I/O and file processing in the "core" framework of Java class libraries refer to
I/O and file processing guidelines in the "core" framework of Java class libraries
Java is a widely used programming language in software development, and its powerful class library provides developers with many functionally rich tools. Among them, the I/O (input/output) and file processing modules in Java's "core" framework are very important. This article will introduce you to some key concepts and techniques of I/O and file processing in Java class libraries, and provide some Java code examples.
I/O (input/output) is a common concept in computer systems. In Java, I/O is mainly used for input and output of data, such as reading data from files or writing data to files. The I/O modules in the Java class library contain many classes and interfaces to make it easier to handle input and output operations.
File processing in Java includes operations such as reading, writing, copying, moving, and deleting files. File processing is one of the common tasks in many Java applications, so the Java class library provides some classes and methods for file processing.
Let's start with the I/O module in the Java class library. Here are some commonly used Java I/O classes and interfaces:
1. InputStream: An abstract class used to read data from a source, such as a file or network connection.
InputStream inputStream = new FileInputStream("example.txt");
int data = inputStream.read();
while (data != -1) {
//Processing read data
System.out.println(data);
data = inputStream.read();
}
inputStream.close();
2. OutputStream: An abstract class used to write data to a target (such as a file or network connection).
OutputStream outputStream = new FileOutputStream("example.txt");
byte[] data = "Hello, World!".getBytes();
outputStream.write(data);
outputStream.close();
3. Reader: An abstract class used to read data from the source in characters.
Reader reader = new FileReader("example.txt");
int data = reader.read();
while (data != -1) {
//Processing read characters
System.out.println((char) data);
data = reader.read();
}
reader.close();
4. Writer: An abstract class used to write data to the target in characters.
Writer writer = new FileWriter("example.txt");
String data = "Hello, World!";
writer.write(data);
writer.close();
Next, let's take a look at the file processing module in the Java class library. Here are some commonly used Java file processing classes and methods:
1. File: Represents a file or directory in the file system.
File file = new File("example.txt");
System. out. println (file. getName())// Output File Name
System. out. println (file. isFile())// Check if it is a file
System. out. println (file. isDirectory())// Check if it is a directory
2. Files: Provides static methods for performing file operations.
Path path = Paths.get("example.txt");
Files. copy (path, Paths. get ("copy. txt"))// Copying Files
Files. move (path, Paths. get ("new_directory/example. txt"))// move file
Files. delete (path)// Delete files
3. FileInputStream and FileOutputStream: Classes used to read data from and write data to files.
InputStream inputStream = new FileInputStream("example.txt");
OutputStream outputStream = new FileOutputStream("output.txt");
int data = inputStream.read();
while (data != -1) {
//Processing read data
outputStream.write(data);
data = inputStream.read();
}
inputStream.close();
outputStream.close();
These are just some basic concepts and techniques of the I/O and file processing modules in the Java class library. Java's class library provides more advanced features and powerful classes to meet various I/O and file processing needs. Whether you are dealing with data input/output or file operations, mastering these core concepts and techniques is crucial to helping you develop Java applications more effectively.