使用out反射调用动态java方法

Question

I have data type which contains 100 properties and 100 getter methods (getproperty1....getproperty100).

I get an input from the user like

Property1
Property2
.
.
Property100

How can I invoke in a quick way the method in this logic

For property1 I need to invoke getproperty1
For propertyI I need to invoke getpropertyI

How can I do this with out using if else , or switch statement or reflection in an efficient way.

Thanks

Answer 1

Your best bet is probably going to be an array or hashmap of some type, and access it by index/key:

public class DataType {
    private Map<String, DataProperty> data = new HashMap<String, DataProperty>();

    public DataProperty getProperty(String key) {
        return data.get(key);
    }

    public void setProperty(String key, DataProperty value) {
        data.put(key, value);
    }
}

Although, 100 properties seems like a lot... see if you should break it up or otherwise re-organize it.

Answer 2

1. If you need to invoke multiple methods I would suggest using the Strategy design pattern. In it's simplest form you could try

public interface Command<T> {
    public T getProperty();
}

and then create as many implementations as necessary.

2. If you are only interested in the return type and not the actual invokation the Map<String, T> would be a better alternative.

3. If you want to pass around the information in your program a good alternative would be to use the enum approach

public enum Command {
   Property1("some value"),
   Property2("some other value");

   private String str;
   public Command(String str) {
       this.str = str;
   }

   public String getVal() {
       return str;
   }
}

Which can be used like

Command cmd = ...
String value = cmd.getVal();

Answer 3

You could refactor the class to be a Map. If you have a large number of objects like that it seems more along the lines of a map than an object.

Map<String, Object>