Class String

java.lang.Object

java.lang.String

All Implemented Interfaces:: Serializable, CharSequence, Comparable<String>, Constable, ConstantDesc

public final class String extends Object implements Serializable, Comparable<String>, CharSequence, Constable, ConstantDesc

The String class represents character strings. All string literals in Java programs, such as "abc", are implemented as instances of this class.

Strings are constant; their values cannot be changed after they are created. String buffers support mutable strings. Because String objects are immutable they can be shared. For example:

     String str = "abc";

is equivalent to:

     char data[] = {'a', 'b', 'c'};
     String str = new String(data);

Here are some more examples of how strings can be used:

     System.out.println("abc");
     String cde = "cde";
     System.out.println("abc" + cde);
     String c = "abc".substring(2, 3);
     String d = cde.substring(1, 2);

The class String includes methods for examining individual characters of the sequence, for comparing strings, for searching strings, for extracting substrings, and for creating a copy of a string with all characters translated to uppercase or to lowercase. Case mapping is based on the Unicode Standard version specified by the Character class.

The Java language provides special support for the string concatenation operator ( + ), and for conversion of other objects to strings. For additional information on string concatenation and conversion, see The Java Language Specification.

Unless otherwise noted, passing a null argument to a constructor or method in this class will cause a NullPointerException to be thrown.

A String represents a string in the UTF-16 format in which supplementary characters are represented by surrogate pairs (see the section Unicode Character Representations in the Character class for more information). Index values refer to char code units, so a supplementary character uses two positions in a String.

The String class provides methods for dealing with Unicode code points (i.e., characters), in addition to those for dealing with Unicode code units (i.e., char values).

Unless otherwise noted, methods for comparing Strings do not take locale into account. The Collator class provides methods for finer-grain, locale-sensitive String comparison.

Implementation Note:

The implementation of the string concatenation operator is left to the discretion of a Java compiler, as long as the compiler ultimately conforms to The Java Language Specification. For example, the javac compiler may implement the operator with StringBuffer, StringBuilder, or java.lang.invoke.StringConcatFactory depending on the JDK version. The implementation of string conversion is typically through the method toString, defined by Object and inherited by all classes in Java.

See Java Language Specification:

15.18.1 String Concatenation Operator +

Since:

1.0

See Also:

Field Summary

Modifier and Type	Field	Description
`static final Comparator<String>`	`CASE_INSENSITIVE_ORDER`	A Comparator that orders `String` objects as by `compareToIgnoreCase`.

Constructor Summary

Constructor	Description
`String()`	Initializes a newly created `String` object so that it represents an empty character sequence.
`String(byte[] bytes)`	Constructs a new `String` by decoding the specified array of bytes using the `default charset`.
`String(byte[] ascii, int hibyte)`	Deprecated. This method does not properly convert bytes into characters.
`String(byte[] bytes, int offset, int length)`	Constructs a new `String` by decoding the specified subarray of bytes using the `default charset`.
`String(byte[] ascii, int hibyte, int offset, int count)`	Deprecated. This method does not properly convert bytes into characters.
`String(byte[] bytes, int offset, int length, String charsetName)`	Constructs a new `String` by decoding the specified subarray of bytes using the specified charset.
`String(byte[] bytes, int offset, int length, Charset charset)`	Constructs a new `String` by decoding the specified subarray of bytes using the specified charset.
`String(byte[] bytes, String charsetName)`	Constructs a new `String` by decoding the specified array of bytes using the specified charset.
`String(byte[] bytes, Charset charset)`	Constructs a new `String` by decoding the specified array of bytes using the specified charset.
`String(char[] value)`	Allocates a new `String` so that it represents the sequence of characters currently contained in the character array argument.
`String(char[] value, int offset, int count)`	Allocates a new `String` that contains characters from a subarray of the character array argument.
`String(int[] codePoints, int offset, int count)`	Allocates a new `String` that contains characters from a subarray of the Unicode code point array argument.
`String(String original)`	Initializes a newly created `String` object so that it represents the same sequence of characters as the argument; in other words, the newly created string is a copy of the argument string.
`String(StringBuffer buffer)`	Allocates a new string that contains the sequence of characters currently contained in the string buffer argument.
`String(StringBuilder builder)`	Allocates a new string that contains the sequence of characters currently contained in the string builder argument.

Method Summary

Modifier and Type	Method	Description
`char`	`charAt(int index)`	Returns the `char` value at the specified index.
`IntStream`	`chars()`	Returns a stream of `int` zero-extending the `char` values from this sequence.
`int`	`codePointAt(int index)`	Returns the character (Unicode code point) at the specified index.
`int`	`codePointBefore(int index)`	Returns the character (Unicode code point) before the specified index.
`int`	`codePointCount(int beginIndex, int endIndex)`	Returns the number of Unicode code points in the specified text range of this `String`.
`IntStream`	`codePoints()`	Returns a stream of code point values from this sequence.
`int`	`compareTo(String anotherString)`	Compares two strings lexicographically.
`int`	`compareToIgnoreCase(String str)`	Compares two strings lexicographically, ignoring case differences.
`String`	`concat(String str)`	Concatenates the specified string to the end of this string.
`boolean`	`contains(CharSequence s)`	Returns true if and only if this string contains the specified sequence of char values.
`boolean`	`contentEquals(CharSequence cs)`	Compares this string to the specified `CharSequence`.
`boolean`	`contentEquals(StringBuffer sb)`	Compares this string to the specified `StringBuffer`.
`static String`	`copyValueOf(char[] data)`	Equivalent to `valueOf(char[])`.
`static String`	`copyValueOf(char[] data, int offset, int count)`	Equivalent to `valueOf(char[], int, int)`.
`Optional<String>`	`describeConstable()`	Returns an `Optional` containing the nominal descriptor for this instance, which is the instance itself.
`boolean`	`endsWith(String suffix)`	Tests if this string ends with the specified suffix.
`boolean`	`equals(Object anObject)`	Compares this string to the specified object.
`boolean`	`equalsIgnoreCase(String anotherString)`	Compares this `String` to another `String`, ignoring case considerations.
`static String`	`format(String format, Object... args)`	Returns a formatted string using the specified format string and arguments.
`static String`	`format(Locale l, String format, Object... args)`	Returns a formatted string using the specified locale, format string, and arguments.
`String`	`formatted(Object... args)`	Formats using this string as the format string, and the supplied arguments.
`byte[]`	`getBytes()`	Encodes this `String` into a sequence of bytes using the `default charset`, storing the result into a new byte array.
`void`	`getBytes(int srcBegin, int srcEnd, byte[] dst, int dstBegin)`	Deprecated. This method does not properly convert characters into bytes.
`byte[]`	`getBytes(String charsetName)`	Encodes this `String` into a sequence of bytes using the named charset, storing the result into a new byte array.
`byte[]`	`getBytes(Charset charset)`	Encodes this `String` into a sequence of bytes using the given charset, storing the result into a new byte array.
`void`	`getChars(int srcBegin, int srcEnd, char[] dst, int dstBegin)`	Copies characters from this string into the destination character array.
`int`	`hashCode()`	Returns a hash code for this string.
`String`	`indent(int n)`	Adjusts the indentation of each line of this string based on the value of `n`, and normalizes line termination characters.
`int`	`indexOf(int ch)`	Returns the index within this string of the first occurrence of the specified character.
`int`	`indexOf(int ch, int fromIndex)`	Returns the index within this string of the first occurrence of the specified character, starting the search at the specified index.
`int`	`indexOf(int ch, int beginIndex, int endIndex)`	Returns the index within this string of the first occurrence of the specified character, starting the search at `beginIndex` and stopping before `endIndex`.
`int`	`indexOf(String str)`	Returns the index within this string of the first occurrence of the specified substring.
`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.
`int`	`indexOf(String str, int beginIndex, int endIndex)`	Returns the index of the first occurrence of the specified substring within the specified index range of `this` string.
`String`	`intern()`	Returns a canonical representation for the string object.
`boolean`	`isBlank()`	Returns `true` if the string is empty or contains only white space codepoints, otherwise `false`.
`boolean`	`isEmpty()`	Returns `true` if, and only if, `length()` is `0`.
`static String`	`join(CharSequence delimiter, CharSequence... elements)`	Returns a new String composed of copies of the `CharSequence elements` joined together with a copy of the specified `delimiter`.
`static String`	`join(CharSequence delimiter, Iterable<? extends CharSequence> elements)`	Returns a new `String` composed of copies of the `CharSequence elements` joined together with a copy of the specified `delimiter`.
`int`	`lastIndexOf(int ch)`	Returns the index within this string of the last occurrence of the specified character.
`int`	`lastIndexOf(int ch, int fromIndex)`	Returns the index within this string of the last occurrence of the specified character, searching backward starting at the specified index.
`int`	`lastIndexOf(String str)`	Returns the index within this string of the last occurrence of the specified substring.
`int`	`lastIndexOf(String str, int fromIndex)`	Returns the index within this string of the last occurrence of the specified substring, searching backward starting at the specified index.
`int`	`length()`	Returns the length of this string.
`Stream<String>`	`lines()`	Returns a stream of lines extracted from this string, separated by line terminators.
`boolean`	`matches(String regex)`	Tells whether or not this string matches the given regular expression.
`int`	`offsetByCodePoints(int index, int codePointOffset)`	Returns the index within this `String` that is offset from the given `index` by `codePointOffset` code points.
`boolean`	`regionMatches(boolean ignoreCase, int toffset, String other, int ooffset, int len)`	Tests if two string regions are equal.
`boolean`	`regionMatches(int toffset, String other, int ooffset, int len)`	Tests if two string regions are equal.
`String`	`repeat(int count)`	Returns a string whose value is the concatenation of this string repeated `count` times.
`String`	`replace(char oldChar, char newChar)`	Returns a string resulting from replacing all occurrences of `oldChar` in this string with `newChar`.
`String`	`replace(CharSequence target, CharSequence replacement)`	Replaces each substring of this string that matches the literal target sequence with the specified literal replacement sequence.
`String`	`replaceAll(String regex, String replacement)`	Replaces each substring of this string that matches the given regular expression with the given replacement.
`String`	`replaceFirst(String regex, String replacement)`	Replaces the first substring of this string that matches the given regular expression with the given replacement.
`String`	`resolveConstantDesc(MethodHandles.Lookup lookup)`	Resolves this instance as a `ConstantDesc`, the result of which is the instance itself.
`String[]`	`split(String regex)`	Splits this string around matches of the given regular expression.
`String[]`	`split(String regex, int limit)`	Splits this string around matches of the given regular expression.
`String[]`	`splitWithDelimiters(String regex, int limit)`	Splits this string around matches of the given regular expression and returns both the strings and the matching delimiters.
`boolean`	`startsWith(String prefix)`	Tests if this string starts with the specified prefix.
`boolean`	`startsWith(String prefix, int toffset)`	Tests if the substring of this string beginning at the specified index starts with the specified prefix.
`String`	`strip()`	Returns a string whose value is this string, with all leading and trailing white space removed.
`String`	`stripIndent()`	Returns a string whose value is this string, with incidental white space removed from the beginning and end of every line.
`String`	`stripLeading()`	Returns a string whose value is this string, with all leading white space removed.
`String`	`stripTrailing()`	Returns a string whose value is this string, with all trailing white space removed.
`CharSequence`	`subSequence(int beginIndex, int endIndex)`	Returns a character sequence that is a subsequence of this sequence.
`String`	`substring(int beginIndex)`	Returns a string that is a substring of this string.
`String`	`substring(int beginIndex, int endIndex)`	Returns a string that is a substring of this string.
`char[]`	`toCharArray()`	Converts this string to a new character array.
`String`	`toLowerCase()`	Converts all of the characters in this `String` to lower case using the rules of the default locale.
`String`	`toLowerCase(Locale locale)`	Converts all of the characters in this `String` to lower case using the rules of the given `Locale`.
`String`	`toString()`	This object (which is already a string!)
`String`	`toUpperCase()`	Converts all of the characters in this `String` to upper case using the rules of the default locale.
`String`	`toUpperCase(Locale locale)`	Converts all of the characters in this `String` to upper case using the rules of the given `Locale`.
`<R> R`	`transform(Function<? super String,? extends R> f)`	This method allows the application of a function to `this` string.
`String`	`translateEscapes()`	Returns a string whose value is this string, with escape sequences translated as if in a string literal.
`String`	`trim()`	Returns a string whose value is this string, with all leading and trailing space removed, where space is defined as any character whose codepoint is less than or equal to `'U+0020'` (the space character).
`static String`	`valueOf(boolean b)`	Returns the string representation of the `boolean` argument.
`static String`	`valueOf(char c)`	Returns the string representation of the `char` argument.
`static String`	`valueOf(char[] data)`	Returns the string representation of the `char` array argument.
`static String`	`valueOf(char[] data, int offset, int count)`	Returns the string representation of a specific subarray of the `char` array argument.
`static String`	`valueOf(double d)`	Returns the string representation of the `double` argument.
`static String`	`valueOf(float f)`	Returns the string representation of the `float` argument.
`static String`	`valueOf(int i)`	Returns the string representation of the `int` argument.
`static String`	`valueOf(long l)`	Returns the string representation of the `long` argument.
`static String`	`valueOf(Object obj)`	Returns the string representation of the `Object` argument.

Methods declared in class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Details

CASE_INSENSITIVE_ORDER

public static final Comparator<String> CASE_INSENSITIVE_ORDER

A Comparator that orders String objects as by compareToIgnoreCase. This comparator is serializable.

Note that this Comparator does not take locale into account, and will result in an unsatisfactory ordering for certain locales. The Collator class provides locale-sensitive comparison.

Since:

1.2

See Also:

Constructor Details

String

public String()

Initializes a newly created String object so that it represents an empty character sequence. Note that use of this constructor is unnecessary since Strings are immutable.

String

public String(String original)

Initializes a newly created String object so that it represents the same sequence of characters as the argument; in other words, the newly created string is a copy of the argument string. Unless an explicit copy of original is needed, use of this constructor is unnecessary since Strings are immutable.

Parameters:: original - A String

String

public String(char[] value)

Allocates a new String so that it represents the sequence of characters currently contained in the character array argument. The contents of the character array are copied; subsequent modification of the character array does not affect the newly created string.

Parameters:: value - The initial value of the string

String

public String(char[] value, int offset, int count)

Allocates a new String that contains characters from a subarray of the character array argument. The offset argument is the index of the first character of the subarray and the count argument specifies the length of the subarray. The contents of the subarray are copied; subsequent modification of the character array does not affect the newly created string.

Parameters:: value - Array that is the source of characters; offset - The initial offset; count - The length
Throws:: IndexOutOfBoundsException - If offset is negative, count is negative, or offset is greater than value.length - count

String

public String(int[] codePoints, int offset, int count)

Allocates a new String that contains characters from a subarray of the Unicode code point array argument. The offset argument is the index of the first code point of the subarray and the count argument specifies the length of the subarray. The contents of the subarray are converted to chars; subsequent modification of the int array does not affect the newly created string.

Parameters:: codePoints - Array that is the source of Unicode code points; offset - The initial offset; count - The length
Throws:: IllegalArgumentException - If any invalid Unicode code point is found in codePoints; IndexOutOfBoundsException - If offset is negative, count is negative, or offset is greater than codePoints.length - count
Since:: 1.5

String

@Deprecated(since="1.1") public String(byte[] ascii, int hibyte, int offset, int count)

Deprecated.

This method does not properly convert bytes into characters. As of JDK 1.1, the preferred way to do this is via the String constructors that take a Charset, charset name, or that use the default charset.

Allocates a new String constructed from a subarray of an array of 8-bit integer values.

The offset argument is the index of the first byte of the subarray, and the count argument specifies the length of the subarray.

Each byte in the subarray is converted to a char as specified in the String(byte[],int) constructor.

Parameters:

ascii - The bytes to be converted to characters

hibyte - The top 8 bits of each 16-bit Unicode code unit

offset - The initial offset

count - The length

Throws:

IndexOutOfBoundsException - If offset is negative, count is negative, or offset is greater than ascii.length - count

See Also:

String

@Deprecated(since="1.1") public String(byte[] ascii, int hibyte)

Deprecated.

Allocates a new String containing characters constructed from an array of 8-bit integer values. Each character c in the resulting string is constructed from the corresponding component b in the byte array such that:

     c == (char)(((hibyte & 0xff) << 8)
                         | (b & 0xff))

Parameters:

ascii - The bytes to be converted to characters

hibyte - The top 8 bits of each 16-bit Unicode code unit

See Also:

String

public String(byte[] bytes, int offset, int length, String charsetName) throws UnsupportedEncodingException

Constructs a new String by decoding the specified subarray of bytes using the specified charset. The length of the new String is a function of the charset, and hence may not be equal to the length of the subarray.

The behavior of this constructor when the given bytes are not valid in the given charset is unspecified. The CharsetDecoder class should be used when more control over the decoding process is required.

Parameters:: bytes - The bytes to be decoded into characters; offset - The index of the first byte to decode; length - The number of bytes to decode; charsetName - The name of a supported charset
Throws:: UnsupportedEncodingException - If the named charset is not supported; IndexOutOfBoundsException - If offset is negative, length is negative, or offset is greater than bytes.length - length
Since:: 1.1

String

public String(byte[] bytes, int offset, int length, Charset charset)

This method always replaces malformed-input and unmappable-character sequences with this charset's default replacement string. The CharsetDecoder class should be used when more control over the decoding process is required.

Parameters:: bytes - The bytes to be decoded into characters; offset - The index of the first byte to decode; length - The number of bytes to decode; charset - The charset to be used to decode the bytes
Throws:: IndexOutOfBoundsException - If offset is negative, length is negative, or offset is greater than bytes.length - length
Since:: 1.6

String

public String(byte[] bytes, String charsetName) throws UnsupportedEncodingException

Constructs a new String by decoding the specified array of bytes using the specified charset. The length of the new String is a function of the charset, and hence may not be equal to the length of the byte array.

Parameters:: bytes - The bytes to be decoded into characters; charsetName - The name of a supported charset
Throws:: UnsupportedEncodingException - If the named charset is not supported
Since:: 1.1

String

public String(byte[] bytes, Charset charset)

Parameters:: bytes - The bytes to be decoded into characters; charset - The charset to be used to decode the bytes
Since:: 1.6

String

public String(byte[] bytes, int offset, int length)

Constructs a new String by decoding the specified subarray of bytes using the default charset. The length of the new String is a function of the charset, and hence may not be equal to the length of the subarray.

The behavior of this constructor when the given bytes are not valid in the default charset is unspecified. The CharsetDecoder class should be used when more control over the decoding process is required.

Parameters:: bytes - The bytes to be decoded into characters; offset - The index of the first byte to decode; length - The number of bytes to decode
Throws:: IndexOutOfBoundsException - If offset is negative, length is negative, or offset is greater than bytes.length - length
Since:: 1.1

String

public String(byte[] bytes)

Constructs a new String by decoding the specified array of bytes using the default charset. The length of the new String is a function of the charset, and hence may not be equal to the length of the byte array.

Parameters:: bytes - The bytes to be decoded into characters
Since:: 1.1

String

public String(StringBuffer buffer)

Allocates a new string that contains the sequence of characters currently contained in the string buffer argument. The contents of the string buffer are copied; subsequent modification of the string buffer does not affect the newly created string.

Parameters:: buffer - A StringBuffer

String

public String(StringBuilder builder)

Allocates a new string that contains the sequence of characters currently contained in the string builder argument. The contents of the string builder are copied; subsequent modification of the string builder does not affect the newly created string.

This constructor is provided to ease migration to StringBuilder. Obtaining a string from a string builder via the toString method is likely to run faster and is generally preferred.

Parameters:: builder - A StringBuilder
Since:: 1.5

Method Details

length

public int length()

Returns the length of this string. The length is equal to the number of Unicode code units in the string.

Specified by:: length in interface CharSequence
Returns:: the length of the sequence of characters represented by this object.

isEmpty

public boolean isEmpty()

Returns true if, and only if, length() is 0.

Specified by:: isEmpty in interface CharSequence
Returns:: true if length() is 0, otherwise false
Since:: 1.6

charAt

public char charAt(int index)

Returns the char value at the specified index. An index ranges from 0 to length() - 1. The first char value of the sequence is at index 0, the next at index 1, and so on, as for array indexing.

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

Specified by:: charAt in interface CharSequence
Parameters:: index - the index of the char value.
Returns:: the char value at the specified index of this string. The first char value is at index 0.
Throws:: IndexOutOfBoundsException - if the index argument is negative or not less than the length of this string.

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 String, 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.

Parameters:: index - the index to the char values
Returns:: the code point value of the character at the index
Throws:: IndexOutOfBoundsException - if the index argument is negative or not less than the length of this string.
Since:: 1.5

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.

Parameters:: index - the index following the code point that should be returned
Returns:: the Unicode code point value before the given index.
Throws:: IndexOutOfBoundsException - if the index argument is less than 1 or greater than the length of this string.
Since:: 1.5

codePointCount

public int codePointCount(int beginIndex, int endIndex)

Returns the number of Unicode code points in the specified text range of this String. 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 the text range count as one code point each.

Parameters:: beginIndex - the index to the first char of the text range.; endIndex - the index after the last char of the text range.
Returns:: the number of Unicode code points in the specified text range
Throws:: IndexOutOfBoundsException - if the beginIndex is negative, or endIndex is larger than the length of this String, or beginIndex is larger than endIndex.
Since:: 1.5

offsetByCodePoints

public int offsetByCodePoints(int index, int codePointOffset)

Returns the index within this String 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.

Parameters:: index - the index to be offset; codePointOffset - the offset in code points
Returns:: the index within this String
Throws:: IndexOutOfBoundsException - if index is negative or larger than the length of this String, or if codePointOffset is positive and the substring starting with index has fewer than codePointOffset code points, or if codePointOffset is negative and the substring before index has fewer than the absolute value of codePointOffset code points.
Since:: 1.5

getChars

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

Copies characters from this string into the destination character array.

The first character to be copied is at index srcBegin; the last character to be copied is at index srcEnd-1 (thus 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

Parameters:

srcBegin - index of the first character in the string to copy.

srcEnd - index after the last character in the string to copy.

dst - the destination array.

dstBegin - the start offset in the destination array.

Throws:

IndexOutOfBoundsException - If any of the following is true:

srcBegin is negative.
srcBegin is greater than srcEnd
srcEnd is greater than the length of this string
dstBegin is negative
dstBegin+(srcEnd-srcBegin) is larger than dst.length

getBytes

@Deprecated(since="1.1") public void getBytes(int srcBegin, int srcEnd, byte[] dst, int dstBegin)

Deprecated.

This method does not properly convert characters into bytes. As of JDK 1.1, the preferred way to do this is via the getBytes() method, which uses the default charset.

Copies characters from this string into the destination byte array. Each byte receives the 8 low-order bits of the corresponding character. The eight high-order bits of each character are not copied and do not participate in the transfer in any way.

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, converted to bytes, are copied into the subarray of dst starting at index dstBegin and ending at index:

     dstBegin + (srcEnd-srcBegin) - 1

Parameters:

srcBegin - Index of the first character in the string to copy

srcEnd - Index after the last character in the string to copy

dst - The destination array

dstBegin - The start offset in the destination array

Throws:

IndexOutOfBoundsException - If any of the following is true:

srcBegin is negative
srcBegin is greater than srcEnd
srcEnd is greater than the length of this String
dstBegin is negative
dstBegin+(srcEnd-srcBegin) is larger than dst.length

getBytes

public byte[] getBytes(String charsetName) throws UnsupportedEncodingException

Encodes this String into a sequence of bytes using the named charset, storing the result into a new byte array.

The behavior of this method when this string cannot be encoded in the given charset is unspecified. The CharsetEncoder class should be used when more control over the encoding process is required.

Parameters:: charsetName - The name of a supported charset
Returns:: The resultant byte array
Throws:: UnsupportedEncodingException - If the named charset is not supported
Since:: 1.1

getBytes

public byte[] getBytes(Charset charset)

Encodes this String into a sequence of bytes using the given charset, storing the result into a new byte array.

This method always replaces malformed-input and unmappable-character sequences with this charset's default replacement byte array. The CharsetEncoder class should be used when more control over the encoding process is required.

Parameters:: charset - The Charset to be used to encode the String
Returns:: The resultant byte array
Since:: 1.6

getBytes

public byte[] getBytes()

Encodes this String into a sequence of bytes using the default charset, storing the result into a new byte array.

The behavior of this method when this string cannot be encoded in the default charset is unspecified. The CharsetEncoder class should be used when more control over the encoding process is required.

Returns:: The resultant byte array
Since:: 1.1

equals

public boolean equals(Object anObject)

Compares this string to the specified object. The result is true if and only if the argument is not null and is a String object that represents the same sequence of characters as this object.

For finer-grained String comparison, refer to Collator.

Overrides:

equals in class Object

Parameters:

anObject - The object to compare this String against

Returns:

true if the given object represents a String equivalent to this string, false otherwise

See Also:

contentEquals

public boolean contentEquals(StringBuffer sb)

Compares this string to the specified StringBuffer. The result is true if and only if this String represents the same sequence of characters as the specified StringBuffer. This method synchronizes on the StringBuffer.

For finer-grained String comparison, refer to Collator.

Parameters:: sb - The StringBuffer to compare this String against
Returns:: true if this String represents the same sequence of characters as the specified StringBuffer, false otherwise
Since:: 1.4

contentEquals

public boolean contentEquals(CharSequence cs)

Compares this string to the specified CharSequence. The result is true if and only if this String represents the same sequence of char values as the specified sequence. Note that if the CharSequence is a StringBuffer then the method synchronizes on it.

For finer-grained String comparison, refer to Collator.

Parameters:: cs - The sequence to compare this String against
Returns:: true if this String represents the same sequence of char values as the specified sequence, false otherwise
Since:: 1.5

equalsIgnoreCase

public boolean equalsIgnoreCase(String anotherString)

Compares this String to another String, ignoring case considerations. Two strings are considered equal ignoring case if they are of the same length and corresponding Unicode code points in the two strings are equal ignoring case.

Two Unicode code points are considered the same ignoring case if at least one of the following is true:

The two Unicode code points are the same (as compared by the == operator)
Calling Character.toLowerCase(Character.toUpperCase(int)) on each Unicode code point produces the same result

Note that this method does not take locale into account, and will result in unsatisfactory results for certain locales. The Collator class provides locale-sensitive comparison.

Parameters:

anotherString - The String to compare this String against

Returns:

true if the argument is not null and it represents an equivalent String ignoring case; false otherwise

See Also:

compareTo

public int compareTo(String anotherString)

Compares two strings lexicographically. The comparison is based on the Unicode value of each character in the strings. The character sequence represented by this String object is compared lexicographically to the character sequence represented by the argument string. The result is a negative integer if this String object lexicographically precedes the argument string. The result is a positive integer if this String object lexicographically follows the argument string. The result is zero if the strings are equal; compareTo returns 0