CODEWITHSUNDEEP
javaclass
Jason4Ever
Jason4Ever

Reputation: 1479

how i do this with java?

i have string contain the name of class which i need to define it ,

// this is the name of language class which i need to define it
String language = "english";

i can define it as :

english eng = new english();

but this method is for fixed names , but in my case , the string "language" may change to another class name , for example next time may be as :

String language = "french";

so i need to know a dynamic method to define the class of "language" string , to load any class with out using fixed method of defining such as :

french eng = new french();

Upvotes: 0

Views: 83

Answers (2)

Bozho
Bozho

Reputation: 597274

You can, but you shouldn't.

The quick solution is reflection. You can do Class.forName(className) and the class will be located (note that it should also include a package)

The better solution is to provide another mechanism for creation - factory, for example, and an interface common to all languages.:

interface Language { .. }

public class English implements Language { .. }
public class French implements Language { .. }

public class LanguageFactory {
     private static Map<String, Language> languageRegistry;
     public static Language createLanguage(String name) {
         return languageRegistry.get(name);
     }
     public synchronized void init() {
         //populate the registry
     }
}

(the registry is initialized once, by calling .put("english", new English())

Upvotes: 2

kasavbere
kasavbere

Reputation: 6003

public class Language{
    String name;
    public Language(String name){
        this.name=name;
    }
}

caller:

Language english = new Language("English");

But if you are not starting from scratch and the classes already exist, use reflection.

Upvotes: 1

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