Iss #62 - Resolve some of the code smell in the common lib

Various issues discovered through new Sonar scanning that while not bugs, made code less maintainable. This addresses some of those issues.

core/src/main/java/org/eclipsefoundation/core/helper/ParameterHelper.java

@@ -13,7 +13,8 @@ package org.eclipsefoundation.core.helper;
 
 import java.util.ArrayList;
 import java.util.List;
-import java.util.Set;
+import java.util.Map.Entry;
+import java.util.stream.Collectors;
 
 import javax.annotation.PostConstruct;
 import javax.enterprise.context.ApplicationScoped;
@@ -36,51 +37,50 @@ import io.quarkus.runtime.Startup;
 @ApplicationScoped
 public class ParameterHelper {
 
-	@Inject
-	Instance<UrlParameterNamespace> urlParamImpls;
+    @Inject
+    Instance<UrlParameterNamespace> urlParamImpls;
 
-	// maintain internal list of key names to reduce churn. These are only created
-	// at build time
-	private List<String> urlParamNames;
+    // maintain internal list of key names to reduce churn. These are only created
+    // at build time
+    private List<String> urlParamNames;
 
-	/**
-	 * Create the list of parameter key names once upon creation of this class
-	 */
-	@PostConstruct
-	void initialize() {
-		// use array list for better random access + lookups
-		this.urlParamNames = new ArrayList<>();
-		// populate a list with each
-		urlParamImpls.forEach(
-				namespace -> namespace.getParameters().stream().forEach(param -> urlParamNames.add(param.getName())));
-	}
+    /**
+     * Create the list of parameter key names once upon creation of this class
+     */
+    @PostConstruct
+    void initialize() {
+        // use array list for better random access + lookups
+        this.urlParamNames = new ArrayList<>();
+        // populate a list with each
+        urlParamImpls.forEach(namespace -> namespace.getParameters().stream().forEach(param -> urlParamNames.add(param.getName())));
+    }
 
-	/**
-	 * Filters out unknown parameters by name/key. Creates and returns a new map
-	 * with the known/tracked parameters. Tracked parameters are added through
-	 * implementations of the {@link UrlParameterNamespace} interface.
-	 * 
-	 * @param src multivalued parameter map to filter
-	 * @return a map containing the filtered parameter values
-	 */
-	public MultivaluedMap<String, String> filterUnknownParameters(MultivaluedMap<String, String> src) {
-		MultivaluedMap<String, String> out = new MultivaluedMapImpl<>();
-		Set<String> keys = src.keySet();
-		for (String key : keys) {
-			if (urlParamNames.contains(key)) {
-				out.addAll(key, src.get(key));
-			}
-		}
-		return out;
-	}
+    /**
+     * Filters out unknown parameters by name/key. Creates and returns a new map with the known/tracked parameters. Tracked
+     * parameters are added through implementations of the {@link UrlParameterNamespace} interface.
+     * 
+     * @param src multivalued parameter map to filter
+     * @return a map containing the filtered parameter values
+     */
+    public MultivaluedMap<String, String> filterUnknownParameters(MultivaluedMap<String, String> src) {
+        return src
+                .entrySet()
+                .stream()
+                .filter(e -> urlParamNames.contains(e.getKey()))
+                .collect(Collectors.toMap(Entry::getKey, Entry::getValue, (prevVal, addVals) -> {
+                    // merge the 2 lists and return
+                    prevVal.addAll(addVals);
+                    return prevVal;
+                }, MultivaluedMapImpl<String, String>::new));
+    }
 
-	/**
-	 * Returns a list of parameter names, as generated from reading in the
-	 * parameters present in the {@link UrlParameterNamespace} implementations.
-	 * 
-	 * @return list of tracked parameter names.
-	 */
-	public List<String> getValidParameters() {
-		return new ArrayList<>(urlParamNames);
-	}
+    /**
+     * Returns a list of parameter names, as generated from reading in the parameters present in the
+     * {@link UrlParameterNamespace} implementations.
+     * 
+     * @return list of tracked parameter names.
+     */
+    public List<String> getValidParameters() {
+        return new ArrayList<>(urlParamNames);
+    }
 }