Java 輸入流全景指南：緩衝、數據解析、行號與推回

核心流類別

常見讀取模式

逐行讀取

DataInputStream in = new DataInputStream(new BufferedInputStream(new FileInputStream(f)));
String line;
while ((line = in.readLine()) != null) { ... }

內存字串流

StringBufferInputStream mem = new StringBufferInputStream(str);
DataInputStream in = new DataInputStream(mem);
while (in.available() > 0) System.out.print((char) in.readByte());

行號追蹤

LineNumberInputStream lnis = new LineNumberInputStream(new StringBufferInputStream(s2));
DataInputStream in = new DataInputStream(lnis);
while ((line = in.readLine()) != null) {
    System.out.println(lnis.getLineNumber() + ": " + line);
}

EOF 檢測

readLine() 返回 null、read() 返回 -1、available() == 0、捕獲 EOFException 四種方式視場景選擇。