codebase cleanup - remove redundant code constructs, use modern APIs

Signed-off-by: Lukas Jungmann <lukas.jungmann@oracle.com>

api/src/main/java/jakarta/mail/Flags.java

@@ -177,7 +177,7 @@ public Flags() {
     public Flags(Flags flags) {
         this.system_flags = flags.system_flags;
         if (flags.user_flags != null)
-            this.user_flags = (Hashtable) flags.user_flags.clone();
+            this.user_flags = (Hashtable<String, String>) flags.user_flags.clone();
     }
 
     /**
@@ -492,7 +492,7 @@ public Object clone() {
             // ignore, can't happen
         }
         if (this.user_flags != null)
-            f.user_flags = (Hashtable) this.user_flags.clone();
+            f.user_flags = (Hashtable<String, String>) this.user_flags.clone();
         return f;
     }
 

api/src/main/java/jakarta/mail/Folder.java

@@ -1307,7 +1307,7 @@ public Message[] search(SearchTerm term, Message[] msgs)
             }
         }
 
-        return matchedMsgs.toArray(new Message[matchedMsgs.size()]);
+        return matchedMsgs.toArray(new Message[0]);
     }
 
     /*
@@ -1626,7 +1626,6 @@ protected void notifyMessageChangedListeners(int type, Message msg) {
     /*
      * Add the event and vector of listeners to the queue to be delivered.
      */
-    @SuppressWarnings("unchecked")
     private void queueEvent(MailEvent event,
                             Vector<? extends EventListener> vector) {
         /*
@@ -1637,7 +1636,8 @@ private void queueEvent(MailEvent event,
          * of this event will not take effect until after the event is
          * delivered.
          */
-        Vector<? extends EventListener> v = (Vector) vector.clone();
+        @SuppressWarnings("unchecked")
+        Vector<? extends EventListener> v = (Vector<? extends EventListener>) vector.clone();
         q.enqueue(event, v);
     }
 

api/src/main/java/jakarta/mail/MailLogger.java

@@ -226,7 +226,7 @@ public void log(Level level, String msg) {
      */
     public void log(Level level, String msg, Object param1) {
         if (debug) {
-            msg = MessageFormat.format(msg, new Object[]{param1});
+            msg = MessageFormat.format(msg, param1);
             debugOut(msg);
         }
 

api/src/main/java/jakarta/mail/MessagingException.java

@@ -132,7 +132,7 @@ public synchronized String toString() {
                 sb.append(mex.superToString());
                 n = mex.next;
             } else {
-                sb.append(n.toString());
+                sb.append(n);
                 n = null;
             }
         }

api/src/main/java/jakarta/mail/Service.java

@@ -628,7 +628,7 @@ protected void queueEvent(MailEvent event,
          * delivered.
          */
         @SuppressWarnings("unchecked")
-        Vector<? extends EventListener> v = (Vector) vector.clone();
+        Vector<? extends EventListener> v = (Vector<? extends EventListener>) vector.clone();
         q.enqueue(event, v);
     }
 

api/src/main/java/jakarta/mail/Session.java

@@ -510,7 +510,7 @@ public synchronized Provider[] getProviders() {
      */
     public synchronized Provider getProvider(String protocol) throws NoSuchProviderException {
 
-        if (protocol == null || protocol.length() <= 0) {
+        if (protocol == null || protocol.length() == 0) {
             throw new NoSuchProviderException("Invalid protocol: null");
         }
 
@@ -538,7 +538,7 @@ public synchronized Provider getProvider(String protocol) throws NoSuchProviderE
             throw new NoSuchProviderException("No provider for " + protocol);
         } else {
             if (logger.isLoggable(Level.FINE)) {
-                logger.fine("getProvider() returning " + _provider.toString());
+                logger.fine("getProvider() returning " + _provider);
             }
             return _provider;
         }
@@ -1053,9 +1053,9 @@ public void load(InputStream is) throws IOException {
             // dump the output of the tables for debugging
             logger.config("Tables of loaded providers");
             logger.config("Providers Listed By Class Name: " +
-                    providersByClassName.toString());
+                    providersByClassName);
             logger.config("Providers Listed By Protocol: " +
-                    providersByProtocol.toString());
+                    providersByProtocol);
         }
     }
 
@@ -1102,7 +1102,7 @@ private void loadProvidersFromStream(InputStream is) throws IOException {
 
                 // check if a valid Provider; else, continue
                 if (type == null || protocol == null || className == null
-                        || protocol.length() <= 0 || className.length() <= 0) {
+                        || protocol.length() == 0 || className.length() == 0) {
 
                     logger.log(Level.CONFIG, "Bad provider entry: {0}",
                             currLine);
@@ -1189,12 +1189,9 @@ private void loadFile(String name, StreamLoader loader) {
             logger.log(Level.CONFIG, "successfully loaded file: {0}", name);
         } catch (FileNotFoundException fex) {
             // ignore it
-        } catch (IOException e) {
+        } catch (IOException | SecurityException e) {
             if (logger.isLoggable(Level.CONFIG))
                 logger.log(Level.CONFIG, "not loading file: " + name, e);
-        } catch (SecurityException sex) {
-            if (logger.isLoggable(Level.CONFIG))
-                logger.log(Level.CONFIG, "not loading file: " + name, sex);
         } finally {
             try {
                 if (clis != null)
@@ -1220,10 +1217,8 @@ private void loadResource(String name, Class<?> cl, StreamLoader loader, boolean
                     logger.log(Level.WARNING,
                             "expected resource not found: {0}", name);
             }
-        } catch (IOException e) {
+        } catch (IOException | SecurityException e) {
             logger.log(Level.CONFIG, "Exception loading resource", e);
-        } catch (SecurityException sex) {
-            logger.log(Level.CONFIG, "Exception loading resource", sex);
         } finally {
             try {
                 if (clis != null)
@@ -1267,12 +1262,9 @@ private void loadAllResources(String name, Class<?> cl, StreamLoader loader) {
                         }
                     } catch (FileNotFoundException fex) {
                         // ignore it
-                    } catch (IOException ioex) {
+                    } catch (IOException | SecurityException ioex) {
                         logger.log(Level.CONFIG, "Exception loading resource",
                                 ioex);
-                    } catch (SecurityException sex) {
-                        logger.log(Level.CONFIG, "Exception loading resource",
-                                sex);
                     } finally {
                         try {
                             if (clis != null)
@@ -1349,8 +1341,7 @@ public URL[] run() {
                         ret = new URL[v.size()];
                         v.toArray(ret);
                     }
-                } catch (IOException ioex) {
-                } catch (SecurityException ex) {
+                } catch (IOException | SecurityException ioex) {
                 }
                 return ret;
             }
@@ -1369,8 +1360,7 @@ public URL[] run() {
                         ret = new URL[v.size()];
                         v.toArray(ret);
                     }
-                } catch (IOException ioex) {
-                } catch (SecurityException ex) {
+                } catch (IOException | SecurityException ioex) {
                 }
                 return ret;
             }

api/src/main/java/jakarta/mail/Transport.java

@@ -20,6 +20,7 @@
 import jakarta.mail.event.TransportListener;
 
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -251,8 +252,7 @@ private static void send0(Message msg, Address[] addresses,
             if ((transport = s.getTransport(protaddresses[0])) == null) {
                 // Could not find an appropriate Transport ..
                 // Mark these addresses invalid.
-                for (int j = 0; j < protaddresses.length; j++)
-                    invalid.add(protaddresses[j]);
+                Collections.addAll(invalid, protaddresses);
                 continue;
             }
             try {
@@ -269,20 +269,17 @@ private static void send0(Message msg, Address[] addresses,
                 // retrieve invalid addresses
                 Address[] a = sex.getInvalidAddresses();
                 if (a != null)
-                    for (int j = 0; j < a.length; j++)
-                        invalid.add(a[j]);
+                    Collections.addAll(invalid, a);
 
                 // retrieve validSent addresses
                 a = sex.getValidSentAddresses();
                 if (a != null)
-                    for (int k = 0; k < a.length; k++)
-                        validSent.add(a[k]);
+                    Collections.addAll(validSent, a);
 
                 // retrieve validUnsent addresses
                 Address[] c = sex.getValidUnsentAddresses();
                 if (c != null)
-                    for (int l = 0; l < c.length; l++)
-                        validUnsent.add(c[l]);
+                    Collections.addAll(validUnsent, c);
             } catch (MessagingException mex) {
                 sendFailed = true;
                 // chain the exception we're catching to any previous ones

api/src/main/java/jakarta/mail/URLName.java

@@ -19,13 +19,14 @@
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.OutputStreamWriter;
-import java.io.UnsupportedEncodingException;
 import java.net.InetAddress;
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.net.UnknownHostException;
+import java.nio.charset.StandardCharsets;
 import java.util.BitSet;
 import java.util.Locale;
+import java.util.Objects;
 
 
 /**
@@ -201,7 +202,7 @@ public String toString() {
                 // add port (if needed)
                 if (port != -1) {
                     tempURL.append(":");
-                    tempURL.append(Integer.toString(port));
+                    tempURL.append(port);
                 }
                 if (file != null)
                     tempURL.append("/");
@@ -424,8 +425,7 @@ public boolean equals(Object obj) {
         URLName u2 = (URLName) obj;
 
         // compare protocols
-        if (!(protocol == u2.protocol ||
-                (protocol != null && protocol.equals(u2.protocol))))
+        if (!(Objects.equals(protocol, u2.protocol)))
             return false;
 
         // compare hosts
@@ -445,8 +445,7 @@ public boolean equals(Object obj) {
         // at this point, hosts match
 
         // compare usernames
-        if (!(username == u2.username ||
-                (username != null && username.equals(u2.username))))
+        if (!(Objects.equals(username, u2.username)))
             return false;
 
         // Forget about password since it doesn't
@@ -566,7 +565,7 @@ static String encode(String s) {
             return null;
         // the common case is no encoding is needed
         for (int i = 0; i < s.length(); i++) {
-            int c = (int) s.charAt(i);
+            int c = s.charAt(i);
             if (c == ' ' || !dontNeedEncoding.get(c))
                 return _encode(s);
         }
@@ -580,7 +579,7 @@ private static String _encode(String s) {
         OutputStreamWriter writer = new OutputStreamWriter(buf);
 
         for (int i = 0; i < s.length(); i++) {
-            int c = (int) s.charAt(i);
+            int c = s.charAt(i);
             if (dontNeedEncoding.get(c)) {
                 if (c == ' ') {
                     c = '+';
@@ -680,12 +679,8 @@ static String decode(String s) {
         }
         // Undo conversion to external encoding
         String result = sb.toString();
-        try {
-            byte[] inputBytes = result.getBytes("8859_1");
-            result = new String(inputBytes);
-        } catch (UnsupportedEncodingException e) {
-            // The system should always have 8859_1
-        }
+        byte[] inputBytes = result.getBytes(StandardCharsets.ISO_8859_1);
+        result = new String(inputBytes);
         return result;
     }
 

api/src/main/java/jakarta/mail/internet/HeaderTokenizer.java

@@ -332,7 +332,7 @@ else if (c == ')')
             currentPos++; // re-position currentPos
             char[] ch = new char[1];
             ch[0] = c;
-            return new Token((int) c, new String(ch));
+            return new Token(c, new String(ch));
         }
 
         // Check for ATOM

api/src/main/java/jakarta/mail/internet/InternetAddress.java

@@ -605,8 +605,7 @@ private static int lengthOfLastSegment(String s, int used) {
     public static InternetAddress getLocalAddress(Session session) {
         try {
             return _getLocalAddress(session);
-        } catch (SecurityException sex) {    // ignore it
-        } catch (AddressException ex) {        // ignore it
+        } catch (SecurityException | AddressException sex) {    // ignore it
         } catch (UnknownHostException ex) {
         }    // ignore it
         return null;

api/src/main/java/jakarta/mail/internet/MimeBodyPart.java

@@ -34,14 +34,13 @@
 import jakarta.mail.util.StreamProvider.EncoderTypes;
 
 import java.io.BufferedInputStream;
-import java.io.BufferedOutputStream;
 import java.io.ByteArrayInputStream;
 import java.io.File;
-import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.io.UnsupportedEncodingException;
+import java.nio.file.Files;
 import java.util.ArrayList;
 import java.util.Enumeration;
 import java.util.HashMap;
@@ -948,28 +947,7 @@ public String getEncoding() {
      * @since JavaMail 1.4
      */
     public void saveFile(File file) throws IOException, MessagingException {
-        OutputStream out = null;
-        InputStream in = null;
-        try {
-            out = new BufferedOutputStream(new FileOutputStream(file));
-            in = this.getInputStream();
-            byte[] buf = new byte[8192];
-            int len;
-            while ((len = in.read(buf)) > 0)
-                out.write(buf, 0, len);
-        } finally {
-            // close streams, but don't mask original exception, if any
-            try {
-                if (in != null)
-                    in.close();
-            } catch (IOException ex) {
-            }
-            try {
-                if (out != null)
-                    out.close();
-            } catch (IOException ex) {
-            }
-        }
+        Files.copy(getInputStream(), file.toPath());
     }
 
     /**

api/src/main/java/jakarta/mail/internet/MimeMessage.java

@@ -1826,7 +1826,7 @@ private Address[] eliminateDuplicates(List<Address> v, Address[] addrs) {
             boolean found = false;
             // search the list for this address
             for (int j = 0; j < v.size(); j++) {
-                if (((InternetAddress) v.get(j)).equals(addrs[i])) {
+                if (v.get(j).equals(addrs[i])) {
                     // found it; count it and remove it from the input array
                     found = true;
                     gone++;

api/src/main/java/jakarta/mail/internet/MimeMultipart.java

@@ -544,7 +544,7 @@ public synchronized void writeTo(OutputStream os)
         } else {
             for (int i = 0; i < parts.size(); i++) {
                 los.writeln(boundary); // put out boundary
-                ((MimeBodyPart) parts.elementAt(i)).writeTo(os);
+                parts.elementAt(i).writeTo(os);
                 los.writeln(); // put out empty line
             }
         }

api/src/main/java/jakarta/mail/internet/MimePartDataSource.java

@@ -136,7 +136,7 @@ public String getContentType() {
     public String getName() {
         try {
             if (part instanceof MimeBodyPart)
-                return ((MimeBodyPart) part).getFileName();
+                return part.getFileName();
         } catch (MessagingException mex) {
             // ignore it
         }

api/src/main/java/jakarta/mail/internet/MimeUtil.java

@@ -46,13 +46,9 @@ class MimeUtil {
                 if (clsHandler == null)
                     clsHandler = Class.forName(cth);
                 meth = clsHandler.getMethod("cleanContentType",
-                        new Class<?>[]{MimePart.class, String.class});
+                        MimePart.class, String.class);
             }
-        } catch (ClassNotFoundException ex) {
-            // ignore it
-        } catch (NoSuchMethodException ex) {
-            // ignore it
-        } catch (RuntimeException ex) {
+        } catch (ClassNotFoundException | RuntimeException | NoSuchMethodException ex) {
             // ignore it
         } finally {
             cleanContentType = meth;