StringBuffer

[Venkat Ramsimha]

public synchronized StringBuffer insert(int offset, String s)

Hi all
Can anybody provide a program with the implementation of the above method

Thanks&Cheers
venkat

[Joe Sondow]

You can read the implementation code. It came with your JDK. Open your JDK folder and find the src.zip file. Unzip that file to a directory, and you can browse all of Sun's implementation code for the built-in classes, with the exception of native methods.

Here's the code for that method from the StringBuffer.java source file:

    public synchronized StringBuffer insert(int offset, String str) {
        if ((offset < 0) || (offset > count)) {
            throw new StringIndexOutOfBoundsException();
        }
 
        if (str == null) {
            str = String.valueOf(str);
        }
        int len = str.length();
        int newcount = count + len;
        if (newcount > value.length)
            expandCapacity(newcount);
        else if (shared)
            copy();
        System.arraycopy(value, offset, value, offset + len, count - offset);
        str.getChars(0, len, value, offset);
        count = newcount;
        return this;
    }

[Saranyan Narayanan]

Joe,
Venkat is probably asking , can a sample program show me how to use String buffer method insert()

[Raghu Shree]

I just give the simple example of how to use the StringBuffer method insert(). Some of the different version of insert method is given below.

public java.lang.StringBuffer insert(int, boolean);
public synchronized java.lang.StringBuffer insert(int, char);
public java.lang.StringBuffer insert(int, int);
public java.lang.StringBuffer insert(int, long);
public java.lang.StringBuffer insert(int, float);
public java.lang.StringBuffer insert(int, double);
public java.lang.StringBuffer insert(int offset, char[] str);

Here argument no 1 means place of the position to be inserted.
argument no 2 means which type of representation to be inserteed.

class testStringBuffer
{
 public static void main(String args[])
 {
 char a[]={'H','e','l','l','o'};
 StringBuffer s = new StringBuffer("Java Programming");
 System.out.println(s.insert(4,true));
 System.out.println(s.insert(4,'-'));
 System.out.println(s.insert(4,1));
 System.out.println(s.insert(4,111L));
 System.out.println(s.insert(4,1.00f));
 System.out.println(s.insert(4,1.00));
 System.out.println(s.insert(4,new String(" Good")));
 System.out.println(s.insert(4,a));
 System.out.println (s.insert(4,"Hai"));
}
}

Output of the above program is

Javatrue Programming
Java-true Programming
Java1-true Programming
Java1111-true Programming
Java1.01111-true Programming
Java1.01.01111-true Programming
Java Good1.01.01111-true Programming
JavaHello Good1.01.01111-true Programming
JavaHaiHello Good1.01.01111-true Programming