X-Git-Url: https://git.argeo.org/?a=blobdiff_plain;f=org.argeo.util%2Fsrc%2Forg%2Fargeo%2Futil%2FLangUtils.java;h=1aee28c03c776d7438cc266e4842dee7e21af671;hb=3c1cdc594d954520b14646102b366290bdad58c7;hp=3c0baed1c8047ad0c9cccb10a77c12a84def8912;hpb=2d6b7c0c3badea29451c4d8e41ebb5aca2258806;p=lgpl%2Fargeo-commons.git

diff --git a/org.argeo.util/src/org/argeo/util/LangUtils.java b/org.argeo.util/src/org/argeo/util/LangUtils.java
index 3c0baed1c..1aee28c03 100644
--- a/org.argeo.util/src/org/argeo/util/LangUtils.java
+++ b/org.argeo.util/src/org/argeo/util/LangUtils.java
@@ -7,14 +7,24 @@ import java.io.Writer;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.StandardOpenOption;
+import java.time.ZonedDateTime;
+import java.time.temporal.ChronoUnit;
+import java.time.temporal.Temporal;
+import java.util.ArrayList;
+import java.util.Collection;
 import java.util.Dictionary;
 import java.util.Enumeration;
+import java.util.HashMap;
 import java.util.Hashtable;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
 import java.util.Properties;
 
 import javax.naming.InvalidNameException;
 import javax.naming.ldap.LdapName;
 
+/** Utilities around Java basic features. */
 public class LangUtils {
 	/*
 	 * NON-API OSGi
@@ -30,22 +40,97 @@ public class LangUtils {
 		return res;
 	}
 
+//	/*
+//	 * MAP
+//	 */
+//	/**
+//	 * Creates a new {@link Map} with one key-value pair. Key should not be null,
+//	 * but if the value is null, it returns an empty {@link Map}.
+//	 * 
+//	 * @deprecated Use {@link Collections#singletonMap(Object, Object)} instead.
+//	 */
+//	@Deprecated
+//	public static Map<String, Object> map(String key, Object value) {
+//		assert key != null;
+//		HashMap<String, Object> props = new HashMap<>();
+//		if (value != null)
+//			props.put(key, value);
+//		return props;
+//	}
+
 	/*
 	 * DICTIONARY
 	 */
 
 	/**
-	 * Creates a new {@link Dictionary} with one key-value pair (neither key not
-	 * value should be null)
+	 * Creates a new {@link Dictionary} with one key-value pair. Key should not be
+	 * null, but if the value is null, it returns an empty {@link Dictionary}.
 	 */
-	public static Dictionary<String, Object> init(String key, Object value) {
+	public static Dictionary<String, Object> dict(String key, Object value) {
 		assert key != null;
-		assert value != null;
 		Hashtable<String, Object> props = new Hashtable<>();
-		props.put(key, value);
+		if (value != null)
+			props.put(key, value);
 		return props;
 	}
 
+	/** @deprecated Use {@link #dict(String, Object)} instead. */
+	@Deprecated
+	public static Dictionary<String, Object> dico(String key, Object value) {
+		return dict(key, value);
+	}
+
+	/** Converts a {@link Dictionary} to a {@link Map} of strings. */
+	public static Map<String, String> dictToStringMap(Dictionary<String, ?> properties) {
+		if (properties == null) {
+			return null;
+		}
+		Map<String, String> res = new HashMap<>(properties.size());
+		Enumeration<String> keys = properties.keys();
+		while (keys.hasMoreElements()) {
+			String key = keys.nextElement();
+			res.put(key, properties.get(key).toString());
+		}
+		return res;
+	}
+
+	/** Converts a {@link Dictionary} to a {@link Map}. */
+	public static Map<String, Object> dictToMap(Dictionary<String, ?> properties) {
+		if (properties == null) {
+			return null;
+		}
+		Map<String, Object> res = new HashMap<>(properties.size());
+		Enumeration<String> keys = properties.keys();
+		while (keys.hasMoreElements()) {
+			String key = keys.nextElement();
+			res.put(key, properties.get(key));
+		}
+		return res;
+	}
+
+	/**
+	 * Get a string property from this map, expecting to find it, or
+	 * <code>null</code> if not found.
+	 */
+	public static String get(Map<String, ?> map, String key) {
+		Object res = map.get(key);
+		if (res == null)
+			return null;
+		return res.toString();
+	}
+
+	/**
+	 * Get a string property from this map, expecting to find it.
+	 * 
+	 * @throws IllegalArgumentException if the key was not found
+	 */
+	public static String getNotNull(Map<String, ?> map, String key) {
+		Object res = map.get(key);
+		if (res == null)
+			throw new IllegalArgumentException("Map " + map + " should contain key " + key);
+		return res.toString();
+	}
+
 	/**
 	 * Wraps the keys of the provided {@link Dictionary} as an {@link Iterable}.
 	 */
@@ -54,11 +139,11 @@ public class LangUtils {
 		return new DictionaryKeys(props);
 	}
 
-	public static String toJson(Dictionary<String, ?> props) {
+	static String toJson(Dictionary<String, ?> props) {
 		return toJson(props, false);
 	}
 
-	public static String toJson(Dictionary<String, ?> props, boolean pretty) {
+	static String toJson(Dictionary<String, ?> props, boolean pretty) {
 		StringBuilder sb = new StringBuilder();
 		sb.append('{');
 		if (pretty)
@@ -83,7 +168,7 @@ public class LangUtils {
 		return sb.toString();
 	}
 
-	public static void storeAsProperties(Dictionary<String, Object> props, Path path) throws IOException {
+	static void storeAsProperties(Dictionary<String, Object> props, Path path) throws IOException {
 		if (props == null)
 			throw new IllegalArgumentException("Props cannot be null");
 		Properties toStore = new Properties();
@@ -96,7 +181,7 @@ public class LangUtils {
 		}
 	}
 
-	public static void appendAsLdif(String dnBase, String dnKey, Dictionary<String, Object> props, Path path)
+	static void appendAsLdif(String dnBase, String dnKey, Dictionary<String, Object> props, Path path)
 			throws IOException {
 		if (props == null)
 			throw new IllegalArgumentException("Props cannot be null");
@@ -126,7 +211,7 @@ public class LangUtils {
 		}
 	}
 
-	public static Dictionary<String, Object> loadFromProperties(Path path) throws IOException {
+	static Dictionary<String, Object> loadFromProperties(Path path) throws IOException {
 		Properties toLoad = new Properties();
 		try (InputStream in = Files.newInputStream(path)) {
 			toLoad.load(in);
@@ -137,6 +222,107 @@ public class LangUtils {
 		return res;
 	}
 
+	/*
+	 * COLLECTIONS
+	 */
+	/**
+	 * Convert a comma-separated separated {@link String} or a {@link String} array
+	 * to a {@link List} of {@link String}, trimming them. Useful to quickly
+	 * interpret OSGi services properties.
+	 * 
+	 * @return a {@link List} containing the trimmed {@link String}s, or an empty
+	 *         {@link List} if the argument was <code>null</code>.
+	 */
+	public static List<String> toStringList(Object value) {
+		List<String> values = new ArrayList<>();
+		if (value == null)
+			return values;
+		String[] arr;
+		if (value instanceof String) {
+			arr = ((String) value).split(",");
+		} else if (value instanceof String[]) {
+			arr = (String[]) value;
+		} else {
+			throw new IllegalArgumentException("Unsupported value type " + value.getClass());
+		}
+		for (String str : arr) {
+			values.add(str.trim());
+		}
+		return values;
+	}
+
+	/** Size of an {@link Iterable}, optimised if it is a {@link Collection}. */
+	public static int size(Iterable<?> iterable) {
+		if (iterable instanceof Collection)
+			return ((Collection<?>) iterable).size();
+
+		int size = 0;
+		for (Iterator<?> it = iterable.iterator(); it.hasNext(); size++)
+			it.next();
+		return size;
+	}
+
+	public static <T> T getAt(Iterable<T> iterable, int index) {
+		if (iterable instanceof List) {
+			List<T> lst = ((List<T>) iterable);
+			if (index >= lst.size())
+				throw new IllegalArgumentException("Index " + index + " is not available (size is " + lst.size() + ")");
+			return lst.get(index);
+		}
+		int i = 0;
+		for (Iterator<T> it = iterable.iterator(); it.hasNext(); i++) {
+			if (i == index)
+				return it.next();
+			else
+				it.next();
+		}
+		throw new IllegalArgumentException("Index " + index + " is not available (size is " + i + ")");
+	}
+
+	/*
+	 * EXCEPTIONS
+	 */
+	/**
+	 * Chain the messages of all causes (one per line, <b>starts with a line
+	 * return</b>) without all the stack
+	 */
+	public static String chainCausesMessages(Throwable t) {
+		StringBuffer buf = new StringBuffer();
+		chainCauseMessage(buf, t);
+		return buf.toString();
+	}
+
+	/** Recursive chaining of messages */
+	private static void chainCauseMessage(StringBuffer buf, Throwable t) {
+		buf.append('\n').append(' ').append(t.getClass().getCanonicalName()).append(": ").append(t.getMessage());
+		if (t.getCause() != null)
+			chainCauseMessage(buf, t.getCause());
+	}
+
+	/*
+	 * TIME
+	 */
+	/** Formats time elapsed since start. */
+	public static String since(ZonedDateTime start) {
+		ZonedDateTime now = ZonedDateTime.now();
+		return duration(start, now);
+	}
+
+	/** Formats a duration. */
+	public static String duration(Temporal start, Temporal end) {
+		long count = ChronoUnit.DAYS.between(start, end);
+		if (count != 0)
+			return count > 1 ? count + " days" : count + " day";
+		count = ChronoUnit.HOURS.between(start, end);
+		if (count != 0)
+			return count > 1 ? count + " hours" : count + " hours";
+		count = ChronoUnit.MINUTES.between(start, end);
+		if (count != 0)
+			return count > 1 ? count + " minutes" : count + " minute";
+		count = ChronoUnit.SECONDS.between(start, end);
+		return count > 1 ? count + " seconds" : count + " second";
+	}
+
 	/** Singleton constructor. */
 	private LangUtils() {