Java Tutorial/Development/Regular Expressions
Содержание
- 1 Pattern match: J.*\\d[-\\d\\d-\\d\\d
- 2 Replace all words with another string
- 3 Replace first three digits with "digit"
- 4 Replace one string with another string
- 5 Replace "*" with "^"
- 6 Split string with comma
- 7 Validate Address
- 8 Validate city and state
- 9 Validate Phone
- 10 Validate the first name and last name
- 11 Validate Zip
Pattern match: J.*\\d[-\\d\\d-\\d\\d
<source lang="java">
import java.util.regex.Matcher; import java.util.regex.Pattern; public class MainClass {
public static void main( String args[] )
{
// create regular expression
Pattern expression =
Pattern.rupile( "J.*\\d[0-35-9]-\\d\\d-\\d\\d" );
String string1 = "Jack"s Birthday is 05-12-75\n" +
"Joe"s Birthday is 11-04-68\n" +
"Tom"s Birthday is 04-28-73\n" +
"Lee" +
"s Birthday is 12-17-77";
// match regular expression to string and print matches
Matcher matcher = expression.matcher( string1 );
while ( matcher.find() )
System.out.println( matcher.group() );
}
}</source>
Jack"s Birthday is 05-12-75 Joe"s Birthday is 11-04-68
Replace all words with another string
<source lang="java">
public class MainClass {
public static void main( String args[] )
{
String firstString = "This sentence ends in 5 stars *****";
String secondString = "1, 2, 3, 4, 5, 6, 7, 8";
System.out.printf( "Original String 1: %s\n", firstString );
// replace words with "word"
System.out.printf( "Every word replaced by \"word\": %s\n\n",
firstString.replaceAll( "\\w+", "word" ) );
System.out.printf( "Original String 2: %s\n", secondString );
}
}</source>
Original String 1: This sentence ends in 5 stars ***** Every word replaced by "word": word word word word word word ***** Original String 2: 1, 2, 3, 4, 5, 6, 7, 8
Replace first three digits with "digit"
<source lang="java">
public class MainClass {
public static void main( String args[] )
{
String firstString = "This sentence ends in 5 stars *****";
String secondString = "1, 2, 3, 4, 5, 6, 7, 8";
System.out.printf( "Original String 1: %s\n", firstString );
// replace first three digits with "digit"
for ( int i = 0; i < 3; i++ )
secondString = secondString.replaceFirst( "\\d", "digit" );
System.out.printf(
"First 3 digits replaced by \"digit\" : %s\n", secondString );
}
}</source>
Original String 1: This sentence ends in 5 stars ***** First 3 digits replaced by "digit" : digit, digit, digit, 4, 5, 6, 7, 8
Replace one string with another string
<source lang="java">
public class MainClass {
public static void main( String args[] )
{
String firstString = "This sentence ends in 5 stars *****";
System.out.printf( "Original String 1: %s\n", firstString );
// replace "stars" with "carets"
firstString = firstString.replaceAll( "stars", "carets" );
System.out.printf(
"\"carets\" substituted for \"stars\": %s\n", firstString );
}
}</source>
Original String 1: This sentence ends in 5 stars ***** "carets" substituted for "stars": This sentence ends in 5 carets *****
Replace "*" with "^"
<source lang="java">
public class MainClass {
public static void main( String args[] )
{
String firstString = "This sentence ends in 5 stars *****";
System.out.printf( "Original String 1: %s\n", firstString );
// replace "*" with "^"
firstString = firstString.replaceAll( "\\*", "^" );
System.out.printf( "^ substituted for *: %s\n", firstString );
}
}</source>
Original String 1: This sentence ends in 5 stars ***** ^ substituted for *: This sentence ends in 5 stars ^^^^^
Split string with comma
<source lang="java">
public class MainClass {
public static void main( String args[] )
{
String secondString = "1, 2, 3, 4, 5, 6, 7, 8";
String output = "String split at commas: [";
String[] results = secondString.split( ",\\s*" ); // split on commas
for ( String string : results )
output += "\"" + string + "\", ";
output = output.substring( 0, output.length() - 2 ) + "]";
System.out.println( output );
}
}</source>
String split at commas: ["1", "2", "3", "4", "5", "6", "7", "8"]
Validate Address
<source lang="java">
public class MainClass {
public static void main( String[] args )
{
System.out.println(validateAddress("123, Street"));
}
// validate address
public static boolean validateAddress( String address )
{
return address.matches(
"\\d+\\s+([a-zA-Z]+|[a-zA-Z]+\\s[a-zA-Z]+)" );
} // end method validateAddress
}</source>
Validate city and state
<source lang="java">
public class MainClass {
public static void main( String[] args )
{
System.out.println(validateCity("Street"));
System.out.println(validateState("CA"));
}
// validate city
public static boolean validateCity( String city )
{
return city.matches( "([a-zA-Z]+|[a-zA-Z]+\\s[a-zA-Z]+)" );
} // end method validateCity
// validate state
public static boolean validateState( String state )
{
return state.matches( "([a-zA-Z]+|[a-zA-Z]+\\s[a-zA-Z]+)" ) ;
} // end method validateState
}</source>
Validate Phone
<source lang="java">
public class MainClass {
public static void main( String[] args )
{
System.out.println(validatePhone("123-456-1111"));
}
public static boolean validatePhone( String phone )
{
return phone.matches( "[1-9]\\d{2}-[1-9]\\d{2}-\\d{4}" );
} // end method validatePhone
}</source>
Validate the first name and last name
<source lang="java">
public class MainClass {
public static void main( String[] args )
{
System.out.println(validateFirstName("Tom"));
System.out.println(validateLastName("Tom"));
}
// validate first name
public static boolean validateFirstName( String firstName )
{
return firstName.matches( "[A-Z][a-zA-Z]*" );
} // end method validateFirstName
// validate last name
public static boolean validateLastName( String lastName )
{
return lastName.matches( "[a-zA-z]+([ "-][a-zA-Z]+)*" );
} // end method validateLastName
}</source>
Validate Zip
<source lang="java">
public class MainClass {
public static void main( String[] args )
{
System.out.println(validateZip("123456"));
}
// validate zip
public static boolean validateZip( String zip )
{
return zip.matches( "\\d{5}" );
}
}</source>
