I am absolutely new to Java. I am creating a Servlet and getting the error interface is expected here.
I am using IntelliJ 14.
My Servlet code is as follows:-
package ERPdetector;
import javax.servlet.http.*;
import javax.servlet.*;
import java.io.*;
public class ErpServlet implements HttpServlet {
[Code] ....
import java.io.*;
class addition {
public static void main(String[] args) {
int num1,num2,sum;
try {
DataInputStream x=new DatainputStream(system.in);
[Code] ,,,,,
I am a beginner want to compile servlet with following path
javac -classpath Program FilesApache Software FoundationTomcat 5.5commonlibservlet-api.jar;classes:.-d classes srccomexamplewebBeerSelect.java
Problem arises as follows:
javac: invalid flag: FilesApache
Usage: javac <options> <source files>
use -help for a list of possible options
I am currently working on a Java project, below are my attempts at coding so far:
public class MyZoo
{
// zoo identifier
private String zooId;
// a number used in generating a unique identifier for the next animal to be added to the zoo
private int nextAnimalIdNumber;
// zstorage for the Animal objects
private TreeMap<String, Animal> animals;
[Code] ....
I currently cannot get the printAllAnimals() method to work as it should.
When executing the method printAllAnimals(), it does not do anything, when it is supposed to use the Collection object c, so that animals stored in the zoo can easily be checked.
I am having a hard time trying to understand interface concept.
-what is an interface?
-What the use of an interface?
-what does implement or to implement means?
-What does implementation means?
I have 2 files which are as follows:
ICharacterReader.java::
import java.io.EOFException;
public interface ICharacterReader {
char GetNextChar() throws EOFException;
void Dispose();
}
And another file:
SimpleCharacterReader.java::
import java.io.EOFException;
import java.util.Random;
public class SimpleCharacterReader implements ICharacterReader {
private int m_Pos = 0;
[Code] ....
My task is as follows:
1.) Write a class that takes an ICharacterReader interface as an argument and returns a list of word frequencies ordered by word count and then alphabetically.
And also write a main method of a console application that exercises this class using a SimpleCharacterReader, and prints the output to the console.
For example, if the stream returns "It was the best of times, it was the worst of times" then the output will be:
it - 2;
of - 2;
the - 2;
times -2;
was - 2;
best - 1;
worst - 1;
2.) Test the answers in part 1, by writing unit test cases.
How to pass interface as an argument and what is meant by "writing unit test case"?
why don't I define my methods in a class, rather than going a level up and declaring it first in an abstract class/interface? If the point is to have different implementations for different needs, then we have the option to override the methods.
View Replies View RelatedModify the program in Assign4 to synchronize access to the instance variable, balance. Save the program as SyncBank.java. Because balance is a double and not an object, it cannot be used as the monitor. Use synchronized methods or synchronized blocks of code as appropriate. Simultaneously test two threads as was done in Assign4. Because the threads can complete too quickly to determine if they are interfering with each other, delay the adding of a deposit by inserting the following code within the synchronized block or method:
try {
Thread.currentThread().sleep(10000); //sleep for milliseconds
}
catch(InterruptedException e) {
}
My code attempt so far:
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;
import java.net.*;
import java.text.DecimalFormat;
public class SyncBank extends HttpServlet //throws ServletException, IOException
[Code] .....
Using Eclipse I have imported a WAR with source. I have exported that project as a new war and it ran fine. I then added my own package and exported the war again. The jar file does not show up in /WEB-INF/lib folder. When I deploy the war on a tomcat server it barfs the following error:
Caused by: org.springframework.beans.factory.CannotLoadBeanClassException: Cannot find class [com.sharpline.fields.form.fields.TextAreaFormType] for bean with name 'com.sharpline.fields.form.fields.TextAreaFormType#53c37' defined in ServletContext resource [WEB-INF/activiti-standalone-context.xml]; nested exception is java.lang.ClassNotFoundException:
[Code] .....
It looks to me like my class (jar) is missing in the final war. How do I resolve this?
Actually I am working on java ee6 web application i tried to set value and max age for the cookie...but I was unable to set maxage what ever the max age value i give .it shows as -1.but my browser accepts and stores cookie.
<i>
"
Cookie sa=new Cookie("ssample", "welcome");
sa.setMaxAge(120);
response.addCookie(sa);
"</i>
using HttpServlet methods. What I want to do is to delay an HttpServletResponse. I set up some response.setHeader but then I want to wait a while after setting other values as the length of data to send and the content itself.
I tried to do that in 2 ways:
1. by using Thread.sleep() - in this case even with sleep of 100 ms the response seems to be lost.
2. by response.wait(TIME) - in this case it will never reach the block after wait, whatever TIME value I use.
Is it possible to compare 100 objects using comparator interface in java?
View Replies View RelatedSo I created an interface which has the method
int getCalls();
I am trying to implement this method in another class but I'm not sure how to do so. My attempt is:
public getCalls(){ return getCalls(); }
When I run the program it sends the following exception:
Exception in thread "main" java.lang.StackOverflowError
at FibonacciForget.getCalls(FibonacciForget.java:14)
and it highlights the [return getCalls();] part.
What is the correct way to implement the getCalls() method?
how to do multiple inheritance without sing interface in java?
View Replies View Relatedthe problem which im facing when executing jar file is it is not working same as when i run file using the IDE.When run jar file, it won't open the new frame even the user and pass combination correct.But when i'm compiling using the IDE, it works as charm. The main menu popped up after i logged in.I've tried Clean and Build and it's not working too.
View Replies View Relatedon my computer, i have configured the environment variables as
CATALINA_HOME : D:apache-tomcat-8.0.9-windows-x64apache-tomcat-8.0.9;
CLASSPATH : D:apache-tomcat-8.0.9-windows-x64apache-tomcat-8.0.9libservlet-api.jar;D:apache-tomcat-8.0.9-windows-x64apache-tomcat-8.0.9libjsp-api.jar;.;
JAVA_HOME : C:Program FilesJavajdk1.8.0_05
path : D:apache-tomcat-8.0.9-windows-x64apache-tomcat-8.0.9in
In reference to the book "Head First Servlets and JSP, 2nd edition", chapter-3(), page-81, the command to compile the servlet file to the desired location is
javac -classpath UsersertApplications2 omcatcommonlibservlet-api.jar:classes:. -d classes src/com/example/web/BeerSelect.java (from the Myprojects/beer-V1 directory)
Whereas I have written
javac -classpath D:apache-tomcat-8.0.9-windows-x64apache-tomcat-8.0.9libservlet-api.jar;classes;. -d classes src/com/example/web/BeerSelect.java
(from the same directory as can be confirmed from the attachment of screenshot of error). this code is in accordance to the location of the respective files in my system, in particular the servlet-api.jar file.
After doing this, my computer is showing the error : file not found.
How do I resolve this? Actually, I don't understand completely what this code is trying to accomplish.
I need to download large amount files, what should I care, Is the following code have problem on download large files
private static byte[] load(String filename) throws IOException {
FileInputStream fis = new FileInputStream(filename);
byte[] data = new byte[fis.available()];
fis.read(data);
fis.close();
return data;
}
I have been trying to find all day long a way to secure my .ear file from modifications made by third parties... My product is packaged as an .ear file which i send for deployment to other administrators. What i am looking for is a way to "sign" my version of .ear versus the deployed version of .ear to be sure that no modification has been made to my code...
View Replies View RelatedI am working on netbeans IDE , but I understand how the application know the parametres for the connections. I understand what is a Context , specifically i understand this code about the init method
Context initCtx = new InitialContext();
Context envCtx = (Context) initCtx.lookup("java:comp/env");
servicioConexiones = (DataSource) envCtx.lookup("jdbc/bd_tutorias");
I want to know how the application knows to use these connection parameters, on the Context.xml
<?xml version="1.0" encoding="UTF-8"?>
<Context antiJARLocking="true" path="/tutorias_pag480">
<Resource auth="Container" driverClassName="com.mysql.jdbc.Driver"
maxActive="8" maxIdle="4" name="jdbc/bd_tutorias" password="mysqladmin"
type="javax.sql.DataSource" removeAbandoned="true"
url="jdbc:mysql://localhost:3306/bd_tutorias" username="root"/>
</Context>
I'm trying to share an hashmap(or any other stuff to share data) between a java class and a servlet. The hashmap has to be filled into the servlet with some data and then I have to get those data from the java class.
What is the best approach? I cannot use a DTO because I have several concurrent requests to my servlet.
I have a servlet that is called from an web application and creates a Session. The sessionId of this session is passed to a swing application using the approach below:
Re: Trasnferring data from a JNLP call to swing dynamically
From my swing application I want to connect to the same servlet passing the sessionid. The purpose is to work with the same session created before.
It's not working. I'm calling the servlet from the swing application using [URL] ....
Is it possible ?
How to create a new object for each request in servlets? Where init() will be useful here?
View Replies View RelatedThe users of our a enterprise Java based web application must access a third web application through simple HTML links and then navigate in the target application. But for security reasons and constraints the direct exchange between the browers of users and server of the other web application is not allowed. Our web application must retrieve the web page from the other application and must return it to the users's browser. Is there a convenient way to implement this requirement in J2EE ? In this case our web application must play the role of a simple reverse proxy, must request a target JSP page from other application and process it to rewrite the URLs contained in the HTML page, then send the response to user's web browser.
View Replies View RelatedHow we can renew the session Id of the logged in user in order to prevent any session fixation problems. Is there any API in servlets to do it?
View Replies View RelatedDo not want to use loop and Character.isLetter to validation string , not sure at how to using regular expression?
If I want 8 characters string length, the first 3 is letter, the remind character is number ...
^[a-z0-9_-]{8}$
^[a-zA-Z]{3} + [/d]{5} $ ??
XML request message using HTTP POST is received by the Servlet interface. While we are reading and trying to parse the InputStreamObject, we are getting the following error message.
doPost java.io.CharConversionException: Characters larger than 4 bytes are not supported: byte 0x8e implies a length of more than 4 bytes
It looks like we are receiving some invalid Non-ASCII characters in the XML message.
The above error is thrown intermittently. Whenever we have this CharConversionException, the servlet gets corrupted and it impacts few good xml messages that follows after the error.
I need to know the following:
1. How to fix this exception and skip the bad message?
2. Is it possible to log the entire xml message in the catch block, whenever we have this exception?
NOTE: we tried different ways, not able to print the xml message, as the inputstream seems to be closed/null, when it reaches the catch block.
Tried the below code , but the servlet process/thread hungs and throws the below error:
Thread "WebContainer : 3" (00000028) has been active for 667781 milliseconds and may be hung. There is/are 1 thread(s) in total in the server that may be hung.
Below is the code snippet:
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/xml");
request.setCharacterEncoding("ISO-8859-1");
OutputStream out = response.getOutputStream();
InputStream inputStream=null;
[Code] ....
Issue of either fixing/overcoming the actual exception and printing out the entire xml message(bad one) in ours log during the catch block.