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[lgpl/argeo-commons.git] / org.argeo.util / src / org / argeo / util / LangUtils.java

diff --git a/org.argeo.util/src/org/argeo/util/LangUtils.java b/org.argeo.util/src/org/argeo/util/LangUtils.java
new file mode 100644 (file)
index 0000000..c94db9d
--- /dev/null
+++ b/org.argeo.util/src/org/argeo/util/LangUtils.java
@@ -0,0 +1,80 @@
+package org.argeo.util;
+
+import java.util.Dictionary;
+import java.util.Enumeration;
+import java.util.Hashtable;
+
+public class LangUtils {
+       /*
+        * NON-API OSGi
+        */
+       /**
+        * Returns an array with the names of the provided classes. Useful when
+        * registering services with multiple interfaces in OSGi.
+        */
+       public static String[] names(Class<?>... clzz) {
+               String[] res = new String[clzz.length];
+               for (int i = 0; i < clzz.length; i++)
+                       res[i] = clzz[i].getName();
+               return res;
+       }
+
+       /*
+        * DICTIONARY
+        */
+
+       /**
+        * Creates a new {@link Dictionary} with one key-value pair (neith key not
+        * value should be null)
+        */
+       public static Dictionary<String, Object> init(String key, Object value) {
+               assert key != null;
+               assert value != null;
+               Hashtable<String, Object> props = new Hashtable<>();
+               props.put(key, value);
+               return props;
+       }
+
+       /**
+        * Wraps the keys of the provided {@link Dictionary} as an {@link Iterable}.
+        */
+       public static Iterable<String> keys(Dictionary<String, ?> props) {
+               assert props != null;
+               return new DictionaryKeys(props);
+       }
+
+       public static String toJson(Dictionary<String, ?> props) {
+               return toJson(props, false);
+       }
+
+       public static String toJson(Dictionary<String, ?> props, boolean pretty) {
+               StringBuilder sb = new StringBuilder();
+               sb.append('{');
+               if (pretty)
+                       sb.append('\n');
+               Enumeration<String> keys = props.keys();
+               while (keys.hasMoreElements()) {
+                       String key = keys.nextElement();
+                       if (pretty)
+                               sb.append(' ');
+                       sb.append('\"').append(key).append('\"');
+                       if (pretty)
+                               sb.append(" : ");
+                       else
+                               sb.append(':');
+                       sb.append('\"').append(props.get(key)).append('\"');
+                       if (keys.hasMoreElements())
+                               sb.append(", ");
+                       if (pretty)
+                               sb.append('\n');
+               }
+               sb.append('}');
+               return sb.toString();
+       }
+
+       /** Singleton constructor. */
+       private LangUtils() {
+
+       }
+
+}