Java get class name of arrayList of object and type cast the array list without loop

Question

I have List of objects and need to type cast from class name. e.g

public void foo(List configs){
    //configs type cast code
    configs.forEach(config -> {
        String value = config.getValue();
    });
}

Is there any way to do this?

You need a List<SomeClassWithGetValueMethod> to make it work. You need to see how generic works. — AxelH
– AxelH, Commented Apr 4, 2018 at 10:15

davidxxx · Accepted Answer · 2018-04-04 10:16:54Z

1

Use a generic type : List<Config>.
The compiler handles the generic of raw Collections as Object. So it is like if you had declared : List<Object>.

Supposing you have a List of Config instances, you could write :

public void foo(List<Config> configs){
    configs.forEach(config -> {
                String value = config.getValue();
                // use the value ...
              });    
}

edited Apr 4, 2018 at 10:16

answered Apr 4, 2018 at 10:07

davidxxx

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2 Comments

nilesh Over a year ago

but it gives me error "The method getValue() is undefined for the type Object" in for loop. thats why I mentioned for loop specifically.

davidxxx Over a year ago

@ Joop Eggen Right. I added it.

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