What is Builder design pattern in Java?
In Java, there are three primary issues associated with Abstract Factory and Factory Designs when there are numerous attributes in the Object. The first issue is that it is difficult to maintain the organization of arguments from the client’s side, when too many arguments move from the client program to the factory class. Secondly, in factory pattern, it is imperative to include all parameters and optional ones need to be sent as NULL. However, when an object has too many attributes, some might be optional. Lastly, the complexity of an object with too many parameters might be inherent, influencing the complexity of factory classes.
It is possible to corrects these mistakes by introducing a constructor that has a specified number of parameters and diverse setter methods, which set the optional attributes or parameters. Although, this might create another issue. The problem with introducing a constructor is that it might cause the object’s state to be inconsistent. In such a case, the developer or programmer implements builder pattern to resolve the issue. Builder patterns corrects the error by providing an easy step-by-step process of building an object.
Therefore, in java, Builder design pattern is a method that resolves the issues caused by objects with a lot of attributes. In answering what it is, it is important to understand how to implement it. There are four steps involved in applying the builder design pattern.
- How to implement Builder Design Pattern Generate a static nested class, as the first step and copy all the arguments to the Builder class from the outer class. Additionally, it is imperative to follow the naming convention technique. For instance, if the name of the class is House, then the name of the builder class will be HouseBuilder.
- The second step is ensure that the Java Builder has a public constructor. with all the attributes needed, which represent parameters.
- The third step in to include methods in the Java Builder. The aim of the method is to create and set the optional parameters. In doing so, it should also return the same Builder Object after creating the alternative attribute.
- The last step engrosses providing a build() method inside the builder class, which will return the object required by the client program. In this case, the programmer needs to have a private constructor. The private constructor ought to be in the class. The argument will be Builder class.
In conclusion, it is a solution that helps programmers to deal with the three challenges created by objects with numerous attributes.