import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.nio.channels.FileLock; public class FileLockTest { public static void main(String[] args) { try ( var channel = new FileOutputStream("a.txt…

Chapter 2 Learning Java language fundamentals exercises: 1.What  is Unicode? Unicode is a computing industry standard for consistently encoding,representing,and handling text that's expressed in most of world's writing system 2.What is a comment? A c…

曹海成的专栏 http://blog.csdn.net/caohaicheng/article/details/38071097 http://blog.csdn.net/a5489888/article/details/8278301 http://blog.csdn.net/fmh2011/article/details/39205759 http://blog.csdn.net/caohaicheng/article/details/38116481 java nio http://blo…

I/O Streams, it simplifies I/O operations, write a whole object out to stream & read back. File I/O and file system operations, including random access files. Classes about I/O Streams most are in java.io, about File I/O are in java.nio.file. I/O Str…

Java is using Unicode set Java is case sensitive Comments, C/C++ style abstract, const, final, int, public, throw, assert, continue, finally, interface, return, throws, boolean, default, float, long, short, transient, break, do, for, native, static,…

Java characteristics: Java .class files are machine-independent, including the endianness. Java .class files are not optimized .class files comprises "bytecode" different from "interpreted languages" in an additional step javac (source…

这个课程的参考视频在youtube. 主要学到的知识点有: set up needs Java SE JDK, NetBeans IDE class name should be the same like .java file name. .java is java file, .jar is compiled code. "clean and build" did clean old .jar file and create a new .jar file. For keyboar…

import java.io.IOException; import java.nio.file.*; public class WatchServiceTest { public static void main(String[] args) throws IOException, InterruptedException { WatchService watchService = FileSystems.getDefault().newWatchService(); Paths.get("C…

import java.io.IOException; import java.nio.file.*; import java.nio.file.attribute.BasicFileAttributes; public class FileVisitorTest { public static void main(String[] args) throws Exception { // 遍历g:\publish\codes\15目录下的所有文件和子目录 Files.walkFileTree(P…

import java.nio.file.Path; import java.nio.file.Paths; public class PathTest { public static void main(String[] args) throws Exception { Path path = Paths.get("."); System.out.println("path里包含的路径数目" + path.getNameCount()); System.out.p…