Guava (GOOGLE Common Libraares) input/output framework introduction and use guideline
Guava (Google Common Libraares) is a open source project of Google, which provides many universal libraries for improving the development efficiency of Java program and simplified operations.This article will introduce the INPUT/OUTPUT framework in Guava and provide relevant usage guidelines and Java code examples.
1. Introduction to Guava
Guava is a powerful, stable and widely popular Java open source library, which aims to enhance the native function of Java programming language.It provides many practical tools, collection and functional programming support, which can help developers write code more concisely and efficiently.
Second, Guava's Input/OUTPUT framework
The Guava's Input/OUTPUT framework provides some tool classes and interfaces for processing input and output, making it simpler and elegant in the Java program to read and write, flow operations, and process I/O abnormalities.
1. FILES class
The Files class provides a set of static methods to operate files and directory.It can help us complete some common file operations, such as judging whether files exist, create directory, copy, move, delete files, etc.
Below is a sample code using the Files class to copy files:
import com.google.common.io.Files;
import java.io.File;
import java.io.IOException;
public class FileCopyExample {
public static void main(String[] args) {
File source = new File("source.txt");
File destination = new File("destination.txt");
try {
Files.copy(source, destination);
System.out.println("File copied successfully.");
} catch (IOException e) {
System.err.println("Error copying file: " + e.getMessage());
}
}
}
2. Bytesource and bytesink interface
Bytesource and bytesink interfaces represent the source and receiver that can be read from it and the source of bytes can be read from it.These two interfaces provide a set of methods to perform basic I/O operations and support streaming operations.
The following is a sample code that uses ByteSource and bytesink to copy files:
import com.google.common.io.ByteSource;
import com.google.common.io.ByteSink;
import com.google.common.io.Files;
import java.io.File;
import java.io.IOException;
public class FileCopyExample {
public static void main(String[] args) {
File source = new File("source.txt");
File destination = new File("destination.txt");
ByteSource byteSource = Files.asByteSource(source);
ByteSink byteSink = Files.asByteSink(destination);
try {
byteSource.copyTo(byteSink);
System.out.println("File copied successfully.");
} catch (IOException e) {
System.err.println("Error copying file: " + e.getMessage());
}
}
}
3. Charsource and Charsink interface
The Charsource and Charsink interfaces are similar to Bytesource and bytesink. The difference is that they are read and write for character streaming.These two interfaces provide a set of methods for character I/O, which facilitates the processing of text files.
Here are examples of reading and writing text files using Charsource and Charsink:
import com.google.common.io.CharSource;
import com.google.common.io.CharSink;
import com.google.common.io.Files;
import java.io.File;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
public class FileReadWriteExample {
public static void main(String[] args) {
File file = new File("file.txt");
try {
CharSource charSource = Files.asCharSource(file, StandardCharsets.UTF_8);
String content = charSource.read();
CharSink charSink = Files.asCharSink(file, StandardCharsets.UTF_8);
charSink.write(content);
System.out.println("File read and written successfully.");
} catch (IOException e) {
System.err.println("Error reading or writing file: " + e.getMessage());
}
}
}
3. Use Guide
To use Guava's Input/Output framework, you need to add the dependencies of the Guava library.You can introduce the Guava library by adding the following code to the construction file of the project:
groovy
dependencies {
implementation 'com.google.guava:guava:30.1-jre'
}
After introducing the Guava library, you can use the Files class, bytesource, bytesink, Charsource, and Charsink to process the input and output.
Fourth, summary
This article introduces Guava's INPUT/OUTPUT framework, including the Files class, bytesource and bytesink interfaces, and Charsource and Charsink interfaces.By using the Guava's Input/OUTPUT framework, developers can more conveniently perform the operation of file reading and writing, byte flow, and character streaming, and handle related abnormalities.It is hoped that this article can help readers better understand and use Guava's input/output framework.
