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')
复制代码 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ID
- String 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();
- }
-
- }
复制代码 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Update
- out.print(" <form action='Update' method='post'> ");
- out.print("<table align='center'> <tr><td>姓名:<input type='text' value='"+rs.getString("name")+"'
复制代码 - 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
- }
- }
-
- }
复制代码 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SQL
- String 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);
- }
-
- }
复制代码 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add
- out.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();
- }
-
- }
复制代码 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";
-
- @Override
- protected void doPost(HttpServletRequest req, HttpServletResponse resp)
- throws ServletException, IOException
- {
- // TODO Auto-generated method stub
- doGet(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)
复制代码 - 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();
- }
-
- }
复制代码 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>
复制代码 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…… 以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持程序员之家。 |