MCR-3229 enable PMD rule LooseCoupling

mycore-base/src/main/java/org/mycore/access/MCRAccessCacheHelper.java

@@ -40,7 +40,7 @@ public class MCRAccessCacheHelper {
     public static void clearPermissionCache(String id) {
         LOGGER.info("Invalidate all permissions for obj {} from local cache", id);
 
-        final ArrayList<String> idsToClear = new ArrayList<>();
+        List<String> idsToClear = new ArrayList<>();
         idsToClear.add(id);
         collectDescendants(idsToClear, id);
         MCRAccessManager.invalidPermissionCacheByID(idsToClear.toArray(new String[0]));
@@ -53,7 +53,7 @@ public static void clearPermissionCache(String id) {
     public static void clearAllPermissionCaches(String id) {
         LOGGER.info("Invalidate all permissions for obj {} from all caches", id);
 
-        final ArrayList<String> idsToClear = new ArrayList<>();
+        List<String> idsToClear = new ArrayList<>();
         idsToClear.add(id);
         collectDescendants(idsToClear, id);
         MCRAccessManager.invalidAllPermissionCachesById(idsToClear.toArray(new String[0]));

mycore-base/src/main/java/org/mycore/access/mcrimpl/MCRAccessControlSystem.java

@@ -23,6 +23,7 @@
 import java.util.Date;
 import java.util.HashMap;
 import java.util.Hashtable;
+import java.util.Map;
 
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
@@ -45,7 +46,7 @@
  */
 public class MCRAccessControlSystem extends MCRAccessBaseImpl {
     private static MCRAccessControlSystem singleton;
-    private static final HashMap<String, Integer> NEXT_FREE_RULE_ID = new HashMap<>();
+    private static final Map<String, Integer> NEXT_FREE_RULE_ID = new HashMap<>();
 
     public static final String SYSTEM_RULE_PREFIX = "SYSTEMRULE";
 
@@ -61,14 +62,14 @@ public class MCRAccessControlSystem extends MCRAccessBaseImpl {
 
     boolean disabled;
 
-    static Hashtable<String, String> ruleIDTable = new Hashtable<>();
+    static Map<String, String> ruleIDTable = new Hashtable<>();
 
     private static final Logger LOGGER = LogManager.getLogger(MCRAccessControlSystem.class);
 
     private MCRAccessControlSystem() {
         String pools = MCRConfiguration2.getString("MCR.Access.AccessPermissions").orElse("read,write,delete");
 
-        if (pools.trim().length() == 0) {
+        if (pools.isBlank()) {
             disabled = true;
         }
 
@@ -101,7 +102,7 @@ public void createRule(Element rule, String creator, String description) {
     public void addRule(String id, String pool, Element rule, String description) throws MCRException {
         MCRRuleMapping ruleMapping = getAutoGeneratedRuleMapping(rule, "System", pool, id, description);
         String oldRuleID = accessStore.getRuleID(id, pool);
-        if (oldRuleID == null || oldRuleID.equals("")) {
+        if (oldRuleID == null || oldRuleID.isEmpty()) {
             accessStore.createAccessDefinition(ruleMapping);
         } else {
             accessStore.updateAccessDefinition(ruleMapping);
@@ -135,7 +136,7 @@ public void removeAllRules(String id) throws MCRException {
     public void updateRule(String id, String pool, Element rule, String description) throws MCRException {
         MCRRuleMapping ruleMapping = getAutoGeneratedRuleMapping(rule, "System", pool, id, description);
         String oldRuleID = accessStore.getRuleID(id, pool);
-        if (oldRuleID == null || oldRuleID.equals("")) {
+        if (oldRuleID == null || oldRuleID.isEmpty()) {
             LOGGER.debug(
                 "updateRule called for id <{}> and pool <{}>, but no rule is existing, so new rule was created", id,
                 pool);
@@ -347,7 +348,7 @@ public synchronized String getNextFreeRuleID(String prefix) {
      */
     @Override
     public String getNormalizedRuleString(Element rule) {
-        if (rule.getChildren() == null || rule.getChildren().size() == 0) {
+        if (rule.getChildren() == null || rule.getChildren().isEmpty()) {
             return "false";
         }
         Element normalizedRule = normalize(rule.getChildren().getFirst());
@@ -372,9 +373,9 @@ public MCRRuleMapping getAutoGeneratedRuleMapping(Element rule, String creator,
         String description) {
         String ruleString = getNormalizedRuleString(rule);
         String ruleID = ruleIDTable.get(ruleString);
-        if (ruleID == null || ruleID.length() == 0) {
+        if (ruleID == null || ruleID.isEmpty()) {
             Collection<String> existingIDs = ruleStore.retrieveRuleIDs(ruleString, description);
-            if (existingIDs != null && existingIDs.size() > 0) {
+            if (existingIDs != null && !existingIDs.isEmpty()) {
                 // rule yet exists
                 ruleID = existingIDs.iterator().next();
             } else {

mycore-base/src/main/java/org/mycore/access/mcrimpl/MCRAccessDefinition.java

@@ -19,17 +19,18 @@
 package org.mycore.access.mcrimpl;
 
 import java.util.HashMap;
+import java.util.Map;
 
 /**
  * Maps object ids to rules
- * 
+ *
  * @author Arne Seifert
  */
 public class MCRAccessDefinition {
 
     private String objid;
 
-    private HashMap<String, String> pools = new HashMap<>();
+    private Map<String, String> pools = new HashMap<>();
 
     public MCRAccessDefinition() {
         pools.clear();
@@ -43,11 +44,11 @@ public void setObjID(String value) {
         objid = value;
     }
 
-    public HashMap<String, String> getPool() {
+    public Map<String, String> getPool() {
         return pools;
     }
 
-    public void setPool(HashMap<String, String> pool) {
+    public void setPool(Map<String, String> pool) {
         pools = pool;
     }
 

mycore-base/src/main/java/org/mycore/access/mcrimpl/MCRAccessStore.java

@@ -24,6 +24,7 @@
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.Objects;
 
 import org.apache.logging.log4j.LogManager;
@@ -37,7 +38,7 @@
  * must implement this interface. Which database actually will be used can then
  * be configured by reading the value <code>MCR.Persistence.Access.Store.Class</code>
  * from mycore.properties.access
- * 
+ *
  * @author Arne Seifert
  */
 public abstract class MCRAccessStore {
@@ -71,7 +72,7 @@ public abstract class MCRAccessStore {
     public abstract boolean isRuleInUse(String ruleid);
 
     /**
-     * 
+     *
      * @return a collection of all String IDs an access rule is assigned to
      */
     public abstract Collection<String> getDistinctStringIDs();
@@ -96,13 +97,13 @@ public static Collection<String> getPools() {
     /**
      * alle Elemente eines Datentypes aufbereiten
      * @param type document type
-     * 
+     *
      * @return List of MCRAccessDefinition
      * @see MCRAccessDefinition
      */
     public Collection<MCRAccessDefinition> getDefinition(String type) {
         try {
-            HashMap<String, Collection<String>> sqlDefinition = new HashMap<>();
+            Map<String, Collection<String>> sqlDefinition = new HashMap<>();
             Collection<String> pools = getInstance().getDatabasePools();
             //merge pools
             pools.removeAll(getPools());

mycore-base/src/main/java/org/mycore/common/MCRConstants.java

@@ -20,7 +20,8 @@
 
 import java.lang.reflect.Field;
 import java.util.Collection;
-import java.util.HashMap;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 
 import org.apache.logging.log4j.LogManager;
 import org.jdom2.Namespace;
@@ -30,7 +31,7 @@
 /**
  * This class replaces the deprecated MCRDefaults interface and provides some
  * final static fields of common use.
- * 
+ *
  * @author Jens Kupferschmidt
  * @author Thomas Scheffler (yagee)
  * @author Stefan Freitag (sasf)
@@ -119,10 +120,10 @@ public final class MCRConstants {
 
     public static final Namespace MCR_NAMESPACE = Namespace.getNamespace("mcr", MCR_URL);
 
-    private static final HashMap<String, Namespace> NAMESPACES_BY_PREFIX;
+    private static final Map<String, Namespace> NAMESPACES_BY_PREFIX;
 
     static {
-        NAMESPACES_BY_PREFIX = new HashMap<>();
+        NAMESPACES_BY_PREFIX = new ConcurrentHashMap<>();
 
         Field[] fields = MCRConstants.class.getFields();
         for (Field f : fields) {

mycore-base/src/main/java/org/mycore/common/MCRMailer.java

@@ -159,7 +159,7 @@ protected void doGetPost(MCRServletJob job) throws Exception {
     public static void send(String sender, String recipient, String subject, String body) {
         LOGGER.debug("Called plaintext send method with single recipient.");
 
-        ArrayList<String> recipients = new ArrayList<>();
+        List<String> recipients = new ArrayList<>();
         recipients.add(recipient);
         send(sender, null, recipients, null, subject, body, null);
     }
@@ -209,7 +209,7 @@ public static void send(String sender, List<String> recipients, String subject,
     public static void send(String sender, String recipient, String subject, String body, List<String> parts) {
         LOGGER.debug("Called multipart send method with single recipient.");
 
-        ArrayList<String> recipients = new ArrayList<>();
+        List<String> recipients = new ArrayList<>();
         recipients.add(recipient);
         send(sender, null, recipients, null, subject, body, parts);
     }

mycore-base/src/main/java/org/mycore/common/MCRRateLimitBuckets.java

@@ -81,7 +81,7 @@ public static Bucket getOrCreateBucket(String configID) {
         }
         final String dsConfigLimits = MCRConfiguration2.getStringOrThrow(CONFIG_PREFIX + CONFIG_ID + ".Limits");
 
-        final HashMap<String, Long> limitMap = Arrays.stream(dsConfigLimits.split(",")).collect(
+        final Map<String, Long> limitMap = Arrays.stream(dsConfigLimits.split(",")).collect(
             HashMap::new, (map, str) -> map.put(str.split("/")[1].trim(),
                 Long.parseLong(str.split("/")[0].trim())),
             HashMap::putAll);
@@ -96,7 +96,7 @@ public static Bucket getOrCreateBucket(String configID) {
      * @param limitMap a map of time units and the corresponding limit/amount of tokens.
      * @return the created bucket
      */
-    private static Bucket createNewBucket(HashMap<String, Long> limitMap) {
+    private static Bucket createNewBucket(Map<String, Long> limitMap) {
         final LocalBucketBuilder builder = Bucket.builder();
         for (Map.Entry<String, Long> entry : limitMap.entrySet()) {
             final String unit = entry.getKey();

mycore-base/src/main/java/org/mycore/common/MCRUtils.java

@@ -47,6 +47,8 @@
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HexFormat;
+import java.util.List;
+import java.util.Map;
 import java.util.Objects;
 import java.util.Optional;
 import java.util.Properties;
@@ -175,8 +177,8 @@ public static Path writeTextToFile(String textToWrite, String fileName, Charset
      *            the File instance of the basic directory
      * @return an ArrayList with file names as pathes
      */
-    public static ArrayList<String> getAllFileNames(File basedir) {
-        ArrayList<String> out = new ArrayList<>();
+    public static List<String> getAllFileNames(File basedir) {
+        List<String> out = new ArrayList<>();
         File[] stage = basedir.listFiles();
 
         for (File element : stage) {
@@ -199,8 +201,8 @@ public static ArrayList<String> getAllFileNames(File basedir) {
      * @param path    the part of directory path
      * @return an ArrayList with file names as pathes
      */
-    public static ArrayList<String> getAllFileNames(File basedir, String path) {
-        ArrayList<String> out = new ArrayList<>();
+    public static List<String> getAllFileNames(File basedir, String path) {
+        List<String> out = new ArrayList<>();
         File[] stage = basedir.listFiles();
 
         for (File element : stage) {
@@ -223,8 +225,8 @@ public static ArrayList<String> getAllFileNames(File basedir, String path) {
      *            the File instance of the basic directory
      * @return an ArrayList with directory names as pathes
      */
-    public static ArrayList<String> getAllDirectoryNames(File basedir) {
-        ArrayList<String> out = new ArrayList<>();
+    public static List<String> getAllDirectoryNames(File basedir) {
+        List<String> out = new ArrayList<>();
         File[] stage = basedir.listFiles();
 
         for (File element : stage) {
@@ -246,8 +248,8 @@ public static ArrayList<String> getAllDirectoryNames(File basedir) {
      *            the part of directory path
      * @return an ArrayList with directory names as pathes
      */
-    public static ArrayList<String> getAllDirectoryNames(File basedir, String path) {
-        ArrayList<String> out = new ArrayList<>();
+    public static List<String> getAllDirectoryNames(File basedir, String path) {
+        List<String> out = new ArrayList<>();
         File[] stage = basedir.listFiles();
 
         for (File element : stage) {
@@ -409,7 +411,7 @@ public static void untar(Path source, Path expandToDirectory) throws IOException
         try (TarArchiveInputStream tain = new TarArchiveInputStream(Files.newInputStream(source))) {
             TarArchiveEntry tarEntry;
             FileSystem targetFS = expandToDirectory.getFileSystem();
-            HashMap<Path, FileTime> directoryTimes = new HashMap<>();
+            Map<Path, FileTime> directoryTimes = new HashMap<>();
             while ((tarEntry = tain.getNextEntry()) != null) {
                 Path target = MCRPathUtils.getPath(targetFS, tarEntry.getName());
                 Path absoluteTarget = expandToDirectory.resolve(target).normalize().toAbsolutePath();

mycore-base/src/main/java/org/mycore/common/config/MCRConcurrentHashMap.java

@@ -23,6 +23,7 @@
 import java.io.ObjectInputStream;
 import java.io.ObjectOutputStream;
 import java.util.HashMap;
+import java.util.Map;
 import java.util.Objects;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ThreadLocalRandom;
@@ -40,7 +41,7 @@
  */
 @SuppressWarnings("unchecked")
 class MCRConcurrentHashMap<K extends SingletonKey, V> extends ConcurrentHashMap<K, V> {
-    private HashMap<K, RemappedKey> keyMap = new HashMap<>();
+    private Map<K, RemappedKey> keyMap = new HashMap<>();
 
     // Disable serialization
     @SuppressWarnings("unused")
@@ -61,7 +62,7 @@ private void writeObject(ObjectOutputStream ois)
      * In case of collision, the key is automatically remapped via {@link RemappedKey}.
      * It is a wrapper to modify the hashcode of the given SingletonKey to assign a different bucket
      * within the internal table, in an attempt to resolve the collision.
-     * 
+     *
      * <p>The mapping function must not modify the map during computation of any key other then a {@link SingletonKey}
      * @see java.util.concurrent.ConcurrentHashMap#computeIfAbsent(java.lang.Object, java.util.function.Function)
      */