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Error Instantiating servlet class in tomcat log

Greenhorn

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posted 12 years ago

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hi everyone!

I am geting an error of instantiating servlet class in tomcat log.
I am using tomcat 6.0.24.
My servlet is on serial port communication.

I have added a comm.jar (for serial port communication) in "c:\pgm files\apache software foundation\tomcat 6.0\lib "

I had set my classpath to "c:\pgm files\apache software foundation\tomcat 6.0\lib\*.jar"

I added a lib folder in my WEB-INF/lib path and copied the comm.jar to there as well.... I even tried extracting files to my WEB-INF/classes ... but still i am getting the error

.

Someone please respond.... waiting for your reply. Thanku!

Bear Bibeault

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posted 12 years ago

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Please read: ItDoesntWorkIsUseless

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g venki

Greenhorn

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posted 12 years ago

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Hi. Thanks for your reply!
My error report in tomcat log is:

Exception:

javax.servlet.ServletException: Error instantiating servlet class SerialWrite

org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:852)
org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
java.lang.Thread.run(Unknown Source)

root cause:

java.lang.InstantiationException: SerialWrite
java.lang.Class.newInstance0(Unknown Source)
java.lang.Class.newInstance(Unknown Source)

org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:852)
org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
java.lang.Thread.run(Unknown Source)

S Shehab

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posted 12 years ago

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Hi are you doing any jobs in the init() of the servlet ?

Thanks,
Sherif

g venki

Greenhorn

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posted 12 years ago

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Sherif Shehab wrote:Hi are you doing any jobs in the init() of the servlet ?

Hi there.No i am not doing any thing in my init()

import java.io.*;
import java.net.*;
import javax.comm.*;
import java.util.*;

import javax.servlet.*;
import javax.servlet.http.*;

public class SerialWrite extends HttpServlet implements SerialPortEventListener{
   
    static String output="";
    static Enumeration portList;
static CommPortIdentifier portId;
static String dest = "+919491735737";
static String messageString = "Hello Testing11";
static InputStream inputStream;

static SerialPort serialPort;
static OutputStream outputStream;

protected void processRequest(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        response.setContentType("text/html;charset=UTF-8");
        PrintWriter out = response.getWriter();
         out.println("<html>");
         out.println("<h1>");
         out.println("hi");
         out.println("</h1>");
         out.println("</html>");
        
        //try {
         main(request,response);

}

public void serialEvent(SerialPortEvent event)
{
System.out.println(" Event type: "+event.getEventType());
switch (event.getEventType())
{
case SerialPortEvent.BI:
case SerialPortEvent.OE:
case SerialPortEvent.FE:
case SerialPortEvent.PE:
case SerialPortEvent.CD:
case SerialPortEvent.CTS:
case SerialPortEvent.DSR:
case SerialPortEvent.RI:
case SerialPortEvent.OUTPUT_BUFFER_EMPTY:
System.out.println("Error");
break;
case SerialPortEvent.DATA_AVAILABLE:
{

BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
String line = "";
try
{

while ( (line = reader.readLine()) != null)
{
System.out.println("::::"+line);
if(line.equalsIgnoreCase("OK") || (line.indexOf("+CMGS") != -1))
{

output=line;
//System.out.println("1"+line);

}
//System.out.println("output is:"+output);
Thread.sleep(10);

}
}
catch (Exception e)
{
System.out.println("Error while reading Port "+e);
}
break;

}
} //switch
}

public SerialWrite(SerialPort serial)
{

}

public void main(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException 
{
 response.setContentType("text/html;charset=UTF-8");
        PrintWriter out = response.getWriter();

try
{
int i=0;
String line0 = "AT\r\n";
String line1 = "AT+CMGF=1\r\n";
//String line3 = "AT+CMGS=""\"" dest "\"""\r\n";
//String line="AT+CMGS=
String line3 = "AT+CMGS=\"+919966601424\"\r\n";
//String line4 = messageString;
String line4 = "hi\r\n";
String line5 = "\032\r";
//System.out.println(" number: "+line3);
System.out.println("A for Apple");

portList = CommPortIdentifier.getPortIdentifiers();
while (portList.hasMoreElements())
{
portId = (CommPortIdentifier) portList.nextElement();
if (portId.getPortType() == CommPortIdentifier.PORT_SERIAL)
{
//System.out.println("PORT ID:"+portId.getName());
if ( portId.getName().equals("COM11"))
{
System.out.println("SMS Sending....Port Found");
try
{
serialPort = (SerialPort) portId.open("SerialTestApp", 2000);
//System.out.println(" Darling neku port ochindhi... pandaga chesko ");
try
{
inputStream = serialPort.getInputStream();
try
{
serialPort.addEventListener(this);
}
catch (TooManyListenersException e)
{
System.out.println("Exception in Adding Listener"+e);
}
serialPort.notifyOnDataAvailable(true);

}
catch (Exception ex)
{
System.out.println("Exception in getting InputStream"+ex);
}

}
catch (PortInUseException e)
{
out.println("Port In Use "+e);
}
try
{
outputStream = serialPort.getOutputStream();
}
catch (IOException e)
{
out.println("Error writing to output stream "+e);
}
try
{
//System.out.println(" Babu... Ikkad dhaka ochindha? ");
serialPort.setSerialPortParams(
460800,
SerialPort.DATABITS_8,
SerialPort.STOPBITS_1,
SerialPort.PARITY_NONE);
}
catch (UnsupportedCommOperationException e)
{
 out.println(" Darlng error amma " +e);
}
try {
	  //serialPort.setFlowControlMode(
	    //    SerialPort.FLOWCONTROL_Hardware);
	  
	   //If CTS/RTS is needed
	  serialPort.setFlowControlMode(
	        SerialPort.FLOWCONTROL_RTSCTS_IN |
	          SerialPort.FLOWCONTROL_RTSCTS_OUT);
	} 
catch (UnsupportedCommOperationException ex) {
  out.println(ex.getMessage());
}
try
{
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
//String line = "";
//DataInputStream is;
//PrintStream os;
//is= new DataInputStream(thePort.getInputStream());
//os= new PrinStream(thePort.getOutputStream(), true);
//os.print("AT");
//os.print("\r\n");
outputStream.write(line0.getBytes());
Thread.sleep(10);
out.println(" number: "+line0);
//String response = InputStream.readLine();
//System.out.println(" msg from HT "+response);
while(!output.equalsIgnoreCase("ok"))
{ 
//System.out.println("got itt?"+output);
Thread.sleep(10);
}
output="";

outputStream.write(line1.getBytes());
out.println(" number: "+line1.getBytes());
while(!output.equalsIgnoreCase("ok"))
{
//System.out.println("got iit?"+output);
Thread.sleep(10);
}
output="";
outputStream.write(line3.getBytes());
//System.out.println(" number: "+line3.getBytes());
Thread.sleep(10);
//System.out.println(" NO PROBS");
outputStream.write(line4.getBytes());
Thread.sleep(10);
//System.out.println(" PROBS ");
outputStream.write(line5.getBytes());
//System.out.println(" PROBBS ");
//outputStream.write("\r\n".getBytes());
outputStream.flush();
while(!output.equalsIgnoreCase("ok"))
//System.out.println("h:"
Thread.sleep(10);

output="";

out.println("Message Sent !!!");
}
catch (IOException e)
{
out.println("Error writing message " + e);
} 
catch(Exception e){}

}
}
}
}
catch(ArrayIndexOutOfBoundsException e)
{
 out.println("Error dude "+e);
}
}
          /* TODO output your page here
            out.println("<html>");
            out.println("<head>");
            out.println("<title>Servlet SerialWrite</title>");  
            out.println("</head>");
            out.println("<body>");
            out.println("<h1>Servlet SerialWrite at " + request.getContextPath () + "</h1>");
            out.println("</body>");
            out.println("</html>");
     
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        processRequest(request, response);
    }

protected void doPost(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        processRequest(request, response);
    }

public String getServletInfo() {
        return "Short description";
    }
    // </editor-fold>

}

It has no compile errors... I have even executed the code sucessfully in JAVA and i am successful in sending an sms to a number...

But i want to do redirection from my JSP to the Java Pgm. So i have created the above servlet and the error above is displayed. Somebody please help me in resolving it.

Thank U.

Ulf Dittmer

Rancher

Posts: 43028

posted 12 years ago

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That class has a constructor - servlets should never have a constructor, and absolutely, positively not one that takes parameters.

g venki

Greenhorn

Posts: 8

posted 12 years ago

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Ulf Dittmer wrote:That class has a constructor - servlets should never have a constructor, and absolutely, positively not one that takes parameters.

Hi.

But i am not creating any object for the class, hence the constructor will not be invoked. Anyways i will try once again by deleting it. Thanks for your valuabl reply.

Ulf Dittmer

Rancher

Posts: 43028

posted 12 years ago

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But i am not creating any object for the class, hence the constructor will not be invoked.

YOUR code does not call any constructors (which is as it should be), but the servlet container sure does. How could the servlet container invoke non-static methods if it didn't construct an object first? But what the servlet container expects is no-argument constructor; not anything with parameters.

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