I/O / Streams :: How To Iterate Over Files In A Directory One By One
Oct 5, 2014
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 ?
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?
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();
Within tomcat "webapps" directory, have lots of scanned PDF files (size in KB and MB).Using Java and JSP, I want to search for any user entered text in these scanned PDF files.The result must display the name of those PDF files which has that entered text.
If I specify the directory in file type or path string type how can I get a list of files that are file type .yml in that folder, so I can loop through and do something with each single file.yml in that specified directory.
How can I Cache the data I'm reading from a collection of text files in a directory using a TreeMap? Currently my program reads the data from several text files in a directory and the saves that information in a text file called output.txt. I would like to cache this data in order to use it later. How can I do this using the TreeMap Class? These are the keys,values: TreeMap The data I'd like to Cache is (date from the file, time of the file, current time).
import java.io.*; public class CacheData { public static void main(String[] args) throws IOException { String target_dir = "C:Files"; String output = "C:Filesoutput.txt"; File dir = new File(target_dir); File[] files = dir.listFiles();
I have to be able to read files that have been serialized in VB. 2 things, 1 they are serialized in Binary, and I tried to look up on how to serialize/deserialize in Binary, but didn't have much support...
Also in the VB code they talk about "TYPES" which seems to be to just be a class full of stuff...
I need to read the contents of file A, and B and store it in file C by joining the contents of A and B and also counting the number of letters/characters present in it.
I've come up with this so far.
import java.io.FileInputstream; import java.io.FileNotFoundException; import java.io.IOException; public class JavaApplication43{ public static putwrite(string fname) throws FileNotFoundException, IOException
My requirement is - I need to browse the folder and select multiples and upload all the selected files at once. note that here i need to use single browse button ONLY.
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.
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 would like to know how I can iterate through objects . I have a manually created linked list (without using the built-in method one). So in the memory my object looks like this(attachment).I would like to do a for loop or while loop to get each element under the test3.head.
I have used unmarshalling concept to retrieve the data elements... I have to check whether the elements satisfy few regulations when compared with data in Database. So, i thought of grouping the employees depending on EType. I have created a Map with linkedlist of employees. Say Map<String, LinkedList<Employe>>EmpMap=new Map<String, LinkedList<Employe>>();
I have already created a class named Employee which has all the setter and getter methods for employee.
Here am going to take Etype(Employee type) as key and linkedlist(list of employees of certain type) as value. How to iterate these linked lists and place them in my Map.
I facing issue with nested <c:forEach in my jsp page.I am using jstl.jar..Here is my code
in JAVA I have --> List<ProductDefViewBean> productList = new ArrayList<ProductDefViewBean>(); productList.add(objProductDefViewBean); request.setAttribute("ProductList", productList); <%@ taglib uri="http://java.sun.com/jstl/core" prefix="c" %>
[code]...
javax.servlet.jsp.JspTagException: Don't know how to iterate over supplied "items" in <forEach>
I have done this before in C++ but now I want to do it in Java. I am not sure how to iterate through a ArrayList, I have look several places because lets be honest the first stop is normally google. I tried the examples but with no luck.
package org.search.BFS; import java.util.Queue; public class BFS extends Graph { private Queue<Integer> q; BFS(int s) { //mark all the vertices as not visited.
Also the below is giving me a Type safety: The expression of type ArrayList[] needs unchecked conversation to conform to ArrayList<Integer>[]
I have a JSP code which will open the contents of a excel file.
Now i need this contents of the excel file to be added dynamically to a table in the sameJSP. How to proceed.At the maximum 10 rows can be added dynamically.
Assuming i have a table in JSP which has heading first name,last name,DOB and Gender. After opening the excel through JSP the contents needs to be iterated and added to the columns mentioned.
Is there anyway to iterate an enum type without an instance. As some context, consider the following code:
Java Code: public interface GenericChecker { public bool isValid(String str); } mh_sh_highlight_all('java'); Java Code: public class EnumChecker<T extends Enum<T> > extends GenericChecker { private Class<T> enumType; //No instance
[code]....
toString method of the enum types has been overridden so that it returns the name assigned to the enum rather than the enum name itself. For example an enum might be SOME_ENUM("Assigned name"), therefore toString returns "Assigned name" rather than "SOME_ENUM". The idea is that a field from a table can be handed to the isValid(String) function on the GenericChecker base, and the derived class will then check to see if the field matches valid data as far as it is concerned.Thus, I can create a whole bunch of checkers easliy:
I have an 46x9 array. I only have 108 values in the array for which I need to perform preliminary computations. How do I get the read to only read the 108 values whose values are greater than 0 and skip the other 495 whose values are 0?
I am learning iterating through lists. What I have so far is two Hash Sets and two Tree sets. Hash Set 1 and Tree set 1 include the words from Roughing it by Mark Twain. Hash set 2 and tree set 2 include the words from Adventures of Huckleberry Finn by Mark Twain. (Everything is read from a file I made).
I am stuck trying to find out how to "Iterate through the words in HashSet1 and search for these words in both TreeSet2 and in HashSet2".Here is my code:
public class UsingSets { public static void main(String[] args) throws FileNotFoundException { String riHashIterator = null; HashSet<String> riHash = new HashSet<>(); Scanner input = new Scanner(new File("roughingit.txt")); while(input.hasNext()){ String riHashWords = input.next(); riHashWords = riHashWords.toLowerCase(); riHash.add(riHashWords);
my getDisplayValue() method. I am trying to iterate though an Array to display a value in a calculator, but I doesn't work. I keep on getting these weird magical numbers at the end of the iteration. Note that this is done in BlueJ.
Calculator -> UserInterface -> CalcEngine and Calculator -> CalcEngine. public class CalcEngine { //Instance variables used. //These are all the instance variables I used to implement //a complete calculator solution.