标签：ram string bytes style 知识 strong sre 17. convert
这个课程的参考视频和图片来自youtube。
主要学到的知识点有：
We want to handle the bad Error. (e.g bad input / bugs in program)
1. File() : A Java representation of a file.
File file = new File("test.txt");
2. PrintWriter() : Write to a file.
// Write 2 lines(Johnson, 26) into the test.txt file. (If not exist then create one, otherwise will overwrite it.) PrintWriter output = new PrintWriter(file); output.println("Johnson"); output.println("26"); output.close();
3. Scanner() : Read from a file.
Scanner input = new Scanner(file); String name = input.nextLine(); int age = input.nextLine();
4. Object Serialization : convert an object into a series of bytes so they can be written to disk
public class Student implements Serializable {
Read from a file as bytes and deserialize a data input stream back into an object
// deserialize the collection of students FileinputStream fi = new FileinputSream(file); ObjectInputStream input = new ObjectOutputStream(fi); while(input.hasNext()){ Student s =(Student) input.readObject(); students.add(s); } input.close();// Important when writing a file as operating system will deny other programs access until the file is closed fi.close();
Write to a file as bytes and serialize an object into a data input stream
// serialize the collection of students FileOutputStream fo = new FileOutputSream(file); ObjectOutputStream output = new ObjectOutputStream(fo); for(Student s: students){ output.writeObject(s); } output.close();// Important when writing a file as operating system will deny other programs access until the file is closed fo.close();
[Java in NetBeans] Lesson 17. File Input/Output.
标签：ram string bytes style 知识 strong sre 17. convert
原文地址：https://www.cnblogs.com/Johnsonxiong/p/10204160.html
