diff --git a/app/src/main/java/org/fdroid/fdroid/AndroidXMLDecompress.java b/app/src/main/java/org/fdroid/fdroid/AndroidXMLDecompress.java
index b543764b1..86ed380d3 100644
--- a/app/src/main/java/org/fdroid/fdroid/AndroidXMLDecompress.java
+++ b/app/src/main/java/org/fdroid/fdroid/AndroidXMLDecompress.java
@@ -68,7 +68,7 @@ import java.util.zip.ZipFile;
  * @see <a href="https://stackoverflow.com/a/4761689">a binary XML parser</a>
  */
 public class AndroidXMLDecompress {
-    public static int startTag = 0x00100102;
+    public static final int START_TAG = 0x00100102;
 
     /**
      * Just get the XML attributes from the {@code <manifest>} element.
@@ -82,7 +82,7 @@ public class AndroidXMLDecompress {
         int stringTableOffset = stringIndexTableOffset + numbStrings * 4;
         int xmlTagOffset = littleEndianWord(binaryXml, 3 * 4);
         for (int i = xmlTagOffset; i < binaryXml.length - 4; i += 4) {
-            if (littleEndianWord(binaryXml, i) == startTag) {
+            if (littleEndianWord(binaryXml, i) == START_TAG) {
                 xmlTagOffset = i;
                 break;
             }
@@ -92,11 +92,11 @@ public class AndroidXMLDecompress {
         while (offset < binaryXml.length) {
             int tag0 = littleEndianWord(binaryXml, offset);
 
-            if (tag0 == startTag) {
+            if (tag0 == START_TAG) {
                 int numbAttrs = littleEndianWord(binaryXml, offset + 7 * 4);
                 offset += 9 * 4;
 
-                HashMap<String, Object> attributes = new HashMap<String, Object>(3);
+                HashMap<String, Object> attributes = new HashMap<>(3);
                 for (int i = 0; i < numbAttrs; i++) {
                     int attributeNameStringIndex = littleEndianWord(binaryXml, offset + 1 * 4);
                     int attributeValueStringIndex = littleEndianWord(binaryXml, offset + 2 * 4);
@@ -117,7 +117,7 @@ public class AndroidXMLDecompress {
             // we only need the first <manifest> start tag
             break;
         }
-        return new HashMap<String, Object>(0);
+        return new HashMap<>(0);
     }
 
     public static byte[] getManifestFromFilename(String filename) throws IOException {
@@ -137,9 +137,7 @@ public class AndroidXMLDecompress {
         is.read(buf);
 
         is.close();
-        if (zip != null) {
-            zip.close();
-        }
+        zip.close();
         return buf;
     }
 
diff --git a/app/src/main/java/org/fdroid/fdroid/AppDetails.java b/app/src/main/java/org/fdroid/fdroid/AppDetails.java
index a431bd01b..073a86a14 100644
--- a/app/src/main/java/org/fdroid/fdroid/AppDetails.java
+++ b/app/src/main/java/org/fdroid/fdroid/AppDetails.java
@@ -865,8 +865,7 @@ public class AppDetails extends AppCompatActivity {
     }
 
     private void startDownload(Apk apk, String repoAddress) {
-        String urlString = Utils.getApkUrl(repoAddress, apk);
-        activeDownloadUrlString = urlString;
+        activeDownloadUrlString = Utils.getApkUrl(repoAddress, apk);
         registerDownloaderReceivers();
         headerFragment.startProgress();
         DownloaderService.queue(this, apk.packageName, activeDownloadUrlString);
diff --git a/app/src/main/java/org/fdroid/fdroid/installer/Installer.java b/app/src/main/java/org/fdroid/fdroid/installer/Installer.java
index 3ead44b3c..a0a549448 100644
--- a/app/src/main/java/org/fdroid/fdroid/installer/Installer.java
+++ b/app/src/main/java/org/fdroid/fdroid/installer/Installer.java
@@ -162,10 +162,7 @@ public abstract class Installer {
             return false;
         }
         Hasher hasher = new Hasher(hashType, apkFile);
-        if (hasher != null && hasher.match(hash)) {
-            return true;
-        }
-        return false;
+        return hasher.match(hash);
     }
 
     /**
diff --git a/app/src/main/java/org/fdroid/fdroid/net/DownloaderService.java b/app/src/main/java/org/fdroid/fdroid/net/DownloaderService.java
index 2d31a6574..05e5cce37 100644
--- a/app/src/main/java/org/fdroid/fdroid/net/DownloaderService.java
+++ b/app/src/main/java/org/fdroid/fdroid/net/DownloaderService.java
@@ -94,7 +94,7 @@ public class DownloaderService extends Service {
     private static volatile Downloader downloader;
     private LocalBroadcastManager localBroadcastManager;
 
-    private static final HashMap<String, Integer> QUEUE_WHATS = new HashMap<String, Integer>();
+    private static final HashMap<String, Integer> QUEUE_WHATS = new HashMap<>();
     private int what;
 
     private final class ServiceHandler extends Handler {