Replace StringUtil.toHtml with StringEscapeUtils.escapeHtml

Apache commons is providing Html-escaping, no need to reinvent the wheel:

> It supports all known HTML 4.0 entities, including funky accents. Note that the
> commonly used apostrophe escape character (') is not a legal entity and so
> is not supported).

So I manually checked that nothing is relying on escaped single-quotes,
and didn't manage to find anything that does.

airsonic-main/src/main/java/org/airsonic/player/ajax/CoverArtService.java

@@ -25,8 +25,8 @@ import org.airsonic.player.service.LastFmService;
 import org.airsonic.player.service.MediaFileService;
 import org.airsonic.player.service.SecurityService;
 import org.airsonic.player.util.FileUtil;
-import org.airsonic.player.util.StringUtil;
 import org.apache.commons.io.IOUtils;
+import org.apache.commons.lang.StringEscapeUtils;
 import org.apache.http.client.config.RequestConfig;
 import org.apache.http.client.methods.CloseableHttpResponse;
 import org.apache.http.client.methods.HttpGet;
@@ -109,7 +109,7 @@ public class CoverArtService {
                 // Check permissions.
                 File newCoverFile = new File(path, "cover." + suffix);
                 if (!securityService.isWriteAllowed(newCoverFile)) {
-                    throw new Exception("Permission denied: " + StringUtil.toHtml(newCoverFile.getPath()));
+                    throw new Exception("Permission denied: " + StringEscapeUtils.escapeHtml(newCoverFile.getPath()));
                 }
 
                 // If file exists, create a backup.

airsonic-main/src/main/java/org/airsonic/player/ajax/NowPlayingService.java

@@ -22,6 +22,7 @@ package org.airsonic.player.ajax;
 import org.airsonic.player.domain.*;
 import org.airsonic.player.service.*;
 import org.airsonic.player.util.StringUtil;
+import org.apache.commons.lang.StringEscapeUtils;
 import org.apache.commons.lang.StringUtils;
 import org.directwebremoting.WebContext;
 import org.directwebremoting.WebContextFactory;
@@ -129,14 +130,14 @@ public class NowPlayingService {
                 avatarUrl = url + "avatar.view?usernameUtf8Hex=" + StringUtil.utf8HexEncode(username);
             }
 
-            String tooltip = StringUtil.toHtml(artist) + " – " + StringUtil.toHtml(title);
+            String tooltip = StringEscapeUtils.escapeHtml(artist) + " – " + StringEscapeUtils.escapeHtml(title);
 
             if (StringUtils.isNotBlank(player.getName())) {
                 username += "@" + player.getName();
             }
-            artist = StringUtil.toHtml(StringUtils.abbreviate(artist, 25));
-            title = StringUtil.toHtml(StringUtils.abbreviate(title, 25));
-            username = StringUtil.toHtml(StringUtils.abbreviate(username, 25));
+            artist = StringEscapeUtils.escapeHtml(StringUtils.abbreviate(artist, 25));
+            title = StringEscapeUtils.escapeHtml(StringUtils.abbreviate(title, 25));
+            username = StringEscapeUtils.escapeHtml(StringUtils.abbreviate(username, 25));
 
             long minutesAgo = status.getMinutesAgo();
 

airsonic-main/src/main/java/org/airsonic/player/controller/SetMusicFileInfoController.java

@@ -21,7 +21,7 @@ package org.airsonic.player.controller;
 
 import org.airsonic.player.domain.MediaFile;
 import org.airsonic.player.service.MediaFileService;
-import org.airsonic.player.util.StringUtil;
+import org.apache.commons.lang.StringEscapeUtils;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Controller;
 import org.springframework.web.bind.ServletRequestUtils;
@@ -52,7 +52,7 @@ public class SetMusicFileInfoController {
         MediaFile mediaFile = mediaFileService.getMediaFile(id);
 
         if ("comment".equals(action)) {
-            mediaFile.setComment(StringUtil.toHtml(request.getParameter("comment")));
+            mediaFile.setComment(StringEscapeUtils.escapeHtml(request.getParameter("comment")));
             mediaFileService.updateMediaFile(mediaFile);
         }
 

airsonic-main/src/main/java/org/airsonic/player/controller/UploadController.java

@@ -28,10 +28,10 @@ import org.airsonic.player.service.StatusService;
 import org.airsonic.player.upload.MonitoredDiskFileItemFactory;
 import org.airsonic.player.upload.UploadListener;
 import org.airsonic.player.util.FileUtil;
-import org.airsonic.player.util.StringUtil;
 import org.apache.commons.fileupload.FileItem;
 import org.apache.commons.fileupload.FileItemFactory;
 import org.apache.commons.fileupload.servlet.ServletFileUpload;
+import org.apache.commons.lang.StringEscapeUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -127,7 +127,7 @@ public class UploadController {
                         File targetFile = new File(dir, new File(fileName).getName());
 
                         if (!securityService.isUploadAllowed(targetFile)) {
-                            throw new Exception("Permission denied: " + StringUtil.toHtml(targetFile.getPath()));
+                            throw new Exception("Permission denied: " + StringEscapeUtils.escapeHtml(targetFile.getPath()));
                         }
 
                         if (!dir.exists()) {
@@ -174,13 +174,13 @@ public class UploadController {
                 ZipEntry entry = (ZipEntry) entries.nextElement();
                 File entryFile = new File(file.getParentFile(), entry.getName());
                 if (!entryFile.toPath().normalize().startsWith(file.getParentFile().toPath())) {
-                    throw new Exception("Bad zip filename: " + StringUtil.toHtml(entryFile.getPath()));
+                    throw new Exception("Bad zip filename: " + StringEscapeUtils.escapeHtml(entryFile.getPath()));
                 }
 
                 if (!entry.isDirectory()) {
 
                     if (!securityService.isUploadAllowed(entryFile)) {
-                        throw new Exception("Permission denied: " + StringUtil.toHtml(entryFile.getPath()));
+                        throw new Exception("Permission denied: " + StringEscapeUtils.escapeHtml(entryFile.getPath()));
                     }
 
                     entryFile.getParentFile().mkdirs();

airsonic-main/src/main/java/org/airsonic/player/util/StringUtil.java

@@ -20,6 +20,7 @@
 package org.airsonic.player.util;
 
 import org.apache.commons.codec.binary.Hex;
+import org.apache.commons.lang.StringEscapeUtils;
 import org.apache.commons.lang.StringUtils;
 
 import java.io.*;
@@ -43,14 +44,6 @@ public final class StringUtil {
 
     public static final String ENCODING_UTF8 = "UTF-8";
 
-    private static final String[][] HTML_SUBSTITUTIONS = {
-            {"&", "&"},
-            {"<", "&lt;"},
-            {">", "&gt;"},
-            {"'", "&#39;"},
-            {"\"", "&#34;"},
-    };
-
     private static final String[][] MIME_TYPES = {
             {"mp3", "audio/mpeg"},
             {"ogg", "audio/ogg"},
@@ -97,40 +90,6 @@ public final class StringUtil {
     private StringUtil() {
     }
 
-    /**
-     * Returns the specified string converted to a format suitable for
-     * HTML. All single-quote, double-quote, greater-than, less-than and
-     * ampersand characters are replaces with their corresponding HTML
-     * Character Entity code.
-     *
-     * @param s the string to convert
-     * @return the converted string
-     */
-    public static String toHtml(String s) {
-        if (s == null) {
-            return null;
-        }
-        for (String[] substitution : HTML_SUBSTITUTIONS) {
-            if (s.contains(substitution[0])) {
-                s = s.replaceAll(substitution[0], substitution[1]);
-            }
-        }
-        return s;
-    }
-
-
-    /**
-     * Removes the suffix (the substring after the last dot) of the given string. The dot is
-     * also removed.
-     *
-     * @param s The string in question, e.g., "foo.mp3".
-     * @return The string without the suffix, e.g., "foo".
-     */
-    public static String removeSuffix(String s) {
-        int index = s.lastIndexOf('.');
-        return index == -1 ? s : s.substring(0, index);
-    }
-
     /**
      * Returns the proper MIME type for the given suffix.
      *

airsonic-main/src/test/java/org/airsonic/player/util/StringUtilTestCase.java

@@ -20,6 +20,7 @@
 package org.airsonic.player.util;
 
 import junit.framework.TestCase;
+import org.apache.commons.lang.StringEscapeUtils;
 
 import java.util.Arrays;
 import java.util.Locale;
@@ -32,20 +33,11 @@ import java.util.Locale;
 public class StringUtilTestCase extends TestCase {
 
     public void testToHtml() {
-        assertEquals(null, StringUtil.toHtml(null));
-        assertEquals("", StringUtil.toHtml(""));
-        assertEquals(" ", StringUtil.toHtml(" "));
-        assertEquals("q & a", StringUtil.toHtml("q & a"));
-        assertEquals("q &amp; a &lt;&gt; b", StringUtil.toHtml("q & a <> b"));
-    }
-
-    public void testRemoveSuffix() {
-        assertEquals("Error in removeSuffix().", "foo", StringUtil.removeSuffix("foo.mp3"));
-        assertEquals("Error in removeSuffix().", "", StringUtil.removeSuffix(".mp3"));
-        assertEquals("Error in removeSuffix().", "foo.bar", StringUtil.removeSuffix("foo.bar.mp3"));
-        assertEquals("Error in removeSuffix().", "foo.", StringUtil.removeSuffix("foo..mp3"));
-        assertEquals("Error in removeSuffix().", "foo", StringUtil.removeSuffix("foo"));
-        assertEquals("Error in removeSuffix().", "", StringUtil.removeSuffix(""));
+        assertEquals(null, StringEscapeUtils.escapeHtml(null));
+        assertEquals("", StringEscapeUtils.escapeHtml(""));
+        assertEquals(" ", StringEscapeUtils.escapeHtml(" "));
+        assertEquals("q &amp; a", StringEscapeUtils.escapeHtml("q & a"));
+        assertEquals("q &amp; a &lt;&gt; b", StringEscapeUtils.escapeHtml("q & a <> b"));
     }
 
     public void testGetMimeType() {