Java class library to implement the skills of the command line automatic completion function
Java class library to implement the skills of the command line automatic completion function
When developing command line applications, providing users with automatic completion functions can greatly improve operational efficiency and user experience.There are many ways to implement the command line automatic completion function in the Java class library. The following will introduce some common techniques.
1. Use the Readline library provided by Java
Java's Readline library is a class library for reading input streams and providing line -based editing and automatic completion functions.It can be used by the following steps:
1. First, read the command line of the user input using the `Readline ()` method.
import java.io.IOException;
import jline.console.ConsoleReader;
public class AutoCompleteExample {
public static void main(String[] args) throws IOException {
ConsoleReader reader = new ConsoleReader();
String line;
while ((line = reader.readLine("> ")) != null) {
// Process the command line of the user input
}
}
}
2. Then create a automatic replenishment class and add it to the `Consolereader`.
import java.util.List;
import jline.console.completer.Completer;
public class CommandCompleter implements Completer {
@Override
public int complete(String buffer, int cursor, List<CharSequence> candidates) {
// Break the candidate list according to the value of Buffer and Cursor, and add it to the Candidates
return cursor;
}
}
public class AutoCompleteExample {
public static void main(String[] args) throws IOException {
ConsoleReader reader = new ConsoleReader();
CommandCompleter completer = new CommandCompleter();
reader.addCompleter(completer);
String line;
while ((line = reader.readLine("> ")) != null) {
// Process the command line of the user input
}
}
}
In the `CommandCompleter` method of` CommandCompleter`, you can implement your own logic to generate a candidate list.For example, you can get the commands input from the user based on the existing command, or obtain the candidate items from external storage.
Second, use a third -party library
In addition to the Readline library provided by Java, some third -party libraries can also implement the command line automatic completion function.
1. Jline: Jline is a library for reading and editing for Java command lines. It provides support for automatic completion function.You can use JLINE like the Readline library above.
2. Cliche: Cliche is a simple and easy -to -use command line interactive framework, which provides a built -in automatic completion function.You can use the annotations provided to define commands and parameters, and automatically complement the TAB key.
import com.googlecode.cliche.AutoComplete;
import com.googlecode.cliche.Command;
import com.googlecode.cliche.Param;
public class AutoCompleteExample {
private String[] commands = {"command1", "command2"};
@Command
public String executeCommand(@Param(name = "command", completion = "commands") String command) {
// Excuting an order
return "Command executed: " + command;
}
public static void main(String[] args) throws IOException {
AutoCompleteExample example = new AutoCompleteExample();
AutoComplete.create(example).run(null);
}
}
In the above example, the parameters are defined by using the@Param` annotation, and the `Completion` attribute is` Commands`, so that the candidate list for automatic completion can be generated.
Summarize
Implementing the command line automatic completion function can improve user experience and operational efficiency. There are many ways to implement the Java class library, including using the Readline library provided by Java and some popular third -party libraries.You can choose the appropriate method according to your needs to implement the command line automatic completion function.
