpringApplicationRunListeners.java:48)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:292)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1118)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1107)
	at com.meituan.hotel.data.cis.snapstore.Main.main(Main.java:14)

Process finished with exit code 1

objc[63185]: Class JavaLaunchHelper is implemented in both /Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/bin/java (0x1015774c0) and /Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/jre/lib/libinstrument.dylib (0x1035ff4e0). One of the two will be used. Which one is undefined.
Exception in thread "main" java.lang.AbstractMethodError: org.apache.logging.log4j.core.config.ConfigurationFactory.getConfiguration(Lorg/apache/logging/log4j/core/config/ConfigurationSource;)Lorg/apache/logging/log4j/core/config/Configuration;
	at org.apache.logging.log4j.core.config.ConfigurationFactory$Factory.getConfiguration(ConfigurationFactory.java:472)
	at org.apache.logging.log4j.core.config.ConfigurationFactory$Factory.getConfiguration(ConfigurationFactory.java:442)
	at org.apache.logging.log4j.core.config.ConfigurationFactory.getConfiguration(ConfigurationFactory.java:254)
	at org.apache.logging.log4j.core.LoggerContext.reconfigure(LoggerContext.java:425)
	at org.apache.logging.log4j.core.LoggerContext.reconfigure(LoggerContext.java:442)
	at org.apache.logging.log4j.core.LoggerContext.start(LoggerContext.java:138)
	at org.apache.logging.log4j.core.impl.Log4jContextFactory.getContext(Log4jContextFactory.java:147)
	at org.apache.logging.log4j.core.impl.Log4jContextFactory.getContext(Log4jContextFactory.java:41)
	at org.apache.logging.log4j.LogManager.getContext(LogManager.java:175)
	at org.apache.logging.log4j.spi.AbstractLoggerAdapter.getContext(AbstractLoggerAdapter.java:102)
	at org.apache.logging.slf4j.Log4jLoggerFactory.getContext(Log4jLoggerFactory.java:43)
	at org.apache.logging.log4j.spi.AbstractLoggerAdapter.getLogger(AbstractLoggerAdapter.java:42)
	at org.apache.logging.slf4j.Log4jLoggerFactory.getLogger(Log4jLoggerFactory.java:29)
	at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:358)
	at org.apache.commons.logging.impl.SLF4JLogFactory.getInstance(SLF4JLogFactory.java:156)
	at org.apache.commons.logging.impl.SLF4JLogFactory.getInstance(SLF4JLogFactory.java:132)
	at org.apache.commons.logging.LogFactory.getLog(LogFactory.java:655)
	at org.springframework.boot.SpringApplication.<clinit>(SpringApplication.java:179)
	at com.meituan.hotel.data.cis.snapstore.Main.main(Main.java:14)

Process finished with exit code 1

===========================================================================================

执行mysql进入 打开就会出现的报错ERROR 2006 (HY000): MySQL server has gone away