adding equals, hash, and toString

Author: springframeworkguru

src/main/java/guru/springframework/spring5webapp/model/Publisher.java

@@ -40,4 +40,28 @@ public String getAddress() {
     public void setAddress(String address) {
         this.address = address;
     }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+
+        Publisher publisher = (Publisher) o;
+
+        return id != null ? id.equals(publisher.id) : publisher.id == null;
+    }
+
+    @Override
+    public int hashCode() {
+        return id != null ? id.hashCode() : 0;
+    }
+
+    @Override
+    public String toString() {
+        return "Publisher{" +
+                "id=" + id +
+                ", name='" + name + '\'' +
+                ", address='" + address + '\'' +
+                '}';
+    }
 }