public class StringBuilder
extends java.lang.Object
implements java.lang.Appendable, java.lang.CharSequence
StringBuilder that implements equals and hashcode.CharSequence,
Appendable,
StringBuilder,
String| Constructor and Description |
|---|
StringBuilder()
Constructs an instance with an initial capacity of
16. |
StringBuilder(java.lang.CharSequence seq)
Constructs an instance that's initialized with the contents of the specified
CharSequence. |
StringBuilder(int capacity)
Constructs an instance with the specified capacity.
|
StringBuilder(java.lang.String string)
Constructs an instance that's initialized with the contents of the specified
String. |
StringBuilder(StringBuilder builder) |
| Modifier and Type | Method and Description |
|---|---|
StringBuilder |
append(boolean b)
Appends the string representation of the specified
boolean value. |
StringBuilder |
append(char c)
Appends the string representation of the specified
char value. |
StringBuilder |
append(char[] ch)
Appends the string representation of the specified
char[]. |
StringBuilder |
append(char[] str,
int offset,
int len)
Appends the string representation of the specified subset of the
char[]. |
StringBuilder |
append(java.lang.CharSequence csq)
Appends the string representation of the specified
CharSequence. |
StringBuilder |
append(java.lang.CharSequence csq,
int start,
int end)
Appends the string representation of the specified subsequence of the
CharSequence. |
StringBuilder |
append(double d)
Appends the string representation of the specified
double value. |
StringBuilder |
append(float f)
Appends the string representation of the specified
float value. |
StringBuilder |
append(int value)
Appends the string representation of the specified
int value. |
StringBuilder |
append(int value,
int minLength)
Appends the string representation of the specified
int value. |
StringBuilder |
append(int value,
int minLength,
char prefix)
Appends the string representation of the specified
int value. |
StringBuilder |
append(long value)
Appends the string representation of the specified
long value. |
StringBuilder |
append(long value,
int minLength)
Appends the string representation of the specified
long value. |
StringBuilder |
append(long value,
int minLength,
char prefix)
Appends the string representation of the specified
long value. |
StringBuilder |
append(java.lang.Object obj)
Appends the string representation of the specified
Object. |
StringBuilder |
append(java.lang.String str)
Appends the contents of the specified string.
|
StringBuilder |
append(StringBuilder builder) |
StringBuilder |
append(StringBuilder builder,
int start,
int end) |
StringBuilder |
appendCodePoint(int codePoint)
Appends the encoded Unicode code point.
|
StringBuilder |
appendLine(java.lang.String str)
Appends the contents of the specified string, then create a new line.
|
int |
capacity()
Returns the number of characters that can be held without growing.
|
char |
charAt(int index)
Retrieves the character at the
index. |
void |
clear()
Sets length to 0.
|
int |
codePointAt(int index)
Retrieves the Unicode code point value at the
index. |
int |
codePointBefore(int index)
Retrieves the Unicode code point value that precedes the
index. |
int |
codePointCount(int beginIndex,
int endIndex)
Calculates the number of Unicode code points between
beginIndex and endIndex. |
boolean |
contains(java.lang.String subString) |
boolean |
containsIgnoreCase(java.lang.String subString) |
StringBuilder |
delete(int start,
int end)
Deletes a sequence of characters specified by
start and end. |
StringBuilder |
deleteCharAt(int index)
Deletes the character at the specified index.
|
void |
ensureCapacity(int min)
Ensures that this object has a minimum capacity available before requiring the internal buffer to be enlarged.
|
boolean |
equals(java.lang.Object obj) |
boolean |
equalsIgnoreCase(java.lang.String other) |
boolean |
equalsIgnoreCase(StringBuilder other) |
void |
getChars(int start,
int end,
char[] dest,
int destStart)
Copies the requested sequence of characters to the
char[] passed starting at destStart. |
int |
hashCode() |
int |
indexOf(java.lang.String string)
Searches for the first index of the specified character.
|
int |
indexOf(java.lang.String subString,
int start)
Searches for the index of the specified character.
|
int |
indexOfIgnoreCase(java.lang.String subString,
int start) |
StringBuilder |
insert(int offset,
boolean b)
Inserts the string representation of the specified
boolean value at the specified offset. |
StringBuilder |
insert(int offset,
char c)
Inserts the string representation of the specified
char value at the specified offset. |
StringBuilder |
insert(int offset,
char[] ch)
Inserts the string representation of the specified
char[] at the specified offset. |
StringBuilder |
insert(int offset,
char[] str,
int strOffset,
int strLen)
Inserts the string representation of the specified subsequence of the
char[] at the specified offset. |
StringBuilder |
insert(int offset,
java.lang.CharSequence s)
Inserts the string representation of the specified
CharSequence at the specified offset. |
StringBuilder |
insert(int offset,
java.lang.CharSequence s,
int start,
int end)
Inserts the string representation of the specified subsequence of the
CharSequence at the specified offset. |
StringBuilder |
insert(int offset,
double d)
Inserts the string representation of the specified
double value at the specified offset. |
StringBuilder |
insert(int offset,
float f)
Inserts the string representation of the specified
float value at the specified offset. |
StringBuilder |
insert(int offset,
int i)
Inserts the string representation of the specified
int value at the specified offset. |
StringBuilder |
insert(int offset,
long l)
Inserts the string representation of the specified
long value at the specified offset. |
StringBuilder |
insert(int offset,
java.lang.Object obj)
Inserts the string representation of the specified
Object at the specified offset. |
StringBuilder |
insert(int offset,
java.lang.String str)
Inserts the specified string at the specified
offset. |
boolean |
isEmpty() |
int |
lastIndexOf(java.lang.String string)
Searches for the last index of the specified character.
|
int |
lastIndexOf(java.lang.String subString,
int start)
Searches for the index of the specified character.
|
int |
length()
The current length.
|
boolean |
notEmpty() |
static int |
numChars(int value,
int radix) |
static int |
numChars(long value,
int radix) |
int |
offsetByCodePoints(int index,
int codePointOffset)
Returns the index that is offset
codePointOffset code points from index. |
StringBuilder |
replace(char find,
java.lang.String replace)
Replaces all instances of
find with replace. |
StringBuilder |
replace(int start,
int end,
java.lang.String str)
Replaces the specified subsequence in this builder with the specified string.
|
StringBuilder |
replace(java.lang.String find,
java.lang.String replace)
Replaces all instances of
find with replace. |
StringBuilder |
reverse()
Reverses the order of characters in this builder.
|
void |
setCharAt(int index,
char ch)
Sets the character at the
index. |
void |
setLength(int newLength)
Sets the current length to a new value.
|
java.lang.CharSequence |
subSequence(int start,
int end)
Returns a
CharSequence of the subsequence from the start index to the end index. |
java.lang.String |
substring(int start)
Returns the String value of the subsequence from the
start index to the current end. |
java.lang.String |
substring(int start,
int end)
Returns the String value of the subsequence from the
start index to the end index. |
java.lang.String |
toString()
Returns the current String representation.
|
void |
trimToSize()
Trims off any extra capacity beyond the current length.
|
public StringBuilder()
16.capacity()public StringBuilder(int capacity)
capacity - the initial capacity to use.java.lang.NegativeArraySizeException - if the specified capacity is negative.capacity()public StringBuilder(java.lang.CharSequence seq)
CharSequence. The capacity of the new
builder will be the length of the CharSequence plus 16.seq - the CharSequence to copy into the builder.java.lang.NullPointerException - if seq is null.public StringBuilder(StringBuilder builder)
public StringBuilder(java.lang.String string)
String. The capacity of the new
builder will be the length of the String plus 16.string - the String to copy into the builder.java.lang.NullPointerException - if str is null.public static int numChars(int value,
int radix)
public static int numChars(long value,
int radix)
public int capacity()
ensureCapacity(int),
lengthpublic char charAt(int index)
index.charAt in interface java.lang.CharSequenceindex - the index of the character to retrieve.java.lang.IndexOutOfBoundsException - if index is negative or greater than or equal to the current length().public void ensureCapacity(int min)
minimumCapacity is larger than the current capacity(), then the
capacity will be increased to the largest value of either the minimumCapacity or the current capacity multiplied by
two plus two. Although this is the general policy, there is no guarantee that the capacity will change.min - the new minimum capacity to set.public void getChars(int start,
int end,
char[] dest,
int destStart)
char[] passed starting at destStart.start - the inclusive start index of the characters to copy.end - the exclusive end index of the characters to copy.dest - the char[] to copy the characters to.destStart - the inclusive start index of dest to begin copying to.java.lang.IndexOutOfBoundsException - if the start is negative, the destStart is negative, the start is
greater than end, the end is greater than the current length() or
destStart + end - begin is greater than dest.length.public int length()
length in interface java.lang.CharSequencepublic void setCharAt(int index,
char ch)
index.index - the zero-based index of the character to replace.ch - the character to set.java.lang.IndexOutOfBoundsException - if index is negative or greater than or equal to the current length().public void setLength(int newLength)
char value of