7、struts2 案例( 模型驱动、 防止表单重复提交--拦截器 、数据回显 、值栈 、 OGNL表达式综合运用)

struts2 案例

技术点：
模型驱动
防止表单重复提交–拦截器
数据回显
值栈
OGNL表达式
通配符、路径匹配原则、常量
数据处理的集中方式
请求数据自动封装以及类型转换

1、导包
c3p0-0.9.1.2.jar
commons-dbutils-1.6.jar
commons-fileupload-1.2.2.jar
commons-io-2.0.1.jar
commons-lang3-3.1.jar
freemarker-2.3.19.jar
javassist-3.11.0.GA.jar
mysql-connector-java-5.1.12-bin.jar
ognl-3.0.5.jar
struts2-core-2.3.4.1.jar
xwork-core-2.3.4.1.jar
2、配置web.xml 注册struts核心过滤器

<!-- Struts2的功能的初始化是通过过滤器引入 -->    <filter>        <filter-name>struts2</filter-name>        <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>    </filter>    <filter-mapping>        <filter-name>struts2</filter-name>        <url-pattern>/*</url-pattern>    </filter-mapping>

3、配置struts.xml

<struts>    <!-- 更改主题 -->    <constant name="struts.ui.theme" value="simple"></constant>    <package name="emp" extends="struts-default">        <!-- 全局视图 -->        <global-results>            <result name="error">/error/error.jsp</result>        </global-results>        <action name="emp_*" class="cn.itcast.action.EmployeeAction" method="{1}">            <!-- 防止表单重复提交，第二步： 配置" 防止表单重复提交拦截器" -->            <interceptor-ref name="defaultStack"></interceptor-ref>            <interceptor-ref name="token">                <!-- 指定拦截哪些方法需要防止表单重复提交(save) -->                <param name="includeMethods">save</param>            </interceptor-ref>            <!-- 防止表单重复提交，第三步： 如果用户重复提交了跳转到指定的错误页面  -->            <result name="invalid.token" type="redirectAction">emp_list</result>            <!-- 首页显示 -->            <result name="list">/WEB-INF/list.jsp</result>            <!-- 进入修改页面 -->            <result name="update">/WEB-INF/update.jsp</result>            <!--             <result name="addsuccess" type="redirectAction">emp_list</result>             -->        </action>    </package></struts>

4、开发Action

  /** * 员工管理Action * */public class EmployeeAction extends ActionSupport implements ModelDriven<Employee>{    /****封装数据****/    private Employee employee = new Employee();    public Employee getEmployee() {        return employee;    }    public void setEmployee(Employee employee) {        this.employee = employee;    }    // 重写模型驱动方法    @Override    public Employee getModel() {        return employee;    }    /****调用的Service****/    private IEmployeeService employeeService = new EmployeeService();    /**     * 1. 添加员工     */    public String save() {        try {            // 调用service保存            employeeService.save(employee);            // 添加成功，去到列表页面            return list();            //return "addsuccess";        } catch (Exception e) {            e.printStackTrace();            return ERROR;        }    }    /**     * 2. 列表显示     */    public String list() {        try {            // 查询全部            List<Employee> listEmp = employeeService.getAll();            // 保存到request域            ActionContext.getContext().getContextMap().put("listEmp", listEmp);            return "list";        } catch (Exception e) {            e.printStackTrace();            return ERROR;        }    }    /**     * 3. 进入修改页面     */    public String viewUpdate() {        try {            // 3.1 获取当前修改的记录的主键值            int id = employee.getId();            // 3.2 service查询            Employee emp = employeeService.findById(id);            // 3.3 数据回显            // a. 先得到值栈            ValueStack vs = ActionContext.getContext().getValueStack();            vs.pop();   //移除栈顶元素            vs.push(emp);   // emp对象放入栈顶            return "update";        } catch (Exception e) {            e.printStackTrace();            return ERROR;        }    }    /**     * 4. 修改员工     */    public String update() {        try {            // 调用service修改            employeeService.update(employee);            return list();        } catch (Exception e) {            e.printStackTrace();            return ERROR;        }    }}

5、开发entity

public class Employee {    private int id;// INT PRIMARY KEY AUTO_INCREMENT,    private String empName;// VARCHAR(20),    private Date workDate;// DATE -- 入职时间    public int getId() {        return id;    }    public void setId(int id) {        this.id = id;    }    public String getEmpName() {        return empName;    }    public void setEmpName(String empName) {        this.empName = empName;    }    public Date getWorkDate() {        return workDate;    }    public void setWorkDate(Date workDate) {        this.workDate = workDate;    }}

6、开发dao

创建 – 创建数据库
CREATE DATABASE hib_demo DEFAULT CHARACTER SET utf8;
– 建表
CREATE TABLE employee (
id INT PRIMARY KEY AUTO_INCREMENT,
empName VARCHAR(20),
workDate DATE – 入职时间
)

dao接口

/** * 数据访问层接口 *  * */public interface IEmployeeDao {    /**     * 查询全部员工     */    List<Employee> getAll();    /**     * 根据主键查询     */    Employee findById(int id);    /**     * 添加员工     */    void save(Employee emp);    /**     * 修改员工     */    void update(Employee emp);}

dao方法实现

public class EmployeeDao implements IEmployeeDao{    @Override    public Employee findById(int id) {        String sql = "select * from employee where id=?";        try {            return JdbcUtils.getQuerrRunner().query(sql, new BeanHandler<Employee>(Employee.class),id);        } catch (SQLException e) {            throw new RuntimeException(e);        }    }    @Override    public List<Employee> getAll() {        String sql = "select * from employee";        try {            return JdbcUtils.getQuerrRunner().query(sql, new BeanListHandler<Employee>(Employee.class));        } catch (SQLException e) {            throw new RuntimeException(e);        }    }    @Override    public void save(Employee emp) {        String sql = "insert into employee(empName,workDate) values(?,?)";        try {            JdbcUtils.getQuerrRunner().update(sql, emp.getEmpName(),emp.getWorkDate());        } catch (SQLException e) {            throw new RuntimeException(e);        }    }    @Override    public void update(Employee emp) {        String sql = "update employee set empName=?,workDate=? where id=?";        try {            JdbcUtils.getQuerrRunner().update(sql, emp.getEmpName(),emp.getWorkDate(),emp.getId());        } catch (SQLException e) {            throw new RuntimeException(e);        }    }}

7、导入 JdbcUtils,以及配置好c3p0

  /** * 封装常用的操作 * */public class JdbcUtils {    // 初始化连接池    private static DataSource dataSource;    static {        dataSource = new ComboPooledDataSource();    }    public static DataSource getDataSource() {        return dataSource;    }    /**     * 创建DbUtils常用工具类对象     */    public static QueryRunner getQuerrRunner() {        return new QueryRunner(dataSource);    }}

c3p0配置文件

<c3p0-config>  <default-config>     <property name="driverClass">com.mysql.jdbc.Driver</property>      <property name="jdbcUrl">jdbc:mysql:///hib_demo</property>      <property name="user">root</property>      <property name="password">root</property>      <property name="initialPoolSize">5</property>      <property name="maxPoolSize">10</property>   </default-config>  <named-config name="oracleConfig">    <property name="driverClass">com.mysql.jdbc.Driver</property>      <property name="jdbcUrl">jdbc:mysql:///day17</property>      <property name="user">root</property>      <property name="password">root</property>      <property name="initialPoolSize">5</property>      <property name="maxPoolSize">10</property>    </named-config></c3p0-config>

8、开发services

/** * 业务逻辑层接口 *  * */public interface IEmployeeService {    /**     * 查询全部员工     */    List<Employee> getAll();    /**     * 根据主键查询     */    Employee findById(int id);    /**     * 添加员工     */    void save(Employee emp);    /**     * 修改员工     */    void update(Employee emp);}

public class EmployeeService implements IEmployeeService{    private IEmployeeDao employeeDao = new EmployeeDao();    @Override    public Employee findById(int id) {        try {            return employeeDao.findById(id);        } catch (Exception e) {            throw new RuntimeException(e);        }    }    @Override    public List<Employee> getAll() {        try {            return employeeDao.getAll();        } catch (Exception e) {            throw new RuntimeException(e);        }    }    @Override    public void save(Employee emp) {        try {            employeeDao.save(emp);        } catch (Exception e) {            throw new RuntimeException(e);        }    }    @Override    public void update(Employee emp) {        try {            employeeDao.update(emp);        } catch (Exception e) {            throw new RuntimeException(e);        }    }}

9、相关jsp页面
webroot下 add.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%><%@taglib uri="/struts-tags" prefix="s" %><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html>  <head>    <title>Add</title>    <meta http-equiv="pragma" content="no-cache">    <meta http-equiv="cache-control" content="no-cache">    <meta http-equiv="expires" content="0">      </head>  <body>    <s:form action="/emp_save" method="post">        <!-- 防止表单重复提交，第一步：生成id(客户端、服务器) -->        <s:token></s:token>        <table>            <tr>                <td>员工名：</td>                <td><s:textfield name="empName" /></td>            </tr>            <tr>                <td>日期：</td>                <td><s:textfield name="workDate" /></td>            </tr>            <tr>                <td colspan="2">                    <s:submit value="保存员工"></s:submit>                </td>            </tr>        </table>    </s:form>  </body></html>

WebRoot/WEB-INF 下 list.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%><%@taglib uri="/struts-tags" prefix="s" %><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html>  <head>    <title>list</title>    <meta http-equiv="pragma" content="no-cache">    <meta http-equiv="cache-control" content="no-cache">    <meta http-equiv="expires" content="0">      </head>  <body>     <table border="1" align="center">        <tr>            <th>序号</th>            <th>编号</th>            <th>员工名称</th>            <th>日志日期</th>            <th>操作</th>        </tr>        <!-- 1. 先判断；2.  再迭代 -->        <s:if test="#request.listEmp != null">            <s:iterator var="emp" value="#request.listEmp" status="st">                <tr>                    <td><s:property value="#st.count"/></td>                    <td><s:property value="#emp.id"/></td>                    <td><s:property value="#emp.empName"/></td>                    <td><s:property value="#emp.workDate"/></td>                    <td>                        <s:a href="emp_viewUpdate?id=%{#emp.id}">修改</s:a>                    </td>                </tr>            </s:iterator>        </s:if>        <s:else>            <tr>                <td colspan="5">对不起，没有你要显示的数据</td>            </tr>        </s:else>     </table>  </body></html>

WebRoot/WEB-INF 下 update.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%><%@taglib uri="/struts-tags" prefix="s" %><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html>  <head>    <title>Add</title>    <meta http-equiv="pragma" content="no-cache">    <meta http-equiv="cache-control" content="no-cache">    <meta http-equiv="expires" content="0">      </head>  <body>    <s:form action="/emp_update" method="post">        <!-- 隐藏域，保存主键 -->        <s:hidden name="id"></s:hidden>        <table>            <tr>                <td>员工名：</td>                <td><s:textfield name="empName" /></td>            </tr>            <tr>                <td>日期：</td>                <!--                 <td><s:date name="workDate" format="yyyy-MM-dd"/>                    <s:hidden name="workDate"></s:hidden>                </td>                 -->                 <td>                    <s:textfield name="workDate" />                 </td>            </tr>            <tr>                <td colspan="2">                    <s:submit value="修改员工"></s:submit>                </td>            </tr>        </table>    </s:form>  </body></html>