SshTarget.java

package com.github.ruediste1.btrbck.dom;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

import com.google.common.base.Strings;

/**
 * Describes the target of an ssh connection
 */
public class SshTarget {
    private Integer port;
    private String host;
    private String user;

    public SshTarget() {}

    /**
     * Create a new {@link SshTarget} by parsing the given string. the format is
     * 
     * <pre>
     * {@code
     * [<user>@]<host>[:<port>]
     * }
     * </pre>
     */
    public static SshTarget parse(String s) {
        Pattern p = Pattern
                .compile("((?<user>[^@]*)@)?(?<host>[^:]+)(:(?<port>.*))?");
        Matcher matcher = p.matcher(s);
        if (!matcher.matches()) {
            return null;
        }
        SshTarget result = new SshTarget();
        result = result.withHost(matcher.group("host"));
        result = result.withUser(matcher.group("user"));
        String portString = matcher.group("port");
        if (portString != null) {
            result = result.withPort(Integer.parseInt(portString));
        }
        return result;
    }

    @Override
    public String toString() {
        StringBuilder sb = new StringBuilder();
        if (!Strings.isNullOrEmpty(user)) {
            sb.append(user);
            sb.append("@");
        }
        sb.append(host);
        if (port != null) {
            sb.append(":");
            sb.append(port);
        }
        return sb.toString();
    }

    private SshTarget(SshTarget other) {
        host = other.host;
        port = other.port;
        user = other.user;
    }

    public Integer getPort() {
        return port;
    }

    public SshTarget withPort(Integer port) {
        SshTarget result = new SshTarget(this);
        result.port = port;
        return result;
    }

    public String getHost() {
        return host;
    }

    public SshTarget withHost(String host) {
        SshTarget result = new SshTarget(this);
        result.host = host;
        return result;
    }

    public String getUser() {
        return user;
    }

    public SshTarget withUser(String user) {
        SshTarget result = new SshTarget(this);
        result.user = user;
        return result;
    }
}