JavaWeb应用实例:用servlet实现oracle 基本增删改查
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2024-03-08 12:04:16
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：
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。