Write Interface Directory To Manipulate Entries In Telephone Directory
Mar 12, 2014
this is the following task i am trying to do. Write an interface Directory to manipulate entries in a telephone directory for the University. The interface must support the following operations:
1) The ability to insert new entries into the directory. Entries should be stored in alphabetical order of surname.
2) Delete entries from the directory either by name or number
3) Provide a lookup method that will find the extension no of a member of staff given
his/her name. You should try to make this method run as efficiently as possible.
4) Change a person's telephone number
5) Print the telephone directory in a neatly tabulated fashion.
Write a class ArrayDirectory that implements this interface using an array to store the telephone directory information. The class must store the surname and initial for each member of staff and their telephone extension (a four digit number which may start with a zero). You may find it useful to define a class Entry to store information about individual entries. The entries should be read into the array from a text file consisting of multiple lines in the following format:
Surname<tab>Initials<tab>Telephone extension
The part that i am stuck on is trying to do the entry method, delete entries method, loop up method, change persons telephone number and be able to print it.
Write an interface Directory to manipulate entries in a telephone directory for the University. The interface must support the following operations:
1) The ability to insert new entries into the directory. Entries should be stored in alphabetical order of surname. 2) Delete entries from the directory either by name or number 3) Provide a lookup method that will find the extension no of a member of staff given his/her name. You should try to make this method run as efficiently as possible. 4) Change a person's telephone number 5) Print the telephone directory in a neatly tabulated fashion.
Write a class ArrayDirectory that implements this interface using an array to store the telephone directory information. The class must store the surname and initial for each member of staff and their telephone extension (a four digit number which may start with a zero). You may find it useful to define a class Entry to store information about individual entries. The entries should be read into the array from a text file consisting of multiple lines in the following format:
Surname<tab>Initials<tab>Telephone extension
Write a main program that reads in data from a file and then tests all the methods of your class interface. Note it is not necessary to write data back to disk (even if it has changed) in this project.
For data insertion and lookup, you should measure the performance for the average case (e.g. looking up a record in the middle of the data). To do this you can use the static method System.currentTimeMillis() which returns the time in milliseconds. To get an accurate measure of the time to perform an operation it is a good idea to perform each operation 1000 (or even 10000) times and measure the time taken. This will remove any problems due to the system clock having a coarse granularity (not ticking very often). Make sure you only time the method and not any input/output associated with it. Your documentation should include a discussion of these results.
Part 2
You decide that your solution to part 1 may be too slow to be useful when used with a real large telephone directory and make the following changes to attempt to improve the performance of your program:
1). Provide a second implementation (ListDirectory) of the Directory interface using the Java Collections List interface and LinkedList classes. 2). The changes in 1) should make adding, deleting and modifying records more efficientbut will probably reduce the time to lookup numbers. To overcome this you use a technique called hashing. Instead of storing all the records on one list you use a series of lists. The data for all people whose surname begins with "A" is stored on the first list, records for all people whose surname begins with "B" on a second list and so on. Write a third implementation (HashDirectory) of the Directory interface using this technique.
Again, you should measure the performance for the best, worst and average cases of implementations 1) and 2) above. Compare the efficiency of each of the 3 implementations in your documentation.
Part 3
Choose one of your 3 implementations from Parts 1 and 2 and embed it in a graphical user interface that allows users to perform all the methods in the Directory interface using a mouse and keyboard appropriately.
Consider the url-pattern: <url-pattern> /Beer/* </url-pattern>
The web app structure is: -
webapps | -->AdviceApp | -->WEB-INF --> {{Beer}} This can be real or virtual.
My book says that /Beer/* can be a real or a virtual directory. What is the difference between the two and how do I create a virtual directory in tomcat ?
I need to write the exact directory path like C:LisaestUpdate to a properties file.
I am trying it by
FileInputStream in = new FileInputStream(test.properties); Properties props = new Properties(); props.load(in); in.close(); FileOutputStream out = new FileOutputStream(newprop.properties); props.setProperty("myDirectory","C:Lisa estUpdate" ); props.store(out, null); out.close();
but the properties file is updated as C:Lisa estUpdate
Extra comes before :.
How can I remove that.
Even I tried it with an command but got same output.
So i have this program that is supposed to execute a command when a button is clicked. I get an error: java.io.IOException: Cannot run program "/Users /brianallison/Documents/Java/RELAP5": error=2, No such file or directory
The actual PATH should be /Users/brianallison/Documents/Java/RELAP5 GUI/issrs/Dist.At least that is where the Java app is and the executable that I am trying to execute when the butotn is clicked. Executable name is relap5.x or relap5.exe depending on the OS.
/home/t_bmf/Java/HelloWorld/src/helloworld :will contain a .java file /home/t_bmf/Java/HelloWorld/bin :will contain all .class file
Let say a have a code:
package helloworld; public class HelloWorld { public static void main(String[] arg) { System.out.println("Hello World"); } }
a command to compile this even outside the directory /home/t_bmf/Java/HelloWorld/src/helloworld javac -d /home/t_bmf/Java/HelloWorld/bin /home/t_bmf/Java/HelloWorld/src/helloworld/HelloWorld.java
This will generate a directory /home/t_bmf/Java/HelloWorld/bin/helloworld and file inside this is HelloWorld.class
To run this program I must be in directory /home/t_bmf/Java/HelloWorld/bin and using this command:
java helloworld.HelloWorld
Question:
I already how to run the HelloWorld.class, but I must be in helloworld /home/t_bmf/Java/HelloWorld/bin to run it. Is there's a way to run the class even when I am not in directory /home/t_bmf/Java/HelloWorld/bin? Let's say I'm in /home/t_bmf, can I still run the HelloWorld.class?
I am trying to unzip a zip file to a directory but I've tried several different codes and none of them work.The zip structure is like this:
test.zip New Text Doc.txtNew Folder New Text Doc.txt
and this is the code I am using
try { // Open the zip file ZipFile zipFile = new ZipFile(outputFileName); Enumeration<?> enu = zipFile.entries(); while (enu.hasMoreElements()) { ZipEntry zipEntry = (ZipEntry) enu.nextElement();
In my program I have to get directory name&address, in this directory is none, one, or more *.txt(maybe not *.txt files) and I have to read info from all of them.
On C++ is very easy to do that with "findnext, find last, findfirst", so how can I do this in Java?
I am working on a java logic game and I want it to be able to work on other people's Mac's, so I tried to figure out how to make it create a folder in which it can create files. The file creating is going fine however the folder never seems to create.Here is the code I attempted to use:
Here my code . Iam trying to open text file in window_pane it will open when i click on save it will ask destination to save file if i save example like Read.txt it will save...when i go and check in that folder Read.txt file won't found...what is the error ....
Java Code:
import javax.swing.*; import javax.swing.filechooser.FileFilter; import javax.swing.filechooser.FileNameExtensionFilter; import java.io.*; import java.net.MalformedURLException; import java.awt.*; import java.awt.event.*; public class Read extends JFrame
Here my code am trying to open text file in window_pane it will open when i click on save it will ask destination to save file if i save example like Read.txt it will save...when i go and check in that folder Read.txt file won't found..
Requirements - Use only standard Java API and no apache file utils for this.
Most of the answers I found on the internet either dont meet this requirement or load all file names into an array which can consume too much memory when no. of files = 20,000+. how I can do this. Is there also a way to keep track of new files that were added during the execution of the loop in this code ?
Im trying to create a linked stack that will hold the starting directory to the current directory, so that when i finish a directory it would go back to the parent. as i go through the files in a directory and find a child directory, i have to stack current directory and process the child directory, when thats done, pop the parent from the stack and continue processing it. Here is my code:
//import io File and ioexception import java.io.File; import java.io.IOException;
/*create class that will take a path to a directory, print the name of the argument directory, print the name of each file and directory in argument directory. Prints the directory name and each file and directory inside*/
public class dirStackPrint
[Code] .....
when I run the program, nothing prints, why is that? I'm having trouble understanding the processing of the top, push and pop functions, i have them in my code but they don't seem to be working as they should?
JFileChooser fileChooser = new JFileChooser(); fileChooser.setCurrentDirectory(new File(currentDirectory));
File f = new File(currentDirectory); ArrayList<String> names = new ArrayList<>(Arrays.asList(f.list())); for (String s : names) if (s.startsWith(yearofIssueTXT.getText())) { fileChooser.setSelectedFile(new File(s));
int result = fileChooser.showOpenDialog(addNewCoinBody);
The file is not visible because it is at almost the end of the files in the directory. I want the filechooser to automatically scroll so that the file is seen in the list.
I've written a program to read files in a directory but I'd like for it to only read the text files of that directory.
import java.io.*; public class Data { public static void main(String[] args) throws IOException { String target_dir = "C:files"; File dir = new File(target_dir); File[] files = dir.listFiles();
I am trying to crate an interface for the following file (code). The interface that I am trying to create will display a open dialog box where the user chooses which image (.dcm) it would like to open and then it should open it in a frame. The code below shows opening the image. The image opens when the image is in the same folder as the source code but I need it to open from a given path and I am really confused on how to do that. I have tried a lot of methods but still doesn't seem work. How to make it work.
This is the code (assuming the parameter that you are passing in image.dcm, I have tried a full path name on mac computer which is like /Users/Documents/image.dcm, where this path name never works):
/** * This class displays the first frame of a file from any format * supported by ImageIO. * In the case of DICOM files, stored values are displayed as * is, without using Value of Interest or Presentation LUTs. */ class Read1 { public static void main(String[] s) {
Can we set the class path for one level down the current directory? My structure is like
binlibresourceshexicon.cmdinside the folder dist.
In this case I could run the .cmd file which has java -cp .;lib;resources client.Test .
c: rycpdist>java hexicon.cmdBut if i put the .cmd file inside bin as like this and run as c: rycpdistin>java hexicon.cmdI am getting this error Error: Could not find or load main class
Is there any possibility to set the class path in this case
I need to design a gui that will find out all the dead symbolic link from the directories. And I used the logic and syntax I find out in java orcle docs. And If I will give the direct path name of the symbolic file then it is running fine with the output and enable to find the smbolic link is active or not. Now the real problem is that , I want that logic of detection should run out through the complete files and subdirectories of the directory. So Then I used the tree walk concept to transver through the complete file system of the directory and embed the logic of the detection inside it for detection of the dead symbolic link. But now it showing erroe which is not approacable for me.
import java.io.File; import java.io.IOException; import java.io.PrintStream; import java.nio.file.Files; import java.nio.file.Path; import java.nio.file.Paths; public class To_Transver {
I'm using Ubuntu. After unpacking the tar file for JSE 1.7 version 45, in the the bin directory for adding an entry to PATH variable, I typed
javac
and I get the message
The program 'javac' can be found in the following packages: * default-jdk * ecj * gcj-4.6-jdk * gcj-4.7-jdk * openjdk-7-jdk * openjdk-6-jdk Try: sudo apt-get install <selected package>
I don't really understand the question is the thing. Its about calling a file in the java program. I read the book and i can see how to call a file from a directory and how to save it and edit it but I don't understand what the instructor is asking for. Mostly what files need called and println.
Assuming the object that manages output will be called writer, write a statement that opens a text file called home.html for output by println statements.
To be file-writable and file-readable, an object must be an instance of a class that implements___________.
Write a statemnt that opens a file for input of objects and assigns a reference to the connection to ObjectIn. Assume the file is in the current directory, with the name automobiles. data.
Write a program to calculate the telephone charges for four customers. The data for each customer consists of NAME, PREVIOUS METER READING, PRESENT METER READING. The difference between the two readings gives the number of units used by the customer for the period under consideration.
The amount due for each customer is calculated by: UNITS USED * RATE PER UNIT + RENTAL CHARGE The rate per unit and rental charge is assumed to be the same for all customers and must be input once only.
Your program must:
a. Input the rate and rental charge b. Read the data for each customer and calculate the amount due c. Print the information under suitable headings d. Calculate and print the total amount due to the telephone company
I am trying to understand how package(directory structure) and JAR files work interchangeably. From my understanding JAR is a package file format typically used to aggregate many Java classes. Since many classes are usually contained inside a package, I should be able to create a JAR file from a package, and use them interchangeably. A single JAR file is easier to handle then multiple classes and folders.
To test my understanding of the concept, I am working with the following project structure,
package BookPackage; public class Book{ private String bookname; public Book(String str){ bookname = str; } public String getBookName(){ return bookname; } }
and BookDemo.java contains the following code,
import BookPackage.Book; class BookDemo{ public static void main(String ... args){ Book b = new Book("Lord of the Rings"); System.out.println(b.getBookName()); } }
From the development_directory, I used the following commands to compile and run the project,
...and it compiles and works as expected.Now, I will try to convert the BookPackage folder(package) into single jar file for portability, and I am using the following command to do that,development_directory/ jar -cf bookpkg.jar BookPackage ...this command generates the bookpkg.jar file.
I am going to remove the BookPackage folder to see if bookpkg.jar file really works as a replacement for the BookPackage directory structure.
After removal of BookPackage folder, the development_directory structure looks like this,
If I try CLASSPATH: C:Program FilesMicrosoft JDBC Driver 4.0 for SQL Serversqljdbc_4.0enusqljdbc4.jar I receive a "Could not find or load main class" error.
i have a folder which contains two types of files (for eg: .csv and .tiff) with same names like, abc.csv and abc.tiff.How to compare the list of files with same names while ignoring their extensions.And my second task is to copy the content from csv file and i have to use that name as file name of .tiff file(Ex: if i have a1 as content in csv file, i have to change .tiff file name from abc.tiff to a1.tiff)
