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java convert from string to int

I need to parse the value of a label so that it can be stored as an Integer
JLabel lblSeatNo;
int seatNo;
seatNo = Integer.parseInt(lblSeatNo.getText());
It has worked other times I have used with method, however now I am getting a Number Format Exception and I don't understand why.
If it helps with value of the label can vary, it's general format is something like: "A131" or "B504"
Thankyou.

Assuming you want this as a hex number (that is base 16), you must supply the radix to your parseInt call -
seatNo = Integer.parseInt(lblSeatNo.getText(), 16);
if you want the decimal value (e.g. base 10) and to skip the letter, you could do
seatNo = Integer.parseInt(lblSeatNo.getText().substring(1));

Try int value = Integer.parseInt(hexString, 16); if you know that the string representation will always be hexadecimal. You might also want to check the documentation of the method in question.

Depends on what you are wanting:
If you want to just parse the numbers (not including a, b, etc) then you have to call substring to remove the letter.
if the letter is meant to be there as a hex number then you can call
Integer.parseInt(hexNo, 16)

follow this link
How to parse hex color String to Integer
eg. Integer.parseInt(myHexValue,16)

From your comments it seems like you want to extract just the number from the Seat label. But since you say that you also need to recreate the seat label then in your object you may also want to add a String for the row which will contain the Letter
So you could do something like this (assuming only ever a single letter)
int seatNo = Integer.parseInt(lblSeatNo.getText().substring(1));
String row = lblSeatNo.getText().subString(0,1);
Then to get the label again
String label = row + seatNo;

converts parts of a string to int in java

I was wondering how can I take some numbers in a string and convert them to an integer type? for example if a user entered 12:15pm how can I get 1 and 2 and make an int with value 12?

Given the example above, you could try something like this:
final int value = Integer.parseInt(input.substring(0, input.indexOf(':'))); //value = 12
Where input = 12:15pm in this case.
Generally speaking, just use a combination of String#indexOf(String), String#substring(int, int) and Integer.parseInt(String).

Read the String and Integer API's
You can use the String.split() to get the two numeric strings
You can use Integer.parseInt(...) to convert the String to an int.
Edit: Using the split() you can do something like:
String time = "12:34pm";
int hour = Integer.parseInt( time.split(":")[0] );

Ambiguousness in Android Java source

EditText ed1 = (EditText)findViewById( R.id.editText1 );
int a = Integer.parseInt( ed1.getText().toString() );
Does the above code get the input as numeric from the user and show it as a string?
My requirement is to get the input as integer and return as Strings. How do I do that?

Is the above code referencing that get the input as numeric from the user and show it as string?
The other way round - it's going through these steps:
Find the EditBox
Get the text from the edit box
Parse the text as a number
My requirement is to get the input as integer and return as Strings
Get the input from where? If you're getting the input from a user then it's probably already in a string form. If you're trying to convert an integer from somewhere else in the code, then you could use
String text = Integer.toString(number);
... or you could use a NumberFormat object, which would take different cultural information into account, allowing for grouping of digits etc.

EditText ed1=(EditText)findViewById(R.id.editText1);
String ed1Str = ed1.getText().toString().trim();
int a = Integer.parseInt(ed1Str);
Will make it available as an integer (int a) and as a string (String ed1Str)

The EditText.getText() returns Editable object and you have to convert it to string. You cannot get the number directly from edit text. You can access the text returned from EditText, convert it to String and then covert it into number as you have implemented.

do little modification in above code ed1.setInputType(InputType.TYPE_CLASS_NUMBER);
that will make your edittext only to accept integer values..

explain " double value = Double.valueOf(fstNmElmntLst.item(k).getTextContent()); "

What does this statement do?
double value = Double.valueOf(fstNmElmntLst.item(k).getTextContent());

Quite a lot going on there...
Gets the text content from some list as a string
converts the string to a Double (object wrapper for primitive double)
unboxes the Double to a primitive double
We could break it down
String tmp = fstNmElmntLst.item(k).getTextContent(); // fetch some string
Double wrapper = Double.valueOf(tmp); // convert (parse string to a number)
double value = wrapper; // unbox
A more efficient way to do this would be to use the parseDouble utility function. This avoids an unnecessary intermediate object being created:
double value = Double.parseDouble(fstNmElmntLst.item(k).getTextContent());
If you're new to java, have a look at some starter tutorials on the oracle.com site, for example Number Classes tutorial. If you're ever unsure of a behaviour of particular function just look at the javadocs. Just google something like "Double.valueOf javadoc 6" or setup your IDE properly.
Here's the javadoc for Double.valueOf(String). It will give you the full info on expected inputs, outputs, and other useful info like exceptions, in this case the NumberFormatException, which is thrown if your text can't be interrupted as a number.

It takes a text content of an item with index k from some kind of list fstNmElmntLst and parses that text as a double value.

This is casting from string to double because of array element, but there should be array value numeric else exception will raise.

Apparently getTextContent returns String. The typical way to convert String to double is to use the valueOf method in the class Double. As one can convert from Double to the primitive type double, the way to convert a String to double is to pass the string to valueOf in Double.

Java Double to String conversion without formatting

I have the number 654987. Its an ID in a database. I want to convert it to a string.
The regular Double.ToString(value) makes it into scientific form, 6.54987E5. Something I dont want.
Other formatting functions Ive found checks the current locale and adds appropriate thousand separators and such. Since its an ID, I cant accept any formatting at all.
How to do it?
[Edit] To clarify: Im working on a special database that treats all numeric columns as doubles. Double is the only (numeric) type I can retrieve from the database.

Use a fixed NumberFormat (specifically a DecimalFormat):
double value = getValue();
String str = new DecimalFormat("#").format(value);
alternatively simply cast to int (or long if the range of values it too big):
String str = String.valueOf((long) value);
But then again: why do you have an integer value (i.e. a "whole" number) in a double variable in the first place?

Use Long:
long id = 654987;
String str = Long.toString(id);

If it's an integer id in the database, use an Integer instead. Then it will format as an integer.

How about String.valueOf((long)value);

What about:
Long.toString(value)
or
new String(value)

Also you can use
double value = getValue();
NumberFormat f = NumberFormat.getInstance();
f.setGroupingUsed(false);
String strVal = f.format(value);

If what you are storing is an ID (i.e. something used only to identify another entity, whose actual numeric value has no significance) then you shouldn't be using Double to store it. Precision will almost certainly screw you.
If your database doesn't allow integer values then you should stored IDs as strings. If necessary make the string the string representation of the integer you want to use. With appropriate use of leading zeros you can make the alphabetic order of the string the same as the numeric order of the ints.
That should get you round the issue.

What about Long.toString((long)value) ?

double d = 56789;
String s = d+"";