1. Chapter 14. JDBC, Java Server Pages, and MySQL
Database Management
Systems (II)
Chapter 14. JDBC, Java Server Pages, and MySQL
© 2005 by Dr. G. Wan

2. JDBC, JSP and MySQL
Alternative to Microsoft solutions for distributed database access
Open-source software
JDBC (not an acronym)
Java Server Pages (JSP) using Apache/ Tomcat
MySQL driver (an open-source DBMS developed by M. Mathews)
Running in open environments
Linux, and also Unix
Proprietary systems such as Windows

3. JDBC
JDBC
Allowing programmers to connect to many databases with JDBC drivers
For a listing of drivers, see:
JDBC architecture and components (see figure)
Objects in applications: Connection, Statement, ResultSet, ResultSetMetaData
Driver manager
Driver
Database and DBMS

4. JDBC Architecture DBMS1 DB Driver Manager DBMS2 ODBC Driver
DBMS Driver1
DBMS Driver2
JDBC-ODBC Bridge
DBMS1
DBMS2
ODBC Driver DB
JDBC Architecture
Applications
Connection
Statement
ResultSet
ResultSetMetaData
CallableStatement
PreparedStatement

5. JDBC driver types Type 1: JDBC-ODBC bridge drivers
Type 2: connects to the native API of the DBMS
Type 3: translates JDBC into DBMS-independent network protocol
Can be used for servlets and applets
Type 4: translates JDBC into DBMS-specific network protocol

6. JDBC Driver Types Driver Type Characteristics 1
JDBC-ODBC bridge drivers. Provides a Java API that interfaces to an ODBC driver. Enables processing of ODBC data sources from Java 2
A Java API that connects to the native library of a DBMS product. The Java program and the DBMS must reside on the same machine, or the DBMS program must handle inter-machine communication, if not 3
A Java API that connects to a DBMS-independent network protocol. Can be used for servlets and applets 4
A Java API that connects to a DBMS-dependent network protocol. Can be used for servlets and applets
JDBC Driver Types

7. Java programming language Java was designed to be portable
A Java program is not compiled into machine language, instead, into machine-independent bytecode (portability)
Bytecode is interpreted by the Java virtual machine (JVM)
JVM: a bytecode interpreter that is needed to run Java programs
Different interpreters for different machine environments (Intel, Alpha, etc.)

8. Java performance
Be interpreted, not as fast as code that has been translated into machine language
This may or may not a problem, depending on the application’s workload.

9. A servlet is a Java program invoked via HTTP on the Web server
Java servlet
A servlet is a Java program invoked via HTTP on the Web server
The servlet uses the JVM running on the server
Java applet
An applet is Java bytecode that is designed to run on a client
Applet bytecode is sent to the client machine using HTTP. It is read and interpreted by the Web browser. Most, if not all, Web browsers now run the Java virtual machine
JVM
servlets
Applet
HTTP
Web
Browser
Web
Browser
The protocol used to transmit and receive all data over the World Wide Web. When you type a URL into your browser, you're actually sending an HTTP request to a Web server for a page of information (that's why URLs all begin with " HTTP1.1, the latest version, is currently undergoing revisions to make it work more efficiently with TCP/IP
Web
Browser

10. Using JDBC
No JDBC data source: a connection is built in Java codes via JDBC driver
Steps for using JDBC drivers
Load the driver  Establish a connection to the database  Create a statement  Process the statement
Loading the driver
The directory containing the driver library must be part of the CLASSPATH for the Java compiler and the Java virtual machine
The JDBC-ODBC Bridge driver is installed automatically with the Java 2 SDK, Standard Edition, as package sun.jdbc.odbc
The Java application calls JDBC classes and interfaces to submit SQL statements and retrieve results.
The JDBC API is implemented through the JDBC driver. The JDBC Driver is a set of classes that implement the JDBC interfaces to process JDBC calls and return result sets to a Java application. The database (or data store) stores the data retrieved by the application using the JDBC Driver.

11. Establishing a connection to the database
While there are several ways to load the drivers, the following is one of the most reliable…
Class.forName(“nameofdriver”).newInstance()
Establishing a connection to the database
Create an object that has a connection to the database…
Connection Conn = DriverManager.getConnection(“connectionString”);
Example:
DriverManager.getConnection(“jdbc:mysql:
//localhost/db1?user=abc&password=pwd”);

12. Details regarding the JDBC connection string:
“connectionString” has three parts (each part is delimited with a colon)
Part 1: jdbc:
Part 2: a keyword that identifies the DBMS,
e.g., mysql:
Part 3: a URL for the database, e.g., //localhost/db1?user=abc&password=pwd
Creating a statement
A statement is created by instantiating a new Statement object
Statement Stmt = Conn.createStatement();

13. Processing the statement
The driver’s API documentation will provide details on what statements are available. However, the core statements are standard
Note: a driver’s API is a set of functions that the program may call to receive services
Examples (also see the codes):
ResultSet RS = Stmt.executeQuery(“select * from tab”);
int result = Stmt.executeUpdate(“update tab set name=‘abc’ where id = 1”);
Prepared statement and callable statement
Used to invoke compiled queries and stored procedures in database
Similar to command (but not supported by MySQL)

14. An example of JDBC-ODBC and Java
Build a simple database with Microsoft Access named db1.mdb, and create a table in db1.mdb: named CUSTOMER, which has three fields: CustomerID, Name, AreaCode, PhoneNumber, Street, City, State, and Zip;
input some data into the table; save the database in somewhere in the disk, say C:\.
2. Create a data source for db1.mdb: open the “Control Panel” of Windows 2000/XP; From the item “Administrative Tools”, find the icon for “Data Sources (ODBC)”, and then click on the icon, from the window “ODBC Data Source Administrator” click on the tab “System DSN”,

15. An Example (con’t)
Add a data source, select “Microsoft access driver” and click OK, enter a name for the data source, “test”; and click the tab “select” and find and select the database we just built, db1.mdb. Press “OK”. Now we have created a data source in our Window environment.
Install Java 1.4 or higher on your machine and edit the example in Figure 14-3;

16. Figure 14-3 (modified) import java.io.*; import java.sql.*;
public class GeneralTable {
public static void main(String[] args) {
if (args.length <1) {
System.out.println(Insufficient data provided.”);
return; }
String varTableName= args[0];
varTableName = varTableName.toUpperCase();
System.out.println("Showing Table " + varTableName);
try {
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver").newInstance();
String connString="jdbc:odbc:test";
Check for at least one parameter
Set the variable varTableName to
the input table name
and convert that name to uppercase.
JDBC-ODBC driver is loaded
JDBC-ODBC Bridge
The Bridge is installed automatically with the Java 2 SDK, Standard Edition, as package sun.jdbc.odbc
The Bridge is installed
automatically
with the Java 2 SDK,
Standard Edition,
as package sun.jdbc.odbc
The Bridge driver uses the odbc subprotocol.
URLs for this subprotocol are of the form:
jdbc:odbc:<data-source-name>[;<attribute-name>=<attribute-value>]*

17. System.out.println("Trying connection with "+connString);
Figure 14-3
System.out.println("Trying connection with "+connString);
Connection conn = DriverManager.getConnection(connString);
Statement stmt = conn.createStatement();
String varSQL = "SELECT * FROM " + varTableName;
ResultSet rs = stmt.executeQuery(varSQL);
ResultSetMetaData rsMeta = rs.getMetaData();
String varColNames = "";
int varColCount = rsMeta.getColumnCount();
for (int col =1; col <= varColCount; col++) {
varColNames = varColNames + rsMeta.getColumnName(col) + " "; }
System.out.println(varColNames);
while (rs.next()) {
for (int col=1; col<=varColCount; col++) {
System.out.print(rs.getString(col) + " ");
} System.out.println();
rs.close(); conn.close();
catch (Exception e) { e.printStackTrace(); }

18. An example (con’t) Save it in C:\wan\GeneralTable.java
Compile: C:\wan>javac GeneralTable.java
Run it: C:\wan>java GeneralTable customer

19. Questions
Can JDBC drivers be imported into Java Programs?

20. Figure 14-4
Implement the logic for the View Ridge CustomerInsert procedure in Chapter 7:
Accept four parameters: a new customer’s Name, AreaCode, LocalNumber, and the Nationality of all artists in whom the customer maintains an interest.

21. To be transformed into a java bean
import java.io.*;
import java.sql.*;
public class CustomerInsert {
public static void main(String[] args) {
if (args.length<4) {
System.out.println("insufficient data provided.");
return; }
String varName = args[0];
String varAreaCode = args[1];
String varLocalNumber= args[2];
String varNationality = args[3];
insertData(varName, varAreaCode, varLocalNumber, varNationality);
public static void insertData(String varName, String varAreaCode,
String varLocalNumber, String varNationality) {
System.out.println("Adding row for " + varName);
To be transformed into a java bean

22. try {
//load JDBC driver
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver").newInstance();
String connString="jdbc:odbc:test";
System.out.println("Trying connection with "+connString);
Connection conn = DriverManager.getConnection(connString);
Statement stmt = conn.createStatement();
// Now check for duplicated data
String varSQL = "SELECT Name ";
String varWhere = "FROM CUSTOMER WHERE Name= '";
varWhere = varWhere + varName + "' AND AreaCode = '";
varWhere = varWhere + varAreaCode + "' AND PhoneNumber = '";
varWhere = varWhere + varLocalNumber + "'";
varSQL = varSQL + varWhere;
ResultSet rs= stmt.executeQuery(varSQL);
while (rs.next()) {
// if get here, there is duplicate data
System.out.println("Data Duplicates an existing customer. No change Made.");
rs.close(); stmt.close(); conn.close(); return; }

23. C:\wan>javac CustomerInsert.java
// OK to insert new data
varSQL = "INSERT INTO CUSTOMER (Name, AreaCode, PhoneNumber)";
varSQL = varSQL + " VALUES ('" + varName + "', '";
varSQL = varSQL + varAreaCode + "', '";
varSQL = varSQL + varLocalNumber + "')";
int result = stmt.executeUpdate(varSQL);
if (result == 0) {
System.out.println("Problem with Insert");
rs.close();
stmt.close();
conn.close();
return; }
C:\wan>javac CustomerInsert.java
C:\wan>java CustomerInsert bush us
C:\wan>java GeneralTable customer

24. Needs in Developing Web Applications
Create simple interactive Web pages
separate content generation from presentation
take advantage of reusable, portable objects, simplifying the maintenance of Web applications.
Support complex web sites that are fully integrated with enterprise-level applications

25. What is JSP?
Java Server Pages (JSP) is a technology that lets you mix regular, static HTML with dynamically-generated HTML. JSP lets you create the two parts separately. Here's an example:
<html>
<%java.util.Date date=new java.util.Date();%>
<head>
<meat http-equiv="Content-Type" content="text/html; charset=gb2312">
</head>
<body>
<p><b> Today is: </b></p>
<%=date.getYear()+1900%>
.<%=date.getMonth()+1%>
.<%=date.getDate()%>
</body></html>

26. JSP (Java Server Pages)
JSP: providing a means of creating dynamic Web pages using HTTP, XML, and Java
JSP only allows for Java coding, ASP only allows for JavaScript or VBScript coding
JSP inherits the power and portability of Java
Since Java is powerful and platform-independent, so is JSP
JSP Specifications are located at:

27. JSP
JSP technology separates content generation from presentation and takes advantage of reusable tags and objects, simplifying the maintenance of your web applications.
JSP technology provides the scripting ability you need to create simple interactive Web pages, or it scales to support complex web sites that are fully integrated with enterprise class applications.

28. JSP and Servlets
JSP are transformed into standard Java code (in particular, Java servelet), then they are compiled into bytecode (just like a regular Java program)
Similar to ASP but fundamentally different in underlying technology
Machine independent
JSP: subclasses of the HttpServlet class
Consequently, due to inheritance, you may embed Java code enclosed by <% … %> directly into JSP

29. What are Java Servlets?
Servlets are Java technology's answer to CGI programming. They are programs that run on a Web server and build Web pages.
Building Web pages on the fly is useful for a number of reasons:
The Web page is based on data submitted by the user. For example the results pages from search engines are generated this way, and programs that process orders for e-commerce sites do this as well.
The data changes frequently. For example, a weather-report or news headlines page
The Web page uses information from corporate databases or other such sources. For example, you would use this for making a Web page at an on-line store that lists current prices and number of items in stock.

30. What are the Advantages of JSP?
JSP vs. Pure Servlets.
JSP doesn't give you anything that you couldn't in principle do with a servlet. But it is more convenient to write (and to modify!) regular HTML than to have a zillion println statements that generate the HTML.
By separating the look from the content you can put different people on different tasks: your Web page design experts can build the HTML, leaving places for your servlet programmers to insert the dynamic content.

31. JSP vs. JavaScript
JavaScript can generate HTML dynamically on the client. This is a useful capability, but only handles situations where the dynamic information is based on the client's environment.
With the exception of cookies, HTTP and form submission data is not available to JavaScript.
And, since it runs on the client, JavaScript can't access server-side resources like databases, catalogs, pricing information, and the like.

32. Web Server Applications
To run JSP, the Web server must implement:
Java servlet 2.1+, and
Java Server Pages 1.0+
Apache web server: not support servlets
Apache TomCat: implemented the above specifications
Apache Tomcat
Apache Tomcat: a common Web server application a servlet processor
May run in conjunction with Apache (in a production environment) or standalone (in a development environment)

33. C:\Program Files\Apache Software Foundation\Tomcat 5.5\
Download current version of Tomcat from:
Install it in:
C:\Program Files\Apache Software Foundation\Tomcat 5.5\
Test it:
Directory structure
\bin
\common
\webapps
\lib …
\ROOT …

34. An simple JSP example: test.jsp
<html>
<%java.util.Date date=new java.util.Date();%>
<head> A Test of JSP </head>
<body>
<p><b> Welcome! Today is: </b></p>
<%=date.getYear()+1900%>
. <%=date.getMonth()+1%>
. <%=date.getDate()%>
</body>
</html>

35. An simple JSP example (con’t)
Edit it using an editor, e.g. WordPad.
Save it in:
C:\Program Files\Apache Software Foundation\Tomcat5.5\webapps\ROOT\test.jsp
Start Tomcat:
C:\Program Files\Apache Software Foundation\Tomcat5.5\bin\tomcat5
Open a Web browser and go to:

36. Running JSP JSP compilation process: parse, compile, load and execute
JSP Page Request
JSP
Servlet
Current? no
Parse JSP and
Create Java
Source File
JSP compilation process: parse, compile, load and execute
yes
JSP
Servlet in
Memory?
Compile Java
Source File
yes no
Load the JSP servlet
Execute the JSP
servlet
JSP Page Response

37. Figure 14-6: GeneralTable.jsp
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
page import="java.sql.*" %>
<HTML>
<HEAD>
<TITLE> Table Display Using JDBC and MySQL</TITLE>
<META NAME="author" CONTENT="Oscar LIN">
<META NAME="Keywords" CONTENT="JSP, JDBC, Database Access.">
<META NAME="description" CONTENT="an example of displaying a table using JSP.">
<LINK REL=STYLESHEET HREF="JSP-Style.css" TYPE="text/css">
</HEAD>
<BODY>
<H2> Database Access Example</H2>
<%String varTableName= request.getParameter("Table");
varTableName = varTableName.toUpperCase(); %>
<H3> Showing Data from MySQL Database db1</H3>

38. <%
try {
// Load JDBC driver
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver").newInstance();
String connString="jdbc:odbc:test";
System.out.println("Trying connection with "+connString);
Connection conn = DriverManager.getConnection(connString);
Statement stmt = conn.createStatement();
String varSQL = "SELECT * FROM " + varTableName;
ResultSet rs = stmt.executeQuery(varSQL);
ResultSetMetaData rsMeta = rs.getMetaData();
%>
<TABLE BORDER=1 BGCOLOR=#ffffff CELLSPACE=5><FONT FACE="Arial" COLOR=#000000>
<CAPTION><B> <%=varTableName%> </B></CAPTION></FONT>
<THEAD>

39. <TR> <%
String varColNames = "";
int varColCount = rsMeta.getColumnCount();
for (int col =1; col <= varColCount; col++) {
%> <TH BGCOLOR=#c0c0c0 BORDERCOLOR=# ><FONT SIZE=2 FACE="Arial" COLOR=#000000>
<%=rsMeta.getColumnName(col) %> </FONT> </TH>
<% }%>
</TR>
</THEAD>
<TBODY> <%
while (rs.next()) {
%> <TR VALIGN=TOP> <%
for (int col=1; col<=varColCount; col++) {
%> <TD BORDERCOLOR=#c0c0c0 ><FONT SIZE=2 FACE="Arial" COLOR=#000000
> <%=rs.getString(col) %> <BR> </FONT> </TD>
<% } }

40. //clean up
rs.close();
stmt.close();
conn.close(); }
catch (ClassNotFoundException e) {
out.println("Driver Exception " + e);
} %>
</TR>
</TBODY>
<TFOOT></TFOOT>
</TABLE>
</BODY>
</HTML>
Example: Run it!

41. Java Bean
Model 1.

42. JSP invoking Java Classes (Java Beans)
Important and Useful:
It separates the tasks of writing program logic from generating HTML;
It Reduces the complexity of managing a Web site.
Java Bean
A properly mannered Java class;
A Java class that has three properties:
there are no public instance variables;
All persistent values xxx are accessed using methods named getxxx and setxxx
Bean classes must either have no constructors or it must have one explicitly defined zero-argument constructor

43. An example using Java Bean
Save it into:
C:\Program Files\Apache Software Foundation\Tomcat 5.5\webapps\ROOT\WEB-INF\classes\
Compile it: >javac CustomerInsertBean.java
We get CustomerInsertBean.class
Edit NewCustomer.html
Save it into: C:\Program Files\Apache Software Foundation\Tomcat 5.5\webapps\ROOT\
Edit CustomerInsertUsingBean.jsp
Save it into
C:\Program Files\Apache Software Foundation\Tomcat 5.5\webapps\ROOT\
Start Tomcat
C:\Program Files\Apache Software Foundation\Tomcat 5.5\bin\tomcat5

44. An Example using Java Bean and JDBC
JSP:
Display the result set retrieved from Table
Testinfo in the database db1
Use the Java Bean DBUtil_MySQL.class
Java:
Load the JDBC driver
Set up the connection
Get the ResultSet

45. An example using Java Bean and MySQL
// A Java Bean source code: DBUtil_MySQL.java
package lin;
import java.io.*;
import java.sql.*;
public class DBUtil_MySQL {
// For MySQL
String sDBDriver="com.mysql.jdbc.Driver";
String sConnStr="jdbc:mysql://localhost:3307/"+"db1"+"?user=root";
// for MS ACCESS
//String sDBDriver="sun.jdbc.odbc.JdbcOdbcDriver";
//String sConnStr="jdbc:odbc:test";
Connection conn = null;
ResultSet rs = null;
public DBUtil_MySQL()
try
{ //java.sql.DriverManager.registerDriver();
Class.forName(sDBDriver); }
catch(java.lang.ClassNotFoundException e)
{ System.err.println("testJDBC(): " + e.getMessage()); }
An example using Java Bean and MySQL
It is necessary to use a package,
Otherwise something will go wrong.

46. An example using Java Bean and MySQL
public ResultSet executeQuery(String testJDBC) {
rs = null;
try
conn=DriverManager.getConnection(sConnStr);
Statement stmt = conn.createStatement();
rs=stmt.executeQuery(testJDBC); }
catch(SQLException ex)
System.err.println("aq.executeQuery:"+ex.getMessage());
return rs;
An example using Java Bean and MySQL
Save it in: \webapps\ROOT\WEB-INF\classes\DBUtil_MySQL.java
>javac –d \ DBUtil_MySQL.java
Copy the file we got from the compilation DBUtil_MySQL.class in C:\lin to
C:\Program Files\Apache Software Foundation\Tomcat 5.5\webapps\ROOT\WEB-INF\classes\lin\

47. testDB_MySQL.jsp Save it to: C:\Program Files\
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title> MY FAQ</title>
</head>
<body>
<p><b> This is my name! </b> </p>
page language="java" import ="java.sql.*" pageEncoding="gb2312"
%>
<jsp:useBean id='workM' class="lin.DBUtil_MySQL" />
<jsp:setProperty name="workM" property="*" />
<%
ResultSet RS = workM.executeQuery("SELECT * FROM testinfo");
while (RS.next()) {
ResultSet rs = workM.executeQuery("SELECT * FROM testinfo");
String str_name, str_gender;
out.println("Get data from a database:: ");
<p> </p>
<%
while (rs.next())
{ str_name=rs.getString("name");
str_gender = rs.getString("gender");
out.println(" name is: " + str_name);
out.println(" gender is: " + str_gender);
%> <p> </p> <% }
} RS.close();
%>
</body>
</html>
Save it to:
C:\Program Files\
Apache Software Foundation
\Tomcat 5.5\webapps\ROOT\
Go to:

48. MySQL Downloading MySQL
An open-source DBMS product that runs on Unix, Linux, and Windows
Provides quick and efficient query handling
Allows you to create users, databases, tables, auto incrementing fields, etc.
The MySQL open-source driver may be downloaded from:

49. Get and Install a Recent Version
Download the 4.0 and/or 4.1 versions of the MySQL win32 distribution.
Find the downloaded file, unzip it and start the setup program:
By referring to
Install it to C:\Program Files\mysql40\
Start it: C:\Program Files\mysql40\bin\

50. Limitations Using My SQL
While MySQL is extremely inexpensive and provides many capabilities, it is not as powerful as commercial products, such as Oracle and SQL Server
Using My SQL
MySQL commands: use, show, describe

51. Using MySQL >mysql –P 3307 –u root mysql >Show databases;
>sHow databases; (OK)
>Use db1;
>Show tables;
>Describe testinfo;
>Select * from testinfo; Or
>\q
Edit sql.txt
>bin>mysql –P 3307 –u root mysql <C:\wan\sql.txt

52. Unzip it to get the jar file: mysql-connector-java-3.0.16-ga-bin.jar
The latest version of the driver is MySQL Connector/J
(formerly MM.MySQL driver)
is a Java driver that converts JDBC calls into the network protocol used by the MySQL database.
is a Type 4 JDBC driver and has a complete JDBC feature set that supports the capabilities of MySQL.
Download the driver from
Unzip it to get the jar file: mysql-connector-java ga-bin.jar
copy it to a public place:
…\Tomcat 5.5\common\lib\mysql-connector-java ga-bin.jar

53. JDBC connections
JDBC connection to MySQL is different from other user connections
Same machine: via socket
Different machines: via TCP/IP

54. Concurrency control Backup and recovery
A work-around allows you to grant access to the for the specific account
The wildcard % states that the database may be accessed from any host
Alternatively, you may supply the specific IP address for your local machine –this provides better security
Concurrency control
Limited support: read/write locks
Backup and recovery
Limited support: database/table saving, log files

55. Summary JDBC JSP (Java Server Pages) MySQL Questions?
JDBC driver types
Java Servlet and Applets
JDBC architecture and components
Applications of JDBC
JSP (Java Server Pages)
JSP, Servlets and Apache Tomcat
MySQL
MySQL and JDBC Connections; Concurrency control, and backup and recovery
Questions?