缺少Void方法的返回值？

Question

以下代码给出了编译时错误:缺少返回值和缺少return语句,我将返回什么值Void Type？

final SwingWorker<Void, Void> worker = new SwingWorker<Void, Void>()
{
    @Override
    protected Void doInBackground() throws Exception
    {
        // some code
        if (something)
        {
            return;
        }
    }
 }

Answer 1

Void是不是void,将其更改为void类型,如果你不想返回任何东西.

Void是一个类,void是类型.

/**
 * The {@code Void} class is an uninstantiable placeholder class to hold a
 * reference to the {@code Class} object representing the Java keyword
 * void.
 *
 * @author  unascribed
 * @since   JDK1.1
 */

如果需要Void,则需要return在结尾添加语句.

例:

protected Void doInBackground() throws Exception
    {
        // some code
        if (something)
        {
            return null;
        }
       return null;
    }