1 files changed, 40 insertions, 0 deletions
diff --git a/src/main/java/derms/City.java b/src/main/java/derms/City.java
new file mode 100644
index 0000000..9fc71b8
--- /dev/null
+++ b/src/main/java/derms/City.java
@@ -0,0 +1,40 @@
+package derms;
+
+import java.io.Serializable;
+
+public class City implements Serializable {
+	public static final int codeLen = 3;
+
+	private String code;
+
+	public City(String code) throws IllegalArgumentException {
+		if (code.length() != codeLen)
+			throw new IllegalArgumentException("Invalid city: "+code+"; must be "+codeLen+" letters");
+		this.code = code;
+	}
+
+	public City() {
+		this("XXX");
+	}
+
+	public String getCode() { return code; }
+
+	@Override
+	public String toString() {
+		return code;
+	}
+
+	@Override
+	public boolean equals(Object obj) {
+		if (obj == null || this.getClass() != obj.getClass()) {
+			return false;
+		}
+		City other = (City) obj;
+		return this.code.equals(other.code);
+	}
+
+	@Override
+	public int hashCode() {
+		return code.hashCode();
+	}
+}