package ...; 
import ...; 
// 主要目的：過濾字符編碼；其次，做一些應(yīng)用邏輯判斷等. 
// Filter跟web應(yīng)用一起啟動(dòng) 
// 當(dāng)web應(yīng)用重新啟動(dòng)或銷毀時(shí)，F(xiàn)ilter也被銷毀 
public class MyCharsetFilter implements Filter { 
  private FilterConfig config = null; 
  public void destroy() { 
   System.out.println("MyCharsetFilter準(zhǔn)備銷毀..."); 
  } 
 
  public void doFilter(ServletRequest arg0, ServletResponse arg1, FilterChain chain) throws IOException, ServletException { 
   // 強(qiáng)制類型轉(zhuǎn)換 
   HttpServletRequest request = (HttpServletRequest)arg0; 
   HttpServletResponse response = (HttpServletResponse)arg1; 
   // 獲 取web.xm設(shè)置的編碼集，設(shè)置到Request、Response 中   request.setCharacterEncoding(config.getInitParameter("charset"));   response.setContentType(config.getInitParameter("contentType"));   response.setCharacterEncoding(config.getInitParameter("charset"));   
  // 將請(qǐng)求轉(zhuǎn)發(fā)到目的地 
   chain.doFilter(request, response); 
  } 
 
  public void init(FilterConfig arg0) throws ServletException { 
   this.config = arg0; 
   System.out.println("MyCharsetFilter初始化..."); 
  } 
 } 

<filter> 
  <filter-name>filter</filter-name> 
  <filter-class>dc.gz.filters.MyCharsetFilter</filter-class> 
  <init-param> 
   <param-name>charset</param-name> 
   <param-value>UTF-8</param-value> 
  </init-param> 
  <init-param> 
   <param-name>contentType</param-name> 
   <param-value>text/html;charset=UTF-8</param-value> 
  </init-param> 
 </filter> 
 <filter-mapping> 
  <filter-name>filter</filter-name> 
  <!-- * 代表截獲所有的請(qǐng)求 或指定請(qǐng)求/test.do /xxx.do --> 
  <url-pattern>/*</url-pattern> 
 </filter-mapping>

MyServletContextListener.java 
 package dc.gz.listeners; 
 import javax.servlet.ServletContext; 
 import javax.servlet.ServletContextEvent; 
 import javax.servlet.ServletContextListener; 
 import org.apache.commons.dbcp.BasicDataSource; 
 /** 
 * Web應(yīng)用監(jiān)聽器 
 */ 
 public class MyServletContextListener implements ServletContextListener {  
  // 應(yīng)用監(jiān)聽器的銷毀方法 
  public void contextDestroyed(ServletContextEvent event) { 
   ServletContext sc = event.getServletContext(); 
   // 在整個(gè)web應(yīng)用銷毀之前調(diào)用，將所有應(yīng)用空間所設(shè)置的內(nèi)容清空 
   sc.removeAttribute("dataSource"); 
  System.out.println("銷毀工作完成..."); 
  } 
  // 應(yīng)用監(jiān)聽器的初始化方法 
  public void contextInitialized(ServletContextEvent event) { 
   // 通過這個(gè)事件可以獲取整個(gè)應(yīng)用的空間 
   // 在整個(gè)web應(yīng)用下面啟動(dòng)的時(shí)候做一些初始化的內(nèi)容添加工作 
   ServletContext sc = event.getServletContext(); 
   // 設(shè)置一些基本的內(nèi)容；比如一些參數(shù)或者是一些固定的對(duì)象 
   // 創(chuàng)建DataSource對(duì)象，連接池技術(shù) dbcp 
   BasicDataSource bds = new BasicDataSource(); 
   bds.setDriverClassName("com.mysql.jdbc.Driver");      bds.setUrl("jdbc:mysql://localhost:3306/hibernate"); 
   bds.setUsername("root"); 
   bds.setPassword("root"); 
   bds.setMaxActive(10);//最大連接數(shù) 
   bds.setMaxIdle(5);//最大管理數(shù) 
   //bds.setMaxWait(maxWait); 最大等待時(shí)間 
   // 把 DataSource 放入ServletContext空間中， 
   // 供整個(gè)web應(yīng)用的使用(獲取數(shù)據(jù)庫連接) 
   sc.setAttribute("dataSource", bds); 
   System.out.println("應(yīng)用監(jiān)聽器初始化工作完成..."); 
   System.out.println("已經(jīng)創(chuàng)建DataSource..."); 
  } 
 } 

<!-- 配置應(yīng)用監(jiān)聽器 --> 
 <listener> 
  <listener-class>dc.gz.listeners.MyServletContextListener</listener-class> 
 </listener> 

public Object invoke(Object proxy, Method method, Object[] args) throws Throwable 
{ 
Object result = null; 
System.out.println("before invoke method :" + method.getName()); 
result = method.invoke(this.targetObj, args); 
System.out.println("after invoke method : " + method.getName()); 
return result; 
}