ibdo :: get parameter as string

src/main/java/emissary/core/BaseDataObject.java

@@ -993,33 +993,14 @@ public boolean appendUniqueParameter(final String key, final CharSequence value)
         return true;
     }
 
-    @Override
-    public String getStringParameter(final String key) {
-        return getStringParameter(key, DEFAULT_PARAM_SEPARATOR);
-    }
-
     @Nullable
     @Override
-    public String getStringParameter(final String key, final String sep) {
-        final List<Object> obj = getParameter(key);
-        if (obj == null) {
-            return null;
-        } else if (obj.isEmpty()) {
-            return null;
-        } else if ((obj.size() == 1) && (obj.get(0) instanceof String)) {
-            return (String) obj.get(0);
-        } else if ((obj.size() == 1) && (obj.get(0) == null)) {
-            return null;
-        } else {
-            final StringBuilder sb = new StringBuilder();
-            for (final Object item : obj) {
-                if (sb.length() > 0) {
-                    sb.append(sep);
-                }
-                sb.append(item);
-            }
-            return sb.toString();
+    public String getParameterAsString(final String key) {
+        final var obj = getParameterAsStrings(key);
+        if (obj.size() > 1) {
+            logger.warn("Multiple values for parameter, returning the first - parameter:{}, number of values:{}", key, obj.size());
         }
+        return StringUtils.trimToNull(obj.stream().findFirst().orElse(null));
     }
 
     /**

src/main/java/emissary/core/IBaseDataObject.java

@@ -3,15 +3,20 @@
 import emissary.core.channels.SeekableByteChannelFactory;
 import emissary.directory.DirectoryEntry;
 
+import org.apache.commons.collections4.CollectionUtils;
+import org.apache.commons.lang3.StringUtils;
+
 import java.io.IOException;
 import java.io.InputStream;
 import java.nio.ByteBuffer;
 import java.time.Instant;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.UUID;
+import java.util.stream.Collectors;
 
 public interface IBaseDataObject {
 
@@ -350,17 +355,72 @@ enum MergePolicy {
      * 
      * @param key name of the metadata element
      * @return the string value or null if no such element
+     * @deprecated use {@link #getParameterAsConcatString(String)}
      */
-    String getStringParameter(String key);
+    @Deprecated
+    default String getStringParameter(final String key) {
+        return getParameterAsConcatString(key);
+    }
 
     /**
      * Retrieve a specified metadata element as a string value
      * 
      * @param key name of the metadata element
      * @param sep the separator for multivalued fields
      * @return the string value or null if no such element
+     * @deprecated use {@link #getParameterAsConcatString(String, String)}
      */
-    String getStringParameter(String key, String sep);
+    @Deprecated
+    default String getStringParameter(final String key, final String sep) {
+        return getParameterAsConcatString(key, sep);
+    }
+
+    /**
+     * Retrieve the Collection of metadata values identified by key where each element is converted to a string
+     *
+     * @param key name of the metadata element collection
+     * @return Collection of elements converted to strings
+     */
+    default Collection<String> getParameterAsStrings(final String key) {
+        final var obj = getParameter(key);
+        if (CollectionUtils.isEmpty(obj) || ((obj.size() == 1) && (obj.get(0) == null))) {
+            return Collections.emptyList();
+        } else if ((obj.size() == 1) && (obj.get(0) instanceof String)) {
+            return Collections.singletonList((String) obj.get(0));
+        } else {
+            return obj.stream().map(String::valueOf).collect(Collectors.toList());
+        }
+    }
+
+    /**
+     * Retrieve the metadata value identified by key where the element is converted to a string
+     *
+     * @param key name of the metadata element
+     * @return parameter converted to strings
+     */
+    String getParameterAsString(String key);
+
+    /**
+     * Retrieve a specified metadata element as a string of concatenated values
+     *
+     * @param key name of the metadata element
+     * @return the string value or null if no such element
+     */
+    default String getParameterAsConcatString(final String key) {
+        return getParameterAsConcatString(key, DEFAULT_PARAM_SEPARATOR);
+    }
+
+    /**
+     * Retrieve a specified metadata element as a string of concatenated values
+     *
+     * @param key name of the metadata element
+     * @param sep the separator for multivalued fields
+     * @return the string value or null if no such element
+     */
+    default String getParameterAsConcatString(final String key, final String sep) {
+        final var strParameter = String.join(sep, getParameterAsStrings(key));
+        return StringUtils.isBlank(strParameter) ? null : strParameter;
+    }
 
     /**
      * Retrieve all the metadata elements of this object

src/test/java/emissary/core/BaseDataObjectTest.java

@@ -1463,4 +1463,39 @@ void testNewInputStream() throws IOException {
             assertArrayEquals(bytes2, byteArrayOutputStream.toByteArray());
         }
     }
+
+    @Test
+    void testGetParameterAsString() {
+        this.b.putParameter("A", 1L);
+        this.b.appendParameter("A", "TWO");
+        this.b.appendParameter("A", "THREE");
+        assertEquals("1", this.b.getParameterAsString("A"));
+        assertEquals("1;TWO;THREE", this.b.getParameterAsConcatString("A"));
+
+        this.b.putParameter("A", 2L);
+        assertEquals("2", this.b.getParameterAsString("A"));
+        assertEquals("2", this.b.getParameterAsConcatString("A"));
+
+        this.b.putParameter("A", "THREE");
+        assertEquals("THREE", this.b.getParameterAsString("A"));
+        assertEquals("THREE", this.b.getParameterAsConcatString("A"));
+
+        this.b.putParameter("A", null);
+        assertNull(this.b.getParameterAsString("A"));
+        assertNull(this.b.getParameterAsConcatString("A"));
+
+        this.b.putParameter("A", "");
+        assertNull(this.b.getParameterAsString("A"));
+        assertNull(this.b.getParameterAsConcatString("A"));
+
+        assertNull(this.b.getParameterAsString("DNE"));
+        assertNull(this.b.getParameterAsConcatString("DNE"));
+
+        this.b.putParameter("A", null);
+        this.b.appendParameter("A", "FOUR");
+        this.b.appendParameter("A", "  ");
+        assertEquals("null", this.b.getParameterAsString("A"));
+        assertEquals("null;FOUR;  ", this.b.getParameterAsConcatString("A"));
+    }
+
 }