Java Web 应用实例 servlet实现oracle 基本增删改查

来源：互联网发布：杨他他淘宝客程序编辑：程序博客网时间：2024/04/29 19:52

很久没有写博客了，可能是太懒散，不愿意把时间花在这上面，可是我心里还是知道写博客的重要性的，所以从今天开始，我将与大家分享一下我学JAVA WEB写的一些小实例，我个人是不太喜欢书本上的晦涩的概念的，所以我花了更多的时间在一些应用实例上，我觉得这样的学习方式很适合我，由简到繁，由浅入深

废话不多话，开始我们的第一个实例：

servlet实现oracle 基本增删改查

开发环境：JDK7 +Myeclipse10+tomcat7.0+oracle 11g

首先附上数据库创建脚本：

create table student(id VARCHAR2(50) PRIMARY KEY NOT NULL,name varchar2(50) NOT NULL,calssGrent varchar2(50) NOT NULL ,result varchar(12) NOT NULL);insert into student(id,name,calssGrent,result) values(perseq.nextval,'张三','33','98')

下图为代码结构图和功能演示界面做的比较糟糕只为实现功能：

MMC_01.java

页面 //主界面提供添加，修改删除的方法

package org.lsy.servlet;import java.io.IOException;import java.io.PrintWriter;import java.sql.Connection;import java.sql.DriverManager;import java.sql.ResultSet;import java.sql.Statement;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import oracle.jdbc.oracore.TDSPatch;public class MMC_01 extends HttpServlet{// 驱动程序就是之前在classpath中配置的jdbc的驱动程序的jar包中// 连接地址是由各个数据库生产商单独提供的，所以需要单独记住public static final String DBURL = "jdbc:oracle:thin:@localhost:1521:LIUSY";// 连接数据库的用户名public static final String DBUSER = "scott";// 连接数据库的密码public static final String DBPASS = "tiger";public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException{//设置请求和响应的编码 ，不然页面上容易出现乱码request.setCharacterEncoding("UTF-8");response.setCharacterEncoding("UTF-8");response.setContentType("text/html;UTF-8");//输出流PrintWriter out = response.getWriter();//数据库连接代码try{Connection conn = null; // 表示数据库的连接的对象Statement stmt = null; // 表示数据库的更新操作String sql="insert into student(id,name,calssGrent,result) values('67','刘12宇','33','98')";System.out.println(sql) ;// 1、使用Class类加载驱动程序Class.forName("oracle.jdbc.driver.OracleDriver");// 2、连接数据库conn = DriverManager.getConnection(DBURL, DBUSER, DBPASS);// 3、Statement接口需要通过Connection接口进行实例化操作stmt = conn.createStatement();//用 rs获取查询结果  ，这里的SQL语句最好不要用* 我的字段比较少所以就偷一下懒，－，－ResultSet rs=stmt.executeQuery("select *from student");out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");out.println("<HTML>");out.println("  <HEAD><TITLE>A Servlet</TITLE></HEAD>");out.println("  <BODY>");//输出表头部分out.print("<table align='center' border='1'><tr><td>姓名" +"</td><td>班级</td><td>成绩</td><td>修改</td><td>删除</td></tr>");while(rs.next()){//获取数据库中的IDString id=rs.getString("id");//输出一列元素out.print("<tr><td>"+rs.getString("name")+"</td><td>"+rs.getString("calssGrent")+"" +"</td><td>"+rs.getString("result")+"</td>" +"<td><a href='UpdatePage?id="+id+"'>修改</a></td>" +"<td><a href='delete?id="+id+"'> 删除 </a></td></tr>");}out.println("<td><a href=AddPage>添加数据</a></td>");out.println("  </BODY>");out.println("</HTML>"); conn.close();}catch (Exception e){e.printStackTrace();}out.flush();out.close();}}

UpdatePage.java //获取要修改的数据，并把修改过的数据提交给Update

package org.lsy.servlet;import java.io.IOException;import java.io.PrintWriter;import java.sql.Connection;import java.sql.DriverManager;import java.sql.ResultSet;import java.sql.Statement;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import com.sun.crypto.provider.RSACipher;public class UpdatePage extends HttpServlet{// 连接地址是由各个数据库生产商单独提供的，所以需要单独记住public static final String DBURL = "jdbc:oracle:thin:@localhost:1521:LIUSY";// 连接数据库的用户名public static final String DBUSER = "scott";// 连接数据库的密码public static final String DBPASS = "tiger";public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException{String id=request.getParameter("id");//设置请求和响应的编码 ，不然页面上容易出现乱码request.setCharacterEncoding("UTF-8");response.setCharacterEncoding("UTF-8");response.setContentType("text/html;UTF-8");PrintWriter out = response.getWriter();try{Connection conn = null; // 表示数据库的连接的对象Statement stmt = null; // 表示数据库的更新操作// 1、使用Class类加载驱动程序Class.forName("oracle.jdbc.driver.OracleDriver");// 2、连接数据库conn = DriverManager.getConnection(DBURL, DBUSER, DBPASS);// 3、Statement接口需要通过Connection接口进行实例化操作stmt = conn.createStatement();//用 rs获取查询结果  ，这里的SQL语句最好不要用* 我的字段比较少所以就偷一下懒，－，－ResultSet rs=stmt.executeQuery("select *from student where id='"+id+"'");while (rs.next()){out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");out.println("<HTML>");out.println("  <HEAD><TITLE>A Servlet</TITLE></HEAD>");out.println("  <BODY>");//输入成绩的表单，提交至Updateout.print(" <form action='Update' method='post'> ");out.print("<table align='center'> <tr><td>姓名：<input type='text' value='"+rs.getString("name")+"'

 name='name' size=20 ></td></tr>");out.print("<tr><td>班级：<input type='text' value='"+rs.getString("calssGrent")+"' name='grent' size=20></td></tr>");out.print("<tr><td>成绩：<input type='text' value='"+rs.getString("result")+"' name='result' size=20></td></tr>");//为了作为查询数据库的条件 ，这里要把ID传过去out.print("<input type='hidden' value='"+id+"' name='id'>");out.print("<tr><td><input type='submit' value='修改'><input type='reset' value='重置'></td></tr></table></form>");out.print("  </BODY>");out.println("</HTML>");}out.flush();out.close();}catch (Exception e) {e.printStackTrace();// TODO: handle exception}}}

Update.java 接收要修改的数据，并更新数据库

package org.lsy.servlet;import java.io.IOException;import java.io.PrintWriter;import java.sql.Connection;import java.sql.DriverManager;import java.sql.Statement;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;public class Update extends HttpServlet{// 驱动程序就是之前在classpath中配置的jdbc的驱动程序的jar包中// 连接地址是由各个数据库生产商单独提供的，所以需要单独记住public static final String DBURL = "jdbc:oracle:thin:@localhost:1521:LIUSY";// 连接数据库的用户名public static final String DBUSER = "scott";// 连接数据库的密码public static final String DBPASS = "tiger";public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException{try{request.setCharacterEncoding("UTF-8");response.setCharacterEncoding("UTF-8");response.setContentType("text/html;UTF-8");PrintWriter out = response.getWriter();Connection conn = null; // 表示数据库的连接的对象Statement stmt = null; // 表示数据库的更新操作//获取表单提交的参数String id=request.getParameter("id");System.out.println(id);String name=request.getParameter("name");String grent=request.getParameter("grent");String result=request.getParameter("result");//更新SQLString sqlString="update student set name='"+name+"' ," +"calssGrent='"+grent+"',result='"+result+"' where id='"+id+"'  ";  // 1、使用Class类加载驱动程序Class.forName("oracle.jdbc.driver.OracleDriver");// 2、连接数据库conn = DriverManager.getConnection(DBURL, DBUSER, DBPASS);// 3、Statement接口需要通过Connection接口进行实例化操作stmt = conn.createStatement();int pd=stmt.executeUpdate(sqlString);if(pd!=0){out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");out.println("<HTML>");out.println("  <HEAD><TITLE>A Servlet</TITLE></HEAD>");out.println("  <BODY>");out.print(" 更新成功<br><a href=MMC_01>查看列表</a> ");out.println("  </BODY>");out.println("</HTML>");}out.flush();out.close();stmt.close();conn.close();}catch (Exception e){// TODO: handle exception}}public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException{doGet(request, response);}}

addPage .java，添加数据页面]

package org.lsy.servlet;import java.io.IOException;import java.io.PrintWriter;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;public class AddPage extends HttpServlet{public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException{//设置请求和响应的编码 ，不然页面上容易出现乱码request.setCharacterEncoding("UTF-8");response.setCharacterEncoding("UTF-8");response.setContentType("text/html;UTF-8");PrintWriter out = response.getWriter();out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");out.println("<HTML>");out.println("  <HEAD><TITLE>A Servlet</TITLE></HEAD>");out.println("  <BODY>");//输入成绩的表单，提交至addout.print(" <form action='Add' method='post'> ");out.print("<table align='center'> <tr><td>姓名：<input type='text' name='name' size=20 ></td></tr>");out.print("<tr><td>班级：<input type='text' name='grent' size=20></td></tr>");out.print("<tr><td>成绩：<input type='text' name='result' size=20></td></tr>");out.print("<tr><td><input type='submit' value='添加'><input type='reset' value='重置'></td></tr></table></form>");out.println("<tr><td><a href=MMC_01>查看列表</a></td></tr>");out.println("  </BODY>");out.println("</HTML>");out.flush();out.close();}}

add 接收addpage传来的传，更新数据库

package org.lsy.servlet;import java.io.IOException;import java.io.PrintWriter;import java.sql.Connection;import java.sql.DriverManager;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.Statement;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import com.sun.org.apache.xerces.internal.impl.io.UTF8Reader;import oracle.jdbc.oracore.TDSPatch;public class Add extends HttpServlet{// 驱动程序就是之前在classpath中配置的jdbc的驱动程序的jar包中// 连接地址是由各个数据库生产商单独提供的，所以需要单独记住public static final String DBURL = "jdbc:oracle:thin:@localhost:1521:LIUSY";// 连接数据库的用户名public static final String DBUSER = "scott";// 连接数据库的密码public static final String DBPASS = "tiger";@Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException{// TODO Auto-generated method stubdoGet(req, resp);}public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException{//设置请求和响应的编码 ，不然页面上容易出现乱码request.setCharacterEncoding("UTF-8");response.setCharacterEncoding("UTF-8");response.setContentType("text/html;UTF-8");//输出流PrintWriter out = response.getWriter();//数据库连接代码try{Connection conn = null; // 表示数据库的连接的对象Statement pstmt = null; // 表示数据库的更新操作String nameString=request.getParameter("name");String grentString=request.getParameter("grent");String resultString=request.getParameter("result");System.out.print(nameString);String sql="insert into student(id,name,calssGrent,result)

values(perseq.nextval,'"+nameString+"','"+grentString+"','"+resultString+"')";// 1、使用Class类加载驱动程序Class.forName("oracle.jdbc.driver.OracleDriver");// 2、连接数据库conn = DriverManager.getConnection(DBURL, DBUSER, DBPASS);pstmt=conn.createStatement();int pd=pstmt.executeUpdate(sql);if (pd!=0){out.println("添加成功");out.println("<br><a href=MMC_01>查看列表</a>");}conn.close();}catch (Exception e){e.printStackTrace();}out.flush();out.close();}}

web.xml 配置文件

<?xml version="1.0" encoding="UTF-8"?><web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">  <display-name></display-name>  <welcome-file-list>    <welcome-file>index.jsp</welcome-file>  </welcome-file-list>    <servlet-name>MMC_01</servlet-name>    <servlet-class>org.lsy.servlet.MMC_01</servlet-class>  </servlet>  <servlet>    <servlet-name>delete</servlet-name>    <servlet-class>org.lsy.servlet.delete</servlet-class>  </servlet>  <servlet>    <servlet-name>Add</servlet-name>    <servlet-class>org.lsy.servlet.Add</servlet-class>  </servlet>  <servlet>    <servlet-name>AddPage</servlet-name>    <servlet-class>org.lsy.servlet.AddPage</servlet-class>  </servlet>  <servlet>    <servlet-name>UpdatePage</servlet-name>    <servlet-class>org.lsy.servlet.UpdatePage</servlet-class>  </servlet>  <servlet>    <servlet-name>Update</servlet-name>    <servlet-class>org.lsy.servlet.Update</servlet-class>  </servlet>  <servlet-mapping>    <servlet-name>MMC_01</servlet-name>    <url-pattern>/MMC_01</url-pattern>  </servlet-mapping>  <servlet-mapping>    <servlet-name>delete</servlet-name>    <url-pattern>/delete</url-pattern>  </servlet-mapping>  <servlet-mapping>    <servlet-name>Add</servlet-name>    <url-pattern>/Add</url-pattern>  </servlet-mapping>  <servlet-mapping>    <servlet-name>AddPage</servlet-name>    <url-pattern>/AddPage</url-pattern>  </servlet-mapping>  <servlet-mapping>    <servlet-name>UpdatePage</servlet-name>    <url-pattern>/UpdatePage</url-pattern>  </servlet-mapping>  <servlet-mapping>    <servlet-name>Update</servlet-name>    <url-pattern>/Update</url-pattern>  </servlet-mapping></web-app>

参考资料：JavaWEB 整合开发与项目实战徐明华等；

本人并非老鸟，一直处于学习中，有什么错误的地方还请指证，上面的代码有很多重复的部分，很多不合理的地方，比较数据库连接直接暴露于操作servlet中，为了看的更直观，我就没有更改……

从今天开始会为大家再带来更多的实例，不喜匆喷