Java小知识集结号

来源：互联网发布：批处理关闭端口编辑：程序博客网时间：2024/05/01 21:49

import static java.lang.System.out; 为什么要加上static关键字？

import static 是静态导入，是jdk1.5的新特征,可以不同过调用包名，直接使用包里的静态方法。举个例子来说：用import的情况：public static void main(String args[]){       System.out.println("输出内容");}用import static 的情况：import static java.lang.System.out;public static void main(String args[]){       out.println("输出内容");}两者的输出情况是一样的。

Data Sink vs Processing
 Data sink stream: Acutal IO is performed
 FileReader, CharArrayReader, PipedReader, StringReader
 FileWriter, CharArrayWriter, PipedWriter, StringWriter
 FileInputStream, PipedInputStream, ByteArrayInputStream,
StringBufferInputStream
 FileOutputStream, PipedOutputStream, ByteArrayOutputStream
 Processing stream: Wrapping or connecting another stream for
processing
 BufferedReader, LineNumberReader, InputStreamReader,
FilterReader, PushbackReader
 BufferedWriter, OutputStreamWriter, FilterWriter
 FilterInputStream, LineNumberInputStream,DataInputStream,
BufferedInputStream,PushbackInputStream, ObjectInputStream
 FilterOutputStream, DataOutputStream,
BufferedOutputStream,PrintStream, ObjectOutputStream

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