Question

我有一个Builder模式，其中我有一个静态类，如下所示：

public final class DataKey {

    private DataKey(Builder builder) {

    }

    public static class Builder {
        protected int maxCount = 3;

        // ..some other code here

        /**
         * This should be greater than 0 and less than equal to {@value Builder#maxCount}.
         * 
         * @param count
         * @throws IllegalArgumentException if count is less than 0 and greater than {@value Builder#maxCount}.
         * @return Builder object
         */         
        public Builder addCount(int count) {
            checkArgument(count > 0 && count < (maxCount + 1),
                    "maxCount should be greater than 0 and less than " + (maxCount + 1));
            this.maxCount = count;
            return this;
        }           
    }
}

现在我想在我的addCount方法上添加一个Javadoc，这样我就可以在其上显示maxCount的值，而无需对实际数字进行硬编码。我尝试使用{@value Builder#maxCount}，当我在该方法上查找Javadoc时它没有显示值3？我在这做错了什么？

Answer 1

public static class Builder {
    protected static final int DEFAULT_MAX_COUNT = 3;
    /** count cannot be set to a value higher than this. By default, the value is {@value Builder#DEFAULT_MAX_COUNT}. */
    protected int maxCount = DEFAULT_MAX_COUNT;
    protected int count;

    // ..some other code here

    /**
     * This should be greater than 0 and less than equal to {@link Builder#maxCount}. By default,  {@value Builder#DEFAULT_MAX_COUNT}.
     * 
     * @param count
     * @throws IllegalArgumentException if count is less than 0 and greater than {@link Builder#maxCount}.
     * @return Builder object
     */         
    public Builder setCount(int count) {
        checkArgument(count > 0 && count < (maxCount + 1),
                "count should be greater than 0 and less than " + (maxCount + 1));
        this.count = count;
        return this;
    }

    /** ... */
    public Builder setMaxCount(int maxCount){
        checkArgument(count > 0, "maxCount must be greater than 0"); 
        this.maxCount = maxCount;
    }

    /** ... */
    public int getMaxCount(int maxCount){
         return this.maxCount;
    }

}

IMO，在maxCount中为Builder设置setter和getter是没有意义的，而且应该是常量最大值（DEFAULT_MAX_COUNT）。

javadoc无法显示动态变量的值，因为文档在程序运行时不会更改。 javadoc只是文本，没有程序在运行，因此无法更新值。您可以将其视为闹钟（程序）附带的手册（您的javadoc）。手册可以告诉你各种有用的东西以及如何使用时钟，但它无法告诉你警报的设置（因为它永远不会改变）。 {@value ..}的东西就像时钟的序列号。 “打包”时钟的人知道实际的序列号并将其写出而不是。

PS。完全希望这更符合您的实际需求：

public static class Builder {
    protected static final int MAX_MAX_COUNT = 3;
    /** By default, the value is {@value Builder#MAX_MAX_COUNT}. */
    protected int maxCount = MAX_MAX_COUNT;

    // ..some other code here

    /**
     * This should be greater than 0 and less than equal to {@value Builder#MAX_MAX_COUNT}.
     * 
     * @param maxCount
     * @throws IllegalArgumentException if maxCount is less than 0 and greater than {@link Builder#MAX_MAX_COUNT}.
     * @return Builder object
     */         
    public Builder setMaxCount(int maxCount) {
        checkArgument(maxCount > 0 && maxCount < (MAX_MAX_COUNT + 1),
                "count should be greater than 0 and less than " + (MAX_MAX_COUNT + 1));
        this.maxCount = maxCount;
        return this;
    }
}

Answer 2

您只能对常量执行此操作。当你将变量设为静态最终时，它将起作用。

如何在方法上显示javadoc中变量的值？

2 个答案: