java动态加载配置类_JAVA_编程开发_程序员俱乐部

class="java">
import lombok.extern.slf4j.Slf4j;
import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Component;

import java.io.FileInputStream;
import java.io.IOException;
import java.nio.file.*;
import java.util.Properties;

@Slf4j
@Component
@Scope("singleton")
public class ConfigUtil {

    private final static Properties properties = new Properties();

    static {
        final WatchService[] watchService = {null};

        new Thread(()->{
            try {
                String configFile = System.getProperty("config.file", "/tmp/config.properties");
                log.info("loading config file {}.", configFile);
                properties.load(new FileInputStream(configFile));

                Path configFilePath = Paths.get(configFile);
                watchService[0] = Filesystems.html" target="_blank">Systems.getDefault().newWatchService();
                final Path path = Paths.get(configFilePath.getParent().toString());
                path.register(watchService[0], StandardWatchEventKinds.ENTRY_MODIFY, StandardWatchEventKinds.ENTRY_CREATE);

                while (true) {
                    final WatchKey wk = watchService[0].take();
                    for (WatchEvent<?> event : wk.pollEvents()) {
                        final Path changed = (Path) event.context();
                        log.info(changed + ", " + event.kind());
                        if (changed.endsWith(configFilePath.getFileName())) {
                            log.info("reload config file {}.", configFile);
                            properties.load(new FileInputStream(configFile));
                        }
                    }

                    boolean valid = wk.reset();
                    if (!valid) {
                        log.info("Key has been unregistered.");
                    }
                }
            }catch (Exception e){
                log.info("", e);
            }
        }).start();

        Runtime.getRuntime().addShutdownHook(new Thread(() -> {
            try{
                watchService[0].close();
            } catch(IOException e) {
                e.printStackTrace();
            }
        }));
    }

    public static Object get(String key){
        return properties.get(key);
    }

    public static String stringValue(String key){
        return properties.getProperty(key);
    }

    public static String stringValue(String key, String defaultValue){
        return properties.getProperty(key, defaultValue);
    }

}