General code cleanup

Fix issues identified by findbugs and Eclipse IDE warnings

Signed-off-by: Gary O'Neall <gary@sourceauditor.com>

Author: goneall

src/main/java/org/spdx/library/model/license/ListedLicenses.java

@@ -17,12 +17,9 @@
  */
 package org.spdx.library.model.license;
 
-import java.io.IOException;
-import java.io.InputStream;
 import java.util.List;
 import java.util.Objects;
 import java.util.Optional;
-import java.util.Properties;
 import java.util.concurrent.locks.ReadWriteLock;
 import java.util.concurrent.locks.ReentrantReadWriteLock;
 

src/main/java/org/spdx/storage/listedlicense/SpdxListedLicenseWebStore.java

@@ -21,8 +21,6 @@
 import java.io.InputStream;
 import java.net.URL;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 import org.spdx.library.InvalidSPDXAnalysisException;
 import org.spdx.library.SpdxConstants;
 import org.spdx.utility.DownloadCache;
@@ -34,9 +32,6 @@
  */
 public class SpdxListedLicenseWebStore extends SpdxListedLicenseModelStore {
 
-	private static final Logger logger = LoggerFactory.getLogger(SpdxListedLicenseModelStore.class);
-
-
 	/**
 	 * @throws InvalidSPDXAnalysisException
 	 */

src/main/java/org/spdx/utility/DownloadCache.java

@@ -84,7 +84,7 @@ public final class DownloadCache {
 
     // See https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html
     private final String cacheDir = ((System.getenv("XDG_CACHE_HOME") == null ||
-            System.getenv("XDG_CACHE_HOME").trim() == "") ?
+            System.getenv("XDG_CACHE_HOME").trim().isEmpty()) ?
             System.getProperty("user.home") + File.separator + ".cache" :
             System.getenv("XDG_CACHE_HOME")) +
             File.separator + "Spdx-Java-Library";

src/main/java/org/spdx/utility/compare/SpdxItemComparer.java

@@ -93,15 +93,15 @@ public SpdxItemComparer(Map<SpdxDocument, Map<SpdxDocument, Map<String, String>>
 	public void addDocumentItem(SpdxDocument spdxDocument,
 			SpdxItem spdxItem) throws SpdxCompareException, InvalidSPDXAnalysisException {
 		if (this.itemInProgress) {
-			new SpdxCompareException("Trying to add a document item while another document item is being added.");
+			throw new SpdxCompareException("Trying to add a document item while another document item is being added.");
 		}
 		Optional<String> oName = spdxItem.getName();
 		if (this.name == null) {
 			if (oName.isPresent()) {
 				this.name = oName.get();
 			}
 		} else if (oName.isPresent() && !this.name.equals(oName.get()) && !(this instanceof SpdxSnippetComparer)) {
-			new SpdxCompareException("Names do not match for item being added to comparer: "+
+			throw new SpdxCompareException("Names do not match for item being added to comparer: "+
 					spdxItem.getName()+", expecting "+this.name);
 		}
 		this.itemInProgress = true;
@@ -384,7 +384,7 @@ public boolean isLicenseCommmentsEquals() throws SpdxCompareException {
 	 */
 	protected void checkInProgress() throws SpdxCompareException {
 		if (itemInProgress) {
-			new SpdxCompareException("File compare in progress - can not obtain compare results until compare has completed");
+			throw new SpdxCompareException("File compare in progress - can not obtain compare results until compare has completed");
 		}
 	}
 
@@ -393,7 +393,7 @@ protected void checkInProgress() throws SpdxCompareException {
 	 */
 	protected void checkCompareMade() throws SpdxCompareException {
 		if (this.documentItem.entrySet().size() < 1) {
-			new SpdxCompareException("Trying to obtain results of a file compare before a file compare has been performed");
+			throw new SpdxCompareException("Trying to obtain results of a file compare before a file compare has been performed");
 		}	
 	}