Can't read/write files under Tomcat 6 installed on AWS EC2

Question

I have a webapp running on Tomcat 6, one class checks for existence of directory and creates it if doesn't exist -

// make sure path exists
File f = new File(value);
if (!f.exists()) {
    if (!f.mkdirs()) {
        throw new RuntimeException("Failed creating directory " + value);
    }
}

Now, it all works just fine when running on my local machine, but when executed on EC2 instance, I see the following at catalina.out -

2012-05-30 06:57:28 main ConfigService [INFO] Directory path not exists, creating /usr/share/tomcat6/webapps/ROOT/WEB-INF/data/temp/currency
2012-05-30 06:57:28 main DefaultListableBeanFactory [INFO] Destroying singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@1b4c1d7: defining beans [fetchAppRankingJob,fetchCurrencyRatesJob,fetchReviewsJob,sendDailyReportJob,importSalesReportJob,fetchSalesReportJob,processSalesReportsJob,org.springframework.context.annotation.internalConfigurationAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalRequiredAnnotationProcessor,org.springframework.context.annotation.internalCommonAnnotationProcessor,org.springframework.aop.config.internalAutoProxyCreator,org.springframework.transaction.annotation.AnnotationTransactionAttributeSource#0,org.springframework.transaction.interceptor.TransactionInterceptor#0,org.springframework.transaction.config.internalTransactionAdvisor,org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping#0,org.springframework.format.support.FormattingConversionServiceFactoryBean#0,org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter#0,org.springframework.web.servlet.handler.MappedInterceptor#0,org.springframework.web.servlet.mvc.method.annotation.ExceptionHandlerExceptionResolver#0,org.springframework.web.servlet.mvc.annotation.ResponseStatusExceptionResolver#0,org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver#0,org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping,org.springframework.web.servlet.mvc.HttpRequestHandlerAdapter,org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter,org.springframework.scheduling.support.ScheduledMethodRunnable#0,org.springframework.scheduling.support.ScheduledMethodRunnable#1,org.springframework.scheduling.support.ScheduledMethodRunnable#2,org.springframework.scheduling.support.ScheduledMethodRunnable#3,org.springframework.scheduling.support.ScheduledMethodRunnable#4,org.springframework.scheduling.config.ScheduledTaskRegistrar#0,appsales-scheduler,org.springframework.context.annotation.ConfigurationClassPostProcessor$ImportAwareBeanPostProcessor#0]; root of factory hierarchy
2012-05-30 06:57:28 main ContextLoader [ERROR] Context initialization failed
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'fetchCurrencyRatesJob' defined in file [/var/lib/tomcat6/webapps/ROOT/WEB-INF/classes/com/appround/collect/currency/FetchCurrencyRatesJob.class]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [com.appround.collect.currency.FetchCurrencyRatesJob]: Constructor threw exception; nested exception is java.lang.RuntimeException: Failed creating directory /usr/share/tomcat6/webapps/ROOT/WEB-INF/data/temp/currency
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:997)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:943)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:485)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
        at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:294)
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:225)
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:291)
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:585)
        at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:913)
        at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:464)
        at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:385)
        at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:284)
        at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:111)
        at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4206)
        at org.apache.catalina.core.StandardContext.start(StandardContext.java:4705)
        at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:799)
        at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:779)
        at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:601)
        at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1079)
        at org.apache.catalina.startup.HostConfig.deployDirectories(HostConfig.java:1002)
        at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:506)
        at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1317)
        at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:324)
        at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:142)
        at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1065)
        at org.apache.catalina.core.StandardHost.start(StandardHost.java:840)
        at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1057)
        at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:463)
        at org.apache.catalina.core.StandardService.start(StandardService.java:525)
        at org.apache.catalina.core.StandardServer.start(StandardServer.java:754)
        at org.apache.catalina.startup.Catalina.start(Catalina.java:595)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
        at java.lang.reflect.Method.invoke(Unknown Source)
        at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:289)
        at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:414)
Caused by: org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [com.appround.collect.currency.FetchCurrencyRatesJob]: Constructor threw exception; nested exception is java.lang.RuntimeException: Failed creating directory /usr/share/tomcat6/webapps/ROOT/WEB-INF/data/temp/currency
        at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:162)
        at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:76)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:990)
        ... 37 more
Caused by: java.lang.RuntimeException: Failed creating directory /usr/share/tomcat6/webapps/ROOT/WEB-INF/data/temp/currency
        at com.appround.collect.ConfigService.getPathProperty(ConfigService.java:109)
        at com.appround.collect.currency.FetchCurrencyRatesJob.<init>(FetchCurrencyRatesJob.java:18)
        at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
        at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
        at java.lang.reflect.Constructor.newInstance(Unknown Source)
        at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:147)
        ... 39 more

I prefer writing to /home/ec2-user/collect/data, tried writing to my webapp's directory because it should have writing privilege to WEB-INF folder.

I've tried granting file permission write/read to that folder at /usr/share/tomcat6/conf/catalina.policy -

grant {
    permission java.io.FilePermission "/home/ec2-user/collect/data", "read, write";
    permission java.io.FilePermission "/home/ec2-user/collect/data/*", "read, write";
}

Still, no luck.

Any clue?

Thanks!

Answer 1

I am assuming you are using Amazon Linux since you mention the ec2-user.

What permissions are set on the parent folder /usr/share/tomcat6/webapps/ where you try to create the new one? Usually the user running Tomcat (should also be called tomcat) does not have write permission there unless you set it explicitly using chmod u+w.

In adddition the tomcat user is not allowed to write to a different user's home (/home/ec2-user/ in your case), unless you give the user permissions for this directory. Your example is a little confusing there since you mention trying to write to the webapps folder but specify the ec2-user's home directory in the policy file.

Generally, if you want to create temporary data files, I would suggest using File.createTempFile(..) to create them, they will automatically be placed in the standard temporary folder. If you would like to create a dedicated folder for data files yourself, /var/tmp/ may be better suited since it is the standard unix location for temporary files (/tmp/ may be cleared upon reboot, so please do not put any persistent files there).