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![ServletRequest - Parameters
• String getParameter(String)
– Returns a string containing one value of the specified
parameter, or null if the parameter does not exist.
• String[] getParameterValues(String)
– Returns the values of the specified parameter as an
array of strings, or null if the named parameter does not
exist.
– Useful for parameters with multiple values, like lists
• Enumeration getParameterNames()
– Returns the parameter names as an enumeration of
strings, or an empty enumeration if there are no
parameters or the input stream is empty.](https://image.slidesharecdn.com/144271117-171128114644/75/SERVIET-14-2048.jpg)
![SERVLET2
public class SecondServlet extends HttpServlet
{
public void doPost(HttpServletRequest request, HttpServletRespon
se response){
try{
response.setContentType("text/html");
PrintWriter out = response.getWriter();
Cookie ck[]=request.getCookies();
out.print("Hello "+ck[0].getValue());
out.close();
}catch(Exception e){System.out.println(e);}}}](https://image.slidesharecdn.com/144271117-171128114644/75/SERVIET-27-2048.jpg)
![Example to Connect Java Application with
mysql database
• import java.sql.*;
• class MysqlCon{
• public static void main(String args[]){ try{
• Class.forName("com.mysql.jdbc.Driver");
• Connection con=DriverManager.getConnection(
• "jdbc:mysql://localhost:3306/sonoo","root","root");
• //here sonoo is database name, root is username and password
• Statement stmt=con.createStatement();
• ResultSet rs=stmt.executeQuery("select * from emp");](https://image.slidesharecdn.com/144271117-171128114644/75/SERVIET-68-2048.jpg)
![Cont…
• public static void main(String[] args) {
• try {
• Class loadedClass = Class.forName(CLASS_TO_LOAD);
• System.out.println("Class " + loadedClass + " found successfully!");}
• catch (ClassNotFoundException ex){
• System.err.println("A ClassNotFoundException was caught: " +
ex.getMessage());
• ex.printStackTrace(); }}}](https://image.slidesharecdn.com/144271117-171128114644/75/SERVIET-91-2048.jpg)
More Related Content
![Java Web Programming [2/9] : Servlet Basic](https://cdn.slidesharecdn.com/ss_thumbnails/javaweb-module2-130106070240-phpapp02-thumbnail.jpg?width=640&height=640&fit=bounds)
SERVIET
- 2. Life Cycle ofServlet init(ServletConfig); service(ServletRequest, ServletResponse); destroy(); servlet GenericServlet HttpServlet doGet(HttpServletRequest, HttpServletResponse); doPost(HttpServletRequest, HttpServletResponse); …….
- 3. 3 Servlet Life Cycle •Servlet API life cycle methods – init(): called when servlet is instantiated; must return before any other methods will be called – service(): method called directly by server when an HTTP request is received; default service() method calls doGet() (or related methods covered later) – destroy(): called when server shuts down
- 4. HelloWorld import java.io.*; import javax.servlet.*; importjavax.servlet.http.*; public class HelloWorld extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException { response.setContentType("text/html"); PrintWriter out = response.getWriter(); out.println("<html>"); out.println("<body>"); out.println("<head>"); out.println("<title>Hello CS764!</title>"); out.println("</head>"); out.println("<body>"); out.println("<h1>Hello CS764!</h1>"); out.println("</body>"); out.println("</html>"); out.close(); } }
- 5. <html><head></head> <body> <a href="../servlet/HelloWorld"> <h1>Execute HelloWorldServlet</h1> </a> </body> </html> <html> <head> <title>Hello CS764!</title></head> <body> <h1>Hello CS764!</h1> </body> </html>
- 6. The Servlet API •javax.servlet – Basic servlet API definitions. – What are the inputs and outputs to/from Servlet – Not tied to any specific protocol (e.g., HTTP) – These low-level classes/interfaces usually are not used • javax.servlet.http – HTTP-related definitions – Extension of the basic interfaces to handle the HTTP protocol functionality – This package will be heavily used
- 7. Servlet classes • GenericServletclass – implements Servlet – also implements Serializable, ServletConfig – implements all Servlet methods • HttpServlet class – extends the GenericServlet class – provides a framework for handling the HTTP protocol – has its own subclasses of ServletRequest and ServletResponse that do HTTP things
- 8. HttpServlet methods • HTTPServletclass provides helper methods for handling HTTP requests – doGet (GET and HEAD) – doPost (POST) – doPut, doDelete (rare) – doTrace, doOptions (not overridden) • The service() method dispatches the requests to the appropriate do* methods
- 9. Generic Servlet vs.HTTP Servlet GenericServlet service ( )Server Client HTTPServlet service ( )HTTP Server Browser request response doGet ( ) doPost ( ) request response
- 10. ServletRequest class • Encapsulatesthe clientserver communication • Allows the Servlet access to – Names of the parameters passed in by the client – The protocol being used by the client – The names of the remote host that made the request and the server that received it – The input stream, ServletInputStream, through which the servlet gets data from clients • Subclasses of ServletRequest allow the servlet to retrieve more protocol-specific data – HttpServletRequest for accessing HTTP-specific header information
- 11. ServletRequest - ClientInfo • getRemoteAddr() – Returns the IP address of the client that sent the request • getRemoteHost() – Returns the fully qualified host name of the client that sent the request • getProtocol() – Returns the protocol and version of the request as a string <protocol>/<major version>.<minor version>.
- 12. ServletRequest - URLInfo • getScheme() – Returns the scheme of the URL used in this request, for example "http", "https", or "ftp". • getServerName() – Returns the host name of the server receiving the request • getServerPort() – Returns the port number on which this request was received • getServletPath() – Returns the URL path that got to this script, e.g. “/servlet/com.foo.MyServlet” – Useful for putting in a <FORM> tag
- 13. ServletRequest - Contents •getContentLength() – Returns the size of the request data • getContentType() – Returns the MIME type of the request data • getInputStream() – Returns an input stream for reading binary data in the request body. • getReader() – Returns a buffered reader for reading the request body.
- 14. ServletRequest - Parameters •String getParameter(String) – Returns a string containing one value of the specified parameter, or null if the parameter does not exist. • String[] getParameterValues(String) – Returns the values of the specified parameter as an array of strings, or null if the named parameter does not exist. – Useful for parameters with multiple values, like lists • Enumeration getParameterNames() – Returns the parameter names as an enumeration of strings, or an empty enumeration if there are no parameters or the input stream is empty.
- 15. ServletResponse class • Encapsulatesthe serverclient communication – Gives the servlet methods for replying to the client – Allows the servlet to set the content length and MIME type of the reply – Provides an output stream, ServletOutputStream through which the servlet can send the reply data • Subclasses of ServletResponse give the servlet more protocol-specific capabilities. – HttpServletResponse for manipulating HTTP-specific header information
- 16. ServletResponse • Embodies theresponse • Basic use: response.setContentType("text/html"); PrintWriter out = response.getWriter(); out.println( "<HTML><BODY>Hello</BODY></HTML>"); • setContentType() is usually called before calling getWriter() or getOutputStream()
- 17. ServletResponse - Output •getWriter() – for writing text data • getOutputStream() – for writing binary data – or for writing multipart MIME • And many other methods, similarly to the methods of ServletRequest • Refer the documentation
- 18. import java.io.*; import javax.servlet.*; importjavax.servlet.http.*; public class ServWelcome extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException { response.setContentType("text/html"); PrintWriter out = response.getWriter(); out.println("<HTML>"); out.println("<HEAD><TITLE>First Servlet Program</TITLE></HEAD>"); out.println("<BODY>"); out.println("<H1>Welcome to Servlets</H1>"); out.println("</BODY>"); out.println("</HTML>"); out.close(); } } Servlet Example Servlets are not part of the standard SDK, they are part of the J2EE Servlets normally extend HttpServlet Details of the HTTP request from the client The response to be sent to the client Set the response type to text/html (this is normal) This HTML text is sent to the client Do not forget to close the connection with the client
- 19. Servlet Architecture Overview •Servlet Interface – methods to manage servlet • GenericServlet – implements Servlet • HttpServlet – extends GenericServlet – exposes HTTP-specific functionality Servlet extends doGet() doPost() service() ... Override one or more of: doGet() doPost() service() ... Clas s Interface Class Class Clas s extendsHttpServlet implements GenericServlet UserServlet
- 20. REQUEST METHODS • GET-This method gets the resource at the requested URL. • POST- Asks the server to accept the body info attached. It is like GET request with extra info sent with the request. • HEAD- Asks for only the header part with no body. • PUT- Says to put the body at the requested URL • DELETE- Says to delete the resource at the requested URL. • OPTIONS- Asks for a list of the HTTP methods to which the thing at the request URL can respond. • TRACE-Asks for the loopback of the request message
- 21. DIFFERENCE BETWEEN GETAND POST GET: • GET/test/demo_form.jsp?name1=value1&name2=value2 HTTP/1.1 • In GET method the data is exposed in the URL and only a limited amount of data is sent. Because the data is sent in the URL. POST: • POST/test/demo_form.jsp HTTP/1.1 • In POST method the data is not exposed in the URL and large amount of data is sent. Because the data is sent in the body.
- 22. SESSION TRACKING • Sessionsimply means a particular interval of time. • Session Tracking is a way to maintain state (data) of an user. It is also known as session management in servlet. • It is used to recognize the particular user.
- 23. SESSION TRACKING TECHNIQUE •There are four techniques used in Session tracking: 1. Cookies 2. Hidden Form Field 3. URL Rewriting 4. HttpSession
- 24. COOKIES • A cookieis a small piece of information that is persisted(client-side) between the multiple client requests. • There are two types of cookies in servlets. 1. Non-persistent cookie 2. Persistent cookie • javax.servlet.http.Cookie class provides the functionality of using cookies
- 25. EXAMPLE SERVLET1 public class FirstServletextends HttpServlet { public void doPost(HttpServletRequest request, HttpServletRespon se response){ try{ response.setContentType("text/html"); PrintWriter out = response.getWriter(); String n=request.getParameter("userName"); out.print("Welcome "+n); //creating cookie object Cookie ck=new Cookie("uname",n);
- 26. //adding cookie inthe response response.addCookie(ck); //creating submit button out.print("<form action='servlet2'>"); out.print("<input type='submit' value='go'>"); out.print("</form>"); out.close(); }catch(Exception e){System.out.println(e);} }}
- 27. SERVLET2 public class SecondServletextends HttpServlet { public void doPost(HttpServletRequest request, HttpServletRespon se response){ try{ response.setContentType("text/html"); PrintWriter out = response.getWriter(); Cookie ck[]=request.getCookies(); out.print("Hello "+ck[0].getValue()); out.close(); }catch(Exception e){System.out.println(e);}}}
- 28. • In thisexample,We are storing the name of the user in the cookie object and accessing it in another servlet. • As we know well that session corresponds to the particular user. • So if you access it from too many browsers with different values, you will get the different value.
- 29. HIDDENFIELD • Hidden FormField a hidden (invisible) textfield for maintaining the state of user. • We store the information in the hidden field and get it from another servlet. • To store value in hidden field <input type="hidden" name="uname" value=“Java">
- 30. EXAMPLE SERVLET1 public class FirstServletextends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response){ try{ response.setContentType("text/html"); PrintWriter out = response.getWriter(); String n=request.getParameter("userName"); out.print("Welcome "+n);
- 31. //creating form thathave invisible textfield out.print("<form action='servlet2'>"); out.print("<input type='hidden' name='uname' value='"+n+"'>"); out.print("<input type='submit' value='go'>") out.print("</form>"); out.close(); } catch(Exception e) {System.out.println(e);}}}
- 32. SERVLET2 public class SecondServletextends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) try{ response.setContentType("text/html"); PrintWriter out = response.getWriter(); / /Getting the value from the hidden field String n=request.getParameter("uname"); out.print("Hello "+n); out.close(); }catch(Exception e){System.out.println(e);} } }
- 33. URL REWRITING • Appenda token or identifier to the URL of the next Servlet or the next resource. • Parameter name/value pairs can be sent using the following format: url?name1=value1&name2=value2&?? • A name and a value is separated using an equal = sign, a parameter name/value pair is separated from another parameter using the ampersand(&).
- 34. EXAMPLE SERVLET1 public class FirstServletextends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResp onse response){ try{ response.setContentType("text/html"); PrintWriter out = response.getWriter(); String n=request.getParameter("userName"); out.print("Welcome "+n);
- 35. //appending the usernamein the query string out.print("<a href='servlet2?uname="+n+"'>visit</a>"); out.close(); }catch(Exception e){System.out.println(e);} } SERVLET2 public class SecondServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServl etResponse response) try{ response.setContentType("text/html"); PrintWriter out = response.getWriter();
- 36. //getting value fromthe query string String n=request.getParameter("uname"); out.print("Hello "+n); out.close(); }catch(Exception e) { System.out.println(e);} } }
- 37. HTTP SESSION • Containercreates a session id for each user. • The container uses this id to identify the particular user. • An object of HttpSession can be used to perform two tasks: 1. bind objects 2. view and manipulate information about a session, such as the session identifier, creation time, and last accessed time.
- 38. EXAMPLE SERVLET1 public void doGet(HttpServletRequestrequest, HttpServletRespo nse response){ try{ response.setContentType("text/html"); PrintWriter out = response.getWriter(); String n=request.getParameter("userName"); out.print("Welcome "+n); HttpSession session=request.getSession(); session.setAttribute("uname",n);
- 39. out.print("<a href='servlet2'>visit</a>"); out.close(); }catch(Exception e){System.out.println(e);}} SERVLET2 public class SecondServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletRe sponse response) try { response.setContentType("text/html"); PrintWriter out = response.getWriter();
- 40. HttpSession session=request.getSession(false); String n=(String)session.getAttribute("uname"); out.print("Hello"+n); out.close(); }catch(Exception e){System.out.println(e);} } }
- 41. Apache Tomcat Representation andManagement of Data on the Web
- 42. What is Tomcat? •Tomcat is a Servlet container (Web server that interacts with Servlets) • Tomcat implements the Servlet and the Java Server Pages (JSP) specifications of Sun Microsystems • Tomcat is an open-source, non commercial project – Licensed under the Apache Software License • Tomcat is written in Java (OS independent)
- 43. A Servlet Example publicclass HelloWorld extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { PrintWriter out = response.getWriter(); out.println("<html><head><title>Hello</title></head>"); out.println("<body>"); out.println("<h2>" + new java.util.Date() + "</h2>"); out.println("<h1>Hello World</h1></body></html>"); } } HelloWorld.java http://localhost/dbi/hello
- 44. A JSP Example <html> <head> <title>HelloWorld</title> </head> <body> <h2><%= new java.util.Date() %></h2> <h1>Hello World</h1> </body> </html> hello.jsp http://localhost/dbi/hello.jsp
- 45. Tomcat Directory Structure Tomcat-Home bincommon Tomcat-Base webapps work lib classesROOT myApp1 myApp2server.xml WEB-INF lib classesweb.xml server sharedlogsconf lib classes
- 46. Installing Tomcat • Createa directory for tomcat base – For example: mkdir ~/tomcat-base • Set the environment variable CATALINA_BASE to your tomcat-base directory – For example: setenv CATALINA_BASE ~/tomcat-base – Insert this line into your .cshrc file • Run ~dbi/tomcat/bin/setup • $CATALINA_BASE is now a regular Tomcat base directory, and Tomcat is ready to run
- 47. Running Tomcat • Tostart tomcat use ~dbi/tomcat/bin/catalina run • Or, in background, ~dbi/tomcat/bin/catalina start • To stop tomcat use ~dbi/tomcat/bin/catalina stop • To see the default page of Tomcat from your browser use the URL http://<machine-name>:<port>/ – machine-name is the name of the machine on which Tomcat runs and port is the port you chose for Tomcat • You can also use http://localhost:<port>/ if your browser runs on the same machine as Tomcat
- 49. Choosing a portfor Tomcat • In the file $CATALINA_HOME/conf/server.xml you will find the element Connector of Service “Catalina” • Choose a port (greater than 1024) and change the value of the port attribute to your chosen one: <Server> … <Service name="Catalina”> <Connector port="8090"/> … </Service> … </Server>
- 50.
- 51. JDBC What is JDBC •The java Database Connectivity(JDBC)API is the industry standard for database independent connectivity between the java programming language and wide range of database. • Java API is used to connect and execute query to the database. JDBC API uses jdbc drivers to connects to the database.
- 52. Why JDBC &What is API Why we use JDBC? • Before JDBC, ODBC API was used to connect and execute query to the database. • But ODBC API uses ODBC driver that is written in C language which is platform dependent and unsecured. • That is why Sun Microsystem has defined its own API (JDBC API) that uses JDBC driver written in Java language.
- 53. API What is API •API (Application programming interface) is a document that contains description of all the features of a product or software. • It represents classes and interfaces that software programs can follow to communicate with each other. • An API can be created for applications, libraries, operating systems, etc
- 54. JDBC Driver • JDBCDrivers • JDBC-ODBC Bridge Driver • Native-API Driver • Network Protocol Driver • Thin Driver
- 55. JDBC Drivers JDBC Driveris a software component that enables java application to interact with the database.There are 4 types of JDBC drivers: • JDBC-ODBC bridge driver • Native-API driver (partially java driver) • Network Protocol driver (fully java driver) • Thin driver (fully java driver)
- 56. JDBC-ODBC bridge driver TheJDBC-ODBC bridge driver uses ODBC driver to connect to the database. The JDBC-ODBC bridge driver converts JDBC method calls into the ODBC function calls. This is now discouraged because of thin driver.
- 57. Native-API driver • TheNative API driver uses the client-side libraries of the database. The driver converts JDBC method calls into native calls of the database API. It is not written entirely in java.
- 58. Network Protocol driver •The Network Protocol driver uses middleware (application server) that converts JDBC calls directly or indirectly into the vendor-specific database protocol. It is fully written in java.
- 59. Thin driver • Thethin driver converts JDBC calls directly into the vendor-specific database protocol. That is why it is known as thin driver. It is fully written in Java language.
- 60. RDBMS • MySQL • DriverName : com.mysql.jdbc.Driver • URL Format : jdbc:mysql://hostname/ databaseName • ORACLE • Driver Name : oracle.jdbc.driver.OracleDriver • URL Format : jdbc:oracle:thin:@hostname:port Number:databaseName
- 61. 5 Steps toconnect to the database in java • Register the driver class • Create the connection object • Create the Statement object • Execute the query • Close the connection object
- 62. Register the driverclass • The forName() method of Class class is used to register the driver class. This method is used to dynamically load the driver class. Syntax of forName() method • public static void forName(String className)throws ClassNotFoundException • Example to register the OracleDriver class • Class.forName("oracle.jdbc.driver.OracleDriver");
- 63. Create the connectionobject • The getConnection() method of DriverManager class is used to establish connection with the database. • Syntax of getConnection() method 1) public static Connection getConnection(String url)throws SQLException 2) public static Connection getConnection(String url,String name,String password) throws S QLException. Example to establish connection with the Oracle database • Connection con=DriverManager.getConnection( "jdbc:oracle:thin:@localhost:1521:xe","system","password");
- 64. Create the Statementobject • The createStatement() method of Connection interface is used to create statement. The object of statement is responsible to execute queries with the database. Syntax of createStatement() method • public Statement createStatement()throws SQLException Example to create the statement object • Statement stmt=con.createStatement();
- 65. Execute the query •The executeQuery() method of Statement interface is used to execute queries to the database. This method returns the object of ResultSet that can be used to get all the records of a table. Syntax of executeQuery() method • public ResultSet executeQuery(String sql)throws SQLException Example to execute query • ResultSet rs=stmt.executeQuery("select * from emp"); • while(rs.next()){ • System.out.println(rs.getInt(1)+" "+rs.getString(2)); • }
- 66. Close the connectionobject • By closing connection object statement and ResultSet will be closed automatically. The close() method of Connection interface is used to close the connection. Syntax of close() method • public void close()throws SQLException Example to close connection • con.close();
- 67. Statement, Prepared Statement,Callable Statement • Statement • Use for general-purpose access to your database. Useful when you are using static SQL statements at runtime. The Statement interface cannot accept parameters. • Prepared Statement • Use when you plan to use the SQL statements many times. The PreparedStatement interface accepts input parameters at runtime. • Callable Statement • Use when you want to access database stored procedures. The CallableStatement interface can also accept runtime input parameters.
- 68. Example to ConnectJava Application with mysql database • import java.sql.*; • class MysqlCon{ • public static void main(String args[]){ try{ • Class.forName("com.mysql.jdbc.Driver"); • Connection con=DriverManager.getConnection( • "jdbc:mysql://localhost:3306/sonoo","root","root"); • //here sonoo is database name, root is username and password • Statement stmt=con.createStatement(); • ResultSet rs=stmt.executeQuery("select * from emp");
- 69. Insertion Operation • Stringsql="insert into RegistrationTable(Name,EmailId,Gender,Address,Contact,BikeName,Passw ord)values(?,?,?,?,?,?,?)"; • try{ • Class.forName("com.mysql.jdbc.Driver"); • Connection con=DriverManager.getConnection("jdbc:mysql://localhost/Bike","root","r oot");
- 70. • PreparedStatement pt=con.prepareStatement(sql); •pt.setString(1,jTextField1.getText()); • pt.setString(2,jTextField2.getText()); • if(jRadioButton1.isSelected()){ • String rad_male = jRadioButton1.getText();
- 71. • pt.setString(3,rad_male); • }else •String rad_female = jRadioButton2.getText(); • pt.setString(3,rad_female); } • pt.setString(4,jTextArea1.getText()); • pt.setString(5,jTextField3.getText()); • pt.setString(6,jTextField4.getText()); • pt.setString(7,jTextField5.getText());
- 72. • int n=pt.executeUpdate(); •if(n==1) { • JOptionPane.showMessageDialog(null,"Record Inserted" );} • else{ • JOptionPane.showMessageDialog(null,"Record Not Inserted");}
- 73.
- 74. Deletion Operation • try{ •String s1=jTextField1.getText(); • String sql ="delete from registrationtable where Name = '"+s1+"'"; • Class.forName("com.mysql.jdbc.Driver"); • Connection con =DriverManager.getConnection("jdbc:mysql://localhost/Bike","root","root "); • PreparedStatement pt =con.prepareStatement(sql);
- 75. Cont… • int d=pt.executeUpdate(); •if(d==1){ • JOptionPane.showMessageDialog(null,"Record Deleted"); } • } catch(Exception ex){ • ex.printStackTrace(); }
- 76.
- 77. After Deletion Here amdeleting the record where BookingId = 9
- 78. Retreiving Records • try{ •String sql="select * from registrationtable where Name= ? "; • Class.forName("com.mysql.jdbc.Driver"); • Connection con =DriverManager.getConnection("jdbc:mysql://localhost/Bike","root","root "); • PreparedStatement pt = con.prepareStatement(sql); • pt.setString(1,jTextField1.getText()); • ResultSet rs= pt.executeQuery();
- 79. Cont… • if(rs.next()){ • Strings1 =rs.getString(1); • String s2 =rs.getString(2); • String s3 =rs.getString(3); • String s4 =rs.getString(4); • String s5 =rs.getString(5); • String s6 =rs.getString(6);
- 80. Cont… • jTextField1.setText(s1); • jTextField2.setText(s2); •if(jRadioButton1.getText().contentEquals(s3)){ • jRadioButton1.setSelected(true); • } • else{ • jRadioButton2.setSelected(true); • }
- 81. Cont… • jTextArea1.setText(s4); • jTextField3.setText(s5); •jTextField4.setText(s6); • } • // this.getFrame().setResizable(false); • } • catch(Exception ex){ • ex.printStackTrace(); • }
- 82.
- 83. Update Operation • try{ •String s1=jTextField1.getText(); • String s2=jTextField1.getText(); • String radio=""; • if(jRadioButton1.isSelected()){ • radio=jRadioButton1.getText();} • else{ • radio=jRadioButton2.getText(); } • String s3= jTextArea1.getText();
- 84. Cont… • String s4=jTextField3.getText(); •String s5=jTextField4.getText(); • String sql ="update registrationtable set EmailId='"+s2+"',Gender='"+radio+"',Address='"+s3+"',Contact='"+s4+"', BikeName='"+s5+"'where Name='"+s1+"'"; • Class.forName("com.mysql.jdbc.Driver"); • Connection con=DriverManager.getConnection("jdbc:mysql://localhost/Bike" ,"root","root");
- 85. • PreparedStatement st=con.prepareStatement(sql); •int n=st.executeUpdate(); • if(n==1) { • JOptionPane.showMessageDialog(null, "UPDATED SUCESSFULLY");}} • catch(Exception ex){ • ex.printStackTrace(); }
- 86.
- 87. After Updating Here amupdated the address and contact where BookingId = 7
- 88.
- 89. SQLException Methods • getErrorCode() •getMessage() • getSQLState() • getNextException() • printStackTrace()
- 90. Example • SQLException • Stringsql= "insert into RegistrationTable(Name,EmailId,Gender,Address,Contact,BikeName,Passw ord)values(?,?,?,?,?,?, )"; • //java.sql.SQLException: Parameter index out of range (7 > number of parameters, which is 6). • ClassNotFoundException. • public class ClassNotFoundExceptionExample { • private static final String CLASS_TO_LOAD = "main.java.Utils";
- 91. Cont… • public staticvoid main(String[] args) { • try { • Class loadedClass = Class.forName(CLASS_TO_LOAD); • System.out.println("Class " + loadedClass + " found successfully!");} • catch (ClassNotFoundException ex){ • System.err.println("A ClassNotFoundException was caught: " + ex.getMessage()); • ex.printStackTrace(); }}}
- 92. • Verify thatthe name of the class is correct and that the appropriate .jar file exists in your classpath. If not, you must explicitly add it to your application’s classpath.
- 93.