Android
java.util.regex
public final class

java.util.regex.Matcher

java.lang.Object
java.util.regex.Matcher MatchResult

Provides a means of matching regular expressions against a given input, finding occurrences of regular expressions in a given input, or replacing parts of a given input. A Matcher instance has an associated Pattern instance and an input text. A typical use case is to iteratively find all occurrences of the Pattern, until the end of the input is reached, as the following example illustrates:

 Pattern p = Pattern.compile("[A-Za-z]+");
  
 Matcher m = p.matcher("Hello, Android!");
 while (m.find()) {
     System.out.println(m.group()); // prints "Hello" and "Android"
 }
 

The Matcher has a state that results from the previous operations. For example, it knows whether the most recent attempt to find the Pattern was successful and at which position the next attempt would resume the search. Depending on the application's needs, it may become necessary to explicitly reset() this state from time to time.

Summary

Public Methods

          Matcher  appendReplacement(StringBuffer buffer, String replacement)
Appends a literal part of the input plus a replacement for the current match to a given StringBuffer.
          StringBuffer  appendTail(StringBuffer buffer)
Appends the (unmatched) remainder of the input to the given StringBuffer.
          int  end()
Returns the index of the first character following the text that matched the whole regular expression.
          int  end(int group)
Returns the index of the first character following the text that matched a given group.
          boolean  find(int start)
Returns the next occurrence of the Pattern in the input.
          boolean  find()
Returns the next occurrence of the Pattern in the input.
          String  group(int group)
Returns the text that matched a given group of the regular expression.
          String  group()
Returns the text that matched the whole regular expression.
          int  groupCount()
Returns the number of groups in the results, which is always equal to the number of groups in the original regular expression.
          boolean  hasAnchoringBounds()
Indicates whether this matcher has anchoring bounds enabled.
          boolean  hasTransparentBounds()
Indicates whether this matcher has transparent bounds enabled.
          boolean  hitEnd()
Indicates whether the last match hit the end of the input.
          boolean  lookingAt()
Tries to match the Pattern, starting from the beginning of the region (or the beginning of the input, if no region has been set).
          boolean  matches()
Tries to match the Pattern against the entire region (or the entire input, if no region has been set).
          Pattern  pattern()
Returns the Pattern instance used inside this matcher.
      static    String  quoteReplacement(String s)
Returns a replacement string for the given one that has all backslashes and dollar signs escaped.
          Matcher  region(int start, int end)
Resets this matcher and sets a region.
          int  regionEnd()
Returns this matcher's region end, that is, the first character that is not considered for a match.
          int  regionStart()
Returns this matcher's region start, that is, the first character that is considered for a match.
          String  replaceAll(String replacement)
Replaces all occurrences of this matcher's pattern in the input with a given string.
          String  replaceFirst(String replacement)
Replaces the first occurrence of this matcher's pattern in the input with a given string.
          boolean  requireEnd()
Indicates whether more input might change a successful match into an unsuccessful one.
          Matcher  reset()
Resets the Matcher.
          Matcher  reset(CharSequence input)
Provides a new input and resets the Matcher.
          int  start(int group)
Returns the index of the first character of the text that matched a given group.
          int  start()
Returns the index of the first character of the text that matched the whole regular expression.
          MatchResult  toMatchResult()
Converts the current match into a separate MatchResult instance that is independent from this matcher.
          Matcher  useAnchoringBounds(boolean value)
Determines whether this matcher has anchoring bounds enabled or not.
          Matcher  usePattern(Pattern pattern)
Sets a new pattern for the Matcher.
          Matcher  useTransparentBounds(boolean value)
Determines whether this matcher has transparent bounds enabled or not.

Protected Methods

          void  finalize()
Called by the virtual machine when there are no longer any (non-weak) references to the receiver.
Methods inherited from class java.lang.Object
Methods inherited from interface java.util.regex.MatchResult

Details

Public Methods

public Matcher appendReplacement(StringBuffer buffer, String replacement)

Appends a literal part of the input plus a replacement for the current match to a given StringBuffer. The literal part is exactly the part of the input between the previous match and the current match. The method can be used in conjunction with find() and appendTail(StringBuffer) to walk through the input and replace all occurrences of the Pattern with something else.

Parameters

buffer the StringBuffer to append to.
replacement the replacement text.

Returns

  • the Matcher itself.

Throws

IllegalStateException if no successful match has been made.

public StringBuffer appendTail(StringBuffer buffer)

Appends the (unmatched) remainder of the input to the given StringBuffer. The method can be used in conjunction with find() and appendReplacement(StringBuffer, String) to walk through the input and replace all matches of the Pattern with something else.

Parameters

buffer the StringBuffer to append to.

Returns

  • the StringBuffer.

Throws

IllegalStateException if no successful match has been made.

public int end()

Returns the index of the first character following the text that matched the whole regular expression.

Returns

  • the character index.

Throws

IllegalStateException if no successful match has been made.

public int end(int group)

Returns the index of the first character following the text that matched a given group.

Parameters

group the group, ranging from 0 to groupCount() - 1, with 0 representing the whole pattern.

Returns

  • the character index.

Throws

IllegalStateException if no successful match has been made.

public boolean find(int start)

Returns the next occurrence of the Pattern in the input. The method starts the search from the given character in the input.

Parameters

start The index in the input at which the find operation is to begin. If this is less than the start of the region, it is automatically adjusted to that value. If it is beyond the end of the region, the method will fail.

Returns

  • true if (and only if) a match has been found.

public boolean find()

Returns the next occurrence of the Pattern in the input. If a previous match was successful, the method continues the search from the first character following that match in the input. Otherwise it searches either from the region start (if one has been set), or from position 0.

Returns

  • true if (and only if) a match has been found.

public String group(int group)

Returns the text that matched a given group of the regular expression.

Parameters

group the group, ranging from 0 to groupCount() - 1, with 0 representing the whole pattern.

Returns

  • the text that matched the group.

Throws

IllegalStateException if no successful match has been made.

public String group()

Returns the text that matched the whole regular expression.

Returns

  • the text.

Throws

IllegalStateException if no successful match has been made.

public int groupCount()

Returns the number of groups in the results, which is always equal to the number of groups in the original regular expression.

Returns

  • the number of groups.

public boolean hasAnchoringBounds()

Indicates whether this matcher has anchoring bounds enabled. When anchoring bounds are enabled, the start and end of the input match the '^' and '$' meta-characters, otherwise not. Anchoring bounds are enabled by default.

Returns

  • true if (and only if) the Matcher uses anchoring bounds.

public boolean hasTransparentBounds()

Indicates whether this matcher has transparent bounds enabled. When transparent bounds are enabled, the parts of the input outside the region are subject to lookahead and lookbehind, otherwise they are not. Transparent bounds are disabled by default.

Returns

  • true if (and only if) the Matcher uses anchoring bounds.

public boolean hitEnd()

Indicates whether the last match hit the end of the input.

Returns

  • true if (and only if) the last match hit the end of the input.

public boolean lookingAt()

Tries to match the Pattern, starting from the beginning of the region (or the beginning of the input, if no region has been set). Doesn't require the Pattern to match against the whole region.

Returns

  • true if (and only if) the Pattern matches.

public boolean matches()

Tries to match the Pattern against the entire region (or the entire input, if no region has been set).

Returns

  • true if (and only if) the Pattern matches the entire region.

public Pattern pattern()

Returns the Pattern instance used inside this matcher.

Returns

  • the Pattern instance.

public static String quoteReplacement(String s)

Returns a replacement string for the given one that has all backslashes and dollar signs escaped.

Parameters

s the input string.

Returns

  • the input string, with all backslashes and dollar signs having been escaped.

public Matcher region(int start, int end)

Resets this matcher and sets a region. Only characters inside the region are considered for a match.

Parameters

start the first character of the region.
end the first character after the end of the region.

Returns

  • the Matcher itself.

public int regionEnd()

Returns this matcher's region end, that is, the first character that is not considered for a match.

Returns

  • the end of the region.

public int regionStart()

Returns this matcher's region start, that is, the first character that is considered for a match.

Returns

  • the start of the region.

public String replaceAll(String replacement)

Replaces all occurrences of this matcher's pattern in the input with a given string.

Parameters

replacement the replacement text.

Returns

  • the modified input string.

public String replaceFirst(String replacement)

Replaces the first occurrence of this matcher's pattern in the input with a given string.

Parameters

replacement the replacement text.

Returns

  • the modified input string.

public boolean requireEnd()

Indicates whether more input might change a successful match into an unsuccessful one.

Returns

  • true if (and only if) more input might change a successful match into an unsuccessful one.

public Matcher reset()

Resets the Matcher. This results in the region being set to the whole input. Results of a previous find get lost. The next attempt to find an occurrence of the Pattern in the string will start at the beginning of the input.

Returns

  • the Matcher itself.

public Matcher reset(CharSequence input)

Provides a new input and resets the Matcher. This results in the region being set to the whole input. Results of a previous find get lost. The next attempt to find an occurrence of the Pattern in the string will start at the beginning of the input.

Parameters

input the new input sequence.

Returns

  • the Matcher itself.

public int start(int group)

Returns the index of the first character of the text that matched a given group.

Parameters

group the group, ranging from 0 to groupCount() - 1, with 0 representing the whole pattern.

Returns

  • the character index.

Throws

IllegalStateException if no successful match has been made.

public int start()

Returns the index of the first character of the text that matched the whole regular expression.

Returns

  • the character index.

Throws

IllegalStateException if no successful match has been made.

public MatchResult toMatchResult()

Converts the current match into a separate MatchResult instance that is independent from this matcher. The new object is unaffected when the state of this matcher changes.

Returns

  • the new MatchResult.

Throws

IllegalStateException if no successful match has been made.

public Matcher useAnchoringBounds(boolean value)

Determines whether this matcher has anchoring bounds enabled or not. When anchoring bounds are enabled, the start and end of the input match the '^' and '$' meta-characters, otherwise not. Anchoring bounds are enabled by default.

Parameters

value the new value for anchoring bounds.

Returns

  • the Matcher itself.

public Matcher usePattern(Pattern pattern)

Sets a new pattern for the Matcher. Results of a previous find get lost. The next attempt to find an occurrence of the Pattern in the string will start at the beginning of the input.

Parameters

pattern the new Pattern.

Returns

  • the Matcher itself.

public Matcher useTransparentBounds(boolean value)

Determines whether this matcher has transparent bounds enabled or not. When transparent bounds are enabled, the parts of the input outside the region are subject to lookahead and lookbehind, otherwise they are not. Transparent bounds are disabled by default.

Parameters

value the new value for transparent bounds.

Returns

  • the Matcher itself.

Protected Methods

protected void finalize()

Called by the virtual machine when there are no longer any (non-weak) references to the receiver. Subclasses can use this facility to guarantee that any associated resources are cleaned up before the receiver is garbage collected. Uncaught exceptions which are thrown during the running of the method cause it to terminate immediately, but are otherwise ignored.

Note: The virtual machine assumes that the implementation in class Object is empty.

Copyright 2007 Google Inc. Build 0.9_r1-98467 - 14 Aug 2008 18:48