JavaCore tutorials

Java regular expression 1. How to validate username with regular expression Remember: Username Regular Expression Pattern ^[a-z0-9_-]{3,15}$ Description ^ # Start of the line [a-z0-9_-] # Match characters and symbols in the list, a-z, 0-9, underscore, hyphen {3,15} # Length at least 3 characters and maximum length of 15 $ # End of the line Whole combination is means, 3 to 15 characters with any lower case character, digit or special symbol “_-” only. This is common username pattern that’s widely use in different websites. Example: UsernameValidator.java package org.quangthao.validateUser; import java.util.regex.Matcher; import java.util.regex.Pattern; public class UsernameValidator { private Pattern pattern; //Khuân mẫu private Matcher matcher; //Khớp(phù hợp) private static final String USERNAME_PATTERN="^[a-z0-9_-]{3,15}$"; public UsernameValidator(){ pattern=Pattern.compile(USERNAME_PATTERN); } public boolean validate(final String username){ matcher=pattern.matcher(username); return matcher.matches(); } } TestUsernameValidator.java package org.quangthao.validateUser; public class TestUsernameValidator { private UsernameValidator usernameValidator; public TestUsernameValidator(){ usernameValidator=new UsernameValidator(); } public Object[] ValidUsernameProvider(){ return new Object[]{"mkyong34", "mkyong_2002","mkyong- 2002" ,"mk3-4_yong"}; } public Object[] InvalidUsernameProvider(){ return new Object[]{"mk","mk@yong","mkyong123456789_-"}; } public UsernameValidator getUsernameValidator() { return usernameValidator; } public void setUsernameValidator(UsernameValidator usernameValidator) { this.usernameValidator = usernameValidator; } public static void main(String[] args){ TestUsernameValidator test=new TestUsernameValidator(); boolean valid; Object objectValid[]=test.ValidUsernameProvider(); Object objectInvalid[]=test.InvalidUsernameProvider(); for(int i=0;i<objectValid.length;i++){ valid=test.getUsernameValidator().validate(String.valueOf(objectValid[i])); System.out.println(objectValid[i]+":"+valid); } for(int i=0;i<objectInvalid.length;i++){ valid=test.getUsernameValidator().validate(String.valueOf(objectInvalid[i])); System.out.println(objectInvalid[i]+":"+valid); } } } Result: mkyong34:true mkyong_2002:true mkyong-2002:true mk3-4_yong:true mk:false mk@yong:false mkyong123456789_-:false Reference: How to validate username with regular expression Posted on November 6, 2009 , Last modified : October 11, 2012 By mkyong Username Regular Expression Pattern ^[a-z0-9_-]{3,15}$ Description ^ # Start of the line [a-z0-9_-] # Match characters and symbols in the list, a-z, 0-9, underscore, hyphen {3,15} # Length at least 3 characters and maximum length of 15 $ # End of the line Whole combination is means, 3 to 15 characters with any lower case character, digit or special symbol “_-” only. This is common username pattern that’s widely use in different websites. 1. Java Regular Expression Example UsernameValidator.java package com.mkyong.regex; import java.util.regex.Matcher; import java.util.regex.Pattern; public class UsernameValidator{ private Pattern pattern; private Matcher matcher; private static final String USERNAME_PATTERN = "^[a-z0-9_-]{3,15}$"; public UsernameValidator(){ pattern = Pattern.compile(USERNAME_PATTERN); } /** * Validate username with regular expression * @param username username for validation * @return true valid username, false invalid username */ public boolean validate(final String username){ matcher = pattern.matcher(username); return matcher.matches(); } } 2. Username that match: 1. mkyong34 2. mkyong_2002 3. mkyong-2002 4. mk3-4_yong 3. Username that doesn’t match: 1. mk (too short, min 3 characters) 2. mk@yong (“@” character is not allow) 3. mkyong123456789_- (too long, max characters of 15) 4. Unit Test – UsernameValidator Using testNG to perform unit test. UsernameValidatorTest.java package com.mkyong.regex; import org.testng.Assert; import org.testng.annotations.*; /** * Username validator Testing * @author mkyong * */ public class UsernameValidatorTest { private UsernameValidator usernameValidator; @BeforeClass public void initData(){ usernameValidator = new UsernameValidator(); } @DataProvider public Object[][] ValidUsernameProvider() { return new Object[][]{ {new String[] { "mkyong34", "mkyong_2002","mkyong-2002" ,"mk3-4_yong" }} }; } @DataProvider public Object[][] InvalidUsernameProvider() { return new Object[][]{ {new String[] { "mk","mk@yong","mkyong123456789_-" }} }; } @Test(dataProvider = "ValidUsernameProvider") public void ValidUsernameTest(String[] Username) { for(String temp : Username){ boolean valid = usernameValidator.validate(temp); System.out.println("Username is valid : " + temp + " , " + valid); Assert.assertEquals(true, valid); } } @Test(dataProvider = "InvalidUsernameProvider", dependsOnMethods="ValidUsernameTest") public void InValidUsernameTest(String[] Username) { for(String temp : Username){ boolean valid = usernameValidator.validate(temp); System.out.println("username is valid : " + temp + " , " + valid); Assert.assertEquals(false, valid); } } } 5. Unit Test – Result Username is valid : mkyong34 , true Username is valid : mkyong_2002 , true Username is valid : mkyong-2002 , true Username is valid : mk3-4_yong , true username is valid : mk , false username is valid : mk@yong , false username is valid : mkyong123456789_- , false PASSED: ValidUsernameTest([Ljava.lang.String;@1d4c61c) PASSED: InValidUsernameTest([Ljava.lang.String;@116471f) =============================================== com.mkyong.regexusernameValidatorTest Tests run: 2, Failures: 0, Skips: 0 =============================================== =============================================== mkyong Total tests run: 2, Failures: 0, Skips: 0 =============================================== 2. How to validate password with regular expression Remember: Password Regular Expression Pattern ((?=.*\d)(?=.*[a-z])(?=.*[A-Z])(?=.*[@#$%]).{6,20}) Description ( # Start of group (?=.*\d) # must contains one digit from 0-9 (?=.*[a-z]) # must contains one lowercase characters (?=.*[A-Z]) # must contains one uppercase characters (?=.*[@#$%]) # must contains one special symbols in the list "@#$%" . # match anything with previous condition checking {6,20} # length at least 6 characters and maximum of 20 ) # End of group ?= – means apply the assertion condition, meaningless by itself, always work with other combination Whole combination is means, 6 to 20 characters string with at least one digit, one upper case letter, one lower case letter and one special symbol (“@#$%”). This regular expression pattern is very useful to implement a strong and complex password. Example: PasswordValidator.java package org.quangthao.passwordvalidate; import java.util.regex.Matcher; import java.util.regex.Pattern; public class PasswordValidator { private Pattern pattern; private Matcher matcher; private static final String USERNAME_PATTERN="((?=.*\\d)(?=.*[a-z])(? =.*[A-Z])(?=.*[@#$%]).{6,20})"; public PasswordValidator(){ pattern=Pattern.compile(USERNAME_PATTERN); } public boolean validate(final String username){ matcher=pattern.matcher(username); return matcher.matches(); } } TestPasswordValidator.java package org.quangthao.passwordvalidate; import org.quangthao.validateUser.TestUsernameValidator; public class TestPasswordValidator { private PasswordValidator passwordvalidator; public TestPasswordValidator(){ passwordvalidator=new PasswordValidator(); } public Object[] ValidPasswordProvider(){ return new Object[]{"mkyong1A@", "mkYOn12$"}; } public Object[] InvalidPasswordProvider(){ return new Object[]{"mY1A@","mkyong12@","mkyoNg12*","mkyonG$ $","MKYONG12$"}; } public PasswordValidator getPasswordvalidator() { return passwordvalidator; } public void setPasswordvalidator(PasswordValidator passwordvalidator) { this.passwordvalidator = passwordvalidator; } public static void main(String[] args){ TestPasswordValidator test=new TestPasswordValidator(); boolean valid; Object objectValid[]=test.ValidPasswordProvider(); Object objectInvalid[]=test.InvalidPasswordProvider(); for(int i=0;i<objectValid.length;i++){ valid=test.getPasswordvalidator().validate(String.valueOf(objectValid[i])); System.out.println(objectValid[i]+":"+valid); } for(int i=0;i<objectInvalid.length;i++){ valid=test.getPasswordvalidator().validate(String.valueOf(objectInvalid[i])); System.out.println(objectInvalid[i]+":"+valid); } } } Result: mkyong1A@:true mkYOn12$:true mY1A@:false mkyong12@:false mkyoNg12*:false mkyonG$$:false MKYONG12$:false Reference: How to validate password with regular expression Posted on November 6, 2009 , Last modified : October 11, 2012 By mkyong Password Regular Expression Pattern ((?=.*\d)(?=.*[a-z])(?=.*[A-Z])(?=.*[@#$%]).{6,20}) Description ( # Start of group (?=.*\d) # must contains one digit from 0-9 (?=.*[a-z]) # must contains one lowercase characters (?=.*[A-Z]) # must contains one uppercase characters (?=.*[@#$%]) # must contains one special symbols in the list "@#$%" . # match anything with previous condition checking {6,20} # length at least 6 characters and maximum of 20 ) # End of group ?= – means apply the assertion condition, meaningless by itself, always work with other combination Whole combination is means, 6 to 20 characters string with at least one digit, one upper case letter, one lower case letter and one special symbol (“@#$%”). This regular expression pattern is very useful to implement a strong and complex password. P.S The grouping formula order is doesn’t matter. 1. Java Regular Expression Example PasswordValidator.java package com.mkyong.regex; import java.util.regex.Matcher; import java.util.regex.Pattern; public class PasswordValidator{ private Pattern pattern; private Matcher matcher; private static final String PASSWORD_PATTERN = "((?=.*\\d)(?=.*[a-z])(?=.*[A-Z])(?=.*[@#$%]).{6,20})"; public PasswordValidator(){ pattern = Pattern.compile(PASSWORD_PATTERN); } /** * Validate password with regular expression * @param password password for validation * @return true valid password, false invalid password */ public boolean validate(final String password){ matcher = pattern.matcher(password); return matcher.matches(); } } 2. Password that match: 1. mkyong1A@ 2. mkYOn12$ 3. Password that doesn’t match: 1. mY1A@ , too short, minimum 6 characters 2. mkyong12@ , uppercase characters is required 3. mkyoNg12* , special symbol “*” is not allow here 4. mkyonG$$, digit is required 5. MKYONG12$ , lower case character is required 4. Unit Test – PasswordValidator Unit test with TestNG. PasswordValidatorTest.java package com.mkyong.regex; import org.testng.Assert; import org.testng.annotations.*; /** * Password validator Testing * @author mkyong * */ public class PasswordValidatorTest { private PasswordValidator passwordValidator; @BeforeClass public void initData(){ passwordValidator = new PasswordValidator(); } @DataProvider public Object[][] ValidPasswordProvider() { return new Object[][]{ {new String[] { "mkyong1A@", "mkYOn12$", }} }; } @DataProvider public Object[][] InvalidPasswordProvider() { return new Object[][]{