diff --git a/src/main/java/org/qortal/api/HTMLParser.java b/src/main/java/org/qortal/api/HTMLParser.java
index f1794594..4887cf84 100644
--- a/src/main/java/org/qortal/api/HTMLParser.java
+++ b/src/main/java/org/qortal/api/HTMLParser.java
@@ -82,7 +82,7 @@ public class HTMLParser {
     }
 
     public static boolean isHtmlFile(String path) {
-        if (path.endsWith(".html") || path.endsWith(".htm") || path.equals("")) {
+        if (path.endsWith(".html") || path.endsWith(".htm") || path.isEmpty()) {
             return true;
         }
         return false;
diff --git a/src/main/java/org/qortal/api/gateway/resource/GatewayResource.java b/src/main/java/org/qortal/api/gateway/resource/GatewayResource.java
index fc67594e..7f4b2f88 100644
--- a/src/main/java/org/qortal/api/gateway/resource/GatewayResource.java
+++ b/src/main/java/org/qortal/api/gateway/resource/GatewayResource.java
@@ -80,7 +80,7 @@ public class GatewayResource {
     
     private HttpServletResponse parsePath(String inPath, String qdnContext, String secret58, boolean includeResourceIdInPrefix, boolean async) {
 
-        if (inPath == null || inPath.equals("")) {
+        if (inPath == null || inPath.isEmpty()) {
             // Assume not a real file
             return ArbitraryDataRenderer.getResponse(response, 404, "Error 404: File Not Found");
         }
diff --git a/src/main/java/org/qortal/api/resource/ArbitraryResource.java b/src/main/java/org/qortal/api/resource/ArbitraryResource.java
index fe9e8524..99fc0020 100644
--- a/src/main/java/org/qortal/api/resource/ArbitraryResource.java
+++ b/src/main/java/org/qortal/api/resource/ArbitraryResource.java
@@ -491,7 +491,7 @@ public class ArbitraryResource {
 			
 			List<ArbitraryTransactionData> transactionDataList;
 
-			if (query == null || query.equals("")) {
+			if (query == null || query.isEmpty()) {
 				transactionDataList = ArbitraryDataStorageManager.getInstance().listAllHostedTransactions(repository, limit, offset);
 			} else {
 				transactionDataList = ArbitraryDataStorageManager.getInstance().searchHostedTransactions(repository,query, limit, offset);
diff --git a/src/main/java/org/qortal/arbitrary/ArbitraryDataReader.java b/src/main/java/org/qortal/arbitrary/ArbitraryDataReader.java
index 09154a32..78a9ee86 100644
--- a/src/main/java/org/qortal/arbitrary/ArbitraryDataReader.java
+++ b/src/main/java/org/qortal/arbitrary/ArbitraryDataReader.java
@@ -73,7 +73,7 @@ public class ArbitraryDataReader {
         }
 
         // If identifier is a blank string, or reserved keyword "default", treat it as null
-        if (identifier == null || identifier.equals("") || identifier.equals("default")) {
+        if (identifier == null || identifier.isEmpty() || identifier.equals("default")) {
             identifier = null;
         }
 
diff --git a/src/main/java/org/qortal/arbitrary/ArbitraryDataRenderer.java b/src/main/java/org/qortal/arbitrary/ArbitraryDataRenderer.java
index 9d20df14..5200b5e2 100644
--- a/src/main/java/org/qortal/arbitrary/ArbitraryDataRenderer.java
+++ b/src/main/java/org/qortal/arbitrary/ArbitraryDataRenderer.java
@@ -199,7 +199,7 @@ public class ArbitraryDataRenderer {
     }
 
     private String getFilename(String directory, String userPath) {
-        if (userPath == null || userPath.endsWith("/") || userPath.equals("")) {
+        if (userPath == null || userPath.endsWith("/") || userPath.isEmpty()) {
             // Locate index file
             List<String> indexFiles = ArbitraryDataRenderer.indexFiles();
             for (String indexFile : indexFiles) {
diff --git a/src/main/java/org/qortal/arbitrary/ArbitraryDataResource.java b/src/main/java/org/qortal/arbitrary/ArbitraryDataResource.java
index 16faf838..232d3416 100644
--- a/src/main/java/org/qortal/arbitrary/ArbitraryDataResource.java
+++ b/src/main/java/org/qortal/arbitrary/ArbitraryDataResource.java
@@ -52,7 +52,7 @@ public class ArbitraryDataResource {
         this.service = service;
 
         // If identifier is a blank string, or reserved keyword "default", treat it as null
-        if (identifier == null || identifier.equals("") || identifier.equals("default")) {
+        if (identifier == null || identifier.isEmpty() || identifier.equals("default")) {
             identifier = null;
         }
         this.identifier = identifier;
diff --git a/src/main/java/org/qortal/arbitrary/ArbitraryDataTransactionBuilder.java b/src/main/java/org/qortal/arbitrary/ArbitraryDataTransactionBuilder.java
index 9cfc686a..a77442ec 100644
--- a/src/main/java/org/qortal/arbitrary/ArbitraryDataTransactionBuilder.java
+++ b/src/main/java/org/qortal/arbitrary/ArbitraryDataTransactionBuilder.java
@@ -81,7 +81,7 @@ public class ArbitraryDataTransactionBuilder {
         this.service = service;
 
         // If identifier is a blank string, or reserved keyword "default", treat it as null
-        if (identifier == null || identifier.equals("") || identifier.equals("default")) {
+        if (identifier == null || identifier.isEmpty() || identifier.equals("default")) {
             identifier = null;
         }
         this.identifier = identifier;
diff --git a/src/main/java/org/qortal/arbitrary/ArbitraryDataWriter.java b/src/main/java/org/qortal/arbitrary/ArbitraryDataWriter.java
index 0098e4fa..e3dcbad7 100644
--- a/src/main/java/org/qortal/arbitrary/ArbitraryDataWriter.java
+++ b/src/main/java/org/qortal/arbitrary/ArbitraryDataWriter.java
@@ -78,7 +78,7 @@ public class ArbitraryDataWriter {
         this.compression = compression;
 
         // If identifier is a blank string, or reserved keyword "default", treat it as null
-        if (identifier == null || identifier.equals("") || identifier.equals("default")) {
+        if (identifier == null || identifier.isEmpty() || identifier.equals("default")) {
             identifier = null;
         }
         this.identifier = identifier;