I Am not able to read Properties File using Java.It Means In this Properties File Backward Slash is not working.It is showing like ,this destination :C:Usersxxx.a
String filename="D://Desktop//xxx.properties";
is = new FileInputStream(filename);
Properties prop=new Properties();
prop.load(is);
System.out.println("destination :"+prop.getProperty("destination"));
Property File is the :
destination=C:\Users\xxx.a\
Result is showing
destination :C:Usersxxx.a
But I want to show destination :C:\Usersxxx.a\
Can You Please suggest Me?
\ is an Escape character.
forward slash / is used as path separator in Unix environment.
Back slash \ is used as path separator in Windows environment.
So, You need to use \\ or / as path separator. You can not directly use \ in java. Since, it is an escape character.
So,You need to make changes in your properties file to make your program work.
Use either / or \\ as path separator in your properties file.
In your case you want to show as C:\Users\xxx.a\.
So, use C:\\Users\\xxx.a\\ in your properties file to get output as C:\Users\xxx.a\
The \ character is used as an "escape character" in many programming languages. It gives a special meaning to the next character in the text. For example, \n encodes the special character "new-line".
Use \\ instead of \. This indicates to the parser that you mean the actual symbol, not an escape character. For example, your property value would be:
destination=C:\\Users\\xxx.a\\
You need to add two slashes to your properties file like this:
destination=C:\\Users\\xxx.a\\
The other way is to swap the slashes in the properties file:
destination=C:/Users/xxx.a/
A \ is an escape character so it is removed. Adding two slashes escapes the first so only one is left.
You can store it in D:/Desktop/xxx.properties as
destination=C:/Users/xxx.a/
and show it with a single backslash
String fileName = prop.getProperty("destination");
System.out.println("destination: " + fileName); // shows: C:/Users/xxx.a/
System.out.println("destination: " + Paths.get(fileName)); // shows: C:\Users\xxx.a
Related
I want to store a URL in a properties file. This is the URL:
jdbc\:sqlserver\://dummydata\\SHARED
When programming this in Java, I obviously need to escape the backslashes. So my code ends up looking like this
properties.setProperty("db", "jdbc\\:sqlserver\\://dummydata\\\\SHARED");
The issue with this is that the properties file is saving the String URL and including the backslashes used for escaping, which is an incorrect URL. I was hoping that Java would interpret the backslashes used for escaping so that only the correct URL is saved. Is there a way to achieve this?
You're correct that a property value with : needs to escape the colons in a .properties text file, but you're not writing that text file directly.
You are giving the value to a Properties object using setProperty(), and presumably writing that to a text file using store(), and the store() method will escape the values as needed for you.
You should give the value you want to Properties, and forget about the encoding rules of the text file. Properties will handle all needed encoding. Since the value you want to give is jdbc:sqlserver://dummydata\SHARED, you write a string literal "jdbc:sqlserver://dummydata\\SHARED"
Example
String db = "jdbc:sqlserver://dummydata\\SHARED";
System.out.println(db); // To see actual string value
Properties properties = new Properties();
properties.setProperty("db", db);
try (FileWriter out = new FileWriter("test.properties")) {
properties.store(out, null);
}
Output
jdbc:sqlserver://dummydata\SHARED
Content of test.properties
#Tue Jun 11 11:54:24 EDT 2019
db=jdbc\:sqlserver\://dummydata\\SHARED
As you can see, the store() method has escaped the : and \ for you.
If you save the properties as an XML file instead, there's no need to escape anything, and Properties won't.
Example
try (FileOutputStream out = new FileOutputStream("test.xml")) {
properties.storeToXML(out, null);
}
Content of test.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE properties SYSTEM "http://java.sun.com/dtd/properties.dtd">
<properties>
<entry key="db">jdbc:sqlserver://dummydata\SHARED</entry>
</properties>
Properties.store() escapes backslashes, there is no way around it. I guess my first question is why is this an issue? Are you reading the file in any other way than using Properties.load(). If not they you don't need to worry about it as the load function will remove the escape characters.
properties.load(file);
System.out.println(properties.get("db"));
// output: jdbc\:sqlserver\://dummydata\\SHARED
As an aside are you sure you the URL is correct? Shouldn't you be storing it as properties.setProperty("jdbc:sqlserver://dummydata\SHARED")?
In the documentation for load, it says the following:
The method does not treat a backslash character, \, before a non-valid escape character as an error; the backslash is silently dropped. For example, in a Java string the sequence "\z" would cause a compile time error. In contrast, this method silently drops the backslash. Therefore, this method treats the two character sequence "\b" as equivalent to the single character 'b'.
This means that two backslashes will be treated as a single one because it's not a valid escape sequence. Loading this string should work just fine:
C:\\path\\to\\file
I am saving the path of a file as using Properties in Java into a config file.
this.adb = adb.getAbsolutePath();
this.prop.setProperty("adb", this.adb);
//save config to project root folder
this.prop.store(new FileOutputStream("config"), null);
The contents of config file after saving are:
adb=C\:\\Program Files\\Genymobile\\Genymotion\\tools\\adb.exe
How do I save it without the escape characters so that it can be easy for a user to modify the path manually without having to type in escape characters.
I also tried to save the config file manually without using escape characters, but the program read the property as:
C:Program FilesGenymobileGenymotion oolsadb.exe
And the code for reading properties from the config file is:
prop.load(new FileInputStream("config"));
this.adb = prop.getProperty("adb");
java.util.Properties.store uses backslash to escape special characters (e.g. equal sign in properties keys), so a literal backslash itself will need to be escaped \\. If this behaviour is not what you want, don't use java.util.Properties, roll out your own utility Properties class it should be a simple exercise. If your not sure what an escape character is check this Wikipedia page.
The relevant code in Properties class (saveConvert method)
if (aChar == '\\') {
outBuffer.append('\\'); outBuffer.append('\\');
continue;
}
I am currently trying to split a String folder. I get the value from a file system and it usually looks something like EAM\Testing.
String folder = "EAM\Testing"
String[] parts = folder.split("\\");
I know \ has special rules to it in java.
String folder = "EAM\\Testing"
String[] parts = folder.split("\\\\");
(I know the code above would work if I could control what the input looked like)
My problem is that I can not control what string folder is as input from a location of a file.
Is there a way to get this to work where folder only has one \ in it?
This is for a recycle bin component I am writing for Documentum a enterprise management system. When a document is deleted and the folder doesn't exist anymore I want to recreate it and inorder to recreate it the folder names must be seperate as I have to create them one at a time.
Here is how I get the name of the folder.
File f = new File(relationRecord.getRepeatingString(
"dp_original_folder_paths",
i));
(This gives an input such as \EAM\testing
String folder1 = f.toString();
I then get rid of the first \ by
String folder = folder1.substring(1);
Which gives me EAM\testing
Well if this is literally a file path, you should consider using the Path class, it'll make your life easier.
Path path = Paths.get("C:\\home\\joe\\foo");
System.out.format("toString: %s%n", path.toString());
System.out.format("getFileName: %s%n", path.getFileName());
System.out.format("getName(0): %s%n", path.getName(0));
System.out.format("getNameCount: %d%n", path.getNameCount());
System.out.format("subpath(0,2): %s%n", path.subpath(0,2));
System.out.format("getParent: %s%n", path.getParent());
System.out.format("getRoot: %s%n", path.getRoot());
Your second option
String[] parts = folder.split("\\\\");
Should work fine for your input string. When you write a string literal like "EAM\\Testing", the resulting string has only one slash. You can read some details on escape sequences in Java there.
The reason you need four slashes in split is because \ is an escape character both for string literals and regular expressions (String#split accepts regular expression as its argument)
You should be doing something like this -
String s = "EAM\\testing";
String a[] = s.split("\\\\");
Here you duplicate the backslash once for the String (since \ is an escape character for String) and again for the regex for the same reason.
Your question seems to be "how can I remove a leading \ from a string:
folder = folder.replaceAll("^\\\\", "");
This searches for a back slash at the start if the string, and if found replaces it with nothing (ie deletes it).
Regarding backslash vs forward slash characters in paths, java handles both.
// Dividend Limit check or increase the Dividend
if (dival == 10) {
writer.println("Divident has reached it Limit !");
i++;
// update the file name
String upath = "channel_" + i;
System.out.println(path);
// find channel_1 and replace with the updated path
if (path.contains("channel_1")) {
path = "D:/File Compression/Data/low_freq/low_freq/house_1/"
+ upath + ".dat";
} else {
JOptionPane.showMessageDialog(null, "Invalid File Choosen");
System.exit(0);
}
dival = 10;
} else {
dival = dival + 10;
writer.println("Dividen:" + dival);
}
these lines are in a recursive method. first time it gives right path:
D:/File Compression/Data/low_freq/low_freq/house_1/channel_2.dat
But on the second call it flips the forward slash to back slash:
D:\File Compression\Data\low_freq\low_freq\house_1\channel_1.dat
it works fine if I do not use the condition.
if(path.contains("channel_"))
That is because the File.seperator in Windows is \. Every time you let your path String go through a java.io.File it will replace them. So to fix this, either don't use File as auxiliary tool, or replace the backslashes with forward slashes.
So, what happens is that your path String uses backward slashes. You retrieve that String form a java.io.File which will automatically uses backslashes on Windows. If the path contains "channel_1", then you overwrite the whole string using a hardcoded string with forward slashes.
\ is called as Escape sequence in java which is used in various purposes .
In your case use File.separator
String path = "D:"+File.separator+"File Compression"+File.separator+"Data"+File.separator+"low_freq"+File.separator+"low_freq"+File.separator+"house_1"+File.separator;
Use double slash \\ ! It's a special escape pattern. Like \n or \r.
Escape sequence normally used in text files in Windows, specially in notepad.
The primary Java escape sequences are listed below. They are used to represent non-graphical characters and also characters such as double quotes, single quotes, and backslashes. If you'd like to represent a double quote within a String literal, you can do so with \". If you'd like to represent a single quote within a character literal, you can do so with \'.
In addition to the previous answers. You should not use / or \ hard coded in your application. Because this will harm the portability of your application. rather use,
File.separator
File#separator gives you, the separator depending in your system.
I have a property file and under that I have define a property called:
config.folder = C:\myfolder\configfolder
now the problem is that when loading properties, this property returns me the vale like this:
C:myfolderconfigfolder
I want to replace this single forward slash with back slash so it return me the correct directory path. I know this is not compliance with Java.String. If the user use double forward slash I am able to convert but how can I convert single slash.
A better approach is to change the slash from backslash to forward slash, like so:
config.folder = C:/myfolde/configfolder
Java knows how to interpret this structure.
Change it to: config.folder = C:\\myfolder\\configfolder
I will suggest that you start using System Properties for this i.e. file.separator
String fileSeparator = System.getProperty("file.separator");
Now say you got the path as :
String str = "C:/myfolder/configfolder";
String fileSeparator = System.getProperty("file.separator");
str= str.replace("/", fileSeparator);
System.out.println(str);
OUTPUT is :
C:\myfolder\configfolder
This approach might help you implement your program in any OS For Example UNIX with "/" as the file separator for different components of the file path, and for WINDOWS with "\" as the file separator for components of the file path.
Hope this might help in some way.
Regards
the best way to play with the file path literal is to use the system properties i.e.string file separator =System.getProperty ("file.separator") then you can replace it with ur slash to get the file path regards