StringBuilder

See also:

• StringBuffer
• String

StringBuilder

public StringBuilder ()

Constructs a string builder with no characters in it and an initial capacity of 16 characters.

StringBuilder

public StringBuilder (int capacity)

Constructs a string builder with no characters in it and an initial capacity specified by the capacity argument.

StringBuilder

public StringBuilder (CharSequence seq)

Constructs a string builder that contains the same characters as the specified CharSequence. The initial capacity of the string builder is 16 plus the length of the CharSequence argument.

StringBuilder

public StringBuilder (String str)

Constructs a string builder initialized to the contents of the specified string. The initial capacity of the string builder is 16 plus the length of the string argument.

append

public StringBuilder append (boolean b)

append

public StringBuilder append (long lng)

append

public StringBuilder append (char c)

Appends the specified character to this Appendable.

append

public StringBuilder append (Object obj)

append

public StringBuilder append (char[] str, 
                int offset, 
                int len)

append

public StringBuilder append (double d)

append

public StringBuilder append (char[] str)

append

public StringBuilder append (String str)

append

public StringBuilder append (StringBuffer sb)

Appends the specified StringBuffer to this sequence.

The characters of the StringBuffer argument are appended, in order, to this sequence, increasing the length of this sequence by the length of the argument. If sb is null, then the four characters "null" are appended to this sequence.

Let n be the length of this character sequence just prior to execution of the append method. Then the character at index k in the new character sequence is equal to the character at index k in the old character sequence, if k is less than n; otherwise, it is equal to the character at index k-n in the argument sb.

append

public StringBuilder append (float f)

append

public StringBuilder append (int i)

append

public StringBuilder append (CharSequence s, 
                int start, 
                int end)

Appends a subsequence of the specified character sequence to this Appendable.

An invocation of this method of the form out.append(csq, start, end) when csq is not null, behaves in exactly the same way as the invocation

     out.append(csq.subSequence(start, end)) 

append

public StringBuilder append (CharSequence s)

Appends the specified character sequence to this Appendable.

Depending on which class implements the character sequence csq, the entire sequence may not be appended. For instance, if csq is a CharBuffer then the subsequence to append is defined by the buffer's position and limit.

appendCodePoint

public StringBuilder appendCodePoint (int codePoint)

capacity

public int capacity ()

Returns the current capacity. The capacity is the amount of storage available for newly inserted characters, beyond which an allocation will occur.

charAt

public char charAt (int index)

Returns the char value in this sequence at the specified index. The first char value is at index 0, the next at index 1, and so on, as in array indexing.

The index argument must be greater than or equal to 0, and less than the length of this sequence.

If the char value specified by the index is a surrogate, the surrogate value is returned.

chars

public IntStream chars ()

Returns a stream of int zero-extending the char values from this sequence. Any char which maps to a surrogate code point is passed through uninterpreted.

The stream binds to this sequence when the terminal stream operation commences (specifically, for mutable sequences the spliterator for the stream is late-binding). If the sequence is modified during that operation then the result is undefined.

codePointAt

public int codePointAt (int index)

Returns the character (Unicode code point) at the specified index. The index refers to char values (Unicode code units) and ranges from 0 to length()- 1.

If the char value specified at the given index is in the high-surrogate range, the following index is less than the length of this sequence, and the char value at the following index is in the low-surrogate range, then the supplementary code point corresponding to this surrogate pair is returned. Otherwise, the char value at the given index is returned.

codePointBefore

public int codePointBefore (int index)

Returns the character (Unicode code point) before the specified index. The index refers to char values (Unicode code units) and ranges from 1 to length().

If the char value at (index - 1) is in the low-surrogate range, (index - 2) is not negative, and the char value at (index - 2) is in the high-surrogate range, then the supplementary code point value of the surrogate pair is returned. If the char value at index - 1 is an unpaired low-surrogate or a high-surrogate, the surrogate value is returned.

codePointCount

public int codePointCount (int beginIndex, 
                int endIndex)

Returns the number of Unicode code points in the specified text range of this sequence. The text range begins at the specified beginIndex and extends to the char at index endIndex - 1. Thus the length (in chars) of the text range is endIndex-beginIndex. Unpaired surrogates within this sequence count as one code point each.

codePoints

public IntStream codePoints ()

Returns a stream of code point values from this sequence. Any surrogate pairs encountered in the sequence are combined as if by Character.toCodePoint and the result is passed to the stream. Any other code units, including ordinary BMP characters, unpaired surrogates, and undefined code units, are zero-extended to int values which are then passed to the stream.

The stream binds to this sequence when the terminal stream operation commences (specifically, for mutable sequences the spliterator for the stream is late-binding). If the sequence is modified during that operation then the result is undefined.

compareTo

public int compareTo (StringBuilder another)

Compares two StringBuilder instances lexicographically. This method follows the same rules for lexicographical comparison as defined in the CharSequence.compare(this, another) method.

For finer-grained, locale-sensitive String comparison, refer to Collator.

delete

public StringBuilder delete (int start, 
                int end)

deleteCharAt

public StringBuilder deleteCharAt (int index)

ensureCapacity

public void ensureCapacity (int minimumCapacity)

Ensures that the capacity is at least equal to the specified minimum. If the current capacity is less than the argument, then a new internal array is allocated with greater capacity. The new capacity is the larger of:

• The minimumCapacity argument.
• Twice the old capacity, plus 2.

getChars

public void getChars (int srcBegin, 
                int srcEnd, 
                char[] dst, 
                int dstBegin)

Characters are copied from this sequence into the destination character array dst. The first character to be copied is at index srcBegin; the last character to be copied is at index srcEnd-1. The total number of characters to be copied is srcEnd-srcBegin. The characters are copied into the subarray of dst starting at index dstBegin and ending at index:

dstbegin + (srcEnd-srcBegin) - 1
 

indexOf

public int indexOf (String str)

indexOf

public int indexOf (String str, 
                int fromIndex)

insert

public StringBuilder insert (int offset, 
                char[] str)

insert

public StringBuilder insert (int offset, 
                float f)

insert

public StringBuilder insert (int dstOffset, 
                CharSequence s)

insert

public StringBuilder insert (int offset, 
                char c)

insert

public StringBuilder insert (int offset, 
                long l)

insert

public StringBuilder insert (int index, 
                char[] str, 
                int offset, 
                int len)

insert

public StringBuilder insert (int offset, 
                int i)

insert

public StringBuilder insert (int offset, 
                String str)

insert

public StringBuilder insert (int offset, 
                double d)

insert

public StringBuilder insert (int dstOffset, 
                CharSequence s, 
                int start, 
                int end)

insert

public StringBuilder insert (int offset, 
                boolean b)

insert

public StringBuilder insert (int offset, 
                Object obj)

lastIndexOf

public int lastIndexOf (String str, 
                int fromIndex)

lastIndexOf

public int lastIndexOf (String str)

length

public int length ()

Returns the length (character count).

offsetByCodePoints

public int offsetByCodePoints (int index, 
                int codePointOffset)

Returns the index within this sequence that is offset from the given index by codePointOffset code points. Unpaired surrogates within the text range given by index and codePointOffset count as one code point each.

replace

public StringBuilder replace (int start, 
                int end, 
                String str)

reverse

public StringBuilder reverse ()

setCharAt

public void setCharAt (int index, 
                char ch)

The character at the specified index is set to ch. This sequence is altered to represent a new character sequence that is identical to the old character sequence, except that it contains the character ch at position index.

The index argument must be greater than or equal to 0, and less than the length of this sequence.

setLength

public void setLength (int newLength)

Sets the length of the character sequence. The sequence is changed to a new character sequence whose length is specified by the argument. For every nonnegative index k less than newLength, the character at index k in the new character sequence is the same as the character at index k in the old sequence if k is less than the length of the old character sequence; otherwise, it is the null character '\u0000'. In other words, if the newLength argument is less than the current length, the length is changed to the specified length.

If the newLength argument is greater than or equal to the current length, sufficient null characters ('\u0000') are appended so that length becomes the newLength argument.

The newLength argument must be greater than or equal to 0.

subSequence

public CharSequence subSequence (int start, 
                int end)

Returns a new character sequence that is a subsequence of this sequence.

An invocation of this method of the form

sb.subSequence(begin, end)

sb.substring(begin, end)

substring

public String substring (int start, 
                int end)

Returns a new String that contains a subsequence of characters currently contained in this sequence. The substring begins at the specified start and extends to the character at index end - 1.

substring

public String substring (int start)

Returns a new String that contains a subsequence of characters currently contained in this character sequence. The substring begins at the specified index and extends to the end of this sequence.

toString

public String toString ()

Returns a string representation of the object.

trimToSize

public void trimToSize ()

Attempts to reduce storage used for the character sequence. If the buffer is larger than necessary to hold its current sequence of characters, then it may be resized to become more space efficient. Calling this method may, but is not required to, affect the value returned by a subsequent call to the capacity() method.