Intellij 无法解析方法，即使它是 public (Java)

Question

我用谷歌搜索了很多次，使缓存无效，但我似乎找不到答案。对于背景，这是一个使用约束求解的时间表系统。我有一个名为 Period 的自定义 class，使用 public 方法 getStart() 和 getEnd()。我还有一个摘要classConstraint<V, D>和一个子classDemAvailConstratint<Demonstrator, Period>。正是在这个subclass（另一个类似）中Period和Demonstrator中的方法无法解析。

在 DemAvailConstraint 中，显示错误的方法是 getStart() 和 getEnd() 在 this.period 上调用时，但在其他 Period 对象上调用时则不是。同样，当在 satisfied() 方法中调用 this.getDemonstrator() 时，isAvailable() 也会发生这种情况。这是 Demonstrator 中的 public 方法。知道为什么会这样吗？

以下是 classes（为清楚起见删除了一些方法）：

public abstract class Constraint<V, D> {
    private V variable;
    
    public Constraint(V variable) {
        this.variable = variable;
    }
    
    public abstract boolean satisfied();
    
    public abstract int score();
    
    protected V getVariable() {
        return this.variable;
    }
    
    protected void setVariable(V variable) {
        this.variable = variable;
    }
}

public class DemAvailConstraint<Demonstrator, Period> extends Constraint {
    private Period period;
    private ArrayList<AvailBlock> periodAsBlocks;
    
    public DemAvailConstraint(Demonstrator demonstrator, Period period) {
        super(demonstrator);
        this.period = period;
        periodAsBlocks = new ArrayList<>();
        periodAsBlocks.add( AvailBlock.from(this.period.getStart()) );
        while ( periodAsBlocks.get( periodAsBlocks.size() - 1 ).getEnd().isBefore(this.period.getEnd()) ) {
            periodAsBlocks.add( AvailBlock.from(periodAsBlocks.get( periodAsBlocks.size() - 1 ).getEnd()) );
        }
    }
    
    @Override
    public boolean satisfied() {
        // now we check if the demonstrator is available for each block
        for (AvailBlock block : this.periodAsBlocks) {
            if ( !this.getDemonstrator().isAvailable(block) ) return false;
        }
        return true;
    }
    
...
    
    public Demonstrator getDemonstrator() {
        return (Demonstrator) super.getVariable();
    }
}

public class Period {
    
    private String name;
    private LocalDateTime start;
    // duration in seconds
    private int duration;
    private Lecturer lecturer;
    private ArrayList<Demonstrator> dems;
    private ArrayList<Skill> skills;
    
    /**
     * Basic constructor. Use the factory method from() to make a period from AvailBlock objects.
     * @param name
     * @param start
     * @param duration
     * @param lecturer
     */
    public Period(String name, LocalDateTime start, int duration, Lecturer lecturer) {
        this.name = name;
        this.lecturer = lecturer;
        this.dems = new ArrayList<>();
        this.skills = new ArrayList<>();
        this.duration = duration;
        this.start = start;
    }
    
    /**
     * Static factory method that can create a period from a list of consecutive AvailBlock objects.
     * @param name
     * @param blocks
     * @param lecturer
     * @return
     */
    public static Period from(String name, List<AvailBlock> blocks, Lecturer lecturer)
            throws IllegalArgumentException {
        
        if ( !AvailBlock.isConsecutive(blocks) ) {
            throw new IllegalArgumentException( "Non-consecutive AvailBlock objects." );
        }
        
        ArrayList<AvailBlock> blocksSorted = new ArrayList<>(blocks);
        Collections.sort(blocksSorted);
        LocalDateTime start = blocksSorted.get(0).getStart();
        int duration = blocksSorted.size();
        
        return new Period(name, start, duration, lecturer);
    }
    
...    
    public LocalDateTime getStart() {
        return start;
    
// more getters and setters ...
    
    public LocalDateTime getEnd() {
        return this.start.plusSeconds(this.duration);
    }
    
}

Answer 1

在尝试使缓存无效、更改 JDK 等各种尝试后，我删除了 DemAvailConstraint class 声明中的 <Demonstrator, Period> 部分。我想我知道为什么会这样。添加那段代码使 Demonstrator 和 Period 成为占位符类型，而不是引用我的自定义 classes。这就是 class 无法访问我的方法的原因。我在摘要 class Constraint 中保留了占位符代码 <V, D> （变量和域），我现在想知道我是否真的需要在子 [=18] 中指定这些类型=].

Intellij 无法解析方法，即使它是 public (Java)

Intellij cannot resolve method even though it is public (Java)

java

polymorphism

visibility

constraints

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