io.scalecube.config.examples.ReloadableLocalResourceConfigExample Maven / Gradle / Ivy

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package io.scalecube.config.examples;

import io.scalecube.config.ConfigRegistry;
import io.scalecube.config.ConfigRegistrySettings;
import io.scalecube.config.DurationConfigProperty;
import io.scalecube.config.ListConfigProperty;
import io.scalecube.config.ObjectConfigProperty;
import io.scalecube.config.StringConfigProperty;
import io.scalecube.config.audit.Slf4JConfigEventListener;
import io.scalecube.config.source.DirectoryConfigSource;

import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.nio.file.Path;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.TimeUnit;
import java.util.function.Predicate;

@SuppressWarnings("OptionalGetWithoutIsPresent")
public class ReloadableLocalResourceConfigExample {

  public static void main(String[] args) throws Exception {
    Predicate reloadablePropsPredicate = path -> path.toString().endsWith(".reloadableProps");
    Predicate propsPredicate = path -> path.toString().endsWith(".props");

    String basePath = "config-examples/config";

    ConfigRegistry configRegistry =
        ConfigRegistry.create(
            ConfigRegistrySettings
                .builder()
                .addLastSource("configDirectory",
                    new DirectoryConfigSource(basePath, reloadablePropsPredicate, propsPredicate))
                .addListener(new Slf4JConfigEventListener())
                .reloadIntervalSec(1)
                .build());

    StringConfigProperty prop1 = configRegistry.stringProperty("prop1");
    System.out.println("### Initial filesystem config property: prop1=" + prop1.value().get());
    prop1.addCallback((s1, s2) -> System.out.println(
        "### Callback called for 'prop1' and value updated from='" + s1 + "' to='" + s2 + "'"));

    ObjectConfigProperty objectProperty =
        configRegistry.objectProperty(new HashMap() {
          {
            put("anInt", "reloadable.config.test.intProp");
            put("theList", "reloadable.config.test.listProp");
          }
        }, ObjectConfig.class);
    objectProperty.addCallback((config1, config2) -> System.out.println(
        "### Callback called for objectProperty and value updated from='" + config1 + "' to='" + config2 + "'"));

    File file = createConfigFile(basePath);
    writeProperties(file, new HashMap() {
      {
        put("prop1", "42");
      }
    });
    TimeUnit.SECONDS.sleep(2);
    System.out.println("### Property reloaded: prop1=" + prop1.value().get());

    writeProperties(file, new HashMap() {
      {
        put("prop1", "");
      }
    });
    TimeUnit.SECONDS.sleep(2);
    System.out.println("### Property reloaded again: prop1=" + prop1.value().get());

    writeProperties(file, new HashMap() {
      {
        put("reloadable.config.test.intProp", "1");
        put("reloadable.config.test.listProp", "a,b,c");
      }
    });
    TimeUnit.SECONDS.sleep(2);
    System.out.println("### Object property reloaded: " + objectProperty.value().get());

    file.delete();
    TimeUnit.SECONDS.sleep(2);
    System.out.println("### Property reloaded again and back to its very intial value: prop1=" + prop1.value().get());

    DurationConfigProperty propertyDuration = configRegistry.durationProperty("propertyDuration");
    System.out.println("### Property duration (showing in millis): " + propertyDuration.value().get().toMillis());

    DurationConfigProperty propertyEnhancedDuration = configRegistry.durationProperty("propertyEnhancedDuration");
    System.out.println(
        "### Property enhanced duration (showing in millis): " + propertyEnhancedDuration.value().get().toMillis());

    ListConfigProperty propertyList1 = configRegistry.stringListProperty("propertyList1");
    System.out.println("### Property type-list (string): " + propertyList1.value().get());

    ListConfigProperty propertyList2 = configRegistry.doubleListProperty("propertyList2");
    System.out.println("### Property type-list (double): " + propertyList2.value().get());
  }

  private static void writeProperties(File file, Map props) throws IOException {
    try (BufferedWriter writer = new BufferedWriter(new FileWriter(file))) {
      props.forEach((key, value) -> {
        try {
          writer.write(key + "=" + value + "\n");
        } catch (IOException e) {
          throw new RuntimeException(e);
        }
      });
      writer.flush();
    }
  }

  private static File createConfigFile(String basePath) {
    File file = new File(basePath + "/config.reloadableProps");
    file.deleteOnExit();
    return file;
  }

  public static class ObjectConfig {
    private int anInt;
    private List theList;

    public int getAnInt() {
      return anInt;
    }

    public List getTheList() {
      return theList;
    }

    @Override
    public String toString() {
      return "ObjectConfig{" +
          "anInt=" + anInt +
          ", theList=" + theList +
          '}';
    }
  }
}