你会如何向一个新手网络开发人员或程序员解释一下这个例子(比如facebook公司或谷歌公司)？
android中可用的不同栏有哪些？它们位于何处？支持每种类型的图片将受到高度赞赏,对初学者非常有帮助.
错误堆栈跟踪:
SEVERE: StandardWrapper.Throwable
org.springframework.beans.factory.BeanDefinitionStoreException: IOException parsing XML document from ServletContext resource [/WEB-INF/dispatcher-servlet.xml]; nested exception is java.io.FileNotFoundException: Could not open ServletContext resource [/WEB-INF/dispatcher-servlet.xml]
调度员servlet.xml中
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:p="http://www.springframework.org/schema/p"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:beans="http://springframework.org/schema/beans"
xsi:schemaLocation="http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/mvc/spring-mvc.xsd
http://www.springframework.org/schema/task/spring-task.xsd">
<mvc:annotation-driven/>
<context:component-scan base-package="com.exam.www" />
<!-- Factory bean that creates the Mongo instance -->
<bean id="mongo" class="org.springframework.data.mongodb.core.MongoFactoryBean">
<property name="host" value="localhost" />
</bean>
<!-- MongoTemplate for connecting and quering the documents in the database -->
<bean id="mongoTemplate" class="org.springframework.data.mongodb.core.MongoTemplate">
<constructor-arg name="mongo" ref="mongo" />
<constructor-arg name="databaseName" value="Results" …例:
public String getStudentResult(@RequestParam(value = "regNo", required = true) String regNo, ModelMap model){
如何在此处使用@valid作为regNo参数？
当我的jsp文件在WEB-INF文件夹中时(作为/WEB-INF/file.jsp),我可以从localhost:8080/ProjectCtxtRoot /访问它们,但如果它们放在/ WEB-中我无法访问它们INF/JSP/file.jsp？
我在web.xml中更改了welcome-list标记中的路径,如下所示
<welcome-file-list>
<welcome-file>/JSP/fileName.jsp</welcome-file>
</welcome-file-list>
我还更改了dispatcher-servlet.xml,如下所示
<bean id="jspViewResolver"
class="org.springframework.web.servlet.view.InternalResourceViewResolver"
p:prefix="/WEB-INF/jsp/"
p:suffix=".jsp" />
它仍然无效.用于上述案例的网址是
localhost:8080/ContextRoot/jsp/
localhost:8080/ContextRoot/jsp/fileName.jsp
localhost:8080/ContextRoot/jsp/fileName
它不适用于上述任何网址.
但它正在工作的时候
<welcome-file-list>
<welcome-file>/fileName.jsp</welcome-file>
</welcome-file-list>
dispatcher-servlet.xml如下
<bean id="jspViewResolver"
class="org.springframework.web.servlet.view.InternalResourceViewResolver"
p:prefix="/WEB-INF/"
p:suffix=".jsp" />
用于上述案例的URL是localhost:8080/ContextRoot /并且它可以工作.
我使用tomcat v 7.0服务器.我在Eclipse IDE中刷新我的项目,然后清理它,构建它,使用mvn clean install构建war,然后从tomcat manager主页选择war并进行部署.我每次都这样做.
这就是diapatcher-servlet.xml在整个过程中的外观.我只是改变上面所说的特定部分
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:p="http://www.springframework.org/schema/p"
xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.1.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.1.xsd
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd">
<mvc:annotation-driven/>
<context:component-scan base-package="com.projectName.www" />
<!-- Factory bean that creates the Mongo instance -->
<bean id="mongo" class="org.springframework.data.mongodb.core.MongoFactoryBean">
<property name="host" value="localhost" />
</bean>
<!-- …字段的数据类型是String.我想找到mongoDB中字段的最长和最短值的长度.
我的收藏中共有500000份文件.
所以我在Mac上使用Android Studio.我将Keymap更改为我习惯的"Eclipse".
但现在我想用"Cmd"键替换所有具有"Ctrl"键的快捷键.
我不想手动转到每个快捷方式并执行此操作.怎么这么简单？
如果我配置 UFW 和 Amazon EC2 安全组，这将覆盖另一个安全组，或者它们是否可以毫无问题地共存？
func getRecords(ctx context.Context, ids *[]Id) error {
ctx, cancel := context.WithTimeout(ctx, DefaultTimeout)
defer cancel()
var wg sync.WaitGroup
size := len(*ids)
allErrors := make(chan error, size)
for i := 0; i < size; i++ {
wg.Add(1)
go func(x int){
err := //call to other func which return error type. nil or error
if err != nil { // I will be creating n goroutines. How to exit rightaway if one of
// them return error
allErrors <- err
}
wg.Done()
}(i) …仅在第一次创建表时才有效create index concurrently，还是对将来插入的记录有效？