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Java - Download file from URL with matching file name pattern

I want to download few files from a URL. I know the starting of the file name. But the next part would be different. Mostly a date. But it could be different for different files. From Java code, is there any way to download file with matching pattern?
If I hit the below URL in chrome, all the files are listed and I have to download the required files manually.
http://<ip_address>:<port>/MR/build/report/scan/daily/2021-12-13_120/data/
File names can b like below. It will have known file name and date. The date can be different. Either the same as in URL or some older one.
scan_report_2021_12_13_120.txt
build_report_2021_12_10_110.txt
my_reportdata_2021_11_30_110.txt
As of now, my Java code is like below. I have to pass the complete URL with exact file name to download the files. Most of the cases it would be same as the date and number in URL. So in the program I take the date part from URL and add it to my file name nd pass as the URL. But for some files it might change and for those I have to manually download.
private static void downloadFile(String remoteURLPath, String localPath) {
System.out.println("DownloadFileTest.downloadFile() Downloading from " + remoteURLPath + " to = " + localPath);
FileOutputStream fos = null;
try {
URL website = new URL(remoteURLPath);
ReadableByteChannel rbc = Channels.newChannel(website.openStream());
fos = new FileOutputStream(localPath);
fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (fos != null) {
try {
fos.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
The argument remoteURLPath is passed like http://<ip_address>:<port>/MR/build/report/scan/daily/2021-12-13_120/data/scan_report_2021_12_13_120.txt
And localPath is passed like C:\\MyDir\\MyData\\scan_report_2021_12_13_120.txt
Similarly other files also with date as 2021_12_13_120. Other files wont get downloaded. But will create empty file in the same directory which I will delete later since size is 0.
Is there any way we can pass pattern here?
Like http://<ip_address>:<port>/MR/build/report/scan/daily/2021-12-13_120/data/scan_report_*.txt
And instead of passing complete local path, is there any way to pass only directory where the file should get downloaded with exact same name as in the remote system?
In Linux I can use wget with pattern matching. But was looking for Java way to download in all platforms.
wget -r -np -nH --cut-dirs=10 -A "scan_report*.txt" "http://<ip_address>:<port>/MR/build/report/scan/daily/2021-12-13_120/data/"

Thanks to comment from #FedericoklezCulloca. I modified my code using this answer
The solution I did is read all html page and get all href values as it had only the file names with extension. From there I had another list which I used to get the matching files and those I downloaded then using my code in the Question.
Method to get all href list from URL. may be optimisation can be done. Also I did not use any extra library.
private static List<String> getAllHREFListFromURL(String downloadURL) {
URL url;
InputStream is = null;
List<String> hrefListFromURL = new ArrayList<>();
try {
url = new URL(downloadURL);
is = url.openStream();
byte[] buffer = new byte[1024];
int bytesRead = -1;
StringBuilder page = new StringBuilder(1024);
while ((bytesRead = is.read(buffer)) != -1) {
String str = new String(buffer, 0, bytesRead);
page.append(str);
}
StringBuilder htmlPage = new StringBuilder(page);
String search_start = "href=\"";
String search_end = "\"";
while (!htmlPage.isEmpty()) {
int indexOf = htmlPage.indexOf(search_start);
if (indexOf != -1) {
String substring = htmlPage.substring(indexOf + search_start.length());
String linkName = substring.substring(0, substring.indexOf(search_end));
hrefListFromURL.add(linkName);
htmlPage = new StringBuilder(substring);
} else {
htmlPage = new StringBuilder();
}
}
} catch (MalformedURLException e1) {
e1.printStackTrace();
} catch (IOException ex) {
ex.printStackTrace();
} finally {
try {
is.close();
} catch (Exception e) {
}
}
return hrefListFromURL;
}
Method to get list of files that I needed.
private static List<String> getDownloadList(List<String> allHREFListFromURL) {
List<String> filesList = getMyFilesList();
List<String> downloadList = new ArrayList<>();
for (String fileName : filesList) {
Predicate<String> fileFilter = Pattern.compile(fileName + "*").asPredicate();
List<String> collect = allHREFListFromURL.stream().filter(fileFilter).collect(Collectors.toList());
downloadList.addAll(collect);
}
return downloadList;
}
private static List<String> getMyFilesList() {
List<String> filesList = new ArrayList<>();
filesList.add("scan_report");
filesList.add("build_report");
filesList.add("my_reportdata");
return filesList;
}
The downloadList I iterate and uses my original download method to download.

Append a string in front of line in java?

I am creating a pattern lock based project in android.
I have a file called category.txt
The content of the file is as below
Sports:Race:Arcade:
No what i want is that whenever the user draw a pattern for a specific games category the pattern should get append in front of that category.
eg :
Sports:Race:"string/pattern string to be appended here for race"Arcade:
i have used following code but it is not working.
private void writefile(String getpattern,String category)
{
String str1;
try {
file = new RandomAccessFile(filewrite, "rw");
while((str1 = file.readLine()) != null)
{
String line[] = str1.split(":");
if(line[0].toLowerCase().equals(category.toLowerCase()))
{
String colon=":";
file.write(category.getBytes());
file.write(colon.getBytes());
file.write(getpattern.getBytes());
file.close();
Toast.makeText(getActivity(),"In Writefile",Toast.LENGTH_LONG).show();
}
}
}
catch (FileNotFoundException e)
{
e.printStackTrace();
}
catch(IOException io)
{
io.printStackTrace();
}
}
please help !

Using RandomAccessFile you have to calculate the position. I think it's much easier to just replace the file content with a little help from apache-commons-io FileUtils. This might be not the best idea if you have a very large file but it's quite simple.
String givenCategory = "Sports";
String pattern = "stringToAppend";
final String colon = ":";
try {
List<String> lines = FileUtils.readLines(new File("someFile.txt"));
String modifiedLine = null;
int index = 0;
for (String line : lines) {
String[] categoryFromLine = line.split(colon);
if (givenCategory.equalsIgnoreCase(categoryFromLine[0])) {
modifiedLine = new StringBuilder().append(pattern).append(colon).append(givenCategory).append(colon).toString();
break;
}
index++;
}
if (modifiedLine != null) {
lines.set(index, modifiedLine);
FileUtils.writeLines(new File("someFile.txt"), lines);
}
} catch (IOException e1) {
// do something
}

Gdx.files.internal(...) wrapper not working correctly

I made a wrapper ConfigurationFile class to help handle Gdx.files stuff, and it worked fine for a long time, but now it's not working, and I don't know why.
I have two of the following two methods: internal(...) and local(...). The only difference between the two is handling the load from arguments from (File folder, String name) and (String path).
-Snip Now Unnecessary Information-
UPDATE
After more configuring, I came to find out that they're not behaving the same. I have an assets/files/ folder that Gdx.files.internal(...) will access fine, but ConfigurationFile.internal(...) will access files/, and they're set up the same way. I'll give you the two pieces of code that I used for testing.
Using Gdx.files.internal(...) directly (works as expected):
FileHandle handle = Gdx.files.internal("files/virus_data");
BufferedReader reader = null;
try {
reader = new BufferedReader(handle.reader());
String c = "";
while ((c = reader.readLine()) != null) {
System.out.println(c); // prints out all 5 lines on the file.
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (reader != null) reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
Using ConfigurationFile.internal(...):
// First part, calls ConfigurationFile#internal(String path)
ConfigurationFile config = ConfigurationFile.internal("files/virus_data");
// ConfigurationFile#internal(String path)
public static ConfigurationFile internal(String path) {
ConfigurationFile config = new ConfigurationFile();
// This is literally calling Gdx.files.internal("files/virus_data");
config.handle = Gdx.files.internal(path);
config.file = config.handle.file();
config.folder = config.file.getParentFile();
config.init();
return config;
}
// ConfigurationFile#init()
protected void init() {
// File not found.
// Creates a new folder as a sibling of "assets"
// Creates a new file called "virus_data"
if (!folder.exists()) folder.mkdirs();
if (!file.exists()) {
try {
file.createNewFile();
} catch (IOException e) {
e.printStackTrace();
}
} else loadFile();
}
// ConfigurationFile#loadFile()
protected void loadFile() {
BufferedReader reader = null;
try {
reader = new BufferedReader(handle.reader());
String c = "";
while ((c = reader.readLine()) != null) {
System.out.println(c);
if (!c.contains(":")) continue;
String[] values = c.split(":");
String key = values[0];
String value = values[1];
if (values.length > 2) {
for (int i = 2; i < values.length; i++) {
value += ":" + values[i];
}
}
key = key.trim();
value = value.trim();
mapValues.put(key, value);
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (reader != null) reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
What I'm having trouble understanding is what's the difference between these two ways that it is causing my ConfigurationFile to create a new File in a folder that is a sibling of assets. Could someone tell me why this is happening?

My suggestion is not to use
Gdx.files.internal(folder + "/" + name);
If you have to use the File api, do it this way:
Gdx.files.internal(new File(folder, name).toString());
This way you avoid weird things that could be happening with path separators.
If Gdx maybe needs relative paths for some reason (perhaps relative to some Gdx internal home directory), you could use NIO to do something like
final Path gdxHome = Paths.get("path/to/gdx/home");
//...
File combined = new File(folder, name);
String relativePath = gdxHome.relativize(combined.toPath()).toString();

Okay, so after intense testing, I found out the problem, which I found to be ridiculous.
Since the file is Internal, that means a new File(...) reference can't be properly made to it, but instead it's an InputStream (if I'm correct), but anyways, using the method FileHandle#file() on an Internal file causes some kind of conversion for the path, so after removing anything that dealed with FileHandle#file() for an Internal file fixed it.

better regular expression for matching strings?

I have a "moreinfo" Directory which has some html file and other folder. I am searching the file in the moreinfo directory( and not sub directory in moreinfo) matches with toolId*.The names of the file is same as toolId],
Below is a code snippet how i writing it, In case my toolId = delegatedAccess the list returns 2 file (delegatedAccess.html & delegatedAccess.shopping.html) based on the wide card filter(toolId*)
Is their a better way of writing the regular expression that check until last occurring period and return the file that matches exactly with my toolId?
infoDir =/Users/moreinfo
private String getMoreInfoUrl(File infoDir, String toolId) {
String moreInfoUrl = null;
try {
Collection<File> files = FileUtils.listFiles(infoDir, new WildcardFileFilter(toolId+"*"), null);
if (files.isEmpty()==false) {
File mFile = files.iterator().next();
moreInfoUrl = libraryPath + mFile.getName(); // toolId;
}
} catch (Exception e) {
M_log.info("unable to read moreinfo" + e.getMessage());
}
return moreInfoUrl;
}

This is what i end up doing with all the great comments. I did string manipulation to solve my problem. As Regex was not right solution to it.
private String getMoreInfoUrl(File infoDir, String toolId) {
String moreInfoUrl = null;
try {
Collection<File> files = FileUtils.listFiles(infoDir, new WildcardFileFilter(toolId+"*"), null);
if (files.isEmpty()==false) {
for (File mFile : files) {
int lastIndexOfPeriod = mFile.getName().lastIndexOf('.');
String fNameWithOutExtension = mFile.getName().substring(0,lastIndexOfPeriod);
if(fNameWithOutExtension.equals(toolId)) {
moreInfoUrl = libraryPath + mFile.getName();
break;
}
}
}
} catch (Exception e) {
M_log.info("unable to read moreinfo" + e.getMessage());
}
return moreInfoUrl;
}

Include CSV or XLXS file for selenium

I'm trying to copy a value from a row on a csv or xlxs file and paste it into a textfield on firefox and do some action and loop this until the end of the csv file.
After few research I discovered Selenium for firefox to automatize tasks.
Does someone have an idea of how the implementation will be or help me writing this?
Thanks in advance

You need a csv parser like CsvReader . You can use the following code as a starting point and build up on it. Hope this helps. Happy coding.
public String getValue(String fileName, String rowNum, int colHeader)
{
String returnVal = null;
String relativePath = System.getProperty("user.dir");
String csvPath = relativePath + "\\src\\main\\resources\\CSV\\" + fileName + ".csv" ;
CsvReader r;
try {
r = new CsvReader(csvPath);
while(r.readRecord())
{
String row = r.get(0);
if(row.equalsIgnoreCase(rowNum) )
{
returnVal = r.get(colHeader);
break;
}
}
r.close();
} catch (FileNotFoundException e)
{
e.printStackTrace();
} catch (IOException e)
{
e.printStackTrace();
}
return returnVal;
}