Home » openjdk-7 » java » lang » [javadoc | source]
java.lang
abstract class: AbstractStringBuilder [javadoc | source]
java.lang.Object
   java.lang.AbstractStringBuilder

All Implemented Interfaces:
    CharSequence, Appendable

Direct Known Subclasses:
    StringBuilder, StringBuffer

A mutable sequence of characters.

Implements a modifiable string. At any point in time it contains some particular sequence of characters, but the length and content of the sequence can be changed through certain method calls.

Field Summary
 char[] value    The value is used for character storage. 
 int count    The count is the number of characters used. 
Constructor:
 AbstractStringBuilder() 
 AbstractStringBuilder(int capacity) 
Method from java.lang.AbstractStringBuilder Summary:
append,   append,   append,   append,   append,   append,   append,   append,   append,   append,   append,   append,   append,   appendCodePoint,   capacity,   charAt,   codePointAt,   codePointBefore,   codePointCount,   delete,   deleteCharAt,   ensureCapacity,   expandCapacity,   getChars,   getValue,   indexOf,   indexOf,   insert,   insert,   insert,   insert,   insert,   insert,   insert,   insert,   insert,   insert,   insert,   insert,   lastIndexOf,   lastIndexOf,   length,   offsetByCodePoints,   replace,   reverse,   setCharAt,   setLength,   subSequence,   substring,   substring,   toString,   trimToSize
Methods from java.lang.Object:
clone,   equals,   finalize,   getClass,   hashCode,   notify,   notifyAll,   toString,   wait,   wait,   wait
Method from java.lang.AbstractStringBuilder Detail:
 public AbstractStringBuilder append(Object obj) 
    Appends the string representation of the {@code Object} argument.

    The overall effect is exactly as if the argument were converted to a string by the method String#valueOf(Object) , and the characters of that string were then appended to this character sequence.

 public AbstractStringBuilder append(String str) 
    Appends the specified string to this character sequence.

    The characters of the {@code String} argument are appended, in order, increasing the length of this sequence by the length of the argument. If {@code str} is {@code null}, then the four characters {@code "null"} are appended.

    Let n be the length of this character sequence just prior to execution of the {@code 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 {@code str}.

 public AbstractStringBuilder append(StringBuffer sb) 
 public AbstractStringBuilder append(CharSequence s) 
 public AbstractStringBuilder append(char[] str) 
    Appends the string representation of the {@code char} array argument to this sequence.

    The characters of the array argument are appended, in order, to the contents of this sequence. The length of this sequence increases by the length of the argument.

    The overall effect is exactly as if the argument were converted to a string by the method String#valueOf(char[]) , and the characters of that string were then appended to this character sequence.

 public AbstractStringBuilder append(boolean b) 
    Appends the string representation of the {@code boolean} argument to the sequence.

    The overall effect is exactly as if the argument were converted to a string by the method String#valueOf(boolean) , and the characters of that string were then appended to this character sequence.

 public AbstractStringBuilder append(char c) 
    Appends the string representation of the {@code char} argument to this sequence.

    The argument is appended to the contents of this sequence. The length of this sequence increases by {@code 1}.

    The overall effect is exactly as if the argument were converted to a string by the method String#valueOf(char) , and the character in that string were then appended to this character sequence.

 public AbstractStringBuilder append(int i) 
    Appends the string representation of the {@code int} argument to this sequence.

    The overall effect is exactly as if the argument were converted to a string by the method String#valueOf(int) , and the characters of that string were then appended to this character sequence.

 public AbstractStringBuilder append(long l) 
    Appends the string representation of the {@code long} argument to this sequence.

    The overall effect is exactly as if the argument were converted to a string by the method String#valueOf(long) , and the characters of that string were then appended to this character sequence.

 public AbstractStringBuilder append(float f) 
    Appends the string representation of the {@code float} argument to this sequence.

    The overall effect is exactly as if the argument were converted to a string by the method String#valueOf(float) , and the characters of that string were then appended to this character sequence.

 public AbstractStringBuilder append(double d) 
    Appends the string representation of the {@code double} argument to this sequence.

    The overall effect is exactly as if the argument were converted to a string by the method String#valueOf(double) , and the characters of that string were then appended to this character sequence.

 public AbstractStringBuilder append(CharSequence s,
    int start,
    int end) 
    Appends a subsequence of the specified {@code CharSequence} to this sequence.

    Characters of the argument {@code s}, starting at index {@code start}, are appended, in order, to the contents of this sequence up to the (exclusive) index {@code end}. The length of this sequence is increased by the value of {@code end - start}.

    Let n be the length of this character sequence just prior to execution of the {@code append} method. Then the character at index k in this character sequence becomes equal to the character at index k in this sequence, if k is less than n; otherwise, it is equal to the character at index k+start-n in the argument {@code s}.

    If {@code s} is {@code null}, then this method appends characters as if the s parameter was a sequence containing the four characters {@code "null"}.

 public AbstractStringBuilder append(char[] str,
    int offset,
    int len) 
    Appends the string representation of a subarray of the {@code char} array argument to this sequence.

    Characters of the {@code char} array {@code str}, starting at index {@code offset}, are appended, in order, to the contents of this sequence. The length of this sequence increases by the value of {@code len}.

    The overall effect is exactly as if the arguments were converted to a string by the method String#valueOf(char[],int,int) , and the characters of that string were then appended to this character sequence.

 public AbstractStringBuilder appendCodePoint(int codePoint) 
    Appends the string representation of the {@code codePoint} argument to this sequence.

    The argument is appended to the contents of this sequence. The length of this sequence increases by Character.charCount(codePoint) .

    The overall effect is exactly as if the argument were converted to a {@code char} array by the method Character#toChars(int) and the character in that array were then appended to this character sequence.

 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.
 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.

 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.

 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.

 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.
 public AbstractStringBuilder delete(int start,
    int end) 
    Removes the characters in a substring of this sequence. The substring begins at the specified {@code start} and extends to the character at index {@code end - 1} or to the end of the sequence if no such character exists. If {@code start} is equal to {@code end}, no changes are made.
 public AbstractStringBuilder deleteCharAt(int index) 
    Removes the char at the specified position in this sequence. This sequence is shortened by one char.

    Note: If the character at the given index is a supplementary character, this method does not remove the entire character. If correct handling of supplementary characters is required, determine the number of chars to remove by calling Character.charCount(thisSequence.codePointAt(index)), where thisSequence is this sequence.

 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.
    If the minimumCapacity argument is nonpositive, this method takes no action and simply returns.
  void expandCapacity(int minimumCapacity) 
    This implements the expansion semantics of ensureCapacity with no size check or synchronization.
 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
    
 final char[] getValue() 
    Needed by String for the contentEquals method.
 public int indexOf(String str) 
    Returns the index within this string of the first occurrence of the specified substring. The integer returned is the smallest value k such that:
    this.toString().startsWith(str, k)
    
    is true.
 public int indexOf(String str,
    int fromIndex) 
    Returns the index within this string of the first occurrence of the specified substring, starting at the specified index. The integer returned is the smallest value k for which:
        k >= Math.min(fromIndex, str.length()) &&
                      this.toString().startsWith(str, k)
    
    If no such value of k exists, then -1 is returned.
 public AbstractStringBuilder insert(int offset,
    Object obj) 
    Inserts the string representation of the {@code Object} argument into this character sequence.

    The overall effect is exactly as if the second argument were converted to a string by the method String#valueOf(Object) , and the characters of that string were then inserted into this character sequence at the indicated offset.

    The {@code offset} argument must be greater than or equal to {@code 0}, and less than or equal to the {@linkplain #length() length} of this sequence.

 public AbstractStringBuilder insert(int offset,
    String str) 
    Inserts the string into this character sequence.

    The characters of the {@code String} argument are inserted, in order, into this sequence at the indicated offset, moving up any characters originally above that position and increasing the length of this sequence by the length of the argument. If {@code str} is {@code null}, then the four characters {@code "null"} are inserted into this sequence.

    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 {@code offset}
    • the character at index k{@code -offset} in the argument {@code str}, if k is not less than {@code offset} but is less than {@code offset+str.length()}
    • the character at index k{@code -str.length()} in the old character sequence, if k is not less than {@code offset+str.length()}

    The {@code offset} argument must be greater than or equal to {@code 0}, and less than or equal to the {@linkplain #length() length} of this sequence.

 public AbstractStringBuilder insert(int offset,
    char[] str) 
    Inserts the string representation of the {@code char} array argument into this sequence.

    The characters of the array argument are inserted into the contents of this sequence at the position indicated by {@code offset}. The length of this sequence increases by the length of the argument.

    The overall effect is exactly as if the second argument were converted to a string by the method String#valueOf(char[]) , and the characters of that string were then inserted into this character sequence at the indicated offset.

    The {@code offset} argument must be greater than or equal to {@code 0}, and less than or equal to the {@linkplain #length() length} of this sequence.

 public AbstractStringBuilder insert(int dstOffset,
    CharSequence s) 
    Inserts the specified {@code CharSequence} into this sequence.

    The characters of the {@code CharSequence} argument are inserted, in order, into this sequence at the indicated offset, moving up any characters originally above that position and increasing the length of this sequence by the length of the argument s.

    The result of this method is exactly the same as if it were an invocation of this object's insert (dstOffset, s, 0, s.length()) method.

    If {@code s} is {@code null}, then the four characters {@code "null"} are inserted into this sequence.

 public AbstractStringBuilder insert(int offset,
    boolean b) 
    Inserts the string representation of the {@code boolean} argument into this sequence.

    The overall effect is exactly as if the second argument were converted to a string by the method String#valueOf(boolean) , and the characters of that string were then inserted into this character sequence at the indicated offset.

    The {@code offset} argument must be greater than or equal to {@code 0}, and less than or equal to the {@linkplain #length() length} of this sequence.

 public AbstractStringBuilder insert(int offset,
    char c) 
    Inserts the string representation of the {@code char} argument into this sequence.

    The overall effect is exactly as if the second argument were converted to a string by the method String#valueOf(char) , and the character in that string were then inserted into this character sequence at the indicated offset.

    The {@code offset} argument must be greater than or equal to {@code 0}, and less than or equal to the {@linkplain #length() length} of this sequence.

 public AbstractStringBuilder insert(int offset,
    int i) 
    Inserts the string representation of the second {@code int} argument into this sequence.

    The overall effect is exactly as if the second argument were converted to a string by the method String#valueOf(int) , and the characters of that string were then inserted into this character sequence at the indicated offset.

    The {@code offset} argument must be greater than or equal to {@code 0}, and less than or equal to the {@linkplain #length() length} of this sequence.

 public AbstractStringBuilder insert(int offset,
    long l) 
    Inserts the string representation of the {@code long} argument into this sequence.

    The overall effect is exactly as if the second argument were converted to a string by the method String#valueOf(long) , and the characters of that string were then inserted into this character sequence at the indicated offset.

    The {@code offset} argument must be greater than or equal to {@code 0}, and less than or equal to the {@linkplain #length() length} of this sequence.

 public AbstractStringBuilder insert(int offset,
    float f) 
    Inserts the string representation of the {@code float} argument into this sequence.

    The overall effect is exactly as if the second argument were converted to a string by the method String#valueOf(float) , and the characters of that string were then inserted into this character sequence at the indicated offset.

    The {@code offset} argument must be greater than or equal to {@code 0}, and less than or equal to the {@linkplain #length() length} of this sequence.

 public AbstractStringBuilder insert(int offset,
    double d) 
    Inserts the string representation of the {@code double} argument into this sequence.

    The overall effect is exactly as if the second argument were converted to a string by the method String#valueOf(double) , and the characters of that string were then inserted into this character sequence at the indicated offset.

    The {@code offset} argument must be greater than or equal to {@code 0}, and less than or equal to the {@linkplain #length() length} of this sequence.

 public AbstractStringBuilder insert(int index,
    char[] str,
    int offset,
    int len) 
    Inserts the string representation of a subarray of the {@code str} array argument into this sequence. The subarray begins at the specified {@code offset} and extends {@code len} {@code char}s. The characters of the subarray are inserted into this sequence at the position indicated by {@code index}. The length of this sequence increases by {@code len} {@code char}s.
 public AbstractStringBuilder insert(int dstOffset,
    CharSequence s,
    int start,
    int end) 
    Inserts a subsequence of the specified {@code CharSequence} into this sequence.

    The subsequence of the argument {@code s} specified by {@code start} and {@code end} are inserted, in order, into this sequence at the specified destination offset, moving up any characters originally above that position. The length of this sequence is increased by {@code end - start}.

    The character at index k in this sequence becomes equal to:

    • the character at index k in this sequence, if k is less than {@code dstOffset}
    • the character at index k{@code +start-dstOffset} in the argument {@code s}, if k is greater than or equal to {@code dstOffset} but is less than {@code dstOffset+end-start}
    • the character at index k{@code -(end-start)} in this sequence, if k is greater than or equal to {@code dstOffset+end-start}

    The {@code dstOffset} argument must be greater than or equal to {@code 0}, and less than or equal to the {@linkplain #length() length} of this sequence.

    The start argument must be nonnegative, and not greater than {@code end}.

    The end argument must be greater than or equal to {@code start}, and less than or equal to the length of s.

    If {@code s} is {@code null}, then this method inserts characters as if the s parameter was a sequence containing the four characters {@code "null"}.

 public int lastIndexOf(String str) 
    Returns the index within this string of the rightmost occurrence of the specified substring. The rightmost empty string "" is considered to occur at the index value this.length(). The returned index is the largest value k such that
    this.toString().startsWith(str, k)
    
    is true.
 public int lastIndexOf(String str,
    int fromIndex) 
    Returns the index within this string of the last occurrence of the specified substring. The integer returned is the largest value k such that:
        k <= Math.min(fromIndex, str.length()) &&
                      this.toString().startsWith(str, k)
    
    If no such value of k exists, then -1 is returned.
 public int length() 
    Returns the length (character count).
 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.
 public AbstractStringBuilder replace(int start,
    int end,
    String str) 
    Replaces the characters in a substring of this sequence with characters in the specified String. The substring begins at the specified start and extends to the character at index end - 1 or to the end of the sequence if no such character exists. First the characters in the substring are removed and then the specified String is inserted at start. (This sequence will be lengthened to accommodate the specified String if necessary.)
 public AbstractStringBuilder reverse() 
    Causes this character sequence to be replaced by the reverse of the sequence. If there are any surrogate pairs included in the sequence, these are treated as single characters for the reverse operation. Thus, the order of the high-low surrogates is never reversed. Let n be the character length of this character sequence (not the length in char values) just prior to execution of the reverse method. Then the character at index k in the new character sequence is equal to the character at index n-k-1 in the old character sequence.

    Note that the reverse operation may result in producing surrogate pairs that were unpaired low-surrogates and high-surrogates before the operation. For example, reversing "\uDC00\uD800" produces "\uD800\uDC00" which is a valid surrogate pair.

 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.

 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.

 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)
    behaves in exactly the same way as the invocation
    sb.substring(begin, end)
    This method is provided so that this class can implement the CharSequence interface.

 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.
 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.
 abstract public String toString()
    Returns a string representing the data in this sequence. A new String object is allocated and initialized to contain the character sequence currently represented by this object. This String is then returned. Subsequent changes to this sequence do not affect the contents of the String.
 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.