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DAL-java

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package com.github.leeonky.dal.format;

import com.github.leeonky.dal.token.IllegalTypeException;

import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;

public abstract class BaseFormatter implements Formatter {
    private final Class inputType;

    @SuppressWarnings("unchecked")
    protected BaseFormatter() {
        inputType = (Class) guessInputType(getClass().getGenericSuperclass());
    }

    public static Class guessInputType(Type type) {
        if (type instanceof ParameterizedType) {
            ParameterizedType parameterizedType = (ParameterizedType) type;
            if (parameterizedType.getRawType().equals(BaseFormatter.class))
                return (Class) parameterizedType.getActualTypeArguments()[0];
            else
                return guessInputType(parameterizedType.getRawType());
        } else if (type instanceof Class)
            return guessInputType(((Class) type).getGenericSuperclass());
        throw new IllegalStateException("Cannot guess input type.");
    }

    public static  R toValueOrThrowIllegalTypeException(T arg, ParseBlock parseBlock) {
        try {
            return parseBlock.run(arg);
        } catch (Exception e) {
            throw new IllegalTypeException();
        }
    }

    @Override
    public boolean isValidType(Object input) {
        return inputType.isInstance(input);
    }

    @FunctionalInterface
    public
    interface ParseBlock {
        R2 run(T2 t) throws Exception;
    }
}