diff --git a/core/java/src/gnu/getopt/Getopt.java b/core/java/src/gnu/getopt/Getopt.java
index caf7f49cac..8a9a44720e 100644
--- a/core/java/src/gnu/getopt/Getopt.java
+++ b/core/java/src/gnu/getopt/Getopt.java
@@ -935,8 +935,8 @@ checkLongOption()
                   // +option or -option
                   else
                     {
-                      Object[] msgArgs = { progname, new 
-                               Character(argv[optind-1].charAt(0)).toString(),
+                      Object[] msgArgs = { progname,
+                               Character.toString(argv[optind-1].charAt(0)),
                                pfound.name };
                       System.err.println(MessageFormat.format(
                                _messages.getString("getopt.arguments2"), 
@@ -1138,8 +1138,8 @@ getopt()
                 }
               else
                 {
-                  Object[] msgArgs = { progname, new 
-                                 Character(argv[optind].charAt(0)).toString(), 
+                  Object[] msgArgs = { progname,
+                                 Character.toString(argv[optind].charAt(0)), 
                                  nextchar };
                   System.err.println(MessageFormat.format(
                                  _messages.getString("getopt.unrecognized2"), 
@@ -1176,15 +1176,15 @@ getopt()
           if (posixly_correct)
             {
               // 1003.2 specifies the format of this message
-              Object[] msgArgs = { progname, new 
-                                   Character((char)c).toString() };
+              Object[] msgArgs = { progname,
+                                   Character.toString((char)c) };
               System.err.println(MessageFormat.format(
                             _messages.getString("getopt.illegal"), msgArgs));
             }
           else
             {
-              Object[] msgArgs = { progname, new 
-                                   Character((char)c).toString() };
+              Object[] msgArgs = { progname,
+                                   Character.toString((char)c) };
               System.err.println(MessageFormat.format(
                             _messages.getString("getopt.invalid"), msgArgs));
             }
@@ -1208,8 +1208,8 @@ getopt()
           if (opterr)
             {
               // 1003.2 specifies the format of this message. 
-              Object[] msgArgs = { progname, new 
-                                   Character((char)c).toString() };
+              Object[] msgArgs = { progname,
+                                   Character.toString((char)c) };
               System.err.println(MessageFormat.format(
                             _messages.getString("getopt.requires2"), msgArgs));
             }
@@ -1270,8 +1270,8 @@ getopt()
               if (opterr)
                 {
                   // 1003.2 specifies the format of this message
-                  Object[] msgArgs = { progname, new 
-                                       Character((char)c).toString() };
+                  Object[] msgArgs = { progname,
+                                       Character.toString((char)c) };
                   System.err.println(MessageFormat.format(
                             _messages.getString("getopt.requires2"), msgArgs));
                 }
@@ -1300,8 +1300,8 @@ getopt()
                       if (opterr)
                         {
                           // 1003.2 specifies the format of this message
-                          Object[] msgArgs = { progname, new 
-                                               Character((char)c).toString() };
+                          Object[] msgArgs = { progname,
+                                               Character.toString((char)c) };
                           System.err.println(MessageFormat.format(
                              _messages.getString("getopt.requires2"), msgArgs));
                         }
diff --git a/core/java/src/gnu/getopt/LongOpt.java b/core/java/src/gnu/getopt/LongOpt.java
index 9de9f43ad5..644a4b91f5 100644
--- a/core/java/src/gnu/getopt/LongOpt.java
+++ b/core/java/src/gnu/getopt/LongOpt.java
@@ -127,7 +127,7 @@ LongOpt(String name, int has_arg,
   if ((has_arg != NO_ARGUMENT) && (has_arg != REQUIRED_ARGUMENT) 
      && (has_arg != OPTIONAL_ARGUMENT))
     {
-      Object[] msgArgs = { new Integer(has_arg).toString() };
+      Object[] msgArgs = { Integer.toString(has_arg) };
       throw new IllegalArgumentException(MessageFormat.format(
                     _messages.getString("getopt.invalidValue"), msgArgs));
     }
diff --git a/core/java/src/gnu/gettext/GettextResource.java b/core/java/src/gnu/gettext/GettextResource.java
index d0dbc05128..3733a26eea 100644
--- a/core/java/src/gnu/gettext/GettextResource.java
+++ b/core/java/src/gnu/gettext/GettextResource.java
@@ -148,7 +148,7 @@ public abstract class GettextResource extends ResourceBundle {
               String[] pluralforms = (String[])localValue;
               long i = 0;
               try {
-                i = ((Long) pluralEvalMethod.invoke(catalog, new Object[] { new Long(n) })).longValue();
+                i = ((Long) pluralEvalMethod.invoke(catalog, new Object[] { Long.valueOf(n) })).longValue();
                 if (!(i >= 0 && i < pluralforms.length))
                   i = 0;
               } catch (IllegalAccessException e) {
diff --git a/core/java/src/net/i2p/crypto/provider/I2PProvider.java b/core/java/src/net/i2p/crypto/provider/I2PProvider.java
index b6b26d396d..3c0e28a15d 100644
--- a/core/java/src/net/i2p/crypto/provider/I2PProvider.java
+++ b/core/java/src/net/i2p/crypto/provider/I2PProvider.java
@@ -20,6 +20,8 @@ public final class I2PProvider extends Provider {
      * <code>Security.addProvider()</code> mechanism.
      */
     public I2PProvider() {
+        // following constructor deprecated in Java 9,
+        // replaced by (String,String,String) added in Java 9
         super(PROVIDER_NAME, 0.1, INFO);
 
         AccessController.doPrivileged(new PrivilegedAction<Void>() {
diff --git a/router/java/src/com/southernstorm/noise/protocol/Noise.java b/router/java/src/com/southernstorm/noise/protocol/Noise.java
index 29764faa25..f21184862a 100644
--- a/router/java/src/com/southernstorm/noise/protocol/Noise.java
+++ b/router/java/src/com/southernstorm/noise/protocol/Noise.java
@@ -125,11 +125,10 @@ public final class Noise {
 	static void throwBadTagException() throws BadPaddingException
 	{
 		try {
+			// java since 1.7; android since API 19
 			Class<?> c = Class.forName("javax.crypto.AEADBadTagException");
-			throw (BadPaddingException)(c.newInstance());
-		} catch (ClassNotFoundException e) {
-		} catch (InstantiationException e) {
-		} catch (IllegalAccessException e) {
+			throw (BadPaddingException)(c.getDeclaredConstructor().newInstance());
+		} catch (Exception e) {
 		}
 		throw new BadPaddingException();
 	}