struts操作数据库-工厂篇

最新推荐文章于 2022-08-31 14:39:36 发布

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#数据库 #struts #import #null #string #exception

该博客围绕部门员工查询程序展开，先明确程序需求，即页面生成时从部门表取数据，提交后显示该部门员工。接着介绍数据库建表，按项目开发思想划分模块，给出各模块代码示例，还提及Struts配置文件和JSP页面，最后说明连接Oracle数据库及采用连接池方式连接的方法。

程序要求：程序开始，第一个页面要显示，以这样的信息，一个下拉框用来选择“用户的部门名称”，这个下拉框中的内容要从“部门信息表中取得”（当页面一生成的时候就要获得）。然后按下“提交”按钮，能显示所有该部门的员工。

分析：因为页面一生成的时候就要从“部门表”中获得数据，所以我要采用一种方式让页面生成的时候就能操作action获得数据。数据的显示不再是单一数据，所以在页面上设计到循环。显示出来的一项数据不再是一个数据。

建立数据表：还记得我们在上一篇中建立的数据库吗。

数据库名字叫“user”已经有一个表叫“userTable”，我们现在就在这个数据库中再建立一个

表“depatTable”

部门号码 depatNo 文本

部门名称 depatName 文本

填入几个值：

001 生产部

002 工程部

003 人事部

程序开始

从现在开始，我们将按照真正项目开发的思想来做，模块的划分将细致起来

A模块：提供数据库连接

B模块：actionAndForm模块

C模块: 业务逻辑,提供数据的操作

D模块: 数据实体封装

这些模块实际上就是“包”的概念，在eclipse中建立“包”我就不想说了

A模块(2个类)——package dataConnectFactory

ConnectFactory类

//数据连接工厂

package dataConnectFactory;

import java.sql.*;

public class ConnectFactory

{

//定义数据库的驱动程序（以下给出的是连接odbc数据库的）

private static String strDriver="sun.jdbc.odbc.JdbcOdbcDriver";

//定义数据库的URL（名称）

private static String strConnection="jdbc:odbc:user";

//数据访问的用户名

private static String strUsername="";

//数据库访问的密码

private static String strPassword="";

public static Connection getConnectionByDriver()

throws MyException

{

Connection conn = null;

try

{

Class.forName(strDriver);//注册驱动

conn = //获得连接

DriverManager.getConnection( strConnection,

strUsername,

strPassword);

}

catch(ClassNotFoundException ex1)

{

ex1.printStackTrace();

throw new MyException("Class Not Found!");

}

catch(SQLException ex2)

{

ex2.printStackTrace();

throw new MyException("SQL Error");

}

finally {}

return conn;

}

MyException类

package dataConnectFactory;

//定义自己的异常类

public class MyException extends Exception

{

public MyException()

{

super();

}

public MyException(String message)

{

super(message);

}

B模块(3个类)——package action

UserAction类

package action;

//当第一个查询页面一生成的时候就把部门的信息得到并交给页面

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

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.actions.DispatchAction;

import biz.SearchBiz;

import entity.*;

public class UserAction extends DispatchAction

{

//转到查询界面

public ActionForward toSearch( ActionMapping mapping,

ActionForm form,

HttpServletRequest request,

HttpServletResponse response)

throws Exception

{

//定义错误信息封装

ActionErrors errors = null;

//获取页面表单信息

UserForm uf = (UserForm)form;

//定义部门实体数组

DepartmentEntity[] departs = null;

SearchBiz searchBizDept = null;

try

{

searchBizDept = new SearchBiz();

departs =

searchBizDept.selectDeptEntitys(

new DepartmentEntity());

uf.setDeparts(departs);

}

catch (Exception e)

{

errors = new ActionErrors();

e.printStackTrace();

errors.add(ActionErrors.GLOBAL_ERROR, new ActionError("system.exception"));

return mapping.findForward("error");

}

finally

{

if (errors != null)

{

saveErrors(request, errors);

}

return mapping.findForward("toSearch");

}

package action;

UserForm类

//将所有的实体封装到form中

import org.apache.struts.action.ActionForm;

import entity.*;

public class UserForm extends ActionForm

{

private UserEntity user = new UserEntity();

private UserEntity[] users = null;

private DepartmentEntity depart = new DepartmentEntity();

private DepartmentEntity[] departs = null;

public DepartmentEntity getDepart()

{

return depart;

}

public DepartmentEntity[] getDeparts()

{

return departs;

}

public UserEntity getUser() {

return user;

}

public UserEntity[] getUsers()

{

return users;

}

public void setDepart(DepartmentEntity depart)

{

this.depart = depart;

}

public void setDeparts(DepartmentEntity[] departs)

{

this.departs = departs;

}

public void setUser(UserEntity user)

{

this.user = user;

}

public void setUsers(UserEntity[] users)

{

this.users = users;

}

ResultAction

package action;

//当页面提交后，按照页面提交的条件来查询

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

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.actions.DispatchAction;

import biz.SearchBiz;

import entity.*;

public class ResultAction extends DispatchAction

{

public ActionForward execute ( ActionMapping mapping,

ActionForm form,

HttpServletRequest request,

HttpServletResponse response)

throws Exception

{

//定义错误信息封装

ActionErrors errors = null;

//获取页面表单信息

UserForm uf = (UserForm)form;

//定义用户实体数组

UserEntity[] userEntitys = null;

//定义用户实体

UserEntity userEntity=new UserEntity();

//获得页面上提交的数据

userEntity=uf.getUser();

System.out.println(userEntity.getDepartNo());

SearchBiz searchBiz = null;

try

{

searchBiz = new SearchBiz();

userEntitys = searchBiz.selectUserEntitys(userEntity );

uf.setUsers(userEntitys);

}

catch (Exception e)

{

return mapping.findForward("error");

}

finally

{

}

return mapping.findForward("success");

}

C模块（1个类）——package biz

SearchBiz类

package biz;

//这里完成查询和数据的转换操作等所有数据的操作

import java.sql.Connection;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.util.ArrayList;

import dataConnectFactory.ConnectFactory;

import dataConnectFactory.MyException;

import entity.*;

public class SearchBiz

{

private String strDriver;

private String strConnection;

private String strUsername;

private String strPassword;

//查询用户信息

public UserEntity[] selectUserEntitys(UserEntity userEntity)

throws MyException

{

UserEntity[] employeeEntitys = null;

Connection conn = null;

PreparedStatement pstmt = null;

ResultSet rs = null;

StringBuffer sbSQL = new StringBuffer();

ArrayList list = null;

try

{

conn = ConnectFactory.getConnectionByDriver( );

//生成sql

sbSQL.append(" select ");

sbSQL.append(" userTable.userNo,");

sbSQL.append(" userTable.departNo,");

sbSQL.append(" departTable.departName");

sbSQL.append(" from userTable,departTable");

sbSQL.append(" where

userTable.departNo='"+userEntity.getDepartNo()+"'");

sbSQL.append(" and ");

sbSQL.append(" userTable.departNo = departTable.departNo ");

System.out.println(sbSQL.toString());

pstmt = conn.prepareStatement(sbSQL.toString());

rs = pstmt.executeQuery();

list = parseArray(rs,1);

list.trimToSize();

employeeEntitys = new UserEntity[list.size()];

if (employeeEntitys != null && list.size()>0)

{

employeeEntitys =

(UserEntity[])list.toArray(employeeEntitys);

}

catch(MyException ex1)

{

ex1.printStackTrace();

throw ex1;

}

catch(SQLException ex2)

{

ex2.printStackTrace();

throw new MyException("SQL Error");

}

finally//数据库访问完毕后，关闭相关的连接，

//释放资源，是你应该要做的

{

try

{

if(rs!=null)

{

rs.close();

rs=null;

}

if(pstmt!=null)

{

pstmt.close();

pstmt=null;

}

catch(SQLException e)

{

e.printStackTrace();

}

return employeeEntitys;

}

//查询部门信息

public DepartmentEntity[] selectDeptEntitys(DepartmentEntity departmentEntity)

throws MyException

{

DepartmentEntity[] departmentEntitys = null;

Connection conn = null;

//以前用Statement，现在用PrepareStatement

//那是因为PrepareStatement有一个预编译的过程

PreparedStatement pstmt = null;

ResultSet rs = null;

StringBuffer sbSQL = new StringBuffer();

ArrayList list = null;

try

{

conn = ConnectFactory.getConnectionByDriver();

sbSQL.append("select departNo,departName from departTable");

pstmt = conn.prepareStatement(sbSQL.toString());//预编译

rs = pstmt.executeQuery(); //执行

list = parseArray(rs,2);//把结果集转换为实体数组

list.trimToSize();

departmentEntitys = new DepartmentEntity[list.size()];

if (departmentEntitys != null && list.size()>0)

{

departmentEntitys =

(DepartmentEntity[])list.toArray(departmentEntitys);

}

catch(MyException ex1)

{

ex1.printStackTrace();

throw ex1;

}

catch(SQLException ex2)

{

ex2.printStackTrace();

throw new MyException("SQL Error");

}

catch(Exception ex3)

{

ex3.printStackTrace();

throw new MyException("Exception");

}

finally//数据库访问完毕后，关闭相关的连接，

//释放资源，是你应该要做的

{

try

{

if(rs!=null)

{

rs.close();

rs=null;

}

if(pstmt!=null)

{

pstmt.close();

pstmt=null;

}

catch(SQLException e)

{

e.printStackTrace();

}

return departmentEntitys;

}

//把结果集转换为实体数组的方法

protected ArrayList parseArray(ResultSet rs,long lType) throws SQLException

{

ArrayList list = new ArrayList();

UserEntity userEntity = null;

DepartmentEntity departmentEntity = null;

Object object = null;

try {

while (rs.next())

{

if (lType ==1)

{

userEntity = new UserEntity();

userEntity.setUserNo(rs.getString("userNo"));

userEntity.setDepartNo(rs.getString("departNo"));

userEntity.setDepartName(rs.getString("departName"));

object = (Object) userEntity;

}

else

{

departmentEntity = new DepartmentEntity();

departmentEntity.setDepartmentNo(rs.getString("departNo"));

departmentEntity.setDepartmentName(rs.getString("departName"));

object = (Object) departmentEntity;

}

list.add(object);

}

catch(SQLException ex)

{

ex.printStackTrace();

throw ex;

}

finally {}

return list;

}

D模块（2个类）——package entity

UserEntity类

package entity;

//用户信息实体

public class UserEntity

{

private String userNo = null;

private String userPassword = null;

private String departNo = null;

private String departName = null;

public String getDepartName()

{

return departName==null?"":departName.trim();

}

public String getDepartNo()

{

return departNo==null?"":departNo.trim();

}

public String getUserNo()

{

return userNo==null?"":userNo.trim();

}

public String getUserPassword()

{

return userPassword==null?"":userPassword.trim();

}

public void setDepartName(String departName)

{

this.departName = departName;

}

public void setDepartNo(String departNo)

{

this.departNo = departNo;

}

public void setUserNo(String userNo)

{

this.userNo = userNo;

}

public void setUserPassword(String userPassword)

{

this.userPassword = userPassword;

}

DepartmentEntity类

package entity;

//部门信息实体

public class DepartmentEntity

{

private String departmentNo = null;

private String departmentName = null;

public String getDepartmentName()

{

return departmentName==null?"":departmentName.trim();

}

public String getDepartmentNo()

{

return departmentNo==null?"":departmentNo.trim();

}

public void setDepartmentName(String departmentName)

{

this.departmentName = departmentName;

}

public void setDepartmentNo(String departmentNo)

{

this.departmentNo = departmentNo;

}

配置文件：struts-config.xml

<?xml version="1.0" encoding="ISO-8859-1" ?>

<!DOCTYPE struts-config PUBLIC

"-//Apache Software Foundation//DTD Struts Configuration 1.1//EN"

"http://jakarta.apache.org/struts/dtds/struts-config_1_1.dtd">

<!--

This is the Struts configuration file for the example application,

using the proposed new syntax.

NOTE: You would only flesh out the details in the "form-bean"

declarations if you had a generator tool that used them to create

the corresponding Java classes for you. Otherwise, you would

need only the "form-bean" element itself, with the corresponding

"name" and "type" attributes.

-->

<struts-config>

<form-beans>

<form-bean name="userForm" type="action.UserForm">

</form-bean>

</form-beans>

<global-forwards>

</global-forwards>

<action-mappings>

<action path="/search"

type="action.UserAction"

name="userForm"

scope="request"

parameter="operate"

validate="false"

input="search.jsp">

</action>

<action path="/searchInfo"

type="action.ResultAction"

name="userForm"

scope="request"

input="search.jsp">

</action>

</action-mappings>

</struts-config>

jsp页面

search.jsp

<%@ page contentType="text/html; charset=gb2312" %>

<%@ taglib uri="/WEB-INF/struts-tiles.tld" prefix="tiles" %>

<%@ taglib uri="/WEB-INF/struts-html.tld" prefix="html" %>

<%@ taglib uri="/WEB-INF/struts-logic.tld" prefix="logic" %>

<%@ taglib uri="/WEB-INF/struts-bean.tld" prefix="bean" %>

<title>search employee</title>

<html:form action="searchInfo.do" method="post">

<table>

<tr>

<td>

<html:select property="user.departNo">

<logic:notEmpty name="userForm" property="departs">

<logic:iterate name="userForm" property="departs" id="dept" type="entity.DepartmentEntity">

<html:option value="<%= String.valueOf(dept.getDepartmentNo()) %>"><%= dept.getDepartmentName() %></html:option>

</logic:iterate>

</logic:notEmpty>

</html:select>

</td>

</tr>

<tr>

</tr>

</table>

</html:form>

</center>

success.jsp

<%@ page contentType="text/html; charset=gb2312" %>

<%@ page language="java"%>

<%@ page import="java.util.*;"%>

<%@ taglib uri="/WEB-INF/struts-html.tld" prefix="html" %>

<%@ taglib uri="/WEB-INF/struts-bean.tld" prefix="bean" %>

<%@ taglib uri="/WEB-INF/struts-logic.tld" prefix="logic" %>

<html:html>

<tr>

<th>所在部门编号</th>

<th>所在部门名称 </th>

</tr>

<logic:iterate

name="userForm"

property="users"

id="ue"

type="entity.UserEntity">

<tr>

</tr>

</logic:iterate>

</table>

</center>

</html:html>

error.jsp

Error!!

赶快运行吧

http://localhost:8080/temp3/search.do?operate=toSearch

一点提示：

发现没？运行程序的的时候，在ie地址拦上输入的东西好象不一样了吧？

UserAction中没有execute方法了，换成了toSearch方法。好了，现在我允许你把这个toSearch随便改个名字，就改个myDog好吗？然后再在你的ie上输入：

http://localhost:8080/temp3/search.do?operate=myDog

哈哈，结果一样哦。

很早该提醒你，但是想看你自己是不太笨：

java程序改动后，要重新保存编译成类。

任何的程序改动或者配置文件改动后，请你重新启动你的tomcat

任何的jsp页面改动后，不需要重新启动tomcat，刷新就可以了

重点在这里：

怎么连接oracle数据库：

1：要导入一个classes12.jar这个JAR包，它提供了oracle数据库的相关驱动

2： strDriver="oracle.jdbc.driver.OracleDriver";

strConnection="jdbc:oracle:thin:@￥￥￥￥￥:1521:！！！！！";

strUsername="******";

strPassword="######";

￥￥￥￥￥：数据库服务器的ip地址

！！！！！：数据库的名称

******：访问数据库的名称

######：访问数据库的密码

如何采用连接池的方式连接数据库

1：在D:/tomcat-4.1.18/conf的server.xml中找到

</Host> </Engine></Service></Server>

在这段之前添加添加：

<name>username</name>

</parameter>

<name>password</name>

</parameter>

<name>driverClassName</name>

<value>oracle.jdbc.driver.OracleDriver</value>

</parameter>

<value>jdbc:oracle:thin:@ ￥￥￥￥￥: ！！！！</value>

</parameter>

<name>maxActive</name>

</parameter>

<name>maxIdle</name>

</parameter>

<name>maxWait</name>

</parameter>

</ResourceParams>

</Context>

-----：你要用该连接池的应用工程目录，例如：user

%%%：随便你取个名字，例如：userDB

2：修改你的应用所对应的那个web.xml

在 </web-app>前添加

<resource-ref>

<res-ref-name> jdbc/%%%</res-ref-name>

<res-type>javax.sql.DataSource</res-type>

<res-auth>Container</res-auth>

</resource-ref>

</web-app>

(((((((：你高兴写点什么就写点什么

3：这样来使用

还记得你的public class ConnectFactory吗？

改写成下面的样子

package connectDatabase;

import java.sql.*;

import javax.sql.DataSource;

import javax.naming.Context;

import javax.naming.InitialContext;

import javax.naming.NamingException;

public class ConnectFactory

{

public static Connection getConnectionByDriver()

throws MyException

{

DataSource ds;

Connection conn = null;

//缓冲池连接

try

{

Context initCtx = new InitialContext();

Context envCtx = (Context) initCtx.lookup("java:comp/env");

ds = (DataSource)envCtx.lookup("jdbc/%%%");

if(ds!=null)

{

conn = ds.getConnection();

}

catch(NamingException e)

{

e.printStackTrace();

}

catch(SQLException e1)

{

e1.printStackTrace();

}

finally {}

return conn;

}