String handling clean-ups

* Remove unnecessary empty string for blank lines. * Use the indexed variant of StringBuilder.append() to avoid extra calls to substring(). * Remove unnecessary length() calls when extracting a substring to the end of the string. * Avoid concatenating strings inside StringBuilder.append() calls. * Avoid concatenating strings in loops. * Avoid explicit StringBuilders when concatenation suffices (with no performance impact). * Remove unnecessary explicit .toString() calls. Signed-off-by: Stephen Kitt <[email protected]>
sanen · May 21, 2019 · 8833b6e · 8833b6e
1 parent c827346
commit 8833b6e
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Showing 44 changed files with 238 additions and 261 deletions.
diff --git a/audit/src/main/java/org/apache/karaf/audit/logger/FileEventLogger.java b/audit/src/main/java/org/apache/karaf/audit/logger/FileEventLogger.java
@@ -172,7 +172,7 @@ private void rotate(Path path, long timestamp) {
             String name = fix[0] + "-" + date + fix[1];
             int idx = 0;
             while (sameDate.contains(name)) {
-                name = fix[0] + "-" + date + "-" + Integer.toString(++idx) + fix[1];
+                name = fix[0] + "-" + date + "-" + (++idx) + fix[1];
             }
             paths.add(name);
             Path finalPath = path.resolveSibling(name);

diff --git a/bundle/core/src/main/java/org/apache/karaf/bundle/command/Capabilities.java b/bundle/core/src/main/java/org/apache/karaf/bundle/command/Capabilities.java
@@ -53,7 +53,7 @@ protected Object doExecute(List<Bundle> bundles) throws Exception {
         {
             if (separatorNeeded)
             {
-                System.out.println("");
+                System.out.println();
             }
 
             // Print out any matching generic capabilities.

diff --git a/bundle/core/src/main/java/org/apache/karaf/bundle/command/Classes.java b/bundle/core/src/main/java/org/apache/karaf/bundle/command/Classes.java
@@ -61,10 +61,10 @@ protected void executeOnBundle(Bundle bundle) throws Exception {
                     stringBuilder.append(SimpleAnsi.INTENSITY_BOLD);
                 }
                 if(ids == null || ids.size() != 1) {
-                    stringBuilder.append(bundle.getBundleId() + " | ");
+                    stringBuilder.append(bundle.getBundleId()).append(" | ");
                 }
-                stringBuilder.append(resource + " | ");
-                stringBuilder.append("exported: " + isExported(resource, exports));
+                stringBuilder.append(resource).append(" | ");
+                stringBuilder.append("exported: ").append(isExported(resource, exports));
                 if(localResource) {
                     stringBuilder.append(SimpleAnsi.INTENSITY_NORMAL);
                 }

diff --git a/bundle/core/src/main/java/org/apache/karaf/bundle/command/List.java b/bundle/core/src/main/java/org/apache/karaf/bundle/command/List.java
@@ -185,7 +185,10 @@ private String printHosts(BundleInfo info) {
         builder.append(", Hosts: ");
         boolean first = true;
         for (Bundle host : info.getFragmentHosts()) {
-            builder.append((first ? "" : ", ") + host.getBundleId());
+            if (!first) {
+                builder.append(", ");
+            }
+            builder.append(host.getBundleId());
             first = false;
         }
         return builder.toString();
@@ -199,7 +202,10 @@ private String printFragments(BundleInfo info) {
         builder.append(", Fragments: ");
         boolean first = true;
         for (Bundle host : info.getFragments()) {
-            builder.append((first ? "" : ", ") + host.getBundleId());
+            if (!first) {
+                builder.append(", ");
+            }
+            builder.append(host.getBundleId());
             first = false;
         }
         return builder.toString();

diff --git a/bundle/core/src/main/java/org/apache/karaf/bundle/command/Requirements.java b/bundle/core/src/main/java/org/apache/karaf/bundle/command/Requirements.java
@@ -56,7 +56,7 @@ protected Object doExecute(List<Bundle> bundles) throws Exception {
         Pattern ns = Pattern.compile(namespace.replaceAll("\\.", "\\\\.").replaceAll("\\*", ".*"));
         for (Bundle b : bundles) {
             if (separatorNeeded) {
-                System.out.println("");
+                System.out.println();
             }
 
             // Print out any matching generic requirements.

diff --git a/bundle/core/src/main/java/org/apache/karaf/bundle/command/Services.java b/bundle/core/src/main/java/org/apache/karaf/bundle/command/Services.java
@@ -68,7 +68,7 @@ private void printServices(Bundle bundle, ServiceReference<?>[] refs, boolean sh
             // Print header if we have not already done so.
             if (!headerPrinted) {
                 headerPrinted = true;
-                System.out.println("");
+                System.out.println();
                 String title = ShellUtil.getBundleName(bundle) + ((inUse) ? " uses:" : " provides:");
                 System.out.println(title);
                 System.out.println(ShellUtil.getUnderlineString(title));

diff --git a/bundle/core/src/main/java/org/apache/karaf/bundle/core/internal/BundleInfoImpl.java b/bundle/core/src/main/java/org/apache/karaf/bundle/core/internal/BundleInfoImpl.java
@@ -86,15 +86,15 @@ private void populateFragementInfos(Bundle bundle) {
     }
 
     private String populateRevisions(Bundle bundle) {
-        String ret = "";
         BundleRevisions revisions = bundle.adapt(BundleRevisions.class);
         if (revisions == null) {
-            return ret;
+            return "";
         }
+        StringBuilder ret = new StringBuilder();
         for (BundleRevision revision : revisions.getRevisions()) {
-            ret = ret + "[" + revision + "]" + " ";
+            ret.append("[").append(revision).append("]").append(" ");
         }
-        return ret;
+        return ret.toString();
     }
 
     private void getFragments(BundleRevision revision) {

diff --git a/...tic/boot/src/main/java/org/apache/karaf/diagnostic/core/providers/ThreadDumpProvider.java b/...tic/boot/src/main/java/org/apache/karaf/diagnostic/core/providers/ThreadDumpProvider.java
@@ -49,13 +49,15 @@ protected void writeDump(OutputStreamWriter outputStream) throws Exception {
     }
 
     protected String getDumpThreadString(ThreadInfo threadInfo) {
-        StringBuilder sb = new StringBuilder("\"" + threadInfo.getThreadName() + "\"" + " Id=" + threadInfo.getThreadId() + " "
-                                             + threadInfo.getThreadState());
+        StringBuilder sb = new StringBuilder();
+        sb.append("\"").append(threadInfo.getThreadName()).append("\"").append(" Id=").append(
+            threadInfo.getThreadId()).append(" ").append(threadInfo.getThreadState());
         if (threadInfo.getLockName() != null) {
-            sb.append(" on " + threadInfo.getLockName());
+            sb.append(" on ").append(threadInfo.getLockName());
         }
         if (threadInfo.getLockOwnerName() != null) {
-            sb.append(" owned by \"" + threadInfo.getLockOwnerName() + "\" Id=" + threadInfo.getLockOwnerId());
+            sb.append(" owned by \"").append(threadInfo.getLockOwnerName()).append("\" Id=").append(
+                threadInfo.getLockOwnerId());
         }
         if (threadInfo.isSuspended()) {
             sb.append(" (suspended)");
@@ -68,21 +70,21 @@ protected String getDumpThreadString(ThreadInfo threadInfo) {
         StackTraceElement[] stackTrace = threadInfo.getStackTrace();
         for (; i < stackTrace.length; i++) {
             StackTraceElement ste = stackTrace[i];
-            sb.append("\tat " + ste.toString());
+            sb.append("\tat ").append(ste.toString());
             sb.append('\n');
             if (i == 0 && threadInfo.getLockInfo() != null) {
                 Thread.State ts = threadInfo.getThreadState();
                 switch (ts) {
                 case BLOCKED:
-                    sb.append("\t-  blocked on " + threadInfo.getLockInfo());
+                    sb.append("\t-  blocked on ").append(threadInfo.getLockInfo());
                     sb.append('\n');
                     break;
                 case WAITING:
-                    sb.append("\t-  waiting on " + threadInfo.getLockInfo());
+                    sb.append("\t-  waiting on ").append(threadInfo.getLockInfo());
                     sb.append('\n');
                     break;
                 case TIMED_WAITING:
-                    sb.append("\t-  waiting on " + threadInfo.getLockInfo());
+                    sb.append("\t-  waiting on ").append(threadInfo.getLockInfo());
                     sb.append('\n');
                     break;
                 default:
@@ -91,7 +93,7 @@ protected String getDumpThreadString(ThreadInfo threadInfo) {
 
             for (MonitorInfo mi : threadInfo.getLockedMonitors()) {
                 if (mi.getLockedStackDepth() == i) {
-                    sb.append("\t-  locked " + mi);
+                    sb.append("\t-  locked ").append(mi);
                     sb.append('\n');
                 }
             }
@@ -103,10 +105,10 @@ protected String getDumpThreadString(ThreadInfo threadInfo) {
 
         LockInfo[] locks = threadInfo.getLockedSynchronizers();
         if (locks.length > 0) {
-            sb.append("\n\tNumber of locked synchronizers = " + locks.length);
+            sb.append("\n\tNumber of locked synchronizers = ").append(locks.length);
             sb.append('\n');
             for (LockInfo li : locks) {
-                sb.append("\t- " + li);
+                sb.append("\t- ").append(li);
                 sb.append('\n');
             }
         }

diff --git a/event/src/main/java/org/apache/karaf/event/command/EventSendCommand.java b/event/src/main/java/org/apache/karaf/event/command/EventSendCommand.java
@@ -59,7 +59,7 @@ static Map<String, String> parse(List<String> propList) {
                     throw new IllegalArgumentException("Invalid property " + keyValue);
                 } else {
                     String key = keyValue.substring(0, splitAt);
-                    String value = keyValue.substring(splitAt + 1, keyValue.length());
+                    String value = keyValue.substring(splitAt + 1);
                     properties.put(key, value);
                 }
             }

diff --git a/features/command/src/main/java/org/apache/karaf/features/command/InfoFeatureCommand.java b/features/command/src/main/java/org/apache/karaf/features/command/InfoFeatureCommand.java
@@ -210,7 +210,7 @@ private void displayBundleInformation(Feature feature, String contentType) {
                     sb.append(" start-level=").append(startLevel);
                 }
                 if (featureBundle.isOverriden() != BundleInfo.BundleOverrideMode.NONE) {
-                    sb.append(" (overriden from " + featureBundle.getOriginalLocation() + ")");
+                    sb.append(" (overriden from ").append(featureBundle.getOriginalLocation()).append(")");
                 }
                 System.out.println(sb.toString());
             }

diff --git a/features/core/src/main/java/org/apache/karaf/features/internal/model/Feature.java b/features/core/src/main/java/org/apache/karaf/features/internal/model/Feature.java
@@ -133,7 +133,7 @@ public static org.apache.karaf.features.Feature valueOf(String str) {
         int idx = str.indexOf(VERSION_SEPARATOR);
         if (idx >= 0) {
             String strName = str.substring(0, idx);
-            String strVersion = str.substring(idx + 1, str.length());
+            String strVersion = str.substring(idx + 1);
             return new Feature(strName, strVersion);
         } else {
             return new Feature(str);

diff --git a/http/src/main/java/org/apache/karaf/http/core/internal/ServletServiceImpl.java b/http/src/main/java/org/apache/karaf/http/core/internal/ServletServiceImpl.java
@@ -44,12 +44,11 @@ public List<ServletInfo> getServlets() {
             String servletClassName = " ";
             if (servlet != null) {
                     servletClassName = servlet.getClass().getName();
-                    servletClassName = servletClassName.substring(servletClassName.lastIndexOf(".") + 1,
-                                                                          servletClassName.length());
+                    servletClassName = servletClassName.substring(servletClassName.lastIndexOf(".") + 1);
             }
             String servletName = event.getServletName() != null ? event.getServletName() : " ";
             if (servletName.contains(".")) {
-                servletName = servletName.substring(servletName.lastIndexOf(".") + 1, servletName.length());
+                servletName = servletName.substring(servletName.lastIndexOf(".") + 1);
             }
 
             String alias = event.getAlias();

diff --git a/...modules/src/main/java/org/apache/karaf/jaas/modules/properties/AutoEncryptionSupport.java b/...modules/src/main/java/org/apache/karaf/jaas/modules/properties/AutoEncryptionSupport.java
@@ -108,33 +108,24 @@ void encryptedPassword(Properties users) throws IOException {
         boolean changed = false;
         for (String userName : users.keySet()) {
             String user = userName;
-            String userInfos = users.get(user);
 
             if (user.startsWith(PropertiesBackingEngine.GROUP_PREFIX)) {
                 continue;
             }
 
             // the password is in the first position
-            String[] infos = userInfos.split(",");
+            String[] infos = users.get(user).split(",");
             String storedPassword = infos[0];
 
             // check if the stored password is flagged as encrypted
             String encryptedPassword = encryptionSupport.encrypt(storedPassword);
             if (!storedPassword.equals(encryptedPassword)) {
                 LOGGER.debug("The password isn't flagged as encrypted, encrypt it.");
-                userInfos = encryptedPassword + ",";
-                for (int i = 1; i < infos.length; i++) {
-                    if (i == (infos.length - 1)) {
-                        userInfos = userInfos + infos[i];
-                    } else {
-                        userInfos = userInfos + infos[i] + ",";
-                    }
-                }
                 if (user.contains("\\")) {
                     users.remove(user);
                     user = user.replace("\\", "\\\\");
                 }
-                users.put(user, userInfos);
+                users.put(user, encryptedPassword + "," + String.join(",", infos));
                 changed = true;
             }
         }

diff --git a/management/server/src/main/java/org/apache/karaf/management/KarafMBeanServerGuard.java b/management/server/src/main/java/org/apache/karaf/management/KarafMBeanServerGuard.java
@@ -373,23 +373,23 @@ void handleInvoke(BulkRequestContext context, ObjectName objectName, String oper
 
     private void printDetailedMessage(BulkRequestContext context, ObjectName objectName,
                                       String operationName, Object[] params, String[] signature) throws IOException {
-        String expectedRoles = "";
+        StringBuilder expectedRoles = new StringBuilder();
         for (String role : getRequiredRoles(context, objectName, operationName, params, signature)) {
             if (expectedRoles.length() != 0) {
-                expectedRoles = expectedRoles + ", " + role;
+                expectedRoles.append(", ").append(role);
             } else {
-                expectedRoles = role;
+                expectedRoles = new StringBuilder(role);
             }
         }
-        String currentRoles = "";
+        StringBuilder currentRoles = new StringBuilder();
         for (Principal p : context.getPrincipals()) {
             if (!p.getClass().getName().endsWith("RolePrincipal")) {
                 continue;
             }
             if (currentRoles.length() != 0) {
-                currentRoles = currentRoles + ", " + p.getName();
+                currentRoles.append(", ").append(p.getName());
             } else {
-                currentRoles = p.getName();
+                currentRoles = new StringBuilder(p.getName());
             }
         }
         String matchedPid = null;

diff --git a/maven/core/src/main/java/org/apache/karaf/maven/core/MavenRepositoryURL.java b/maven/core/src/main/java/org/apache/karaf/maven/core/MavenRepositoryURL.java
@@ -391,11 +391,9 @@ public boolean isFileRepository()
     @Override
     public String toString()
     {
-        return new StringBuilder()
-            .append( m_repositoryURL.toString() )
-            .append( ",releases=" ).append( m_releasesEnabled )
-            .append( ",snapshots=" ).append( m_snapshotsEnabled )
-            .toString();
+        return m_repositoryURL.toString()
+            + ",releases=" + m_releasesEnabled
+            + ",snapshots=" + m_snapshotsEnabled;
     }
 
     public String asRepositorySpec() {

diff --git a/obr/src/main/java/org/apache/karaf/obr/command/FindCommand.java b/obr/src/main/java/org/apache/karaf/obr/command/FindCommand.java
@@ -48,7 +48,7 @@ protected void doExecute(RepositoryAdmin admin) throws Exception {
             {
                 if (resIdx > 0)
                 {
-                    System.out.println("");
+                    System.out.println();
                 }
                 printResource(System.out, resources[resIdx]);
             }

diff --git a/obr/src/main/java/org/apache/karaf/obr/command/InfoCommand.java b/obr/src/main/java/org/apache/karaf/obr/command/InfoCommand.java
@@ -51,7 +51,7 @@ protected void doExecute(RepositoryAdmin admin) throws Exception {
                 {
                     if (resIdx > 0)
                     {
-                        System.out.println("");
+                        System.out.println();
                     }
                     printResource(System.out, resources[resIdx]);
                 }

diff --git a/obr/src/main/java/org/apache/karaf/obr/command/ObrCommandSupport.java b/obr/src/main/java/org/apache/karaf/obr/command/ObrCommandSupport.java
@@ -119,7 +119,7 @@ protected void printUnderline(PrintStream out, int length) {
         for (int i = 0; i < length; i++) {
             out.print('-');
         }
-        out.println("");
+        out.println();
     }
 
     protected void doDeploy(RepositoryAdmin admin, List<String> bundles, boolean start, boolean deployOptional) throws Exception {

diff --git a/package/src/main/java/org/apache/karaf/packages/command/Exports.java b/package/src/main/java/org/apache/karaf/packages/command/Exports.java
@@ -124,7 +124,7 @@ private void checkDuplicateExports() {
     private String getBundlesSt(Set<Bundle> bundles) {
         StringBuilder st = new StringBuilder();
         for (Bundle bundle : bundles) {
-            st.append(bundle.getBundleId() + " ");
+            st.append(bundle.getBundleId()).append(" ");
         }
         return st.toString();
     }

diff --git a/services/coordinator/src/main/java/org/eclipse/osgi/util/NLS.java b/services/coordinator/src/main/java/org/eclipse/osgi/util/NLS.java
@@ -107,7 +107,7 @@ public static String bind(String message, Object[] bindings) {
                         break;
                     }
                     // otherwise write out the chars inside the quotes
-                    buffer.append(message.substring(nextIndex, index));
+                    buffer.append(message, nextIndex, index);
                     i = index;
                     break;
                 default :

diff --git a/shell/commands/src/main/java/org/apache/karaf/shell/commands/impl/ThreadsAction.java b/shell/commands/src/main/java/org/apache/karaf/shell/commands/impl/ThreadsAction.java
@@ -280,7 +280,7 @@ private void printThread(String indent) {
             StringBuilder sb = new StringBuilder("\"" + info.getThreadName() + "\"" + " Id="
                     + info.getThreadId() + " in " + info.getThreadState());
             if (info.getLockName() != null) {
-                sb.append(" on lock=" + info.getLockName());
+                sb.append(" on lock=").append(info.getLockName());
             }
             if (info.isSuspended()) {
                 sb.append(" (suspended)");

diff --git a/...l/console/src/main/java/org/apache/felix/gogo/commands/basic/DefaultActionPreparator.java b/...l/console/src/main/java/org/apache/felix/gogo/commands/basic/DefaultActionPreparator.java
@@ -436,9 +436,9 @@ protected void printUsage(CommandSession session, Action action, Map<Option, Fie
             if (options.size() > 0) {
                 out.println(INTENSITY_BOLD + "OPTIONS" + INTENSITY_NORMAL);
                 for (Option option : options) {
-                    String opt = option.name();
+                    StringBuilder opt = new StringBuilder(option.name());
                     for (String alias : option.aliases()) {
-                        opt += ", " + alias;
+                        opt.append(", ").append(alias);
                     }
                     out.print("        ");
                     out.println(INTENSITY_BOLD + opt + INTENSITY_NORMAL);

diff --git a/shell/console/src/main/java/org/apache/karaf/shell/commands/meta/ActionMetaData.java b/shell/console/src/main/java/org/apache/karaf/shell/commands/meta/ActionMetaData.java
@@ -160,9 +160,9 @@ public void printUsage(Action action, PrintStream out, boolean globalScope, int
             if (options.size() > 0) {
                 out.println(INTENSITY_BOLD + "OPTIONS" + INTENSITY_NORMAL);
                 for (Option option : optionsSet) {
-                    String opt = option.name();
+                    StringBuilder opt = new StringBuilder(option.name());
                     for (String alias : option.aliases()) {
-                        opt += ", " + alias;
+                        opt.append(", ").append(alias);
                     }
                     out.print("        ");
                     out.println(INTENSITY_BOLD + opt + INTENSITY_NORMAL);

diff --git a/...e/src/main/java/org/apache/karaf/shell/security/impl/SecuredCommandConfigTransformer.java b/...e/src/main/java/org/apache/karaf/shell/security/impl/SecuredCommandConfigTransformer.java
@@ -130,10 +130,8 @@ private String convertArgs(String commandACLArgs) {
         if (!commandACLArgs.endsWith("/]")) {
             throw new IllegalStateException("Badly formatted argument match: " + commandACLArgs + " Should end with '/]'");
         }
-        StringBuilder sb = new StringBuilder();
-        sb.append("[/.*/,"); // add a wildcard argument since the Function execute method has the arguments as second arg
-        sb.append(commandACLArgs.substring(1));
-        return sb.toString();
+        return "[/.*/," // add a wildcard argument since the Function execute method has the arguments as second arg
+            + commandACLArgs.substring(1);
     }
 
     void deleteServiceGuardConfig(String originatingPid, String scope) throws IOException, InvalidSyntaxException {

diff --git a/shell/console/src/main/java/org/apache/karaf/shell/util/ShellUtil.java b/shell/console/src/main/java/org/apache/karaf/shell/util/ShellUtil.java
@@ -50,8 +50,8 @@ public static String getBundleName(Bundle bundle) {
         if (bundle != null) {
             String name = bundle.getHeaders().get(Constants.BUNDLE_NAME);
             return (name == null)
-                    ? "Bundle " + Long.toString(bundle.getBundleId())
-                    : name + " (" + Long.toString(bundle.getBundleId()) + ")";
+                    ? "Bundle " + bundle.getBundleId()
+                    : name + " (" + bundle.getBundleId() + ")";
         }
         return "[STALE BUNDLE]";
     }