464606 - Support property expansion in "default" attribute of Property.

jetty-xml/src/main/java/org/eclipse/jetty/xml/XmlConfiguration.java

@@ -46,6 +46,8 @@ import java.util.Queue;
 import java.util.ServiceLoader;
 import java.util.Set;
 import java.util.concurrent.atomic.AtomicReference;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 
 import org.eclipse.jetty.util.ArrayQueue;
 import org.eclipse.jetty.util.LazyList;
@@ -79,16 +81,13 @@ import org.xml.sax.SAXException;
 public class XmlConfiguration
 {
     private static final Logger LOG = Log.getLogger(XmlConfiguration.class);
-
     private static final Class<?>[] __primitives =
             {Boolean.TYPE, Character.TYPE, Byte.TYPE, Short.TYPE, Integer.TYPE, Long.TYPE, Float.TYPE, Double.TYPE, Void.TYPE};
-
     private static final Class<?>[] __boxedPrimitives =
             {Boolean.class, Character.class, Byte.class, Short.class, Integer.class, Long.class, Float.class, Double.class, Void.class};
-
     private static final Class<?>[] __supportedCollections =
-            {ArrayList.class, ArrayQueue.class, HashSet.class, Queue.class, List.class, Set.class, Collection.class,};
+            {ArrayList.class, ArrayQueue.class, HashSet.class, Queue.class, List.class, Set.class, Collection.class};
-
+    private static final Pattern __propertyPattern = Pattern.compile("\\$\\{([^\\}]+)\\}");
     private static final Iterable<ConfigurationProcessorFactory> __factoryLoader = ServiceLoader.load(ConfigurationProcessorFactory.class);
     private static final XmlParser __parser = initParser();
     private static XmlParser initParser()
@@ -949,9 +948,23 @@ public class XmlConfiguration
             String defaultValue = node.getAttribute("default");
 
             Object value = null;
-            boolean present = false;
             Map<String,String> properties = _configuration.getProperties();
             if (properties != null && nameAttr != null)
+                value = resolve(properties, nameAttr);
+
+            if (value == null && defaultValue != null)
+                value = interpolate(properties, defaultValue);
+
+            if (idAttr != null)
+                _configuration.getIdMap().put(idAttr, value);
+
+            if (value != null)
+                configure(value, node, 0);
+
+            return value;
+        }
+
+        private String resolve(Map<String, String> properties, String nameAttr)
         {
             String preferredName = null;
             String[] names = nameAttr.split(",");
@@ -963,27 +976,44 @@ public class XmlConfiguration
                 if (preferredName == null)
                     preferredName = name;
 
-                    if (properties.containsKey(name))
+                String value = properties.get(name);
+                if (value != null)
                 {
                     if (!name.equals(preferredName))
                         LOG.warn("Property '{}' is deprecated, use '{}' instead", name, preferredName);
-                        present = true;
-                        value = properties.get(name);
-                        break;
-                    }
-                }
-            }
-            if (!present)
-                value = defaultValue;
-
-            if (idAttr != null)
-                _configuration.getIdMap().put(idAttr, value);
-
-            if (value != null)
-                configure(value, node, 0);
-
                     return value;
                 }
+            }
+            return null;
+        }
+
+        private String interpolate(Map<String, String> properties, String text)
+        {
+            StringBuilder result = new StringBuilder();
+            Matcher matcher = __propertyPattern.matcher(text);
+            int start = 0;
+            while (matcher.find(start))
+            {
+                int match = matcher.start();
+                result.append(text.substring(start, match));
+                String name = matcher.group(1);
+                String dftValue = null;
+                int bar = name.indexOf('|');
+                if (bar > 0)
+                {
+                    dftValue = name.substring(bar + 1).trim();
+                    name = name.substring(0, bar).trim();
+                }
+                String value = resolve(properties, name);
+                if (value == null)
+                    value = dftValue;
+                result.append(value);
+                start = matcher.end();
+            }
+            result.append(text.substring(start, text.length()));
+            String r = result.toString();
+            return r.isEmpty() ? null : r;
+        }
 
         /*
          * Get the value of an element. If no value type is specified, then white space is trimmed out of the value. If it contains multiple value elements they

jetty-xml/src/test/java/org/eclipse/jetty/xml/XmlConfigurationTest.java

@@ -18,13 +18,6 @@
 
 package org.eclipse.jetty.xml;
 
-import static org.hamcrest.CoreMatchers.is;
-import static org.hamcrest.CoreMatchers.not;
-import static org.hamcrest.CoreMatchers.nullValue;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertThat;
-import static org.junit.Assert.assertTrue;
-
 import java.io.ByteArrayInputStream;
 import java.net.URL;
 import java.nio.charset.StandardCharsets;
@@ -36,6 +29,13 @@ import org.junit.Assert;
 import org.junit.Ignore;
 import org.junit.Test;
 
+import static org.hamcrest.CoreMatchers.is;
+import static org.hamcrest.CoreMatchers.not;
+import static org.hamcrest.CoreMatchers.nullValue;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertThat;
+import static org.junit.Assert.assertTrue;
+
 public class XmlConfigurationTest
 {
     protected String _configure="org/eclipse/jetty/xml/configure.xml";
@@ -820,4 +820,32 @@ public class XmlConfigurationTest
         DefaultTestConfiguration config = (DefaultTestConfiguration)xmlConfiguration.configure();
         assertEquals(value, config.getFirst());
     }
+
+    @Test
+    public void testPropertyNotFoundWithPropertyInDefaultValue() throws Exception
+    {
+        String name = "bar";
+        String value = "bar";
+        String defaultValue = "_${bar}_${bar}_";
+        String expectedValue = "_" + value + "_" + value + "_";
+        XmlConfiguration xmlConfiguration = new XmlConfiguration("" +
+                "<Configure class=\"org.eclipse.jetty.xml.DefaultTestConfiguration\">" +
+                "  <Set name=\"first\"><Property name=\"not_found\" default=\"" + defaultValue + "\"/></Set>  " +
+                "</Configure>");
+        xmlConfiguration.getProperties().put(name, value);
+        DefaultTestConfiguration config = (DefaultTestConfiguration)xmlConfiguration.configure();
+        assertEquals(expectedValue, config.getFirst());
+    }
+
+    @Test
+    public void testPropertyNotFoundWithPropertyInDefaultValueNotFoundWithDefault() throws Exception
+    {
+        String value = "bar";
+        XmlConfiguration xmlConfiguration = new XmlConfiguration("" +
+                "<Configure class=\"org.eclipse.jetty.xml.DefaultTestConfiguration\">" +
+                "  <Set name=\"first\"><Property name=\"not_found\" default=\"${not_found|" + value + "}\"/></Set>  " +
+                "</Configure>");
+        DefaultTestConfiguration config = (DefaultTestConfiguration)xmlConfiguration.configure();
+        assertEquals(value, config.getFirst());
+    }
 }