web应用步骤

1.建立一个web项目
2.导入struts2 必须的五个Jar包
commons-logging-1.0.4.jar
freemarker-2.3.8.jar
xwork-2.0.4.jar
commons-lang-2.1.jar
ognl-2.6.11.jar
3.若用jdbc连接，则导入 ojdbc14.jar
4.若用mysql 数据库，则需导入：mysql-connector-java-5.1.6-bin.jar
若用oracle 数据库，则需要导入： classes12.jar
5.配置web.xml文件
基本配置：
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4"
xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">

<filter>
<description>配置Struts2核心的Filter</description>
<filter-name>struts</filter-name>
<filter-class>org.apache.struts2.dispatcher.FilterDispatcher</filter-class>
</filter>
<filter>
<description>处理编码的过滤器</description>
<filter-name>CharacterEncodingFilter</filter-name>
<filter-class>
自已的包.SetCharacterEncodingFilter
</filter-class>
<init-param>
<description>编码名称</description>
<param-name>encoding</param-name>
<param-value>UTF-8</param-value>
</init-param>
</filter>

<filter-mapping>
<filter-name>CharacterEncodingFilter</filter-name>
<url-pattern>*.action</url-pattern>
</filter-mapping>
<filter-mapping>
<filter-name>struts</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
   
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>

6.编写SetCharacterEncodingFilter类
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements.  See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License.  You may obtain a copy of the License at
*
*     http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/


package com.dflw.filter;


import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;


/**
* <p>Example filter that sets the character encoding to be used in parsing the
* incoming request, either unconditionally or only if the client did not
* specify a character encoding.  Configuration of this filter is based on
* the following initialization parameters:</p>
* <ul>
* <li><strong>encoding</strong> - The character encoding to be configured
*     for this request, either conditionally or unconditionally based on
*     the <code>ignore</code> initialization parameter.  This parameter
*     is required, so there is no default.</li>
* <li><strong>ignore</strong> - If set to "true", any character encoding
*     specified by the client is ignored, and the value returned by the
*     <code>selectEncoding()</code> method is set.  If set to "false,
*     <code>selectEncoding()</code> is called <strong>only</strong> if the
*     client has not already specified an encoding.  By default, this
*     parameter is set to "true".</li>
* </ul>
*
* <p>Although this filter can be used unchanged, it is also easy to
* subclass it and make the <code>selectEncoding()</code> method more
* intelligent about what encoding to choose, based on characteristics of
* the incoming request (such as the values of the <code>Accept-Language</code>
* and <code>User-Agent</code> headers, or a value stashed in the current
* user's session.</p>
*
* @author Craig McClanahan
* @version $Revision: 466607 $ $Date: 2006-10-21 17:09:50 -0600 (Sat, 21 Oct 2006) $
*/

public class SetCharacterEncodingFilter implements Filter {


    // ----------------------------------------------------- Instance Variables


    /**
     * The default character encoding to set for requests that pass through
     * this filter.
     */
    protected String encoding = null;


    /**
     * The filter configuration object we are associated with.  If this value
     * is null, this filter instance is not currently configured.
     */
    protected FilterConfig filterConfig = null;


    /**
     * Should a character encoding specified by the client be ignored?
     */
    protected boolean ignore = true;


    // --------------------------------------------------------- Public Methods


    /**
     * Take this filter out of service.
     */
    public void destroy() {

        this.encoding = null;
        this.filterConfig = null;

    }


    /**
     * Select and set (if specified) the character encoding to be used to
     * interpret request parameters for this request.
     *
     * @param request The servlet request we are processing
     * @param result The servlet response we are creating
     * @param chain The filter chain we are processing
     *
     * @exception IOException if an input/output error occurs
     * @exception ServletException if a servlet error occurs
     */
    public void doFilter(ServletRequest request, ServletResponse response,
                         FilterChain chain)
throws IOException, ServletException {

        // Conditionally select and set the character encoding to be used
        if (ignore || (request.getCharacterEncoding() == null)) {
            String encoding = selectEncoding(request);
            if (encoding != null)
                request.setCharacterEncoding(encoding);
        }

// Pass control on to the next filter
        chain.doFilter(request, response);

    }


    /**
     * Place this filter into service.
     *
     * @param filterConfig The filter configuration object
     */
    public void init(FilterConfig filterConfig) throws ServletException {

this.filterConfig = filterConfig;
        this.encoding = filterConfig.getInitParameter("encoding");
        String value = filterConfig.getInitParameter("ignore");
        if (value == null)
            this.ignore = true;
        else if (value.equalsIgnoreCase("true"))
            this.ignore = true;
        else if (value.equalsIgnoreCase("yes"))
            this.ignore = true;
        else
            this.ignore = false;

    }


    // ------------------------------------------------------ Protected Methods


    /**
     * Select an appropriate character encoding to be used, based on the
     * characteristics of the current request and/or filter initialization
     * parameters.  If no character encoding should be set, return
     * <code>null</code>.
     * <p>
     * The default implementation unconditionally returns the value configured
     * by the <strong>encoding</strong> initialization parameter for this
     * filter.
     *
     * @param request The servlet request we are processing
     */
    protected String selectEncoding(ServletRequest request) {

        return (this.encoding);

    }


}
7.配置struts2的配置文件
在src目录下：struts.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
    "http://struts.apache.org/dtds/struts-2.0.dtd">
<struts>
<package name="com.dflw" extends="struts-default" namespace="/test">

<action name="myAction" class="com.dflw.action.MyAction" method="testAction">
<result name="test">/test/MyJsp.jsp</result>
</action>
</package>
</struts>

8.编写取数据库连接的工具类
类一：
package com.dflw.util;

import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.Enumeration;
import java.util.Properties;


public class DBConnectionFactory
{

private static final Properties dbProperties;

private static boolean initialSuccFlag = false;

static
{
dbProperties = new Properties();

String key = null;
String clazzName = null;
try
{
dbProperties.load(JdbConnectionFactory.class
.getResourceAsStream("/db.properties"));
Enumeration<Object> keys = dbProperties.keys();
if (keys != null)
{
while (keys.hasMoreElements())
{
key = (String) keys.nextElement();
if (key.contains(".driver"))
{
clazzName = dbProperties.getProperty(key);
if (clazzName != null && !"".equals(clazzName.trim()))
{
Class.forName(clazzName);
}
else
{
throw new IOException("db.properties中" + key
+ "配置有误，值不允许为空");
}
}
}
}

initialSuccFlag = true;

}
catch (ClassNotFoundException e)
{
System.out.println("加载db.properties失败，在classpath中未找到指定的JDBC驱动类:  " + e.getMessage());
}
catch (IOException e)
{
System.out.println("加载db.properties失败: " + e.getMessage());
}

}

public static Connection getConnection(String name)
{
Connection connection = null;

if(!initialSuccFlag)
{
try
{
throw new Exception("系统启动时发生异常，导致数据库配置信息初始化失败。");
}
catch (Exception e)
{
e.printStackTrace();
}
}

try
{
String type = dbProperties.getProperty(name + ".type");

if ("ORACLE".equalsIgnoreCase(type))
{
String sUrl = dbProperties.getProperty(name + ".url");
String sUser = dbProperties.getProperty(name + ".user");
String sPassword = dbProperties.getProperty(name + ".password");

connection = DriverManager
.getConnection(sUrl, sUser, sPassword);
}
else if ("mysql".equalsIgnoreCase(type))
{
String sUrl = dbProperties.getProperty(name + ".url");
String sUser = dbProperties.getProperty(name + ".user");
String sPassword = dbProperties.getProperty(name + ".password");

connection = DriverManager
.getConnection(sUrl, sUser, sPassword);
}
}
catch (SQLException e)
{
try
{
throw new SQLException("[错误]连接数据库失败：" + e.getMessage());
}
catch (SQLException e1)
{
e1.printStackTrace();
}
}

return connection;
}

}
类二：
package com.dflw.util;

import java.sql.Connection;
import java.sql.SQLException;

public class JdbConnectionFactory{


public Connection createConnection() throws SQLException {
try
{

  return DBConnectionFactory.getConnection("mysql");

}
catch (Exception e)
{
e.printStackTrace();
System.out.println("ORACLE数据库连接失败！");
throw new SQLException(e.getMessage());
}
}

}

配置数据库的连接的属性文件：
mysql.type=mysql
mysql.driver=com.mysql.jdbc.Driver
mysql.url=jdbc:mysql://localhost:3306/dflw_net
mysql.user=root
mysql.password=dflw

ORACLE20.type=ORACLE
ORACLE20.driver=oracle.jdbc.driver.OracleDriver
ORACLE20.url=jdbc:oracle:thin:@21.7.16.20:1521:cdc
ORACLE20.user=zhcard
ORACLE20.password=zhcard


9.编写Action与Service 及前台展示页面JSP
10.把Action及方法配置到
struts.xml文件中：
<action name="myAction" class="com.dflw.action.MyAction" method="testAction">
<result name="test">/test/MyJsp.jsp</result>
</action>

11.把项目部署到tomcat中。