jsp+javaBean查询数据库(异常已解决)
jsp+javaBean查询数据库(异常已解决)
if (rs!=null){//判断RS是否为空 if (!rs.wasNull())也可换成这个判断SQL Null 是空返回true 不是返回false! 这样的话就不用在抛出异常的时候在把值设为空啦null
Bean:
package cn.dakchina;
import java.sql.*;
import cn.dakchina.*;
public class FirstBean {
private String name,pwd,email,phone,qq,zhuanye,address,sex;
private Connection conn;
private ResultSet rs;
private Statement stmt;
public FirstBean(String name)throws SQLException{
this.name=null;
this.pwd=null;
this.email=null;
this.phone=null;
this.qq=null;
this.zhuanye=null;
this.address=null;
this.sex=null;
try{
Class.forName("com.mysql.jdbc.Driver");
String url =
"jdbc:mysql://localhost:3306/mytest";
conn =
DriverManager.getConnection(
url,"root", "123456");
stmt = conn.createStatement(
ResultSet.TYPE_SCROLL_INSENSITIVE,
ResultSet.CONCUR_UPDATABLE);
}catch (SQLException e){
System.out.println(e);
}
catch(ClassNotFoundException e){
}
String query=" select * from userinfor where name='"+name+"'" ;
rs=stmt.executeQuery(query);
}
//初始化数据
public void setName(String name){
this.name=name;
}
public void setPwd(String pwd){
this.pwd=pwd;
}
public void setQQ(String qq){
this.qq=qq;
}
public void setPhone(String phone){
this.phone=phone;
}
public void setAddress(String address){
this.address=address;
}
public void setEmail(String email){
this.email=email;
}
public void setSex(String sex){
this.sex=sex;
}
public void setZhuanye(String zhuanye){
this.zhuanye=zhuanye;
}
//获得数据
public String getName(){
return this.name;
}
public String getPwd(){
return this.pwd;
}
public String getEmail(){
return this.email;
}
public String getAddress(){
return this.address;
}
public String getSex(){
return this.sex;
}
public String getPhone(){
return this.phone;
}
public String getQQ(){
return this.qq;
}
public String getZhuanye(){
return this.zhuanye;
}
public void closeConnection(){
try{
conn.close();
}catch(SQLException e){
e.printStackTrace();
}
conn=null;
}
//从数据库查询数据
public void setData(){
if (rs!=null){//判断RS是否为空 if (!rs.wasNull())也可换成这个判断SQL Null 是空返回true 不是返回false! 这样的话就不用在抛出异常的时候在把值设为空啦null
try{
rs.next(); //。。。。。。不知道为什么不用这一句就会出错，找不到记录 setName(rs.getString("name"));
setPwd(rs.getString("pwd"));
setAddress(rs.getString("userAddress"));
setEmail(rs.getString("useremail"));
setPhone(rs.getString("userphone"));
setQQ(rs.getString("userqq"));
setSex(rs.getString("usersex"));
setZhuanye(rs.getString("zhuanye"));
}catch(Exception e){ //如果扑捉到 Illegal operation on empty result set 则会把name,pwd等实例变量初始化为null，这样一来可以在jsp中判断是否有此用户
this.name=null;
this.pwd=null;
this.email=null;
this.phone=null;
this.qq=null;
this.zhuanye=null;
this.address=null;
this.sex=null;
}
}
else
{
this.name=null;
this.pwd=null;
this.email=null;
this.phone=null;
this.qq=null;
this.zhuanye=null;
this.address=null;
this.sex=null;
}
}
public String noUser(){
return "没有此用户";
}
}
JSP部分:
<%@ page contentType="text/html; charset=gb2312" language="java" import="java.sql.*" errorPage="" %>
<%@ page import="cn.dakchina.*"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" " http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>信息查询</title>
</head>
<body>
<%
String name=request.getParameter("name");
FirstBean fb=new FirstBean(name);
fb.setData();
if (fb.getName()!=null){//判断是否有此用户，如果没有则调用noUser();
out.println("YourName:");
out.println(name);
out.println("<br>");
out.println("YourPwd:");
out.println(fb.getPwd());
out.println("<br>");
out.println("YourEmail:");
out.println(fb.getEmail());
out.println("<br>");
out.println("YourAddress:");
out.println(fb.getAddress());
out.println("<br>");
out.println("YourQQ:");
out.println(fb.getQQ());
out.println("<br>");
out.println("YourPhone:");
out.println(fb.getPhone());
out.println("<br>");
out.println("YourZhuanye:");
out.println(fb.getZhuanye());
}
else out.println(fb.noUser());
%>
</body>
</html>
if (rs!=null){//判断RS是否为空 if (!rs.wasNull())也可换成这个判断SQL Null 是空返回true 不是返回false! 这样的话就不用在抛出异常的时候在把值设为空啦null
Bean:
package cn.dakchina;
import java.sql.*;
import cn.dakchina.*;
public class FirstBean {
private String name,pwd,email,phone,qq,zhuanye,address,sex;
private Connection conn;
private ResultSet rs;
private Statement stmt;
public FirstBean(String name)throws SQLException{
this.name=null;
this.pwd=null;
this.email=null;
this.phone=null;
this.qq=null;
this.zhuanye=null;
this.address=null;
this.sex=null;
try{
Class.forName("com.mysql.jdbc.Driver");
String url =
"jdbc:mysql://localhost:3306/mytest";
conn =
DriverManager.getConnection(
url,"root", "123456");
stmt = conn.createStatement(
ResultSet.TYPE_SCROLL_INSENSITIVE,
ResultSet.CONCUR_UPDATABLE);
}catch (SQLException e){
System.out.println(e);
}
catch(ClassNotFoundException e){
}
String query=" select * from userinfor where name='"+name+"'" ;
rs=stmt.executeQuery(query);
}
//初始化数据
public void setName(String name){
this.name=name;
}
public void setPwd(String pwd){
this.pwd=pwd;
}
public void setQQ(String qq){
this.qq=qq;
}
public void setPhone(String phone){
this.phone=phone;
}
public void setAddress(String address){
this.address=address;
}
public void setEmail(String email){
this.email=email;
}
public void setSex(String sex){
this.sex=sex;
}
public void setZhuanye(String zhuanye){
this.zhuanye=zhuanye;
}
//获得数据
public String getName(){
return this.name;
}
public String getPwd(){
return this.pwd;
}
public String getEmail(){
return this.email;
}
public String getAddress(){
return this.address;
}
public String getSex(){
return this.sex;
}
public String getPhone(){
return this.phone;
}
public String getQQ(){
return this.qq;
}
public String getZhuanye(){
return this.zhuanye;
}
public void closeConnection(){
try{
conn.close();
}catch(SQLException e){
e.printStackTrace();
}
conn=null;
}
//从数据库查询数据
public void setData(){
if (rs!=null){//判断RS是否为空 if (!rs.wasNull())也可换成这个判断SQL Null 是空返回true 不是返回false! 这样的话就不用在抛出异常的时候在把值设为空啦null
try{
rs.next(); //。。。。。。不知道为什么不用这一句就会出错，找不到记录 setName(rs.getString("name"));
setPwd(rs.getString("pwd"));
setAddress(rs.getString("userAddress"));
setEmail(rs.getString("useremail"));
setPhone(rs.getString("userphone"));
setQQ(rs.getString("userqq"));
setSex(rs.getString("usersex"));
setZhuanye(rs.getString("zhuanye"));
}catch(Exception e){ //如果扑捉到 Illegal operation on empty result set 则会把name,pwd等实例变量初始化为null，这样一来可以在jsp中判断是否有此用户
this.name=null;
this.pwd=null;
this.email=null;
this.phone=null;
this.qq=null;
this.zhuanye=null;
this.address=null;
this.sex=null;
}
}
else
{
this.name=null;
this.pwd=null;
this.email=null;
this.phone=null;
this.qq=null;
this.zhuanye=null;
this.address=null;
this.sex=null;
}
}
public String noUser(){
return "没有此用户";
}
}
JSP部分:
<%@ page contentType="text/html; charset=gb2312" language="java" import="java.sql.*" errorPage="" %>
<%@ page import="cn.dakchina.*"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" " http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>信息查询</title>
</head>
<body>
<%
String name=request.getParameter("name");
FirstBean fb=new FirstBean(name);
fb.setData();
if (fb.getName()!=null){//判断是否有此用户，如果没有则调用noUser();
out.println("YourName:");
out.println(name);
out.println("<br>");
out.println("YourPwd:");
out.println(fb.getPwd());
out.println("<br>");
out.println("YourEmail:");
out.println(fb.getEmail());
out.println("<br>");
out.println("YourAddress:");
out.println(fb.getAddress());
out.println("<br>");
out.println("YourQQ:");
out.println(fb.getQQ());
out.println("<br>");
out.println("YourPhone:");
out.println(fb.getPhone());
out.println("<br>");
out.println("YourZhuanye:");
out.println(fb.getZhuanye());
}
else out.println(fb.noUser());
%>
</body>
</html>