日常遇到的小问题

日常开发过程中,总会遇到各种小问题,特此记录下各种解决。

1. eclipse中部署项目到tomcat,启动tomcat时报错: 

Resource is out of sync with the file system: ................

太长只截取前一段,解决办法:需要手动刷新一下资源管理器,eclipse中,工程目录右键,refresh。

2.maven项目打包的时候,mybatis的*mapper.xml都没得打包,解决方法pom.xml中build节点中加入:

         <resources>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.xml</include>
                </includes>
                <filtering>false</filtering>
            </resource>
        </resources>    

 3.mybatis的数据库连接配置信息写在properties配置文件中,然后做spring做单元测试的时候,总是报出

Could not load driverClass ${jdbc.driverClass}

错误的原因很明显,相关的连接参数信息并没有正确的去读取properties配置文件中的相关信息,本地项目使用的mybaits版本号3.1.1。网上查找解决办法,是由于

<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.reserve.core.dao" />
        <property name="sqlSessionFactory" ref="sqlSessionFactory"></property>
</bean>

中的sqlSessionFactory注入问题,改用sqlSessionFactoryBeanName注入就没有问题(不要使用sqlSessionFactory属性注入,使用 sqlSessionFactoryBeanName注入),因为这时不会立即初始化sqlSessionFactory,传入的只是名字,非bean, 所以不会引发提前初始化问题。

<property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"></property>

 4.获取泛型T.class。最近最项目中,用到泛型设计,但是要获取T.class,方法如下:

public abstract class DataSyncProService<T extends Data> implements DataSyncService{
    
    private Class<T> entityClass;//获取泛型T的T.class
    
    public DataSyncProService(){
        Type genType = getClass().getGenericSuperclass();
        Type[] params = ((ParameterizedType) genType).getActualTypeArguments(); 
        entityClass = (Class) params[0]; 
    }
    ....
}

截取部分代码,子类的构造函数会调用父类的构造函数,所以当子类实例化的时候,父类的entityClass 已经得到了T.class。

本地代码其中一个子类定义:

public class MerinfoImpl extends DataSyncProService<MerInfo>

另外,照搬一段资料,虽然现在还不是很懂:

这是泛型擦拭法使得Generic无法获取自己的Generic Type类型。实际上BadClass<String>()实例化以后Class里面就不包括T的信息了,
对于Class而言T已经被擦拭为Object,而真正的T参数被转到使用T的方法(或者变量声明或者其它使用T的地方)里面(如果没有那就没有存根),
所以无法反射到T的具体类别,也就无法得到T.class。而getGenericSuperclass()是Generic继承的特例,对于这种情况子类会保存父类的Generic参数类型,
返回一个ParameterizedType,这时可以获取到父类的T.class了,这也正是子类确定应该继承什么T的方法

 5.jquery修改css中带有!important的样式属性

html : <select class="select1" id="jq-sql-content"></select>
外部样式为 .select1{color: #e3e3e3!important;}
如果直接使用:$("#jq-sql-content").css("color","black")或者$("#jq-sql-content").css("color","black!important"),都是无效的
正确用法$("#jq-sql-content").css("cssText","color:black!important"),多个属性的话$("#jq-sql-content").css("cssText","color:black!important;属性名:值!important;")

 

6、linux安装activemq

  安装完毕之后,启动时候报错如下

  

2018-06-05 11:26:06,750 | WARN  | Exception thrown from LifecycleProcessor on context close | org.apache.activemq.xbean.XBeanBrokerFactory$1 | main
java.lang.IllegalStateException: LifecycleProcessor not initialized - call 'refresh' before invoking lifecycle methods via the context: org.apache.activemq.xbean.XBeanBrokerFactory$1@6bbee61a: startup date [Tue Jun 05 11:26:03 CST 2018]; root of context hierarchy
    at org.springframework.context.support.AbstractApplicationContext.getLifecycleProcessor(AbstractApplicationContext.java:360)
    at org.springframework.context.support.AbstractApplicationContext.doClose(AbstractApplicationContext.java:1057)
    at org.springframework.context.support.AbstractApplicationContext.close(AbstractApplicationContext.java:1010)
    at org.apache.activemq.hooks.SpringContextHook.run(SpringContextHook.java:30)
    at org.apache.activemq.broker.BrokerService.stop(BrokerService.java:809)
    at org.apache.activemq.xbean.XBeanBrokerService.stop(XBeanBrokerService.java:122)
    at org.apache.activemq.broker.BrokerService.start(BrokerService.java:601)
    at org.apache.activemq.xbean.XBeanBrokerService.afterPropertiesSet(XBeanBrokerService.java:73)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeCustomInitMethod(AbstractAutowireCapableBeanFactory.java:1638)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1579)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1509)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:521)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:458)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:296)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:223)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:293)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:628)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:932)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:479)
    at org.apache.xbean.spring.context.ResourceXmlApplicationContext.<init>(ResourceXmlApplicationContext.java:64)
    at org.apache.xbean.spring.context.ResourceXmlApplicationContext.<init>(ResourceXmlApplicationContext.java:52)
    at org.apache.activemq.xbean.XBeanBrokerFactory$1.<init>(XBeanBrokerFactory.java:104)
    at org.apache.activemq.xbean.XBeanBrokerFactory.createApplicationContext(XBeanBrokerFactory.java:104)
    at org.apache.activemq.xbean.XBeanBrokerFactory.createBroker(XBeanBrokerFactory.java:67)
    at org.apache.activemq.broker.BrokerFactory.createBroker(BrokerFactory.java:71)
    at org.apache.activemq.broker.BrokerFactory.createBroker(BrokerFactory.java:54)
    at org.apache.activemq.console.command.StartCommand.runTask(StartCommand.java:87)
    at org.apache.activemq.console.command.AbstractCommand.execute(AbstractCommand.java:57)
    at org.apache.activemq.console.command.ShellCommand.runTask(ShellCommand.java:150)
    at org.apache.activemq.console.command.AbstractCommand.execute(AbstractCommand.java:57)
    at org.apache.activemq.console.command.ShellCommand.main(ShellCommand.java:104)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.apache.activemq.console.Main.runTaskClass(Main.java:262)
    at org.apache.activemq.console.Main.main(Main.java:115)

首先确定的是并不是权限问题,权限问题在./bin/activemq start启动是就会报出permission denied。查询资料,得知此根源为当前主机名,去除主机名中的下划线即可。永久生效的话,需修改/etc/sysconfig/network和/etc/hostname文件。临时生效直接命令hostname "你要定义的主机名",再下次重启之前都有效。


 7、VMware centos6.9选择链接克隆ip以及网络链接问题

    选择链接克隆,与原始虚拟机共享同一虚拟磁盘文件,不能脱离原始虚拟机独立运行。但采用共享磁盘文件却大大缩短了创建克隆虚拟机的时间,同时还节省了宝贵的物理磁盘空间。通过链接克隆,可以轻松的为不同的任务创建一个独立的虚拟机。 

    首先,打开/etc/udev/rules.d/70-persistent-net.rules内容如下面例子所示:

记住eth1的网卡地址:000c:29:3d:83:b1

    接下来,编辑  vi   /etc/sysconfig/network-scripts/ifcfg-eth0

      将 DEVICE="eth0"  改成  DEVICE="eth1"  ,
      将 HWADDR="00:0c:29:46:62:f9" 改成上面的mac地址  HWADDR="00:0c:29:3d:83:b1"

重启网络:service network restart    或者  /etc/init.d/network restart

 

posted @ 2016-07-13 10:10  阿呆很呆非常呆  阅读(455)  评论(0编辑  收藏  举报