Develop Reference

Replace multiple substrings within a string

I have string such as
String url = "www.test.com/blabla/?p1=v1?p2=v2?p3=v3"
I would like to replace the "substrings" "v1","v2" and "v3" with other values. How can I achieve this?

Does something like this work for your case?
String url = "www.test.com/blabla/?p1=v1?p2=v2?p3=v3";
String result = String.format(url.replaceAll("v[0-9]", "%s"), "arg1", "arg2", "arg3");
System.out.println(result); //www.test.com/blabla/?p1=arg1?p2=arg2?p3=arg3
Edit:
Just a brief explanation of what this does, it replaces all the v1,v2,v3,v4,v5,v6,v7,v8,v9,v0 in the original url for %s and then uses this in the format method so you can attribute what you want it to be.

How to add "-" in between two stings on Android?

Example:
cname = "name"
ccurt = "last name"
Required output = name - last name
But current output = namelast name
How to get output as above? The used code is below for your reference,
Code used:
long id= AddDbHelper.createReminder(cname +ccurt,de,reminderDateTime);

use
String output=cname+"-"+ccurt;

I guess you can use StringBuilder
StringBuilder tmp = new StringBuilder();
tmp.append(cname);
tmp.append("-");
tmp.append(ccurt);
String fullName = tmp.toString();
Or simply:
String fullName = new StringBuilder(cname).append(" - ").append(ccurt).toString();
StringBuilder
A modifiable sequence of characters for use in creating strings. This
class is intended as a direct replacement of StringBuffer for
non-concurrent use; unlike StringBuffer this class is not
synchronized.

Simply use
String output=cname+" - "+ccurt;

Cleaning a file name in Java

I want to write a script that will clean my .mp3 files.
I was able to write a few line that change the name but I want to write an automatic script that will erase all the undesired characters $%_!?7 and etc. while changing the name in the next format Artist space dash Song.
File file = new File("C://Users//nikita//Desktop//$%#Artis8t_-_35&Son5g.mp3");
String Original = file.toString();
String New = "Code to change 'Original' to 'Artist - Song'";
File file2 = new File("C://Users//nikita//Desktop//" + New + ".mp3");
file.renameTo(file2);
I feel like I should make a list with all possible characters and then run the String through this list and erase all of the listed characters but I am not sure how to do it.
String test = "$%$#Arti56st_-_54^So65ng.mp3";
Edit 1:
When I try using the method remove, it still doesn't change the name.
String test = "$%$#Arti56st_-_54^So65ng.mp3";
System.out.println("Original: " + test);
test.replace( "[0-9]%#&\\$", "");
System.out.println("New: " + test);
The code above returns the following output
Original: $%$#Arti56st_-_54^So65ng.mp3
New: $%$#Arti56st_-_54^So65ng.mp3

I'd suggest something like this:
public static String santizeFilename(String original){
Pattern p = Pattern.compile("(.*)-(.*)\\.mp3");
Matcher m = p.matcher(original);
if (m.matches()){
String artist = m.group(1).replaceAll("[^a-zA-Z ]", "");
String song = m.group(2).replaceAll("[^a-zA-Z ]", "");
return String.format("%s - %s", artist, song);
}
else {
throw new IllegalArgumentException("Failed to match filename : "+original);
}
}
(Edit - changed whitelist regex to exclude digits and underscores)
Two points in particular - when sanitizing strings, it's a good idea to whitelist permitted characters, rather than blacklisting the ones you want to exclude, so you won't be surprised by edge cases later. (You may want a less restrictive whitelist than I've used here, but it's easy to vary)
It's also a good idea to handle the case that the filename doesn't match the expected pattern. If your code comes across something other than an MP3, how would you like it to respond? Here I've through an exception, so the calling code can catch and handle that appropriately.

String new = original.replace( "[0-9]%#&\\$", "")
this should replace almost all the characters you don't want
or you can come up with your own regex
https://docs.oracle.com/javase/tutorial/essential/regex/

Get URL from string with text

I have a bunch of strings like this:
Some text, bla-bla http://www.easypolls.net/poll.html?p=51e5a300e4b084575d8568bb#.UeWjBcCzaaA.twitter
And I need to parse this String to two:
Some text, bla-bla
http://www.easypolls.net/poll.html?p=51e5a300e4b084575d8568bb#.UeWjBcCzaaA.twitter
I need separate them, but, of course, it's enough to parse only URL.
Can you help me, how can I parse url from string like this.

By using split :
String str = "Some text, bla-bla http://www.easypolls.net/poll.html?p=51e5a300e4b084575d8568bb#.UeWjBcCzaaA.twitter";
String [] ar = str.split("http\\.*");
System.out.println(ar[0]);
System.out.println("http"+ar[1]);

This depends on how robust you want your parser to be. If you can reasonably expect every url to start with http://, then you can use
string.indexOf("http://");
This returns the index of the first character of the string you pass in (and -1 if the string does not appear).
Full code to return a substring with just the URL:
string.substring(string.indexOf("http://"));
Here's the documentation for Java's String class. Let this become your friend in programming! http://docs.oracle.com/javase/7/docs/api/java/lang/String.html

Try something like this:
String string = "sometext http://www.something.com";
String url = string.substring(string.indexOf("http"), string.length());
System.out.println(url);
or use split.

I know in PHP you'd be able to run the explode() (http://www.php.net/manual/en/function.explode.php) function. You'd choose which character you want to explode at. For instance, you could explode at "http://"
So running the code via PHP would look like:
$string = "Some text, bla-bla http://www.easypolls.net/poll.html?p=51e5a300e4b084575d8568bb#.UeWjBcCzaaA.twitter";
$pieces = explode("http://", $string);
echo $pieces[0]; // Would print "Some text, bla-bla"
echo $pieces[1]; // Would print "www.easypolls.net/poll.html?p=51e5a300e4b084575d8568bb#.UeWjBcCzaaA.twitter"

parsing a string using string tokenizer twice

I am getting input string as below from some procedure
service:jmx:t3://10.20.30.40:9031/jndi/weblogic.management.mbeanservers.runtime
I want to parse it in java and get out
t3
10.20.30.40
9031
into separate strings
I think I can use string tokenizer but I have to tokenize 2 times ?Any better way to handle this?

Use the JMXServiceUrl class. It will parse the URL for you. No need to battle with regex or String splits.
String url = "service:jmx:t3://10.20.30.40:9031/jndi/weblogic.management.mbeanservers.runtime";
JMXServiceURL jmxServiceURL = new JMXServiceURL(url);
System.out.println(jmxServiceURL.getHost());
System.out.println(jmxServiceURL.getPort());
System.out.println(jmxServiceURL.getProtocol());
Prints
10.20.30.40
9031
t3

If it's only a somehow composed String and you can ignorie performance, I would prefer a readable solution (more than regex ;-)) like this:
int pos_1 = input.indexOf("//");
String s1 = input.substring(0, pos_1);
String input_2 = input.substring(pos_1 + 2);
int pos_2 = input_2.indexOf(":");
String s2 = input_2.substring(0, pos_2);
...

Regex is a good approach. You should find the pattern for your string and group with parenthesis what you want. Maybe this could be enough for you:
service\\:jmx\\:(?<groupName01>[a-z0-9]+)\\://(?<groupName02>[0-9\\.]+)\\:(?<groupName03>[o-9]+)
See Java Regex
If you use java earlier from 7, do not use ?<groupName> in the pattern. It will be grouped by number.

Do a simple string split
String s = "service:jmx:t3://10.20.30.40:9031/jndi/weblogic.management.mbeanservers.runtime";
String tokens[] = s.split("[:/]");
System.out.println(tokens[2]);
System.out.println(tokens[5]);
System.out.println(tokens[6]);