一、SSM
1.通配符的匹配很全面, 但无法找到元素 ‘context:component-scan’ 的声明
idea中,启动项目报错。反复查阅n多资料无果。最终发现是导入了没有用到的头文件信息导致,删除无用的后解决。(这点我也很怀疑,但几乎可以肯定出现这种问题检查头文件信息就是了)
2.用@ResponseBody注解进行返回List<对象>的json数据时出现了:nested exception is java.lang.IllegalArgumentException: No converter found for return value of type: class java.util.ArrayList错误
写得一个aopdemo,controller讲数据以array list形式回给页面,页面解析直接讲数据解析在浏览器界面。问题原因:缺少解析array list的包。
解决:
手动添加pom配置
<jackson.version>2.5.4</jackson.version>
com.fasterxml.jackson.core
jackson-core
jackson.version</version></dependency><dependency><groupId>com.fasterxml.jackson.core</groupId><artifactId>jackson−databind</artifactId><version>{jackson.version}</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>jackson.version</version></dependency><dependency><groupId>com.fasterxml.jackson.core</groupId><artifactId>jackson−databind</artifactId><version>{jackson.version}
同时在springMVC配置文件中添加
mvc:annotation-driven
mvc:message-converters
</mvc:message-converters>
</mvc:annotation-driven>
二、IDEA
1、Servlet should have a mapping less… (Ctrl+F1)
查了所有配置及依赖,确认无误。idea是个神奇的东西,大体应该是没有在项目结构中指定web.xml,将其加入后正常。
2.Application context not configured for this file
spring-mybatis.xml遇到的问题,通常是web.xml中没有配置spring相关文件
3.MVC application context in module File is included in 4contexts
也不知道咋回事,反正移除后,提示消失了。
4.@Override注解报错:@Override is not allowed when implementing interface method
jdk版本太低了,我只是用maven项目做了一个demo,没有配置jdk、tomcat等信息,导致此问题产生。
pom加配置处理,<version>酌情处理。
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.2</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
</plugins>
</build>
三、MySQL
1.q: Access denied for user ‘用户名 ‘@’% ’ to database ‘数据库名 ’
说白了,没有赋予他创建数据库权限。
GRANT ALL PRIVILEGES ON . TO 用户名 @’%’ IDENTIFIED BY '密码 ';
四、Tomcat
1.tomcat启动报错,用命令窗口catalina run 运行tomcat报错如下:
java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/SKLSUG]]
at java.util.concurrent.FutureTask.report(FutureTask.java:122)
at java.util.concurrent.FutureTask.get(FutureTask.java:192)
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:942)
at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:872)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.ContainerBaseStartChild.call(ContainerBase.java:1423)atorg.apache.catalina.core.ContainerBaseStartChild.call(ContainerBase.java:1423)
at org.apache.catalina.core.ContainerBaseStartChild.call(ContainerBase.java:1423)atorg.apache.catalina.core.ContainerBaseStartChild.call(ContainerBase.java:1413)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/SKLSUG]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167)
… 6 more
Caused by: org.apache.catalina.LifecycleException: Failed to start component [org.apache.catalina.webresources.StandardRoot@1305a69d]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167)
at org.apache.catalina.core.StandardContext.resourcesStart(StandardContext.java:4885)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5020)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
… 6 more
Caused by: java.lang.IllegalArgumentException: The main resource set specified [D:\softwarefolder\apache-tomcat-8.5.40\wtpwebapps\SKLSUG] is not valid
at org.apache.catalina.webresources.StandardRoot.createMainResourceSet(StandardRoot.java:748)
at org.apache.catalina.webresources.StandardRoot.startInternal(StandardRoot.java:706)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
… 9 more
05-Aug-2019 02:18:33.905 涓ラ噸 [main] org.apache.catalina.core.ContainerBase.startInternal A child container failed during start
java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost]]
at java.util.concurrent.FutureTask.report(FutureTask.java:122)
at java.util.concurrent.FutureTask.get(FutureTask.java:192)
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:942)
at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:262)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.StandardService.startInternal(StandardService.java:422)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:793)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.startup.Catalina.start(Catalina.java:688)
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.apache.catalina.startup.Bootstrap.start(Bootstrap.java:353)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:493)
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167)
at org.apache.catalina.core.ContainerBaseStartChild.call(ContainerBase.java:1423)atorg.apache.catalina.core.ContainerBaseStartChild.call(ContainerBase.java:1423)
at org.apache.catalina.core.ContainerBaseStartChild.call(ContainerBase.java:1423)atorg.apache.catalina.core.ContainerBaseStartChild.call(ContainerBase.java:1413)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
Caused by: org.apache.catalina.LifecycleException: A child container failed during start
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:953)
at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:872)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
… 6 more
Caused by: java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/SKLSUG]]
at java.util.concurrent.FutureTask.report(FutureTask.java:122)
at java.util.concurrent.FutureTask.get(FutureTask.java:192)
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:942)
… 8 more
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/SKLSUG]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167)
… 6 more
Caused by: org.apache.catalina.LifecycleException: Failed to start component [org.apache.catalina.webresources.StandardRoot@1305a69d]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167)
at org.apache.catalina.core.StandardContext.resourcesStart(StandardContext.java:4885)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5020)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
… 6 more
Caused by: java.lang.IllegalArgumentException: The main resource set specified [D:\softwarefolder\apache-tomcat-8.5.40\wtpwebapps\SKLSUG] is not valid
at org.apache.catalina.webresources.StandardRoot.createMainResourceSet(StandardRoot.java:748)
at org.apache.catalina.webresources.StandardRoot.startInternal(StandardRoot.java:706)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
… 9 more
05-Aug-2019 02:18:33.909 涓ラ噸 [main] org.apache.catalina.startup.Catalina.start The required Server component failed to start so Tomcat is unable to start.
org.apache.catalina.LifecycleException: Failed to start component [StandardServer[8005]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167)
at org.apache.catalina.startup.Catalina.start(Catalina.java:688)
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.apache.catalina.startup.Bootstrap.start(Bootstrap.java:353)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:493)
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardService[Catalina]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167)
at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:793)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
… 7 more
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167)
at org.apache.catalina.core.StandardService.startInternal(StandardService.java:422)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
… 9 more
Caused by: org.apache.catalina.LifecycleException: A child container failed during start
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:953)
at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:262)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
… 11 more
Caused by: java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost]]
at java.util.concurrent.FutureTask.report(FutureTask.java:122)
at java.util.concurrent.FutureTask.get(FutureTask.java:192)
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:942)
… 13 more
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167)
at org.apache.catalina.core.ContainerBaseStartChild.call(ContainerBase.java:1423)atorg.apache.catalina.core.ContainerBaseStartChild.call(ContainerBase.java:1423)
at org.apache.catalina.core.ContainerBaseStartChild.call(ContainerBase.java:1423)atorg.apache.catalina.core.ContainerBaseStartChild.call(ContainerBase.java:1413)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
Caused by: org.apache.catalina.LifecycleException: A child container failed during start
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:953)
at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:872)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
… 6 more
Caused by: java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/SKLSUG]]
at java.util.concurrent.FutureTask.report(FutureTask.java:122)
at java.util.concurrent.FutureTask.get(FutureTask.java:192)
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:942)
… 8 more
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/SKLSUG]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167)
… 6 more
Caused by: org.apache.catalina.LifecycleException: Failed to start component [org.apache.catalina.webresources.StandardRoot@1305a69d]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167)
at org.apache.catalina.core.StandardContext.resourcesStart(StandardContext.java:4885)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5020)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
… 6 more
Caused by: java.lang.IllegalArgumentException: The main resource set specified [D:\softwarefolder\apache-tomcat-8.5.40\wtpwebapps\SKLSUG] is not valid
at org.apache.catalina.webresources.StandardRoot.createMainResourceSet(StandardRoot.java:748)
at org.apache.catalina.webresources.StandardRoot.startInternal(StandardRoot.java:706)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
… 9 more
原来有一个项目被删除了,但是tomcat信息里边还有他,导致一直找不到他。到tomcat文件下的conf文件夹下找server.xml文件。把里边关于不存在项目信息删除即可(一般在最后位置)。