Difference between registerGlobal(), configure(), configureGlobal(),configureGlobalSecurity in Spring security
<p>I have below three code snippets all doing the same thing: creating in-memory authentication. So how it impacts defining it in different method names?</p>

<ol>
<li>registerGlobal</li>
<li>configure</li>
<li>configureGlobal</li>
<li>configureGlobalSecurity</li>
</ol>

<p>First one:</p>

<pre><code>public void registerGlobal(AuthenticationManagerBuilder auth) throws Exception {
    auth
      .inMemoryAuthentication()
        .withUser("user").password("password").roles("USER").and()
        .withUser("admin").password("password").roles("USER","ADMIN");
    }
}
</code></pre>

<p>Second one:</p>

<pre><code>@Override
protected void configure(AuthenticationManagerBuilder auth) throws Exception {
    auth
         .inMemoryAuthentication()
              .withUser("user").password("password").roles("USER");
 }
</code></pre>

<p>Third one:</p>

<pre><code>public void configureGlobal(AuthenticationManagerBuilder auth) throws Exception {
    auth
         .inMemoryAuthentication()
              .withUser("user").password("password").roles("USER");
}
</code></pre>

<p>Fourth:</p>

<pre><code>@Autowired
public void configureGlobalSecurity(AuthenticationManagerBuilder auth)     throws Exception {
    auth.inMemoryAuthentication().withUser("user").password("user").roles("USER");
}
</code></pre>

<p><strong>UPDATE 1 :</strong>
One more thing I would like to add:</p>

<p>configure() method is present in WebSecurityConfigurerAdapter class while others are not present.</p>

<p><strong>UPDATE 2:</strong></p>

<p>I renamed the method in my sample project to below and to my surprise it is working and authenticating the users.</p>

<p><strong>you name it anything and it works</strong></p>

<pre><code>@Autowired
public void anyMethodName(AuthenticationManagerBuilder auth) throws Exception {
            auth.inMemoryAuthentication().withUser("user").password("user").roles("USER");      
}
</code></pre>