Develop Reference

How to get file name having particular content in it using java?

Here I am trying to read a folder containing .sql files and I am getting those files in an array, now my requirement is to read every file and find particular word like as join if join is present in the file return filename or else discard , someone can pls help me with this ..
import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.List;
import java.util.Optional;
import java.util.stream.Stream;
public class Filter {
public static List<String> textFiles(String directory) {
List<String> textFiles = new ArrayList<String>();
File dir = new File(directory);
for (File file : dir.listFiles()) {
if (file.getName().endsWith((".sql"))) {
textFiles.add(file.getName());
}
}
return textFiles;
}
public static void getfilename(String directory) throws IOException {
List<String> textFiles = textFiles(directory);
for (String string : textFiles) {
Path path = Paths.get(string);
try (Stream<String> streamOfLines = Files.lines(path)) {
Optional<String> line = streamOfLines.filter(l -> l.contains("join")).findFirst();
if (line.isPresent()) {
System.out.println(path.getFileName());
} else
System.out.println("Not found");
} catch (Exception e) {
}
}
}
public static void main(String[] args) throws IOException {
getfilename("/home/niteshb/wave1-master/wave1/sql/scripts");
}
}

You can search word in file as belwo, pass the path of file
try(Stream <String> streamOfLines = Files.lines(path)) {
Optional <String> line = streamOfLines.filter(l ->
l.contains(searchTerm))
.findFirst();
if(line.isPresent()){
System.out.println(line.get()); // you can add return true or false
}else
System.out.println("Not found");
}catch(Exception e) {}
}

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.List;
import java.util.Optional;
import java.util.stream.Stream;
public class Filter {
public static List<String> textFiles(String directory) {
List<String> textFiles = new ArrayList<String>();
File dir = new File(directory);
for (File file : dir.listFiles()) {
if (file.getName().endsWith((".sql"))) {
textFiles.add(file.getAbsolutePath());
}
}
System.out.println(textFiles.size());
return textFiles;
}
public static String getfilename(String directory) throws IOException {
List<String> textFiles = textFiles(directory);
for (String string : textFiles) {
Path path = Paths.get(string);
try (Stream<String> streamOfLines = Files.lines(path)) {
Optional<String> line = streamOfLines.filter(l -> l.contains("join")).findFirst();
if (line.isPresent()) {
System.out.println(path.getFileName());
} else
System.out.println("");
} catch (Exception e) {
}
}
return directory;
}
public static void main(String[] args) throws IOException {
getfilename("/home/wave1-master/wave1/sql/");
}
}

Pagination in Getting the File

I have a location where 3000 files is stored. But i want to get the list of 1000 files at a time and in next call another 1000 files and so on.
Please find my below code :
import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Comparator;
import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.Stream;
public class FileSystem {
public static void main(String args[]) throws Exception {
FileSystem.createListFile();
FileSystem.getFileInBatch();
}
private static void getFileInBatch() {
int MAX_INDEX= 1000;
try (Stream<Path> walk = Files.walk(Paths.get("C://FileTest"))) {
List<String> result = walk.filter(p -> Files.isRegularFile(p) && p.getFileName().toString().endsWith(".txt"))
.sorted(Comparator.comparingInt(FileSystem::pathToInt))
.map(x -> x.toString()).limit(MAX_INDEX).collect(Collectors.toList());
result.forEach(System.out::println);
System.out.println(result.size());
} catch (IOException e) {
e.printStackTrace();
}
}
private static int pathToInt(final Path path) {
return Integer.parseInt(path.getFileName()
.toString()
.replaceAll("Aamir(\\d+).txt", "$1")
);
}
private static void createListFile() throws IOException {
for (int i = 0; i < 3000; i++) {
File file = new File("C://FileTest/Aamir" + i + ".txt");
if (file.createNewFile()) {
System.out.println(file.getName() + " is created!");
}
}
}
}
I am able to get the first 1000 (Aamir0.txt to Aamir999.txt) files using the limit in streams.
Now how can i get the next 1000 files ( Aamir1000.txt to Aamir1999.txt)

You can use skip in your Stream. For example:
int toSkip = 1000; // define as method param/etc.
List<String> result = walk.filter(p -> Files.isRegularFile(p) && p.getFileName().toString().endsWith(".txt"))
.sorted(Comparator.comparingInt(FileSystem::pathToInt))
.map(x -> x.toString()).skip(toSkip).limit(MAX_INDEX).collect(Collectors.toList());

I'm trying to read a text file and store it in an arraylist of objects

I'm trying to read a text file and store it in an arraylist of objects, but I keep getting an error saying I cannot convert a String to an Item, which is type of arraylist I am using. I have tried various solutions, but am not quite sure how its is suppossed to be done. I am new to coding and have this assignment due soon. Anything helps!
private void loadFile(String FileName)
{
Scanner in;
Item line;
try
{
in = new Scanner(new File(FileName));
while (in.hasNext())
{
line = in.nextLine();
MyStore.add(line);
}
in.close();
}
catch (IOException e)
{
System.out.println("FILE NOT FOUND.");
}
}
my apologies for not adding the Item class
public class Item
{
private int myId;
private int myInv;
//default constructor
public Item()
{
myId = 0;
myInv = 0;
}
//"normal" constructor
public Item(int id, int inv)
{
myId = id;
myInv = inv;
}
//copy constructor
public Item(Item OtherItem)
{
myId = OtherItem.getId();
myInv = OtherItem.getInv();
}
public int getId()
{
return myId;
}
public int getInv()
{
return myInv;
}
public int compareTo(Item Other)
{
int compare = 0;
if (myId > Other.getId())
{
compare = 1;
}
else if (myId < Other.getId())
{
compare = -1;
}
return compare;
}
public boolean equals(Item Other)
{
boolean equal = false;
if (myId == Other.getId())
{
equal = true;;
}
return equal;
}
public String toString()
{
String Result;
Result = String.format("%8d%8d", myId, myInv);
return Result;
}
}
This is the creation of my arraylist.
private ArrayList MyStore = new ArrayList ();
Here is a sample of my text file.
3679 87
196 60
12490 12
18618 14
2370 65

/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package com.mycompany.rosmery;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
/**
*
* #author Sem-6-INGENIERIAINDU
*/
public class aaa {
public static void main(String arg[]) throws FileNotFoundException, IOException{
BufferedReader files=new BufferedReader(new FileReader(new File("")));
List<String> dto=new ArrayList<>();
String line;
while((line= files.readLine())!= null){
line= files.readLine();
dto.add(line);
//Hacer la logica para esos datos
}
}
}

in.nextLine() returns a String.
So, you cannot assign in.nextLine() to an instance of Item.
Your code may need to correct it as:
List<String> myStore = new ArrayList<String>();
private void loadFile(String FileName)
{
Scanner in;
try
{
in = new Scanner(new File(FileName));
while (in.hasNext())
{
myStore.add(in.nextLine());
}
in.close();
}
catch (IOException e)
{
System.out.println("FILE NOT FOUND.");
}
}
If you want to have a list of Item after reading a file, then you need provide the logic that convert given line of information into an instance of Item.
let's say your file content is in the following format.
id1,inv1
id2,inv2
.
.
Then, you can use the type Item as the following.
List<Item> myStore = new ArrayList<Item>();
private void loadFile(String FileName)
{
Scanner in;
String[] line;
try
{
in = new Scanner(new File(FileName));
while (in.hasNext())
{
line = in.nextLine().split(",");
myStore.add(new Item(line[0], line[1]));
}
in.close();
}
catch (IOException e)
{
System.out.println("FILE NOT FOUND.");
}
}

One of the possible solutions (assuming that the data in file lines is separated by a comma), with using streams:
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.Stream;
public class Main {
public static void main(String[] args) throws IOException {
List<Item> items = loadFile("myfile.txt");
System.out.println(items);
}
private static List<Item> loadFile(String fileName) throws IOException {
try (Stream<String> stream = Files.lines(Paths.get(fileName))) {
return stream
.map(s -> Stream.of(s.split(",")).mapToInt(Integer::parseInt).toArray())
.map(i -> new Item(i[0], i[1]))
.collect(Collectors.toList());
}
}
}
or with foreach:
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.Stream;
public class Main {
public static void main(String[] args) throws IOException {
List<Item> items = new ArrayList<>();
for (String line : loadFile("myfile.txt")) {
String[] data = line.split(",");
int id = Integer.parseInt(data[0]);
int inv = Integer.parseInt(data[1]);
items.add(new Item(id, inv));
}
System.out.println(items);
}
private static List<String> loadFile(String fileName) throws IOException {
try (Stream<String> stream = Files.lines(Paths.get(fileName))) {
return stream.collect(Collectors.toList());
}
}
}

Filtering only .txt files [duplicate]

Is there a built in Java code that will parse a given folder and search it for .txt files?

You can use the listFiles() method provided by the java.io.File class.
import java.io.File;
import java.io.FilenameFilter;
public class Filter {
public File[] finder( String dirName){
File dir = new File(dirName);
return dir.listFiles(new FilenameFilter() {
public boolean accept(File dir, String filename)
{ return filename.endsWith(".txt"); }
} );
}
}

Try:
List<String> textFiles(String directory) {
List<String> textFiles = new ArrayList<String>();
File dir = new File(directory);
for (File file : dir.listFiles()) {
if (file.getName().endsWith((".txt"))) {
textFiles.add(file.getName());
}
}
return textFiles;
}
You want to do a case insensitive search in which case:
if (file.getName().toLowerCase().endsWith((".txt"))) {
If you want to recursively search for through a directory tree for text files, you should be able to adapt the above as either a recursive function or an iterative function using a stack.

import org.apache.commons.io.filefilter.WildcardFileFilter;
.........
.........
File dir = new File(fileDir);
FileFilter fileFilter = new WildcardFileFilter("*.txt");
File[] files = dir.listFiles(fileFilter);
The code above works great for me

It's really useful, I used it with a slight change:
filename=directory.list(new FilenameFilter() {
public boolean accept(File dir, String filename) {
return filename.startsWith(ipro);
}
});

I made my solution based on the posts I found here with Google. And I thought there is no harm to post mine as well even if it is an old thread.
The only plus this code gives is that it can iterate through sub-directories as well.
import java.io.File;
import java.io.FileFilter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import org.apache.commons.io.filefilter.DirectoryFileFilter;
import org.apache.commons.io.filefilter.WildcardFileFilter;
Method is as follows:
List <File> exploreThis(String dirPath){
File topDir = new File(dirPath);
List<File> directories = new ArrayList<>();
directories.add(topDir);
List<File> textFiles = new ArrayList<>();
List<String> filterWildcards = new ArrayList<>();
filterWildcards.add("*.txt");
filterWildcards.add("*.doc");
FileFilter typeFilter = new WildcardFileFilter(filterWildcards);
while (directories.isEmpty() == false)
{
List<File> subDirectories = new ArrayList();
for(File f : directories)
{
subDirectories.addAll(Arrays.asList(f.listFiles((FileFilter)DirectoryFileFilter.INSTANCE)));
textFiles.addAll(Arrays.asList(f.listFiles(typeFilter)));
}
directories.clear();
directories.addAll(subDirectories);
}
return textFiles;
}

import java.io.IOException;
import java.nio.file.FileSystems;
import java.nio.file.FileVisitResult;
import java.nio.file.Path;
import java.nio.file.PathMatcher;
import java.nio.file.SimpleFileVisitor;
import java.nio.file.attribute.BasicFileAttributes;
import java.util.ArrayList;
public class FileFinder extends SimpleFileVisitor<Path> {
private PathMatcher matcher;
public ArrayList<Path> foundPaths = new ArrayList<>();
public FileFinder(String pattern) {
matcher = FileSystems.getDefault().getPathMatcher("glob:" + pattern);
}
#Override
public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
Path name = file.getFileName();
if (matcher.matches(name)) {
foundPaths.add(file);
}
return FileVisitResult.CONTINUE;
}
}
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.LinkOption;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.ArrayList;
public class Main {
public static void main(String[] args) throws IOException {
Path fileDir = Paths.get("files");
FileFinder finder = new FileFinder("*.txt");
Files.walkFileTree(fileDir, finder);
ArrayList<Path> foundFiles = finder.foundPaths;
if (foundFiles.size() > 0) {
for (Path path : foundFiles) {
System.out.println(path.toRealPath(LinkOption.NOFOLLOW_LINKS));
}
} else {
System.out.println("No files were founds!");
}
}
}

import org.apache.commons.io.FileUtils;
List<File> htmFileList = new ArrayList<File>();
for (File file : (List<File>) FileUtils.listFiles(new File(srcDir), new String[]{"txt", "TXT"}, true)) {
htmFileList.add(file);
}
This is my latest code to add all text files from a directory

Here is my platform specific code(unix)
public static List<File> findFiles(String dir, String... names)
{
LinkedList<String> command = new LinkedList<String>();
command.add("/usr/bin/find");
command.add(dir);
List<File> result = new LinkedList<File>();
if (names.length > 1)
{
List<String> newNames = new LinkedList<String>(Arrays.asList(names));
String first = newNames.remove(0);
command.add("-name");
command.add(first);
for (String newName : newNames)
{
command.add("-or");
command.add("-name");
command.add(newName);
}
}
else if (names.length > 0)
{
command.add("-name");
command.add(names[0]);
}
try
{
ProcessBuilder pb = new ProcessBuilder(command);
Process p = pb.start();
p.waitFor();
InputStream is = p.getInputStream();
InputStreamReader isr = new InputStreamReader(is);
BufferedReader br = new BufferedReader(isr);
String line;
while ((line = br.readLine()) != null)
{
// System.err.println(line);
result.add(new File(line));
}
p.destroy();
}
catch (Exception e)
{
e.printStackTrace();
}
return result;
}

Extended Html Unit Driver with screenshot capabilities

I am working on code (java) that will open up a selenium headless browser with HTML Unit webdriver and then take a screenshot. Unfortunately, HTML Unit does not support screenshots on its own, so I had to download an extended version:
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.net.URL;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;
import org.apache.commons.io.FilenameUtils;
import org.apache.commons.io.IOUtils;
import org.openqa.selenium.Capabilities;
import org.openqa.selenium.OutputType;
import org.openqa.selenium.TakesScreenshot;
import org.openqa.selenium.WebDriverException;
import org.openqa.selenium.htmlunit.HtmlUnitDriver;
import org.openqa.selenium.internal.Base64Encoder;
import org.openqa.selenium.remote.CapabilityType;
import org.openqa.selenium.remote.DesiredCapabilities;
import com.gargoylesoftware.htmlunit.BrowserVersion;
import com.gargoylesoftware.htmlunit.WebClient;
import com.gargoylesoftware.htmlunit.WebRequest;
import com.gargoylesoftware.htmlunit.WebWindow;
import com.gargoylesoftware.htmlunit.html.HtmlElement;
import com.gargoylesoftware.htmlunit.html.HtmlPage;
public class ScreenCaptureHtmlUnitDriver extends HtmlUnitDriver implements TakesScreenshot {
private static Map<String, byte[]> imagesCache = Collections.synchronizedMap(new HashMap<String, byte[]>());
private static Map<String, String> cssjsCache = Collections.synchronizedMap(new HashMap<String, String>());
// http://stackoverflow.com/questions/4652777/java-regex-to-get-the-urls-from-css
private final static Pattern cssUrlPattern = Pattern.compile("background(-image)?[\\s]*:[^url]*url[\\s]*\\([\\s]*([^\\)]*)[\\s]*\\)[\\s]*");// ?<url>
public ScreenCaptureHtmlUnitDriver() {
super();
}
public ScreenCaptureHtmlUnitDriver(boolean enableJavascript) {
super(enableJavascript);
}
public ScreenCaptureHtmlUnitDriver(Capabilities capabilities) {
super(capabilities);
}
public ScreenCaptureHtmlUnitDriver(BrowserVersion version) {
super(version);
DesiredCapabilities var = ((DesiredCapabilities) getCapabilities());
var.setCapability(CapabilityType.TAKES_SCREENSHOT, true);
}
//#Override
#SuppressWarnings("unchecked")
public <X> X getScreenshotAs(OutputType<X> target) throws WebDriverException {
byte[] archive = new byte[0];
try {
archive = downloadCssAndImages(getWebClient(), (HtmlPage) getCurrentWindow().getEnclosedPage());
} catch (Exception e) {
}
if(target.equals(OutputType.BASE64)){
return target.convertFromBase64Png(new Base64Encoder().encode(archive));
}
if(target.equals(OutputType.BYTES)){
return (X) archive;
}
return (X) archive;
}
// http://stackoverflow.com/questions/2244272/how-can-i-tell-htmlunits-webclient-to-download-images-and-css
protected byte[] downloadCssAndImages(WebClient webClient, HtmlPage page) throws Exception {
WebWindow currentWindow = webClient.getCurrentWindow();
Map<String, String> urlMapping = new HashMap<String, String>();
Map<String, byte[]> files = new HashMap<String, byte[]>();
WebWindow window = null;
try {
window = webClient.getWebWindowByName(page.getUrl().toString()+"_screenshot");
webClient.getPage(window, new WebRequest(page.getUrl()));
} catch (Exception e) {
window = webClient.openWindow(page.getUrl(), page.getUrl().toString()+"_screenshot");
}
String xPathExpression = "//*[name() = 'img' or name() = 'link' and (#type = 'text/css' or #type = 'image/x-icon') or #type = 'text/javascript']";
List<?> resultList = page.getByXPath(xPathExpression);
Iterator<?> i = resultList.iterator();
while (i.hasNext()) {
try {
HtmlElement el = (HtmlElement) i.next();
String resourceSourcePath = el.getAttribute("src").equals("") ? el.getAttribute("href") : el
.getAttribute("src");
if (resourceSourcePath == null || resourceSourcePath.equals(""))
continue;
URL resourceRemoteLink = page.getFullyQualifiedUrl(resourceSourcePath);
String resourceLocalPath = mapLocalUrl(page, resourceRemoteLink, resourceSourcePath, urlMapping);
urlMapping.put(resourceSourcePath, resourceLocalPath);
if (!resourceRemoteLink.toString().endsWith(".css")) {
byte[] image = downloadImage(webClient, window, resourceRemoteLink);
files.put(resourceLocalPath, image);
} else {
String css = downloadCss(webClient, window, resourceRemoteLink);
for (String cssImagePath : getLinksFromCss(css)) {
URL cssImagelink = page.getFullyQualifiedUrl(cssImagePath.replace("\"", "").replace("\'", "")
.replace(" ", ""));
String cssImageLocalPath = mapLocalUrl(page, cssImagelink, cssImagePath, urlMapping);
files.put(cssImageLocalPath, downloadImage(webClient, window, cssImagelink));
}
files.put(resourceLocalPath, replaceRemoteUrlsWithLocal(css, urlMapping)
.replace("resources/", "./").getBytes());
}
} catch (Exception e) {
}
}
String pagesrc = replaceRemoteUrlsWithLocal(page.getWebResponse().getContentAsString(), urlMapping);
files.put("page.html", pagesrc.getBytes());
webClient.setCurrentWindow(currentWindow);
return createZip(files);
}
String downloadCss(WebClient webClient, WebWindow window, URL resourceUrl) throws Exception {
if (cssjsCache.get(resourceUrl.toString()) == null) {
cssjsCache.put(resourceUrl.toString(), webClient.getPage(window, new WebRequest(resourceUrl))
.getWebResponse().getContentAsString());
}
return cssjsCache.get(resourceUrl.toString());
}
byte[] downloadImage(WebClient webClient, WebWindow window, URL resourceUrl) throws Exception {
if (imagesCache.get(resourceUrl.toString()) == null) {
imagesCache.put(
resourceUrl.toString(),
IOUtils.toByteArray(webClient.getPage(window, new WebRequest(resourceUrl)).getWebResponse()
.getContentAsStream()));
}
return imagesCache.get(resourceUrl.toString());
}
public static byte[] createZip(Map<String, byte[]> files) throws IOException {
ByteArrayOutputStream bos = new ByteArrayOutputStream();
ZipOutputStream zipfile = new ZipOutputStream(bos);
Iterator<String> i = files.keySet().iterator();
String fileName = null;
ZipEntry zipentry = null;
while (i.hasNext()) {
fileName = i.next();
zipentry = new ZipEntry(fileName);
zipfile.putNextEntry(zipentry);
zipfile.write(files.get(fileName));
}
zipfile.close();
return bos.toByteArray();
}
List<String> getLinksFromCss(String css) {
List<String> result = new LinkedList<String>();
Matcher m = cssUrlPattern.matcher(css);
while (m.find()) { // find next match
result.add( m.group(2));
}
return result;
}
String replaceRemoteUrlsWithLocal(String source, Map<String, String> replacement) {
for (String object : replacement.keySet()) {
// background:url(http://org.com/images/image.gif)
source = source.replace(object, replacement.get(object));
}
return source;
}
String mapLocalUrl(HtmlPage page, URL link, String path, Map<String, String> replacementToAdd) throws Exception {
String resultingFileName = "resources/" + FilenameUtils.getName(link.getFile());
replacementToAdd.put(path, resultingFileName);
return resultingFileName;
}
}
Anyway, I found this code, but I am unsure how to use this code to actually take a screenshot.
I would like the screenshot to be a .jpg and to be able to be stored in a certain folder.
In the long haul, I am also going to need to run the screenshot code repeatedly.
Any help would be appreciated.