database - Java: Reading data with type that isn't known in advance -

i'm working on project in have read bunch of features (properties) database (which in form of csv file).

this how file looks (formatted bit easier readability):

isfast; speed; isred;   r;   g;   b      t; 123.4;     f; 0.0; 0.0; 1.0      f;  21.3;     t; 1.0; 0.0; 0.0 ... 

as can see, t/f represent boolean values, while numbers floating point values. properties may later added or removed.

in code need read these values each instance (row) , pass them other code processes data further.

the way i'm dealing have following classes:

public abstract class feature<t> {     public final string name;     public final t value;      public feature(string name, t value) {         this.name = name;         this.value = value;     }      public abstract boolean test(t value); }    public class boolfeature extends feature<boolean> {     public boolfeature(string name, boolean value) {         super(name, value);     }      @override     public boolean test(boolean value) {         return this.value;     } }    public class doublefeature extends feature<double> {     public doublefeature(string name, double value) {         super(name, value);     }      @override     public boolean test(double value) {         return this.value < value;     } } 

i'm parsing csv file , creating boolfeature objects input that's t/f , doublefeatures others, saving in list<feature> or feature[], , passing collection around.

this results in lot of

feature raw type. references generic type feature should parameterized

and

type safety: method test(object) belongs raw type feature. references generic type feature should parameterized

in code like:

public abstract class metric {     protected list<feature> features;      // line gives warning #1 above      public metric(list<feature> features) {         this.features = features;     }      public double getsplitquality(split split) {         return getimpurity(split.yes) + getimpurity(split.no);     }      public abstract double getimpurity(list<instance> instances); }  public class split {     public final list<instance> yes;     public final list<instance> no;      public split(list<instance> instances, feature feature) {         yes = new arraylist<>();         no = new arraylist<>();         (instance inst : instances)             if (inst.features.get(feature.name).test(feature.value))   // line gives warning #2 above                 yes.add(inst);             else                 no.add(inst);     } }  public class instance {     public hashmap<string, feature> features = new hashmap<>();     public string output = null;      public instance(string[] featurenames, string[] csvrow) {         /* parse csv row, creating boolfeatures , doublefeatures            , adding them hashmap, example: */         if (csvrow[0].equals("t") || csvrow[0].equals("f"))             features.put(featurenames[0], new boolfeature(featurenames[0], csvrow[0].equals("t")));     } } 

is there cleaner way deal problem this?

edit

after adding <?> references feature, per answer, line gave warning #2 gives compile time error:

the method test(capture#2-of ?) in type feature not applicable arguments (capture#3-of ?)

your list<feature> uses raw-type feature (as warning says). if know subtype feature has can use generic type e.g list<feature<boolean>>.

however if want list<feature contain boolfeature , doublefeature can make use of wildcard-type list<feature<?>>