How to use the Activeio core framework in the Java library
Activeio is a core framework in a Java library, which provides developers with a method of simplifying and efficiently processing I/O operations.This framework uses event drive to abstract I/O as an event, and to handle these events to achieve data reading and writing.This article will introduce how to use the Activeio framework for I/O operation and provide some Java code examples.
First, we need to introduce Activeio's dependence in the Java project.You can download the jar file of Activeio through Maven or manually and add it to the project.
Once the Activeio library is introduced into the project, we can start using it to process I/O operations.The following is an example of using the Activeio framework for file reading and writing:
import org.activeio.BufferedChannel;
import org.activeio.Channel;
import org.activeio.ReadEvent;
import org.activeio.WriteEvent;
import org.activeio.adapter.channel.BufferedChannelFactory;
import org.activeio.adapter.nio.SelectionKeyHandler;
import org.activeio.adapter.nio.selector.DefaultSelectorThread;
import org.activeio.adapter.nio.selector.NioSelector;
import org.activeio.adapter.nio.selector.SelectorThread;
import org.activeio.adapter.nio.selector.SelectionKeyHandlerFactory;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.nio.ByteBuffer;
public class ActiveIOExample {
public static void main(String[] args) throws Exception {
// Create a file input stream
FileInputStream inputStream = new FileInputStream(new File("input.txt"));
// Create a file output flow
FileOutputStream outputStream = new FileOutputStream(new File("output.txt"));
// Create Activeio's selection device thread
SelectorThread selectorThread = new DefaultSelectorThread();
// Create Activeio's channel factory
BufferedChannelFactory channelFactory = new BufferedChannelFactory();
// Create Activeio's selection key processing factory
SelectionKeyHandlerFactory handlerFactory = new SelectionKeyHandlerFactory();
// Create an input and output Activeio channel
Channel inputChannel = channelFactory.createChannel(inputStream.getChannel());
Channel outputChannel = channelFactory.createChannel(outputStream.getChannel());
// Register the selection device thread and select key processing factory
NioSelector nioSelector = new NioSelector(selectorThread, handlerFactory);
// Register input and output channels
nioSelector.register(inputChannel, new ReadEventHandler());
nioSelector.register(outputChannel, new WriteEventHandler());
// Start the selector thread
selectorThread.start();
// The event cycle of the Activeio framework starts
while (true) {
nioSelector.select();
}
}
private static class ReadEventHandler implements SelectionKeyHandler {
@Override
public void handle(SelectionKey selectionKey) throws Exception {
if (selectionKey.isValid() && selectionKey.isReadable()) {
ReadEvent readEvent = (ReadEvent) selectionKey.attachment();
Channel channel = readEvent.getChannel();
ByteBuffer buffer = readEvent.getBuffer();
// Read data from the channel to the buffer
int bytesRead = channel.read(buffer);
// If you read the data, process it
if (bytesRead != -1) {
buffer.flip (); // Switch to reading mode
byte[] data = new byte[buffer.limit()];
buffer.get(data);
// Perform data processing, here is printing as an example
System.out.println(new String(data));
buffer.clear (); // Clear the buffer, prepare for the next reading
}
}
}
}
private static class WriteEventHandler implements SelectionKeyHandler {
@Override
public void handle(SelectionKey selectionKey) throws Exception {
if (selectionKey.isValid() && selectionKey.isWritable()) {
WriteEvent writeEvent = (WriteEvent) selectionKey.attachment();
Channel channel = writeEvent.getChannel();
ByteBuffer buffer = writeEvent.getBuffer();
// Write the data in the buffer into the channel
channel.write(buffer);
// If the data is not written in the buffer, continue to register and write the event
if (buffer.hasRemaining()) {
selectionKey.interestOps(selectionKey.interestOps() | SelectionKey.OP_WRITE);
}
}
}
}
}
In the above examples, we use the Activeio framework to create a selector thread and channel factory.Then, we created a file input stream and a file output stream, and used the channel factory to pack them into the Activeio channel.Next, we use the selector thread and select key processing factory to register the input and output channel into the selector.
Finally, we call the select () method of the selector in a cycle to trigger the processing of I/O events.In the selector, we use the selection key processing factory to create the processing processor and writing event processor, and associate them with the corresponding channel.In the processing processor, we read data from the channel and process it; in the writing event processor, we write the data in the buffer into the channel.If there is still data in the buffer, continue to register the event.
The above example is just a simple usage of the Activeio framework. You can use more functions provided by Activeio and API according to actual needs for more complicated I/O operations.
