Hello i’m trying to create a page to update a row in my database table i’m using DAO/Servlet with JSP page
DAO code:
public static AnimalUpdateBean updateAnimal(AnimalUpdateBean bean) {
//preparing some objects for connection
PreparedStatement up = null;
Statement stmt = null;
String id = bean.getAnimalId();
String aname = bean.getAnimalName();
String dob = bean.getAnimalDob();
String gender = bean.getAnimalGender();
String breedid = bean.getAnimalBreed();
String remark = bean.getAnimalRemark();
try
{
//connect to DB
currentCon = dbConnection.getConnection();
up = currentCon.prepareStatement("update animal set aname = '"+aname+"' , gender = '"+gender+"', specie_id = '"
+breedid+"' , remark = '"+remark+"' where animal_id = '"+id+"'");
up.executeUpdate();
if (up.executeUpdate()>=1){
stmt=currentCon.createStatement();
rs = stmt.executeQuery("select aname , dob, gender, specie_id , remark from animal where animal_id = '"+id+"'");
}
System.out.println("done");
}
catch (Exception ex)
{
System.out.println("Log In failed: An Exception has occurred! " + ex);
}
//some exception handling
finally
{
if (rs != null) {try {rs.close();} catch (Exception e) {} rs = null;}
if (stmt != null) {try {stmt.close();} catch (Exception e) {}stmt = null;}
if (currentCon != null) {try {currentCon.close();} catch (Exception e) {}currentCon = null;}
}
return bean;
}
}
UpdateAnimal.jsp code:
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ page import="java.util.ArrayList" %>
<%@page import="content.*"%>
<%@page import="java.sql.*"%>
<%@page import="java.util.*"%>
<%@ page session="true"%>
<%@page import="java.io.*"%>
<%@page import="java.net.*"%>
<%@page import="javax.servlet.*"%>
<%@ page language="java"
contentType="text/html; charset=windows-1256"
pageEncoding="windows-1256" %>
<!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=windows-1256">
<title>Update Animal</title>
<link rel="stylesheet"
href="./css/styles.css"
type="text/css"/>
</head>
<body>
<table class="title">
<tr><th>Zoo keeper</th></tr>
</table>
<h1>Update Animal</h1>
<form action="Relay" >
<fieldset>
Animal new name: <input type= "text" name = "aname"><br>
Animal new DOB: <input type= "text" name = "dob"><br>
<br>
Animal new gender:
<select name="gender" id="gender">
<option value="male">Male</option>
<option value="female">Female</option>
</select>
<br>
Animal new Breed: <input type= "text" name = "breedid" ><br>
Animal new remarks: <textarea name = "remark" rows="4" cols="20">
</textarea> <br /> <br/>
<input type="submit" value="submit">
<input type="hidden" name="animal_id" value="<%= request.getParameter("animal_id") %>">
<input type="hidden" name="command" value="UpdateAnimalServlet" >
</fieldset>
</form>
</body></html>
the record being updated come from a select page to view the records when the user click on the name he will be redirected to update page CheckAnimal.jsp
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ page import="java.util.ArrayList" %>
<%@page import="content.*"%>
<%@page import="java.sql.*"%>
<%@page import="java.util.*"%>
<%@ page session="true"%>
<%@page import="java.io.*"%>
<%@page import="java.net.*"%>
<%@page import="javax.servlet.*"%>
<%@ page language="java"
contentType="text/html; charset=windows-1256"
pageEncoding="windows-1256" %>
<!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=windows-1256">
<title>Animal list</title>
<link rel="stylesheet"
href="./css/styles.css"
type="text/css"/>
</head>
<body>
<table class="title">
<tr><th>Zoo keeper</th></tr>
</table>
<h1>Animal list</h1>
Click on animal name to update it!
<center>
<table width="100 % " id='table1' border="1" cellspacing="2" cellpadding="2">
<tr class="tab-highlighted-2">
<td class="tab-highlighted-2" width="15">
<div align="left">Name</div>
</td>
<td class="tab-highlighted-2" width="13">
<div align="left">Age</div>
</td>
<td class="tab-highlighted-2" width="13">
<div align="left">Gender</div>
</td>
<td class="tab-highlighted-2" width="13">
<div align="left">Status</div>
</td>
<td class="tab-highlighted-2" width="13">
<div align="left">Breed</div>
</td>
<td class="tab-highlighted-2" width="13">
<div align="left">Pen #</div>
</td>
<td class="tab-highlighted-2" width="15">
<div align="left">Zoo</div>
</td>
<td class="tab-highlighted-2" width="20">
<div align="left">Remarks</div>
</td>
</tr>
<c:forEach items="${beans}" var="view">
<tr>
<td><a href="/oosd/UpdateAnimal.jsp?animal_id=${view.animalId}&breed=${view.breedId}">${view.animalName}</a></td>
<td>${view.animalDob}</td>
<td>${view.animalGender}</td>
<td>${view.animalSource}</td>
<td>${view.animalBreed}</td>
<td>${view.sectionId}</td>
<td>${view.zooId}</td>
<td>${view.animalRemark}</td>
</tr>
</c:forEach>
</table>
</center>
</body></html>
AnimalUpdateBean.java code:
package content;
public class AnimalUpdateBean {
private String animalId;
private String animalName;
private String animalDob;
private String animalGender;
private String animalBreed;
private String animalRemark;
public String getAnimalId() {return animalId;}
public String getAnimalName() {return animalName;}
public String getAnimalDob() {return animalDob;}
public String getAnimalGender() {return animalGender;}
public String getAnimalBreed() {return animalBreed;}
public String getAnimalRemark() {return animalRemark;}
public void setAnimalId(String animalId) {this.animalId = animalId;}
public void setAnimalName(String animalName) {this.animalName = animalName;}
public void setAnimalDob(String animalDob) {this.animalDob = animalDob;}
public void setAnimalGender(String animalGender) {this.animalGender = animalGender;}
public void setAnimalBreed(String animalBreed) {this.animalBreed = animalBreed;}
public void setAnimalRemark(String animalRemark) {this.animalRemark = animalRemark;}
}
the servlet responsible to start the update is UpdateAnimalServlet:
package content;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
/**
* Servlet implementation class LoginServlet
*/
public class UpdateAnimalServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, java.io.IOException {
try
{
AnimalUpdateBean animal = new AnimalUpdateBean();
animal.setAnimalId(request.getParameter("animal_id"));
animal.setAnimalName(request.getParameter("aname"));
// animal.setAnimalDob(request.getParameter("dob"));
animal.setAnimalGender(request.getParameter("gender"));
animal.setAnimalBreed(request.getParameter("breedid"));
animal.setAnimalRemark(request.getParameter("remark"));
String test = request.getParameter("animal_id");
System.out.println(test);
System.out.println(animal);
animal = DAO.updateAnimal(animal);
response.sendRedirect("/oosd/member.jsp");
}
catch (Throwable theException)
{
System.out.println(theException);
}
}
}
I’m using a Relay servlet that calls AnimalUpdateServlet for execution:
package content;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* Servlet implementation class LoginServlet
*/
public class Relay extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, java.io.IOException {
try
{
String command = request.getParameter("command");
if (command.equals("LoginServlet")){
RequestDispatcher rd =request.getRequestDispatcher("/"+command);
rd.forward(request, response);
//for testing
System.out.println("Request forwarded to " + command + " servlet");
} else if (command.equals("UpdateAnimalServlet")){
RequestDispatcher rd =request.getRequestDispatcher("/"+command);
rd.forward(request, response);
//for testing
System.out.println("Request forwarded to " + command + " servlet");
}
else
System.out.println("=> command='" + command + "'");
String url = "/oosd/" + command;
String encodedUrl = response.encodeRedirectURL(url);
System.out.println(" url=" + url);
System.out.println(" encodedUrl=" + encodedUrl);
response.sendRedirect(encodedUrl);
}
catch (Throwable theException)
{
System.out.println(theException);
}
}
}
and last thing is the web.xml page:
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:javaee="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
<servlet>
<servlet-name>LoginServlet</servlet-name>
<servlet-class>content.LoginServlet</servlet-class>
</servlet>
<servlet>
<servlet-name>UpdateAnimalServlet</servlet-name>
<servlet-class>content.UpdateAnimalServlet</servlet-class>
</servlet>
<servlet>
<servlet-name>SelectAnimalServlet</servlet-name>
<servlet-class>content.SelectAnimalServlet</servlet-class>
</servlet>
<servlet>
<servlet-name>Relay</servlet-name>
<servlet-class>content.Relay</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>SelectAnimalServlet</servlet-name>
<url-pattern>/SelectAnimalServlet</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>UpdateAnimalServlet</servlet-name>
<url-pattern>/UpdateAnimalServlet</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>LoginServlet</servlet-name>
<url-pattern>/LoginServlet</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>Relay</servlet-name>
<url-pattern>/Relay</url-pattern>
</servlet-mapping>
</web-app>
I keep getting these errors:
Log In failed: An Exception has occurred! java.sql.SQLException: [Microsoft][ODBC Microsoft Access Driver] Data type mismatch in criteria expression.
java.lang.IllegalStateException: Cannot call sendRedirect() after the response has been committed
I have checked the data entry and all correct name text, gender text, specie_id number, remark text i even put the dob on hold until this work i’m using access database and here is the connection code:
package content;
import java.sql.*;
public class dbConnection {
static Connection con;
static String url;
public static Connection getConnection()
{
try
{
String url = "jdbc:odbc:oosd";
// assuming "DataSource" is your DataSource name
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
try
{
con = DriverManager.getConnection(url,"","");
// assuming your SQL Server's username is "username"
// and password is "password"
}
catch (SQLException ex)
{
ex.printStackTrace();
}
}
catch(ClassNotFoundException e)
{
System.out.println(e);
}
return con;
}
}
Any idea where is my mistake here ?
as specie_id is a number and that’s what the thrown exception is stating “Data type mismatch in criteria expression.” and because of this exception sendRedirect error is occuring as because of the SQLException data has been already written to the response.
your query should be something like
same would be required if animal_id is also a number.