Develop Reference

How do I read only a specific part of the string in Android Studio?

If a send a string in the following format: 1234,1234,1234,1234; from Arduino to Android Studio (java (intelliJ)) based. with the amount of characters between every komma changing. How do i make it so that my code only reads the string from for example 0 to the , Or from the first , to the second ,?

If you are using Java, I would recommend looking into the Java.String.split() method. This method will split your string in an array of strings, depending on your delimiter. For example :
String s = "1234,1234,1234,1234";
String[] result = s.split(",");

You can split the input string based on any special character,in your case ,, as follows
String inputString = "1234,1234,1234,1234";
String[] separated = inputString.split(",");
Log.i("MainActivity",separated[0]) // prints the first string which is 1234
// to loop over all strings
for(String s : separated){
Log.i("MainActivity",s)
}

Android : Split string with { character

I have an string
String name = "\"edge_followed_by\":{\"count\":46199005},\"followed_by_viewer\":false,"
I want only this 46199005.
But { shows an error, when try to split the string
String[] separated = name.split("edge_followed_by\":{\"count\":");
Showing a suggestion , number expected and want me to replace with *.
Can anyone help me in this.

Just replace { with \{.
split is trying to use it as a part of regular expression.

Ideally, you should use JSON to parse this if you have proper structure. but if you want to get only the number you can split it using ":" and then split using "}". it should give you the exact number.

Why not to use:
String[] separated = name.split(":");
separated[2].split("}")[0];

Your string is not exact JSON object otherwise you can simply do json parsing and get the count value.
You can get count value using subtring operations like below:
String name = "\"edge_followed_by\":{\"count\":46199005},\"followed_by_viewer\":false,";
String substr = name.substring(name.indexOf("\"count\":") + 10);
String finalstr = substr.substring( 0, substr.indexOf("},"));
Log.d("Extracted_Value", finalstr); // output -> 46199005
There can be multiple ways. This is just one. Hope it will help you!

How can i get few characters from String?

I want to retrieve few characters from string i.e., String data on the basis of first colon (:) used in string . The String data possibilities are,
String data = "smsto:....."
String data = "MECARD:....."
String data = "geo:....."
String data = "tel:....."
String data = "MATMSG:....."
I want to make a generic String lets say,
String type = "characters up to first colon"
So i do not have to create String type for every possibility and i can call intents according to the type

It looks like you want the scheme of a uri. You can use Uri.parse(data).getScheme(). This will return smsto, MECARD, geo, tel etc...
Check out the Developers site: http://developer.android.com/reference/android/net/Uri.html#getScheme()

Note: #Alessandro's method is probably more efficient. I just got that one off the top of my head.
You can use this to get characters up to first ':':
String[] parts = data.split(":");
String beforeColon = parts[0];
// do whatever with beforeColon
But I don't see what your purpose is, which would help giving you a better solution.

You should use the method indexOf - with that you can get the index of a certain char. Then you retrieve the substring starting from that index. For example:
int index = string.indexOf(':');
String substring = string.substring(index + 1);

How to remove brackets and quotation marks from JSON String

I have a ArrayAdapter the places JSON strings into a list view. The problem is when it places the strings into the textview it leaves brackets and quotation marks. For example, if the string contained the name Bob. The string would show up in the ListView as ["Bob"]. How do I remove the brackets and quotation marks?
Here is what I use to get the JSON strings,
String username = json2.getString(KEY_USERNAME);
String number = json2.getString(KEY_NUMBER);
String content = json2.getString(KEY_COMMENT);
tempList2.add (new Item (username, number, content));
customAdapter.addAll(tempList2);

You can use a simple replace:
String bob = "[\"Bob\"]";
bob = bob.replace("[", "").replace("\"", "").replace("]", "");
Log.i("Test", bob);
This will now just print Bob

As an addon to Phil's answer, the end quote (in my chrome browser) did not get removed. I fixed it by using .replace("\"", "") again at the end.

need to retrieve data from the database

I have a very long string in the database that needs to be retrieved into a swipe view.
But,the problem is that the string comprises of set of "\n\n"
Whenever it is separated with this expression i need to put it in another slide,i mean i am using SWIPE view here..
if(tablecolumn==\\n\\n)
{
code to break it to parts
}
Is this how i should be doing it?
If i am wrong,how to break this string to different parts and enable it into SWIPE VIEW in to different swipe view?

You can simply break your string comprising of a special character like this :-
String str ="mynameisjhon.yournameisdash.bla";
, here you have a string concatenated with " . " (period character)
to break this string do this :-
StringTokenizer st = new StringTokenizer(str, "."); //break the string whenever "." occurs
String temp =st.nextToken(); // it will have "my name is jhon" break
String temp2 = st.nextToken();// it will have "your name is dash"
String temp3 = st.nextToken();//it will have "bla"
now your string is breaked into parts!
Anything else?

Load the whole string into your ViewAdapter and seperate it via substring
or load the string in your Activity/Fragment seperate it via substring, put the strings in an ArrayList, an initiate your ViewAdapter with the ArrayList as data source
either way use substring