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JavaWeb应用实例:用servlet实现oracle 基本增删改查

程序员文章站 2024-03-09 08:51:11
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&nbs...

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:

JavaWeb应用实例:用servlet实现oracle 基本增删改查

mmc_01.java

页面 //主界面提供添加,修改删除的方法

JavaWeb应用实例:用servlet实现oracle 基本增删改查

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。