Prefer StringBuilder over StringBuffer

The former is unsynchronized and slightly faster.

src/com/fsck/k9/Account.java

@@ -380,7 +380,7 @@ public class Account implements BaseAccount {
     }
     
     private String combineUuids(String[] uuids) {
-        StringBuffer sb = new StringBuffer();
+        StringBuilder sb = new StringBuilder();
         for (int i = 0, length = uuids.length; i < length; i++) {
             if (sb.length() > 0) {
                 sb.append(',');

src/com/fsck/k9/activity/MessageCompose.java

@@ -727,7 +727,7 @@ public class MessageCompose extends K9Activity implements OnClickListener, OnFoc
     private boolean setRecipients(TextView view, List<String> recipients) {
         boolean recipientAdded = false;
         if (recipients != null) {
-            StringBuffer addressList = new StringBuffer();
+            StringBuilder addressList = new StringBuilder();
             for (String recipient : recipients) {
                 addressList.append(recipient);
                 addressList.append(", ");
@@ -1964,7 +1964,7 @@ public class MessageCompose extends K9Activity implements OnClickListener, OnFoc
                     mInReplyTo = message.getMessageId();
 
                     if (message.getReferences() != null && message.getReferences().length > 0) {
-                        StringBuffer buffy = new StringBuffer();
+                        StringBuilder buffy = new StringBuilder();
                         for (int i = 0; i < message.getReferences().length; i++)
                             buffy.append(message.getReferences()[i]);
 

src/com/fsck/k9/activity/setup/AccountSetupCheckSettings.java

@@ -243,7 +243,7 @@ public class AccountSetupCheckSettings extends K9Activity implements OnClickList
                 }
 
                 mProgressBar.setIndeterminate(false);
-                StringBuffer chainInfo = new StringBuffer(100);
+                StringBuilder chainInfo = new StringBuilder(100);
                 MessageDigest sha1 = null;
                 try {
                     sha1 = MessageDigest.getInstance("SHA-1");
@@ -265,7 +265,7 @@ public class AccountSetupCheckSettings extends K9Activity implements OnClickList
                         if (subjectAlternativeNames != null) {
                             // The list of SubjectAltNames may be very long
                             //TODO: localize this string
-                            StringBuffer altNamesText = new StringBuffer("Subject has " + subjectAlternativeNames.size() + " alternative names\n");
+                            StringBuilder altNamesText = new StringBuilder("Subject has " + subjectAlternativeNames.size() + " alternative names\n");
 
                             // we need these for matching
                             String storeURIHost = (Uri.parse(mAccount.getStoreUri())).getHost();

src/com/fsck/k9/helper/Utility.java

@@ -38,7 +38,7 @@ public class Utility {
 
     public static String readInputStream(InputStream in, String encoding) throws IOException {
         InputStreamReader reader = new InputStreamReader(in, encoding);
-        StringBuffer sb = new StringBuffer();
+        StringBuilder sb = new StringBuilder();
         int count;
         char[] buf = new char[512];
         while ((count = reader.read(buf)) != -1) {

src/com/fsck/k9/mail/Address.java

@@ -179,7 +179,7 @@ public class Address {
         if (addresses == null) {
             return null;
         }
-        StringBuffer sb = new StringBuffer();
+        StringBuilder sb = new StringBuilder();
         for (int i = 0; i < addresses.length; i++) {
             sb.append(addresses[i].toString());
             if (i < addresses.length - 1) {
@@ -201,7 +201,7 @@ public class Address {
         if (addresses == null) {
             return null;
         }
-        StringBuffer sb = new StringBuffer();
+        StringBuilder sb = new StringBuilder();
         for (int i = 0; i < addresses.length; i++) {
             sb.append(addresses[i].toEncodedString());
             if (i < addresses.length - 1) {

src/com/fsck/k9/mail/internet/DecoderUtil.java

@@ -58,7 +58,7 @@ public class DecoderUtil {
         /*
          * Replace _ with =20
          */
-        StringBuffer sb = new StringBuffer();
+        StringBuilder sb = new StringBuilder();
         for (int i = 0; i < encodedWord.length(); i++) {
             char c = encodedWord.charAt(i);
             if (c == '_') {

src/com/fsck/k9/mail/internet/MimeMessage.java

@@ -530,7 +530,7 @@ public class MimeMessage extends Message {
 
         public void epilogue(InputStream is) throws IOException {
             expect(MimeMultipart.class);
-            StringBuffer sb = new StringBuffer();
+            StringBuilder sb = new StringBuilder();
             int b;
             while ((b = is.read()) != -1) {
                 sb.append((char)b);
@@ -540,7 +540,7 @@ public class MimeMessage extends Message {
 
         public void preamble(InputStream is) throws IOException {
             expect(MimeMultipart.class);
-            StringBuffer sb = new StringBuffer();
+            StringBuilder sb = new StringBuilder();
             int b;
             while ((b = is.read()) != -1) {
                 sb.append((char)b);

src/com/fsck/k9/mail/internet/MimeMultipart.java

@@ -37,7 +37,7 @@ public class MimeMultipart extends Multipart {
     }
 
     public String generateBoundary() {
-        StringBuffer sb = new StringBuffer();
+        StringBuilder sb = new StringBuilder();
         sb.append("----");
         for (int i = 0; i < 30; i++) {
             sb.append(Integer.toString((int)(Math.random() * 35), 36));

src/com/fsck/k9/mail/store/ImapResponseParser.java

@@ -281,7 +281,7 @@ public class ImapResponseParser {
     private String parseQuoted() throws IOException {
         expect('"');
 
-        StringBuffer sb = new StringBuffer();
+        StringBuilder sb = new StringBuilder();
         int ch;
         boolean escape = false;
         while ((ch = mIn.read()) != -1) {
@@ -299,7 +299,7 @@ public class ImapResponseParser {
     }
 
     private String readStringUntil(char end) throws IOException {
-        StringBuffer sb = new StringBuffer();
+        StringBuilder sb = new StringBuilder();
         int ch;
         while ((ch = mIn.read()) != -1) {
             if (ch == end) {
@@ -471,7 +471,7 @@ public class ImapResponseParser {
 
         public String getAlertText() {
             if (size() > 1 && equalsIgnoreCase("[ALERT]", get(1))) {
-                StringBuffer sb = new StringBuffer();
+                StringBuilder sb = new StringBuilder();
                 for (int i = 2, count = size(); i < count; i++) {
                     sb.append(get(i).toString());
                     sb.append(' ');

src/com/fsck/k9/mail/store/ImapStore.java

@@ -1417,7 +1417,7 @@ public class ImapStore extends Store {
 //                            String key = (String)keyObj;
 //                            if ("ALERT".equalsIgnoreCase(key))
 //                            {
-//                                StringBuffer sb = new StringBuffer();
+//                                StringBuilder sb = new StringBuilder();
 //                                for (int i = 2, count = response.size(); i < count; i++) {
 //                                    sb.append(response.get(i).toString());
 //                                    sb.append(' ');

src/com/fsck/k9/mail/store/LocalStore.java

@@ -844,7 +844,7 @@ public class LocalStore extends Store implements Serializable {
 
         @Override
         public String toString() {
-            StringBuffer sb = new StringBuffer();
+            StringBuilder sb = new StringBuilder();
             sb.append(command);
             sb.append(": ");
             for (String argument : arguments) {
@@ -1788,7 +1788,7 @@ public class LocalStore extends Store implements Serializable {
                     try {
                         Map<Long, LocalMessage> popMessages = new HashMap<Long, LocalMessage>();
                         List<String> ids = new ArrayList<String>();
-                        StringBuffer questions = new StringBuffer();
+                        StringBuilder questions = new StringBuilder();
 
                         for (int i = 0; i < messages.size(); i++) {
                             if (i != 0) {
@@ -2097,15 +2097,15 @@ public class LocalStore extends Store implements Serializable {
                                 ArrayList<Part> attachments = new ArrayList<Part>();
                                 MimeUtility.collectParts(message, viewables, attachments);
 
-                                StringBuffer sbHtml = new StringBuffer();
+                                StringBuilder sbHtml = new StringBuilder();
-                                StringBuffer sbText = new StringBuffer();
+                                StringBuilder sbText = new StringBuilder();
                                 for (Part viewable : viewables) {
                                     try {
                                         String text = MimeUtility.getTextFromPart(viewable);
 
                                         /*
                                          * Small hack to make sure the string "null" doesn't end up
-                                         * in one of the StringBuffers.
+                                         * in one of the StringBuilders.
                                          */
                                         if (text == null) {
                                             text = "";
@@ -2210,8 +2210,8 @@ public class LocalStore extends Store implements Serializable {
 
                             MimeUtility.collectParts(message, viewables, attachments);
 
-                            StringBuffer sbHtml = new StringBuffer();
+                            StringBuilder sbHtml = new StringBuilder();
-                            StringBuffer sbText = new StringBuffer();
+                            StringBuilder sbText = new StringBuilder();
                             for (int i = 0, count = viewables.size(); i < count; i++) {
                                 Part viewable = viewables.get(i);
                                 try {
@@ -2219,7 +2219,7 @@ public class LocalStore extends Store implements Serializable {
 
                                     /*
                                      * Small hack to make sure the string "null" doesn't end up
-                                     * in one of the StringBuffers.
+                                     * in one of the StringBuilders.
                                      */
                                     if (text == null) {
                                         text = "";

src/com/fsck/k9/mail/store/Pop3Store.java

@@ -825,7 +825,7 @@ public class Pop3Store extends Store {
         }
 
         private String readLine() throws IOException {
-            StringBuffer sb = new StringBuffer();
+            StringBuilder sb = new StringBuilder();
             int d = mIn.read();
             if (d == -1) {
                 throw new IOException("End of stream reached while trying to read line.");

src/com/fsck/k9/mail/store/WebDavStore.java

@@ -398,7 +398,7 @@ public class WebDavStore extends Store {
     }
 
     private String getSpecialFoldersList() {
-        StringBuffer buffer = new StringBuffer(200);
+        StringBuilder buffer = new StringBuilder(200);
         buffer.append("<?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>");
         buffer.append("<propfind xmlns=\"DAV:\">");
         buffer.append("<prop>");
@@ -421,7 +421,7 @@ public class WebDavStore extends Store {
      * WebDAV XML Request body retrieval functions
      */
     private String getFolderListXml() {
-        StringBuffer buffer = new StringBuffer(200);
+        StringBuilder buffer = new StringBuilder(200);
         buffer.append("<?xml version='1.0' ?>");
         buffer.append("<a:searchrequest xmlns:a='DAV:'><a:sql>\r\n");
         buffer.append("SELECT \"DAV:uid\", \"DAV:ishidden\"\r\n");
@@ -432,7 +432,7 @@ public class WebDavStore extends Store {
     }
 
     private String getMessageCountXml(String messageState) {
-        StringBuffer buffer = new StringBuffer(200);
+        StringBuilder buffer = new StringBuilder(200);
         buffer.append("<?xml version='1.0' ?>");
         buffer.append("<a:searchrequest xmlns:a='DAV:'><a:sql>\r\n");
         buffer.append("SELECT \"DAV:visiblecount\"\r\n");
@@ -445,7 +445,7 @@ public class WebDavStore extends Store {
     }
 
     private String getMessageEnvelopeXml(String[] uids) {
-        StringBuffer buffer = new StringBuffer(200);
+        StringBuilder buffer = new StringBuilder(200);
         buffer.append("<?xml version='1.0' ?>");
         buffer.append("<a:searchrequest xmlns:a='DAV:'><a:sql>\r\n");
         buffer.append("SELECT \"DAV:uid\", \"DAV:getcontentlength\",");
@@ -475,7 +475,7 @@ public class WebDavStore extends Store {
     }
 
     private String getMessagesXml() {
-        StringBuffer buffer = new StringBuffer(200);
+        StringBuilder buffer = new StringBuilder(200);
         buffer.append("<?xml version='1.0' ?>");
         buffer.append("<a:searchrequest xmlns:a='DAV:'><a:sql>\r\n");
         buffer.append("SELECT \"DAV:uid\"\r\n");
@@ -486,7 +486,7 @@ public class WebDavStore extends Store {
     }
 
     private String getMessageUrlsXml(String[] uids) {
-        StringBuffer buffer = new StringBuffer(600);
+        StringBuilder buffer = new StringBuilder(600);
         buffer.append("<?xml version='1.0' ?>");
         buffer.append("<a:searchrequest xmlns:a='DAV:'><a:sql>\r\n");
         buffer.append("SELECT \"urn:schemas:httpmail:read\", \"DAV:uid\"\r\n");
@@ -510,7 +510,7 @@ public class WebDavStore extends Store {
             throw new MessagingException("Attempt to get flags on 0 length array for uids");
         }
 
-        StringBuffer buffer = new StringBuffer(200);
+        StringBuilder buffer = new StringBuilder(200);
         buffer.append("<?xml version='1.0' ?>");
         buffer.append("<a:searchrequest xmlns:a='DAV:'><a:sql>\r\n");
         buffer.append("SELECT \"urn:schemas:httpmail:read\", \"DAV:uid\"\r\n");
@@ -529,7 +529,7 @@ public class WebDavStore extends Store {
     }
 
     private String getMarkMessagesReadXml(String[] urls, boolean read) {
-        StringBuffer buffer = new StringBuffer(600);
+        StringBuilder buffer = new StringBuilder(600);
         buffer.append("<?xml version='1.0' ?>\r\n");
         buffer.append("<a:propertyupdate xmlns:a='DAV:' xmlns:b='urn:schemas:httpmail:'>\r\n");
         buffer.append("<a:target>\r\n");
@@ -553,7 +553,7 @@ public class WebDavStore extends Store {
     private String getMoveOrCopyMessagesReadXml(String[] urls, boolean isMove) {
 
         String action = (isMove ? "move" : "copy");
-        StringBuffer buffer = new StringBuffer(600);
+        StringBuilder buffer = new StringBuilder(600);
         buffer.append("<?xml version='1.0' ?>\r\n");
         buffer.append("<a:").append(action).append(" xmlns:a='DAV:' xmlns:b='urn:schemas:httpmail:'>\r\n");
         buffer.append("<a:target>\r\n");
@@ -1488,7 +1488,7 @@ public class WebDavStore extends Store {
 
                     if (entity != null) {
                         InputStream istream = null;
-                        StringBuffer buffer = new StringBuffer();
+                        StringBuilder buffer = new StringBuilder();
                         String tempText = "";
                         String resultText = "";
                         BufferedReader reader;

src/com/fsck/k9/mail/transport/SmtpTransport.java

@@ -429,7 +429,7 @@ public class SmtpTransport extends Transport {
     }
 
     private String readLine() throws IOException {
-        StringBuffer sb = new StringBuffer();
+        StringBuilder sb = new StringBuilder();
         int d;
         while ((d = mIn.read()) != -1) {
             if (((char)d) == '\r') {