java - 为什么Java的FileInputStream read()带参数，而Oracle的文档却说不带参数？

Question

我正在阅读一本 Java 考试准备书。当我读到下面的例子时，我很困惑:

byte [] magicNumber = {( byte) 0xCA, (byte) 0xFE, (byte) 0xBA, (byte) 0xBE}; 
try (FileInputStream fis = new FileInputStream( fileName)) {  
    byte[] u4buffer = new byte[ 4]; 
    if( fis.read( u4buffer) != − 1) { 
        if( Arrays.equals( magicNumber, u4buffer)) { 
            System.out.printf(" The magic number for passed file %s matches that of a .class file", fileName); 
        } else { 
            System.out.printf(" The magic number for passed file %s does not match that of a .class file", fileName); 
        } 
    }
} catch( FileNotFoundException fnfe) { 
    System.err.println(" file does not exist with the given file name "); 
} catch( IOException ioe) { 
    System.err.println(" an I/ O error occurred while processing the file"); 
}

这是什么意思:read(u4buffer)？

Answer 1

查看 FileInputStream 的文档

read 方法使用不同的参数集重载两次。

您可能想阅读有关 method overloading 的更多信息.