Implement SessionEncoder and SessionParser

briar-api/src/main/java/org/briarproject/briar/api/introduction2/Role.java

@@ -0,0 +1,29 @@
+package org.briarproject.briar.api.introduction2;
+
+import org.briarproject.bramble.api.FormatException;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.concurrent.Immutable;
+
+@Immutable
+@NotNullByDefault
+public enum Role {
+
+	INTRODUCER(0), INTRODUCEE(1);
+
+	private final int value;
+
+	Role(int value) {
+		this.value = value;
+	}
+
+	public int getValue() {
+		return value;
+	}
+
+	public static Role fromValue(int value) throws FormatException {
+		for (Role r : values()) if (r.value == value) return r;
+		throw new FormatException();
+	}
+
+}