我已经检查了几乎所有关于stackoverflow的相关文章,但我无法解决我的问题.
这是代码:web.xml:
<display-name>Spring3MVC</display-name>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>/WEB-INF/spring-servlet.xml</param-value>
</context-param>
<listener>
<listener-class> org.springframework.web.context.ContextLoaderListener </listener-class>
</listener>
<servlet>
<servlet-name>spring</servlet-name>
<servlet-class>
org.springframework.web.servlet.DispatcherServlet
</servlet-class>
<load-on-startup>2</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>spring</servlet-name>
<url-pattern>*.html</url-pattern>
<url-pattern>/</url-pattern>
<url-pattern>*.htm</url-pattern>
</servlet-mapping>
</web-app>
为spring-servlet.xml:
<context:component-scan base-package="com.mycompany.elso" />
<bean class="org.springframework.web.servlet.mvc.support.ControllerClassNameHandlerMapping"/>
<bean id="viewResolver"
class="org.springframework.web.servlet.view.UrlBasedViewResolver">
<property name="viewClass"
value="org.springframework.web.servlet.view.JstlView" />
<property name="prefix" value="/WEB-INF/jsp/" />
<property name="suffix" value=".jsp" />
</bean>
myController的:
public class myController {
@RequestMapping("/hello")
public ModelAndView helloWorld() {
String message = "Hello World, Spring 3.0!";
return new ModelAndView("hello", "message", message);
}
}
网页/ index.jsp:
<html>
<head>
<title>Spring …我正在尝试写入已存在的文件.据我在论坛上看到,这段代码应该重写旧文件,但不是重写,而是将文件名放入[]括号中并创建一个新文件.任何的想法？
try {
File file = new File("/home/erik/glassfish3/" + selectedMss + ".ini");
BufferedWriter output = new BufferedWriter(new FileWriter(file));
for (String newline : content) {
output.write(newline + "\n");
}
output.close();
} catch (IOException e) {
e.printStackTrace();
}
我有一个表,我想收集每个组的项目的ID与列上的最大值,但我有一个问题.
SELECT group_id, MAX(time)
FROM mytable
GROUP BY group_id
这样我得到正确的行,但我需要id:
SELECT id,group_id,MAX(time)
FROM mytable
GROUP BY id,group_id
这样我就得到了所有的行.我怎样才能从每个组获得最大值行的ID？
样本数据
id = 1, group_id = 1, time = 2014.01.03
id = 2, group_id = 1, time = 2014.01.04
id = 3, group_id = 2, time = 2014.01.04
id = 4, group_id = 2, time = 2014.01.02
id = 5, group_id = 3, time = 2014.01.01
从那我应该得到身份:2,3,5谢谢!