java - 我有一个无法调用的接口(interface)方法

Question

这个问题在这里已经有了答案:





My program keeps saying that the method cannot be resolved

(2 个回答)


5年前关闭。




我的类(class)Cupple需要调用方法beStored(char)一类DataIterator实现接口(interface)StorableData .

这里是这个接口(interface)的代码StorableData :

package general_classes.cupples;    
public interface StorableData {

    public void beStored(char c);

}

这里是实现的代码:

package general_classes.cupples;
public class Cupple<TYPE_OF_ELEMENTS> implements StorableData {
    public void beStored(char c) {

    }
}

最后，这里是类的代码 DataIterator :

package general_classes.DataIteration;
public class DataIterator<StorableData> {
    private StorableData root_storable_data;
    public List<StorableData> iterate() {
            this.root_storable_data.beStored(read_character);
    }
}

请注意，我没有写完所有的行。

问题是编译器告诉我他“无法解析方法 beStored(int) 。

但是，如您所见，它实际上在界面中。所以有什么问题 ？

完整的代码。

界面 :

package general_classes.cupples;

public interface StorableData {

    public Cupple beStored(int c);

}

执行 :

package general_classes.cupples;

import java.util.ArrayList;

public class Cupple<TYPE_OF_ELEMENTS> extends ArrayList<TYPE_OF_ELEMENTS> implements StorableData {
    private int position_to_insert_element;
    private int number_of_elements;
    private Cupple<TYPE_OF_ELEMENTS> next_cupple;
    private Cupple<TYPE_OF_ELEMENTS> current_empty_cupple;

    public Cupple(int number_of_elements) {
        this.position_to_insert_element = 0;
        this.number_of_elements = number_of_elements;
    }

    public Cupple beStored(int c) {
        Cupple returned_cupple = this;

        if(this.position_to_insert_element > this.number_of_elements) {
            this.next_cupple = returned_cupple = new Cupple<>(this.number_of_elements);

        } else {

            //this.add((TYPE_OF_ELEMENTS) c);
            this.position_to_insert_element++;

        }

        return returned_cupple;

    }

    public Cupple next() {
        return this.next_cupple;
    }
}

类(class) :

package general_classes.DataIteration;

import java.io.IOException;
import java.io.Reader;
import java.util.ArrayList;
import java.util.List;

/**
 * Reads character per character some given data. Stores the character in a
 * list, after having casted it in the specified type by the way.
 * 
 * @author e1300478
 *
 * @param <StorableData>
 *            the wished type of the reading's returned elements
 */
public class DataIterator<StorableData> {

    private Reader reader;
    private List<StorableData> returned_elements_list;
    private StorableData root_storable_data;

    DataIterator(Reader reader, StorableData storable_data) {
        this.reader = reader;
        this.returned_elements_list = new ArrayList<>();
        this.root_storable_data = storable_data;
    }

    public List<StorableData> iterate() throws IOException {

        int read_character;
        do {

            read_character = this.reader.read();
            StorableData storable_data = this.root_storable_data.beStored((int) read_character);
            if(!this.returned_elements_list.contains(storable_data)) {
                this.returned_elements_list.add(storable_data);
            }

        } while (read_character > -1);

        return this.returned_elements_list;

    }

}

Answer 1

The problem is that the compiler tells me that he "cannot resolve the method beStored(int).

这仅仅意味着您正在尝试传递 int输入 beStored方法。如果您再次查看此方法的接口(interface)定义，您会注意到您没有遵守已设置的约定。

public void beStored(char c);

在下面的代码 read_character很可能是 int类型而不是字符因此错误。

this.root_storable_data.beStored(read_character);

解决方案

改变这个:

int read_character;

对此:

char read_character;

也改变这个:

StorableData storable_data = this.root_storable_data.beStored((int) read_character);

对此:

StorableData storable_data = this.root_storable_data.beStored(read_character);