Support for first/last profile name length

service/src/main/java/org/whispersystems/textsecuregcm/util/ExactlySize.java

@@ -0,0 +1,34 @@
+package org.whispersystems.textsecuregcm.util;
+
+import javax.validation.Constraint;
+import javax.validation.Payload;
+import java.lang.annotation.Documented;
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+import static java.lang.annotation.ElementType.*;
+import static java.lang.annotation.ElementType.PARAMETER;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+
+@Target({ FIELD, METHOD, PARAMETER, ANNOTATION_TYPE })
+@Retention(RUNTIME)
+@Constraint(validatedBy = ExactlySizeValidator.class)
+@Documented
+public @interface ExactlySize {
+
+  String message() default "{org.whispersystems.textsecuregcm.util.ExactlySize." +
+      "message}";
+
+  Class<?>[] groups() default { };
+
+  Class<? extends Payload>[] payload() default { };
+
+  int[] value();
+
+  @Target({ FIELD, METHOD, PARAMETER, ANNOTATION_TYPE })
+  @Retention(RUNTIME)
+  @Documented
+  @interface List {
+    ExactlySize[] value();
+  }
+}

service/src/main/java/org/whispersystems/textsecuregcm/util/ExactlySizeValidator.java

@@ -0,0 +1,29 @@
+package org.whispersystems.textsecuregcm.util;
+
+import javax.validation.ConstraintValidator;
+import javax.validation.ConstraintValidatorContext;
+
+
+public class ExactlySizeValidator implements ConstraintValidator<ExactlySize, String> {
+
+  private int[] permittedSizes;
+
+  @Override
+  public void initialize(ExactlySize exactlySize) {
+    this.permittedSizes = exactlySize.value();
+  }
+
+  @Override
+  public boolean isValid(String object, ConstraintValidatorContext constraintContext) {
+    int objectLength;
+
+    if (object == null) objectLength = 0;
+    else                objectLength = object.length();
+
+    for (int permittedSize : permittedSizes) {
+      if (permittedSize == objectLength) return true;
+    }
+
+    return false;
+  }
+}