Here is an example for those who want to Test Spring MockMvc Security Config using Base64 basic authentication.
String basicDigestHeaderValue = "Basic " + new String(Base64.encodeBase64(("<username>:<password>").getBytes()));
this.mockMvc.perform(get("</get/url>").header("Authorization", basicDigestHeaderValue).accept(MediaType.APPLICATION_JSON)).andExpect(status().isOk());
Maven Dependency
<dependency>
<groupId>commons-codec</groupId>
<artifactId>commons-codec</artifactId>
<version>1.3</version>
</dependency>