一个简单的Struts例子

在“一个简单的Struts例子”（http://blog.csdn.net/dickwinters/archive/2004/09/27/118676.aspx）的基础上修改

首先，struts-config.xml中加入如下配置，注意几个主要项目的配置的顺序（http://blog.csdn.net/dickwinters/archive/2004/09/27/118685.aspx）。

<data-sources> <data-source key="A" type="org.apache.commons.dbcp.BasicDataSource"> <set-property property="driverClassName" value="org.gjt.mm.mysql.Driver" /> <set-property property="url" value="jdbc:mysql://localhost/dick?useUnicode=true&characterEncoding=GB18030" /> <set-property property="username" value="root" /> <set-property property="password" value="" /> <set-property property="maxActive" value="10" /> <set-property property="maxWait" value="5000" /> <set-property property="defaultAutoCommit" value="false" /> <set-property property="defaultReadOnly" value="false" /> </data-source> </data-sources>

几个主要文件改动如下：


LoginAction.java

package dick; import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpSession; import javax.servlet.http.HttpServletResponse; import org.apache.struts.action.Action; import org.apache.struts.action.ActionError; import org.apache.struts.action.ActionErrors; import org.apache.struts.action.ActionForm; import org.apache.struts.action.ActionForward; import org.apache.struts.action.ActionMapping; import org.apache.struts.action.ActionServlet; import javax.sql.DataSource; import java.sql.Connection; import java.sql.SQLException; public final class LoginAction extends Action { public ActionForward execute(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException { UserInfoForm userInfoForm = (UserInfoForm) form; //从web层获得用户名和口令 String username = userInfoForm.getUsername().trim(); String password = userInfoForm.getPassword().trim(); //声明错误集对象 ActionErrors errors = new ActionErrors(); //声明数据源和连接对象 DataSource dataSource; Connection cnn=null; //校验输入 if(username.equals("")){ ActionError error=new ActionError("error.missing.username"); errors.add(ActionErrors.GLOBAL_ERROR,error); } if(password.equals("")){ ActionError error=new ActionError("error.missing.password"); errors.add(ActionErrors.GLOBAL_ERROR,error); } //调用业务逻辑 if(errors.size()==0){ String validated = ""; try{ //取得数据库连接 dataSource = getDataSource(request,"A"); cnn = dataSource.getConnection(); UserInfoBo userInfoBo=new UserInfoBo(cnn); validated =userInfoBo.validatePwd(username,password); if(validated.equals("match")){ //一切正常就保存用户信息并转向成功的页面 HttpSession session = request.getSession(); session.setAttribute("userInfoForm", form); return mapping.findForward("success"); } } catch(Throwable e){ //处理可能出现的错误 e.printStackTrace(); ActionError error=new ActionError(e.getMessage()); errors.add(ActionErrors.GLOBAL_ERROR,error); } } //如出错就转向输入页面，并显示相应的错误信息 saveErrors(request, errors); return new ActionForward(mapping.getInput()); } }

UserInfoBo.java

package dick; import java.sql.Connection; import java.sql.SQLException; import java.lang.Exception; public class UserInfoBo { private Connection cnn=null; public UserInfoBo(Connection cnn){ this.cnn=cnn; } public String validatePwd(String username,String password){ String validateResult=""; try{ UserInfoDao userInfoDao = new UserInfoDao(cnn); validateResult=userInfoDao.validatePwd(username,password); if(validateResult.equals("error.logon.invalid")){ //如果用户名与口令不匹配则报此错 throw new RuntimeException("error.logon.invalid"); } else if(validateResult.equals("error.removed.user")){ //如果找不到用户则报此错，这样用户看到的出错信息会更详细 throw new RuntimeException("error.removed.user"); } } catch(Exception e){ throw new RuntimeException(e.getMessage()); } finally{ try{ if(cnn!=null){ cnn.close(); } } catch(SQLException sqle){ sqle.printStackTrace(); throw new RuntimeException("error.unexpected"); } } return validateResult; } }

添加下面的文件：


UserInfoDao.java

package dick; import java.sql.*; public class UserInfoDao { private Connection con; public UserInfoDao(Connection con) { this.con=con; } public String validatePwd(String username,String password){ PreparedStatement ps=null; ResultSet rs=null; String validated="error.logon.invalid"; UserInfoForm userInfoForm=null; String sql="select * from userInfo where username=?"; try{ if(con.isClosed()){ throw new IllegalStateException("error.unexpected"); } ps=con.prepareStatement(sql); ps.setString(1,username); rs=ps.executeQuery(); if(rs.next()){ if(!rs.getString("password").trim().equals(password)){ return validated;//口令不正确返回口令不匹配信息 } else{ validated = "match";//口令正确返回口令匹配信息 return validated; } }else{ validated="error.removed.user";//没有找到该用户 return validated; } }catch(SQLException e){ e.printStackTrace(); throw new RuntimeException("error.unexpected"); }finally{ try{ if(ps!=null) ps.close(); if(rs!=null) rs.close(); }catch(SQLException e){ e.printStackTrace(); throw new RuntimeException("error.unexpected"); } } } }

web.xml, index.jsp, main.jsp, UserInfoForm.java代码不变