Strings

[freesoft_2000]

Hi everyone,

I have a rather silly question but what is the maximum amount of characters the String object can hold?

This is what i mean

String str1 = some buffer that contains about 5 million characters as a string

What i am afraid is that if the String object may throw an exception if i return a huge string object say something down the lines of 5-50 million characters as a string. Will there be stack overflow?

I hope someone can help me with this

Thank You

Yours Sincerely

Richard West

[Norm]

Have you read the doc? What does it say?

[freesoft_2000]

Hi everyone,

Have you read the doc? What does it say?

If you are talking about the String.length() where the maximum is about 2gigs then i know that but what is also an issue for me is the problem of immutable and mutable.

The reason why i am using the string in this way is because the object that is returning the huge string is a document.

String str1 = JTextPane.getText();

Why i need this is because i use this method to search the document for a certain string. Everything works but i am afraid that if the document returns a huge string from the document, i may actually exceed the limit.

On the mutability issue i also felt that because the String object is immutable would it be better if i use the StringBuffer class as that does not create a copy of the string something like that

StringBuffer str1 = new StringBuffer(JTextPane.getText());

Would this in your opinion norm actually make a difference in that the String object is immutable and the StringBuffer object is mutable?

Any help is greatly appreciated

Thank You

Yours Sincerely

Richard West

[Norm]

Write a test program to see how large a string you can put in a String object. Be sure to give the java.exe enough space by using the -Xms option.

Please post the results here so we'll all know.

[prometheuzz]

Hi Richard,

Did you check the rest of the Java forums where you posted this question? I saw that some guys on Daniweb gave some interesting answers, you'd check it out. If the answer is there, could you please leave a note here that your question has been aswered? Otherwise other people here might put some time in it while you've already been answered.

Cheers.

[freesoft_2000]

Hi everyone,

Here are the results. There does not seem to be striaght answer for this but this is far the best so far.

You see since the getText returns a string, i'm stuck with the string immutable object. Now this is what i did

This can hold a maximum of nearly 5 million characters under 64M of Ram

String str1 = JTextPane.getText();

This can hold a maximum of nearly 10 million characters under 64M of Ram

StringBuffer str1 = new StringBuffer(JTextPane.getText());

I tried digging further and found out that this is due to the fact that the StringBuffer is mutable and the String object is immutable, that's why i got nearly twice the characters on the same amount of memory for the StringBuffer.

Please note that i tried this calculation by trial and error so the figures are not very accurate but the factor by which they differ seems fairly consistant

So i think the only solution is to use the StringBuffer and hope the people that use my application keep their characters under 2Gig(which i think is fair)

Yours Sincerely

Richard West

[Norm]

A reason that the Stringbuffer allows more is probably because there is only one copy of the chars in memory. In trying to create a String from a StringBuffer there will be two copies: one in each.
So if you want to have LOTS of chars in memory, you need a suite of methods for StringBuffer to do the functions of those done by the String methods.