JavaWeb应用实例:用servlet实现oracle 基本增删改查

  • Z时代
  • 2024-01-10
  • 分类：IT

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(); 
  } 
}

 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")+"' 

      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); 
  } 
}

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(); 
  } 
}

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)  

 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>

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。

以上是 JavaWeb应用实例:用servlet实现oracle 基本增删改查 的全部内容， 来源链接： utcz.com/p/210818.html

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