Gui B.L Software Engineering-Code and posts about tech and programming

Regex Utility Class
10 April 2014
Sometimes it's useful to have in hand several utility type methods in order to do similar tasks repeatedly. Utility classes are good candidates for a singleton. This example shows a Singleton Regex Utility class that provides several Regex validation methods:
package io.github.guilhebl.util;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class RegexUtil {

<span class="cm">/**
^                 # start-of-string
(?=.*[0-9])       # a digit must occur at least once
(?=.*[a-z])       # a lower case letter must occur at least once
(?=.*[A-Z])       # an upper case letter must occur at least once

### (?=.*[@#$%^&amp;+=])  # a special character must occur at least once

(?=[^\s]+$)       # no whitespace allowed in the entire string
.{6,}             # anything, at least eight places though
$                 # end-of-string
*/</span>
<span class="kd">public</span> <span class="kd">static</span> <span class="kd">final</span> <span class="n">String</span> <span class="n">PASSWORD_PATTERN</span> <span class="o">=</span> <span class="s">"^(?=.*[0-9])(?=.*[a-z])(?=[^\\s]+$).{6,}$"</span><span class="o">;</span>

<span class="kd">private</span> <span class="kd">static</span> <span class="kd">final</span> <span class="n">String</span> <span class="n">EMAIL_PATTERN</span> <span class="o">=</span> <span class="s">"^[_A-Za-z0-9-]+(\\."</span> <span class="o">+</span>
        <span class="s">"[_A-Za-z0-9-]+)*@[A-Za-z0-9]+(\\.[A-Za-z0-9]+)*"</span> <span class="o">+</span>
        <span class="s">"(\\.[A-Za-z]{2,})$"</span><span class="o">;</span>

<span class="kd">private</span> <span class="kd">static</span> <span class="kd">final</span> <span class="n">String</span> <span class="n">FILE_NAME_PATTERN</span> <span class="o">=</span> <span class="s">"[_a-zA-Z0-9\\-\\.]+"</span><span class="o">;</span> 

<span class="kd">private</span> <span class="kd">static</span> <span class="kd">final</span> <span class="n">String</span> <span class="n">PHONE_PATTERN</span> <span class="o">=</span> <span class="s">"^[+]?([0-9]*[\\.\\s\\-\\(\\)]|[0-9]+){3,24}$"</span><span class="o">;</span>

<span class="kd">private</span> <span class="kd">static</span> <span class="n">RegexUtil</span> <span class="n">instance</span><span class="o">;</span>
<span class="kd">private</span> <span class="n">Pattern</span> <span class="n">patternPassword</span><span class="o">;</span>
<span class="kd">private</span> <span class="n">Pattern</span> <span class="n">patternEmail</span><span class="o">;</span>
<span class="kd">private</span> <span class="n">Pattern</span> <span class="n">patternFileName</span><span class="o">;</span>
<span class="kd">private</span> <span class="n">Pattern</span> <span class="n">patternPhone</span><span class="o">;</span>
<span class="kd">private</span> <span class="n">Matcher</span> <span class="n">matcher</span><span class="o">;</span> 

<span class="kd">private</span> <span class="nf">RegexUtil</span><span class="o">()</span> <span class="o">{</span>
    <span class="n">patternEmail</span> <span class="o">=</span> <span class="n">Pattern</span><span class="o">.</span><span class="na">compile</span><span class="o">(</span><span class="n">EMAIL_PATTERN</span><span class="o">);</span>
    <span class="n">patternFileName</span> <span class="o">=</span> <span class="n">Pattern</span><span class="o">.</span><span class="na">compile</span><span class="o">(</span><span class="n">FILE_NAME_PATTERN</span><span class="o">);</span>
    <span class="n">patternPhone</span> <span class="o">=</span> <span class="n">Pattern</span><span class="o">.</span><span class="na">compile</span><span class="o">(</span><span class="n">PHONE_PATTERN</span><span class="o">);</span>
    <span class="n">patternPassword</span> <span class="o">=</span> <span class="n">Pattern</span><span class="o">.</span><span class="na">compile</span><span class="o">(</span><span class="n">PASSWORD_PATTERN</span><span class="o">);</span>
<span class="o">}</span>

<span class="kd">public</span> <span class="kd">static</span> <span class="n">RegexUtil</span> <span class="nf">getInstance</span><span class="o">()</span> <span class="o">{</span>
    <span class="k">if</span> <span class="o">(</span><span class="n">instance</span> <span class="o">==</span> <span class="kc">null</span><span class="o">)</span> 
    <span class="o">{</span>
        <span class="n">instance</span> <span class="o">=</span> <span class="k">new</span> <span class="n">RegexUtil</span><span class="o">();</span>
    <span class="o">}</span>
    <span class="k">return</span> <span class="n">instance</span><span class="o">;</span>
<span class="o">}</span>

<span class="kd">public</span> <span class="kt">boolean</span> <span class="nf">validateIntegerID</span><span class="o">(</span><span class="n">Integer</span> <span class="n">id</span><span class="o">)</span> <span class="o">{</span>
    <span class="k">if</span> <span class="o">(</span><span class="n">id</span> <span class="o">!=</span> <span class="kc">null</span> <span class="o">&amp;&amp;</span> <span class="n">id</span> <span class="o">&gt;=</span> <span class="mi">0</span><span class="o">)</span> <span class="o">{</span>          
        <span class="k">return</span> <span class="kc">true</span><span class="o">;</span>
    <span class="o">}</span>     
    <span class="k">return</span> <span class="kc">false</span><span class="o">;</span>
<span class="o">}</span>

<span class="kd">public</span> <span class="kt">boolean</span> <span class="nf">validateStringTypeRegex</span><span class="o">(</span><span class="n">String</span> <span class="n">text</span><span class="o">,</span> <span class="n">String</span> <span class="n">patternType</span><span class="o">)</span> <span class="o">{</span>
    <span class="k">if</span> <span class="o">(</span><span class="n">text</span> <span class="o">!=</span> <span class="kc">null</span> <span class="o">&amp;&amp;</span> <span class="o">!</span><span class="n">text</span><span class="o">.</span><span class="na">equals</span><span class="o">(</span><span class="s">""</span><span class="o">))</span> <span class="o">{</span> 

        <span class="k">if</span> <span class="o">(</span><span class="n">patternType</span><span class="o">.</span><span class="na">equals</span><span class="o">(</span><span class="s">"email"</span><span class="o">))</span> <span class="o">{</span>
            <span class="n">matcher</span> <span class="o">=</span> <span class="n">patternEmail</span><span class="o">.</span><span class="na">matcher</span><span class="o">(</span><span class="n">text</span><span class="o">);</span>  
        <span class="o">}</span> <span class="k">else</span> <span class="k">if</span> <span class="o">(</span><span class="n">patternType</span><span class="o">.</span><span class="na">equals</span><span class="o">(</span><span class="s">"password"</span><span class="o">))</span> <span class="o">{</span>
            <span class="n">matcher</span> <span class="o">=</span> <span class="n">patternPassword</span><span class="o">.</span><span class="na">matcher</span><span class="o">(</span><span class="n">text</span><span class="o">);</span>   
        <span class="o">}</span> <span class="k">else</span> <span class="k">if</span> <span class="o">(</span><span class="n">patternType</span><span class="o">.</span><span class="na">equals</span><span class="o">(</span><span class="s">"phone"</span><span class="o">))</span> <span class="o">{</span>
            <span class="n">matcher</span> <span class="o">=</span> <span class="n">patternPhone</span><span class="o">.</span><span class="na">matcher</span><span class="o">(</span><span class="n">text</span><span class="o">);</span>  
        <span class="o">}</span> <span class="k">else</span> <span class="k">if</span> <span class="o">(</span><span class="n">patternType</span><span class="o">.</span><span class="na">equals</span><span class="o">(</span><span class="s">"fileName"</span><span class="o">))</span> <span class="o">{</span>
            <span class="n">matcher</span> <span class="o">=</span> <span class="n">patternFileName</span><span class="o">.</span><span class="na">matcher</span><span class="o">(</span><span class="n">text</span><span class="o">);</span>   
        <span class="o">}</span>

        <span class="k">if</span><span class="o">(</span><span class="n">matcher</span><span class="o">.</span><span class="na">matches</span><span class="o">()){</span>
            <span class="k">return</span> <span class="kc">true</span><span class="o">;</span>
        <span class="o">}</span>
    <span class="o">}</span>     
    <span class="k">return</span> <span class="kc">false</span><span class="o">;</span>
<span class="o">}</span>

<span class="kd">public</span> <span class="kt">boolean</span> <span class="nf">validateEmail</span><span class="o">(</span><span class="n">String</span> <span class="n">email</span><span class="o">)</span> <span class="o">{</span>
    <span class="k">return</span> <span class="nf">validateStringTypeRegex</span><span class="o">(</span><span class="n">email</span><span class="o">,</span> <span class="s">"email"</span><span class="o">);</span>
<span class="o">}</span>

<span class="kd">public</span> <span class="kt">boolean</span> <span class="nf">validateFileName</span><span class="o">(</span><span class="n">String</span> <span class="n">fileName</span><span class="o">)</span> <span class="o">{</span>
    <span class="k">return</span> <span class="nf">validateStringTypeRegex</span><span class="o">(</span><span class="n">fileName</span><span class="o">,</span> <span class="s">"fileName"</span><span class="o">);</span>
<span class="o">}</span>

<span class="kd">public</span> <span class="kt">boolean</span> <span class="nf">validatePhoneNumber</span><span class="o">(</span><span class="n">String</span> <span class="n">phone</span><span class="o">)</span> <span class="o">{</span>
    <span class="k">return</span> <span class="nf">validateStringTypeRegex</span><span class="o">(</span><span class="n">phone</span><span class="o">,</span> <span class="s">"phone"</span><span class="o">);</span>
<span class="o">}</span>


}