ThinLoggerFinder.java

   1 package org.argeo.init.logging;
   2
   3 import java.io.Serializable;
   4 import java.lang.System.Logger;
   5 import java.lang.System.LoggerFinder;
   6 import java.util.HashMap;
   7 import java.util.Map;
   8 import java.util.Objects;
   9 import java.util.concurrent.Flow;
  10 import java.util.function.Consumer;
  11
  12 /**
  13  * Factory for Java system logging. As it has to be a public class in order to
  14  * be exposed as a service provider, it is also the main entry point for the
  15  * thin logging system, via static methos.
  16  */
  17 public class ThinLoggerFinder extends LoggerFinder {
  18         private static ThinLogging logging;
  19         private static ThinJavaUtilLogging javaUtilLogging;
  20
  21         public ThinLoggerFinder() {
  22                 if (logging != null)
  23                         throw new IllegalStateException("Only one logging can be initialised.");
  24 //              init();
  25         }
  26
  27         @Override
  28         public Logger getLogger(String name, Module module) {
  29                 lazyInit();
  30                 return logging.getLogger(name, module);
  31         }
  32
  33         private static void init() {
  34                 logging = new ThinLogging();
  35
  36                 Map<String, Object> configuration = new HashMap<>();
  37                 for (Object key : System.getProperties().keySet()) {
  38                         Objects.requireNonNull(key);
  39                         String property = key.toString();
  40                         if (property.startsWith(ThinLogging.LEVEL_PROPERTY_PREFIX)
  41                                         || property.equals(ThinLogging.DEFAULT_LEVEL_PROPERTY))
  42                                 configuration.put(property, System.getProperty(property));
  43                 }
  44                 logging.accept(configuration);
  45         }
  46
  47         /**
  48          * Falls back to java.util.logging if thin logging was not already initialised
  49          * by the {@link LoggerFinder} mechanism.
  50          */
  51         public static void lazyInit() {
  52                 if (logging != null)
  53                         return;
  54                 if (javaUtilLogging != null)
  55                         return;
  56                 init();
  57                 javaUtilLogging = ThinJavaUtilLogging.init();
  58                 javaUtilLogging.readConfiguration(logging.getLevels());
  59         }
  60
  61         public static Consumer<Map<String, Object>> getConfigurationConsumer() {
  62                 Objects.requireNonNull(logging);
  63                 return logging;
  64         }
  65
  66         public static Flow.Publisher<Map<String, Serializable>> getLogEntryPublisher() {
  67                 Objects.requireNonNull(logging);
  68                 return logging.getLogEntryPublisher();
  69         }
  70
  71         static void update(Map<String, Object> configuration) {
  72                 if (logging == null)
  73                         throw new IllegalStateException("Thin logging must be initialized first");
  74                 logging.accept(configuration);
  75                 if (javaUtilLogging != null)
  76                         javaUtilLogging.readConfiguration(logging.getLevels());
  77         }
  78
  79         static Logger getLogger(String name) {
  80                 return logging.getLogger(name, null);
  81         }
  82 }