I want to create a text file into that folder that I am creating here.
File dir = new File("crawl_html");
dir.mkdir();
String hash = MD5Util.md5Hex(url1.toString());
System.out.println("hash:-" + hash);
File file = new File(""+dir+"\""+hash+".txt");
But this code doesn't create the text file into that folder..Instead it makes the text file outside that folder..
One of java.io.File's constructors takes a parent directory. You can do this instead:
final File parentDir = new File("crawl_html");
parentDir.mkdir();
final String hash = "abc";
final String fileName = hash + ".txt";
final File file = new File(parentDir, fileName);
file.createNewFile(); // Creates file crawl_html/abc.txt
What you need is
File file = new File(dir, hash + ".txt");
The key here is the File(File parent, String child) constructor. It creates a file with the specified name under the provided parent directory (provided that directory exists, of course).
The line
new File(""+dir+"\""+hash+".txt");
makes a file named crawl_html"the_hash.txt, because \" inside a String literal is used to represent a double quote caracter, not a backslash. \\ must be used to represent a backslash.
Use the File constructor taking a File (directory) as the first argument, and a file name as a second argument:
new File(dir, hash + ".txt");
your path-delimiter seems off
try:
File file = new File ( "" + dir + "/" + hash + ".txt" );
Related
I have a program which includes the following line of code:
//String s = fileName;
File location = new File(s);
and then I have
//String contents = whatIWantToPrint;
OutputStream print = new FileOutputStream(location);
print.write(contents.getBytes());
print.close();
telling the program to print the string contents to the file s. However the file appears within the folder that the program is in rather than the directory in which the program is in. For example if the program is on the persons desktop I want it to make the file on their desktop.
I used the following line in terminal to make the program a jar file (mac):
jar -cvmf manifest.txt Generate.jar *.class
Someone told me to do this:
String dir = System.getProperty("home.dir"+"/Desktop");
String filePath = dir + File.separator + ss + ".txt";
File location = new File(filePath);
But I'm not sure if that's what will make the program make the file in the desktop and it also throws a security exception so it doesn't work anyways
You should do:
String s= System.getProperty("user.home");
and append path separator and file name
String filePath = s + File.separator + "desktop" + File.separator + "myFile.txt";
You could try this
String DEFAULT_USER_DIR = System
.getProperty("user.home"+"/Desktop");
File location = new File(DEFAULT_USER_DIR);
user.dir returns User's current working directory
See the javadoc here.
The following code writes a string to a specific file.
String content = "Text To be written on a File";
File file = new File("c:/file.txt");
FileOutputStream foutput = new FileOutputStream(file);
if (!file.exists()) {
file.createNewFile();
}
byte[] c = content.getBytes();
foutput.write(c);
foutput.flush();
foutput.close();
I want to use this code in a Jbutton so every time the user clicks it, it writes the string to a NEW text file NOT OVERWRITE the existed one. I tried to do but I couldn't get the result.
Thank you in advance.
There's a couple of different ways you can get this result, it really depends on the application. The two easiest ways to do this would to be either:
Append the current timestamp to the file name
Use the File API to create a "temp file" in the directory, which is guarenteed to have a unique name
Option 1:
String baseDir = "c:/";
File newFile = new File(baseDir, "file_" + System.currentTimeMillis() + ".txt");
// do file IO logic here...
Option 2:
String baseDir = "c:/";
File newFile = File.createTempFile("file", ".txt", new File(baseDir));
// do file IO logic here...
If you want to write it to a new file, you have to create a new file. The name of the text file is always file.txt in your case.
Try this:
private int filecounter = 0; // this is the member of your class. Outside the function.
//inside your function
File file = new File("c:/file" + Integer.(filecounter).toString() + ".txt");
// you do something here.
filecounter++;
This way, your files will be stored as file0.txt, file1.txt etc.
I have a JFilechooser to select a filename and path to store some data. But I also want to store an additional file in the same path, same name but different extension. So:
File file = filechooser.getSelectedFile();
String path = file.getParent();
String filename1 = file.getName();
// Check the extension .ext1 has been added, else add it
if(!filename1.endswith(".ext1")){
filename2 = filename1 + ".ext2";
filename1 += ".ext1";
}
else{
filename2 = filename1;
filename2 = filename2.substring(0, filename2.length-4) + "ext2";
}
// And now, if I want the full path for these files:
System.out.println(path); // E.g. prints "/home/test" withtout the ending slash
System.out.println(path + filename1); // E.g. prints "/home/testfilename1.ext1"
Of course I could add the "/" in the middle of the two strings, but I want it to be platform independent, and in Windows it should be "\" (even if a Windows path file C:\users\test/filename1.ext1 would probably work).
I can think of many dirty ways of doing this which would make the python developer I'm carrying inside cry, but which one would be the most clean and fancy one?
You can use the constants in the File class:
File.separator // e.g. / or \
File.pathSeparator // e.g. : or ;
or for your path + filename1 you can do
File file = new File(path, filename1);
System.out.println(file);
Just use the File class:
System.out.println(new File(file.getParent(), "filename1"));
You can use:
System.getProperty("file.separator");
How can I get file size in Java if I have a relative path to a file such as:
String s = "/documents/19/21704/file2.pdf/0929c695-d023-49d7-a8ff-65ccea46bebc"
I tried with two diferent strings:
String[] separatedPath = s.split("/");
List<String> wordList = Arrays.asList(separatedPath);
String ret = "/" + wordList.get(1) + "/" + wordList.get(2) + "/" + wordList.get(3)+ "/" + wordList.get(4);
s = ret;
In this case s="/documents/19/21704/file2.pdf";
In second case s="/documents/19/21704/file2.pdf/0929c695-d023-49d7-a8ff-65ccea46bebc"
I tried with:
File file1 = new File(s);
long filesize = file1.length();
and with:
String filePath = new File(s).toURI().getPath();
File file2 = new File(filePath);
long filesize2 = file1.length();
and also with (if the problem is in not providing full path):
String absolutePath = FileUtil.getAbsolutePath(file1);
File file3 = new File(absolutePath);
long filesize3 = file3.length();
byte[] bytes1=FileUtil.getBytes(file1);
byte[] bytes2=FileUtil.getBytes(file2);
byte[] bytes3=FileUtil.getBytes(file3);
I am always getting in debug that filesizes in all cases are 0.
Maybe is worth noticing that the three attributes of file1 and file2 and file3 are always:
filePath: which is always null;
path: "/documents/19/21704/liferay-portlet-development.pdf"
prefixLength: 1
Since I am also using Liferay I also tried their utility.
long compId = article.getCompanyId();
long contentLength = DLStoreUtil.getFileSize(compId, CompanyConstants.SYSTEM, s);
I also should notice that in my .xhtml view I can access the file with:
<a target="_blank"
href="/documents/19/21704/file2.pdf/0929c695-d023-49d7-a8ff-65ccea46bebc">
file2.pdf
</a>
Pdf opens in a new window. So it is stored on my server.
What am I doing wrong here? That I cant get the file size from bean?
Any answer would be greatly appreciated.
What am I doing wrong here?
In Java, you can use the File.length() method to get the file size in bytes.
File file =new File("c:\\java_xml_logo.jpg");
if(file.exists()){
double bytes = file.length();
}
System.out.println("bytes : " + bytes);
The problem is that your "relative" path is expressed as an absolute path (begining with "/", which is read as FS root).
A relative file path should look like:
documents/19/21704/file2.pdf/0929c695-d023-49d7-a8ff-65ccea46bebc
./documents/19/21704/file2.pdf/0929c695-d023-49d7-a8ff-65ccea46bebc
Or, you could get your application root folder File and compose the absolute path:
File rootFolder =new File("path to your app root folder");
File myfile=new File(rootFolder, "/documents/19/21704/file2.pdf/0929c695-d023-49d7-a8ff-65ccea46bebc");
In Java, I have a File object representing a folder:
String folderName = "/home/vektor/folder";
File folder = new File(folderName);
Now I want to create another File representing a file in this folder. I want to avoid doing a string concatenation like this:
String fileName = "test.txt";
File file = new File(folderName + "/" + fileName);
Because if I go deeper in creating this structure, I will come up with something like this:
File deepFile = new File(folderName + "/" + anotherFolderName + ... + "/" + fileName);
I would instead like to do something like
File betterFile = folder.createUnder(fileName);
Or even:
File otherFile = SomeFileUtils.createFileInFolder(folder, fileName);
Do you know of such solution?
Note: It's quite OK to use "/" because Java will translate it to "\" for Windows, but it is not clean - I should use something like "file.separator" from System.getProperties().
Look at the Javadoc for File and you will see that the constructor takes a File object as parent.
Use the following form:
File deepFile = new File(folder, fileName);
I would use
String folderName =
String fileName =
File under = new File(folderName, fileName);
or
File folderFile =
String fileName =
File under = new File(folderFile, fileName);
simple as that ;)