# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements.  See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership.  The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License.  You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied.  See the License for the
# specific language governing permissions and limitations
# under the License.

# Base commit: 787a7a7e972719edf7a79009d768f5111e1d93bc

---
 .../checker/schematronequiv/Assertions.java   | 11 +---
 .../messages/MessageEmitterAdapter.java       | 10 ++--
 src/nu/validator/servlet/Main.java            | 50 +++++-----------
 src/nu/validator/servlet/VerifierServlet.java | 10 ++--
 .../servlet/VerifierServletTransaction.java   | 59 ++++++++++---------
 src/nu/validator/source/LocationRecorder.java |  8 +--
 src/nu/validator/source/SourceCode.java       |  6 +-
 .../validation/SimpleDocumentValidator.java   |  3 -
 .../xml/PrudentHttpEntityResolver.java        | 25 ++++----
 9 files changed, 78 insertions(+), 104 deletions(-)

diff --git a/src/nu/validator/checker/schematronequiv/Assertions.java b/src/nu/validator/checker/schematronequiv/Assertions.java
index 6aba4301..0f2da1af 100644
--- a/src/nu/validator/checker/schematronequiv/Assertions.java
+++ b/src/nu/validator/checker/schematronequiv/Assertions.java
@@ -22,8 +22,6 @@
 
 package nu.validator.checker.schematronequiv;
 
-import java.io.ByteArrayInputStream;
-import java.io.StringReader;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.ArrayList;
 import java.util.HashMap;
@@ -35,6 +33,7 @@ import java.util.Map;
 import java.util.Set;
 import java.util.Arrays;
 import java.util.Collections;
+import java.util.logging.Logger;
 
 import javax.servlet.http.HttpServletRequest;
 
@@ -44,7 +43,6 @@ import nu.validator.checker.LocatorImpl;
 import nu.validator.checker.TaintableLocatorImpl;
 import nu.validator.checker.VnuBadAttrValueException;
 import nu.validator.checker.VnuBadElementNameException;
-import nu.validator.client.TestRunner;
 import nu.validator.datatype.AutocompleteDetailsAny;
 import nu.validator.datatype.AutocompleteDetailsDate;
 import nu.validator.datatype.AutocompleteDetailsEmail;
@@ -61,21 +59,16 @@ import nu.validator.datatype.ImageCandidateStringsWidthRequired;
 import nu.validator.datatype.ImageCandidateStrings;
 import nu.validator.datatype.ImageCandidateURL;
 import nu.validator.htmlparser.impl.NCName;
-import nu.validator.messages.MessageEmitterAdapter;
 
 import org.relaxng.datatype.DatatypeException;
 
 import org.xml.sax.Attributes;
 import org.xml.sax.Locator;
 import org.xml.sax.SAXException;
-import org.xml.sax.SAXParseException;
-
-import org.apache.log4j.Logger;
 
 public class Assertions extends Checker {
 
-    private static final Logger log4j = //
-            Logger.getLogger(Assertions.class);
+    private static final Logger log4j = Logger.getLogger(Assertions.class.getName());
 
     private static boolean equalsIgnoreAsciiCase(String one, String other) {
         if (other == null) {
diff --git a/src/nu/validator/messages/MessageEmitterAdapter.java b/src/nu/validator/messages/MessageEmitterAdapter.java
index 4d143d42..aa7e156c 100644
--- a/src/nu/validator/messages/MessageEmitterAdapter.java
+++ b/src/nu/validator/messages/MessageEmitterAdapter.java
@@ -29,6 +29,7 @@ import java.util.HashSet;
 import java.util.Iterator;
 import java.util.LinkedList;
 import java.util.List;
+import java.util.logging.Logger;
 import java.util.Map;
 import java.util.TreeMap;
 import java.util.regex.Pattern;
@@ -80,13 +81,12 @@ import com.thaiopensource.relaxng.exceptions.UnfinishedElementOneOfException;
 import com.thaiopensource.relaxng.exceptions.UnknownElementException;
 import com.thaiopensource.xml.util.Name;
 
-import org.apache.log4j.Logger;
 import com.ibm.icu.text.Normalizer;
 
 @SuppressWarnings("unchecked")
 public class MessageEmitterAdapter implements ErrorHandler {
 
-    private static final Logger log4j = Logger.getLogger(MessageEmitterAdapter.class);
+    private static final Logger log4j = Logger.getLogger(MessageEmitterAdapter.class.getName());
 
     private final static Map<String, char[]> WELL_KNOWN_NAMESPACES = new HashMap<>();
 
@@ -817,7 +817,7 @@ public class MessageEmitterAdapter implements ErrorHandler {
                 && msg != null
                 && (systemId.startsWith("http:") || systemId.startsWith("https:"))) {
             log4j.info(zapLf(new StringBuilder() //
-                    .append(systemId).append('\t').append(msg)));
+                    .append(systemId).append('\t').append(msg)).toString());
         }
         if (errorsOnly && type.getSuperType() == "info") {
             return;
@@ -1241,7 +1241,7 @@ public class MessageEmitterAdapter implements ErrorHandler {
             if (humanReadable == null) {
                 if (loggingOk) {
                     log4j.info(new StringBuilder().append("UNKNOWN_NS:\t").append(
-                            ns));
+                            ns).toString());
                 }
                 messageTextString(messageTextHandler, ELEMENT, atSentenceStart);
                 linkedCodeString(messageTextHandler, element.getLocalName(),
@@ -1287,7 +1287,7 @@ public class MessageEmitterAdapter implements ErrorHandler {
             if (humanReadable == null) {
                 if (loggingOk) {
                     log4j.info(new StringBuilder().append("UNKNOWN_NS:\t").append(
-                            ns));
+                            ns).toString());
                 }
                 messageTextString(messageTextHandler, ATTRIBUTE,
                         atSentenceStart);
diff --git a/src/nu/validator/servlet/Main.java b/src/nu/validator/servlet/Main.java
index 49c70181..1f154a4d 100644
--- a/src/nu/validator/servlet/Main.java
+++ b/src/nu/validator/servlet/Main.java
@@ -38,13 +38,10 @@ import java.net.Socket;
 import java.net.SocketException;
 import java.util.EnumSet;
 import java.util.Enumeration;
+import java.util.logging.Logger;
 
 import javax.servlet.DispatcherType;
 
-import org.apache.log4j.ConsoleAppender;
-import org.apache.log4j.Logger;
-import org.apache.log4j.PatternLayout;
-import org.apache.log4j.PropertyConfigurator;
 import org.eclipse.jetty.http2.server.HTTP2CServerConnectionFactory;
 import org.eclipse.jetty.server.Connector;
 import org.eclipse.jetty.server.HttpConfiguration;
@@ -88,19 +85,19 @@ public class Main {
     private static final void emitStartupMessage(Logger log4j, String host,
             int port) {
         if (isRunningInsideDockerContainer()) {
-            log4j.debug("");
-            log4j.debug("Checker service started.");
+            log4j.fine("");
+            log4j.fine("Checker service started.");
             return;
         }
         String ip;
-        log4j.debug("");
-        log4j.debug("WARNING: Future checker releases will bind by default to"
+        log4j.fine("");
+        log4j.fine("WARNING: Future checker releases will bind by default to"
                 + " 127.0.0.1.");
-        log4j.debug("Your checker deployment might become unreachable unless"
+        log4j.fine("Your checker deployment might become unreachable unless"
                 + " you use the");
-        log4j.debug("nu.validator.servlet.bind-address system property or"
+        log4j.fine("nu.validator.servlet.bind-address system property or"
                 + " --bind-address");
-        log4j.debug("script option to bind the checker to a different"
+        log4j.fine("script option to bind the checker to a different"
                 + " address:");
         try {
             Enumeration<NetworkInterface> interfaces = //
@@ -114,18 +111,18 @@ public class Main {
                     InetAddress addr = addresses.nextElement();
                     ip = addr.getHostAddress();
                     if (addr instanceof Inet4Address) {
-                        log4j.debug("");
-                        log4j.debug(String.format(
+                        log4j.fine("");
+                        log4j.fine(String.format(
                                 "  python ./checker.py --bind-address %s run",
                                 ip));
-                        log4j.debug(String.format("  java"
+                        log4j.fine(String.format("  java"
                                 + " -Dnu.validator.servlet.bind-address=%s"
                                 + " -cp vnu.jar"
                                 + " nu.validator.servlet.Main 8888", ip));
-                        log4j.debug(String.format("  vnu-runtime-image/bin/java"
+                        log4j.fine(String.format("  vnu-runtime-image/bin/java"
                                 + " -Dnu.validator.servlet.bind-address=%s"
                                 + " nu.validator.servlet.Main 8888", ip));
-                        log4j.debug(String.format(
+                        log4j.fine(String.format(
                                 "  vnu-runtime-image\\bin\\java.exe"
                                         + " -Dnu.validator.servlet.bind-address=%s"
                                         + " nu.validator.servlet.Main 8888",
@@ -136,28 +133,13 @@ public class Main {
         } catch (SocketException e) {
             throw new RuntimeException(e);
         }
-        log4j.debug("");
-        log4j.debug(String.format("Checker service started at http://%s:%s/",
+        log4j.fine("");
+        log4j.fine(String.format("Checker service started at http://%s:%s/",
                 host, port));
     }
 
     public static void main(String[] args) throws Exception {
-        if (!"1".equals(System.getProperty(
-                "nu.validator.servlet.read-local-log4j-properties"))) {
-            PropertyConfigurator.configure(
-                    Main.class.getClassLoader().getResource(
-                            "nu/validator/localentities/files/log4j.properties"));
-        } else {
-            PropertyConfigurator.configure(
-                    System.getProperty("nu.validator.servlet.log4j-properties",
-                            "log4j.properties"));
-        }
-        Logger log4j = Logger.getLogger(Main.class);
-        ConsoleAppender console = new ConsoleAppender();
-        console.setLayout(new PatternLayout("%m%n"));
-        console.activateOptions();
-        log4j.setAdditivity(false);
-        log4j.addAppender(console);
+        Logger log4j = Logger.getLogger(Main.class.getName());
 
         ServletContextHandler contextHandler = new ServletContextHandler();
         contextHandler.setContextPath("/");
diff --git a/src/nu/validator/servlet/VerifierServlet.java b/src/nu/validator/servlet/VerifierServlet.java
index 8da1aaf1..a7fc9247 100644
--- a/src/nu/validator/servlet/VerifierServlet.java
+++ b/src/nu/validator/servlet/VerifierServlet.java
@@ -28,6 +28,7 @@ import java.io.InputStream;
 import java.io.OutputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.UnsupportedEncodingException;
+import java.util.logging.Logger;
 
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServlet;
@@ -37,9 +38,6 @@ import javax.servlet.http.HttpServletResponse;
 import nu.validator.messages.MessageEmitterAdapter;
 import nu.validator.xml.PrudentHttpEntityResolver;
 
-import org.apache.log4j.Logger;
-
-
 /**
  * @version $Id$
  * @author hsivonen
@@ -50,7 +48,7 @@ public class VerifierServlet extends HttpServlet {
      */
     private static final long serialVersionUID = 7811043632732680935L;
 
-    private static final Logger log4j = Logger.getLogger(VerifierServlet.class);
+    private static final Logger log4j = Logger.getLogger(VerifierServlet.class.getName());
 
     static final String GENERIC_HOST = System.getProperty("nu.validator.servlet.host.generic", "");
 
@@ -272,8 +270,8 @@ public class VerifierServlet extends HttpServlet {
             response.sendError(HttpServletResponse.SC_METHOD_NOT_ALLOWED);
             return;
         }
-        log4j.debug("pathInfo: " + pathInfo);
-        log4j.debug("serverName: " + serverName);
+        log4j.fine("pathInfo: " + pathInfo);
+        log4j.fine("serverName: " + serverName);
 
         if ("validator.nu".equals(serverName) && "/html5/".equals(pathInfo)) {
                 response.setStatus(HttpServletResponse.SC_MOVED_PERMANENTLY);
diff --git a/src/nu/validator/servlet/VerifierServletTransaction.java b/src/nu/validator/servlet/VerifierServletTransaction.java
index 358bdc62..6c60ee1c 100644
--- a/src/nu/validator/servlet/VerifierServletTransaction.java
+++ b/src/nu/validator/servlet/VerifierServletTransaction.java
@@ -43,6 +43,8 @@ import java.util.HashSet;
 import java.util.LinkedHashSet;
 import java.util.LinkedList;
 import java.util.List;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 import java.util.Map;
 import java.util.Properties;
 import java.util.Set;
@@ -135,7 +137,6 @@ import com.thaiopensource.validate.prop.wrap.WrapProperty;
 import com.thaiopensource.validate.rng.CompactSchemaReader;
 
 import org.apache.http.conn.ConnectTimeoutException;
-import org.apache.log4j.Logger;
 
 import com.ibm.icu.text.Normalizer;
 
@@ -150,7 +151,7 @@ class VerifierServletTransaction implements DocumentModeHandler, SchemaResolver
         HTML, XHTML, TEXT, XML, JSON, RELAXED, SOAP, UNICORN, GNU
     }
 
-    private static final Logger log4j = Logger.getLogger(VerifierServletTransaction.class);
+    private static final Logger log4j = Logger.getLogger(VerifierServletTransaction.class.getName());
 
     private static final Pattern SPACE = Pattern.compile("\\s+");
 
@@ -418,7 +419,7 @@ class VerifierServletTransaction implements DocumentModeHandler, SchemaResolver
 
     static {
         try {
-            log4j.debug("Starting static initializer.");
+            log4j.fine("Starting static initializer.");
 
             lastModified = 0;
             BufferedReader r = new BufferedReader(new InputStreamReader(LocalCacheEntityResolver.getPresetsAsStream(), "UTF-8"));
@@ -429,7 +430,7 @@ class VerifierServletTransaction implements DocumentModeHandler, SchemaResolver
             List<String> urls = new LinkedList<>();
             Properties props = new Properties();
 
-            log4j.debug("Reading miscellaneous properties.");
+            log4j.fine("Reading miscellaneous properties.");
 
             props.load(VerifierServlet.class.getClassLoader().getResourceAsStream(
                     "nu/validator/localentities/files/misc.properties"));
@@ -448,7 +449,7 @@ class VerifierServletTransaction implements DocumentModeHandler, SchemaResolver
                     props.getProperty("nu.validator.servlet.user-agent",
                             "Validator.nu/LV")));
 
-            log4j.debug("Starting to loop over config file lines.");
+            log4j.fine("Starting to loop over config file lines.");
 
             while ((line = r.readLine()) != null) {
                 if ("".equals(line.trim())) {
@@ -461,14 +462,14 @@ class VerifierServletTransaction implements DocumentModeHandler, SchemaResolver
                 urls.add(s[3]);
             }
 
-            log4j.debug("Finished reading config.");
+            log4j.fine("Finished reading config.");
 
             String[] presetDoctypesAsStrings = doctypes.toArray(new String[0]);
             presetNamespaces = namespaces.toArray(new String[0]);
             presetLabels = labels.toArray(new String[0]);
             presetUrls = urls.toArray(new String[0]);
 
-            log4j.debug("Converted config to arrays.");
+            log4j.fine("Converted config to arrays.");
 
             for (int i = 0; i < presetNamespaces.length; i++) {
                 String str = presetNamespaces[i];
@@ -479,18 +480,18 @@ class VerifierServletTransaction implements DocumentModeHandler, SchemaResolver
                 }
             }
 
-            log4j.debug("Prepared namespace array.");
+            log4j.fine("Prepared namespace array.");
 
             presetDoctypes = new int[presetDoctypesAsStrings.length];
             for (int i = 0; i < presetDoctypesAsStrings.length; i++) {
                 presetDoctypes[i] = Integer.parseInt(presetDoctypesAsStrings[i]);
             }
 
-            log4j.debug("Parsed doctype numbers into ints.");
+            log4j.fine("Parsed doctype numbers into ints.");
 
             String prefix = System.getProperty("nu.validator.servlet.cachepathprefix");
 
-            log4j.debug("The cache path prefix is: " + prefix);
+            log4j.fine("The cache path prefix is: " + prefix);
 
             ErrorHandler eh = new SystemErrErrorHandler();
             LocalCacheEntityResolver er = new LocalCacheEntityResolver(new NullEntityResolver());
@@ -503,7 +504,7 @@ class VerifierServletTransaction implements DocumentModeHandler, SchemaResolver
             RngProperty.CHECK_ID_IDREF.add(pmb);
             PropertyMap pMap = pmb.toPropertyMap();
 
-            log4j.debug("Parsing set up. Starting to read schemas.");
+            log4j.fine("Parsing set up. Starting to read schemas.");
 
             SortedMap<String, Schema> schemaMap = new TreeMap<>();
 
@@ -553,7 +554,7 @@ class VerifierServletTransaction implements DocumentModeHandler, SchemaResolver
                 }
             }
 
-            log4j.debug("Schemas read.");
+            log4j.fine("Schemas read.");
 
             preloadedSchemaUrls = new String[schemaMap.size()];
             preloadedSchemas = new Schema[schemaMap.size()];
@@ -582,14 +583,14 @@ class VerifierServletTransaction implements DocumentModeHandler, SchemaResolver
                 i++;
             }
 
-            log4j.debug("Reading spec.");
+            log4j.fine("Reading spec.");
 
             html5spec = Html5SpecBuilder.parseSpec(LocalCacheEntityResolver.getHtml5SpecAsStream());
 
-            log4j.debug("Spec read.");
+            log4j.fine("Spec read.");
 
             if (new File(FILTER_FILE).isFile()) {
-                log4j.debug("Reading filter file " + FILTER_FILE);
+                log4j.fine("Reading filter file " + FILTER_FILE);
                 try (BufferedReader reader = new BufferedReader(
                         new InputStreamReader(new FileInputStream(FILTER_FILE),
                                 "UTF-8"))) {
@@ -612,7 +613,7 @@ class VerifierServletTransaction implements DocumentModeHandler, SchemaResolver
                         }
                     }
                 }
-                log4j.debug("Filter file read.");
+                log4j.fine("Filter file read.");
             }
         } catch (Exception e) {
             throw new RuntimeException(e);
@@ -719,7 +720,7 @@ class VerifierServletTransaction implements DocumentModeHandler, SchemaResolver
         try {
             request.setCharacterEncoding("utf-8");
         } catch (NoSuchMethodError e) {
-            log4j.debug("Vintage Servlet API doesn't support setCharacterEncoding().", e);
+            log4j.log(Level.FINE, "Vintage Servlet API doesn't support setCharacterEncoding().", e);
         }
 
         if (!methodIsGet) {
@@ -978,7 +979,7 @@ class VerifierServletTransaction implements DocumentModeHandler, SchemaResolver
                 validate();
             }
         } catch (SAXException e) {
-            log4j.debug("SAXException: " + e.getMessage());
+            log4j.fine("SAXException: " + e.getMessage());
         }
     }
 
@@ -1167,11 +1168,11 @@ class VerifierServletTransaction implements DocumentModeHandler, SchemaResolver
             }
         } catch (CannotFindPresetSchemaException e) {
         } catch (ResourceNotRetrievableException e) {
-            log4j.debug(e.getMessage());
+            log4j.fine(e.getMessage());
         } catch (NonXmlContentTypeException e) {
-            log4j.debug(e.getMessage());
+            log4j.fine(e.getMessage());
         } catch (FatalSAXException e) {
-            log4j.debug(e.getMessage());
+            log4j.fine(e.getMessage());
         } catch (SocketTimeoutException e) {
             errorHandler.ioError(new IOException(e.getMessage(), null));
         } catch (ConnectTimeoutException e) {
@@ -1181,28 +1182,28 @@ class VerifierServletTransaction implements DocumentModeHandler, SchemaResolver
         } catch (SAXException e) {
             String msg = e.getMessage();
             if (!cannotRecover.equals(msg) && !changingEncoding.equals(msg)) {
-                log4j.debug("SAXException: " + e.getMessage());
+                log4j.fine("SAXException: " + e.getMessage());
             }
         } catch (IOException e) {
             isHtmlOrXhtml = false;
             if (e.getCause() instanceof org.apache.http.TruncatedChunkException) {
-                log4j.debug("TruncatedChunkException", e.getCause());
+                log4j.log(Level.FINE, "TruncatedChunkException", e.getCause());
             } else {
                 errorHandler.ioError(e);
             }
         } catch (IncorrectSchemaException e) {
-            log4j.debug("IncorrectSchemaException", e);
+            log4j.log(Level.FINE, "IncorrectSchemaException", e);
             errorHandler.schemaError(e);
         } catch (RuntimeException e) {
             isHtmlOrXhtml = false;
-            log4j.error("RuntimeException, doc: " + document + " schema: "
+            log4j.log(Level.SEVERE, "RuntimeException, doc: " + document + " schema: "
                     + schemaUrls + " lax: " + laxType, e);
             errorHandler.internalError(
                     e,
                     "Oops. That was not supposed to happen. A bug manifested itself in the application internals. Unable to continue. Sorry. The admin was notified.");
         } catch (Error e) {
             isHtmlOrXhtml = false;
-            log4j.error("Error, doc: " + document + " schema: " + schemaUrls
+            log4j.log(Level.SEVERE, "Error, doc: " + document + " schema: " + schemaUrls
                     + " lax: " + laxType, e);
             errorHandler.internalError(
                     e,
@@ -1448,7 +1449,7 @@ class VerifierServletTransaction implements DocumentModeHandler, SchemaResolver
                 try {
                     stats.incrementField(stats.getFieldFromName(fieldName));
                 } catch (IllegalArgumentException e) {
-                    log4j.error(e.getMessage(), e);
+                    log4j.log(Level.SEVERE, e.getMessage(), e);
                 }
             }
             String langVal = (String) request.getAttribute(
@@ -1834,13 +1835,13 @@ class VerifierServletTransaction implements DocumentModeHandler, SchemaResolver
     private static Schema schemaByUrl(String url, EntityResolver resolver,
             PropertyMap pMap) throws SAXException, IOException,
             IncorrectSchemaException {
-        log4j.debug("Will load schema: " + url);
+        log4j.fine("Will load schema: " + url);
         TypedInputSource schemaInput;
         try {
         schemaInput = (TypedInputSource) resolver.resolveEntity(
                 null, url);
         } catch (ClassCastException e) {
-            log4j.fatal(url, e);
+            log4j.log(Level.SEVERE, url, e);
             throw e;
         }
         SchemaReader sr = null;
diff --git a/src/nu/validator/source/LocationRecorder.java b/src/nu/validator/source/LocationRecorder.java
index efdeb1fb..a296a656 100644
--- a/src/nu/validator/source/LocationRecorder.java
+++ b/src/nu/validator/source/LocationRecorder.java
@@ -22,7 +22,7 @@
 
 package nu.validator.source;
 
-import org.apache.log4j.Logger;
+import java.util.logging.Logger;
 import org.xml.sax.Attributes;
 import org.xml.sax.ContentHandler;
 import org.xml.sax.Locator;
@@ -30,7 +30,7 @@ import org.xml.sax.SAXException;
 import org.xml.sax.ext.LexicalHandler;
 
 final class LocationRecorder implements ContentHandler, LexicalHandler {
-    private static final Logger log4j = Logger.getLogger(LocationRecorder.class);
+    private static final Logger log4j = Logger.getLogger(LocationRecorder.class.getName());
 
     private final SourceCode owner;
     
@@ -51,7 +51,7 @@ final class LocationRecorder implements ContentHandler, LexicalHandler {
     private void addLocatorLocation() {
         if (locator != null) {
             String systemId = locator.getSystemId();
-            log4j.debug(systemId);
+            log4j.fine(systemId);
             if (uri == systemId || (uri != null && uri.equals(systemId))) {
                 owner.addLocatorLocation(locator.getLineNumber(), locator.getColumnNumber());
             }
@@ -97,7 +97,7 @@ final class LocationRecorder implements ContentHandler, LexicalHandler {
     @Override
     public void setDocumentLocator(Locator locator) {
         this.locator = locator;
-        log4j.debug(locator);
+        log4j.fine(String.valueOf(locator));
     }
 
     @Override
diff --git a/src/nu/validator/source/SourceCode.java b/src/nu/validator/source/SourceCode.java
index b7dcfb43..de50ce9d 100644
--- a/src/nu/validator/source/SourceCode.java
+++ b/src/nu/validator/source/SourceCode.java
@@ -28,20 +28,20 @@ import java.util.Iterator;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.SortedSet;
+import java.util.logging.Logger;
 
 import nu.validator.collections.HeadBiasedSortedSet;
 import nu.validator.collections.TailBiasedSortedSet;
 import nu.validator.htmlparser.common.CharacterHandler;
 import nu.validator.xml.TypedInputSource;
 
-import org.apache.log4j.Logger;
 import org.xml.sax.ContentHandler;
 import org.xml.sax.InputSource;
 import org.xml.sax.Locator;
 import org.xml.sax.SAXException;
 
 public final class SourceCode implements CharacterHandler {
-    private static final Logger log4j = Logger.getLogger(SourceCode.class);
+    private static final Logger log4j = Logger.getLogger(SourceCode.class.getName());
 
     private static Location[] SOURCE_LOCATION_ARRAY_TYPE = new Location[0];
 
@@ -183,7 +183,7 @@ public final class SourceCode implements CharacterHandler {
     }
 
     public void addLocatorLocation(int oneBasedLine, int oneBasedColumn) {
-        log4j.debug(oneBasedLine + ", " + oneBasedColumn);
+        log4j.fine(oneBasedLine + ", " + oneBasedColumn);
         reverseSortedLocations.add(new Location(this, oneBasedLine - 1,
                 oneBasedColumn - 1));
     }
diff --git a/src/nu/validator/validation/SimpleDocumentValidator.java b/src/nu/validator/validation/SimpleDocumentValidator.java
index f9600817..b57404a5 100644
--- a/src/nu/validator/validation/SimpleDocumentValidator.java
+++ b/src/nu/validator/validation/SimpleDocumentValidator.java
@@ -79,8 +79,6 @@ import com.thaiopensource.validate.prop.rng.RngProperty;
 import com.thaiopensource.validate.rng.CompactSchemaReader;
 import com.thaiopensource.xml.sax.Jaxp11XMLReaderCreator;
 
-import org.apache.log4j.PropertyConfigurator;
-
 import java.net.*;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -227,7 +225,6 @@ public class SimpleDocumentValidator {
                             "log4j.logger.nu.validator.xml.PrudentHttpEntityResolver",
                             "FATAL");
                 }
-                PropertyConfigurator.configure(properties);
             } catch (IOException e) {
                 e.printStackTrace();
             }
diff --git a/src/nu/validator/xml/PrudentHttpEntityResolver.java b/src/nu/validator/xml/PrudentHttpEntityResolver.java
index f851bc32..22680402 100644
--- a/src/nu/validator/xml/PrudentHttpEntityResolver.java
+++ b/src/nu/validator/xml/PrudentHttpEntityResolver.java
@@ -31,6 +31,8 @@ import java.security.NoSuchAlgorithmException;
 import java.security.cert.CertificateException;
 import java.security.cert.X509Certificate;
 import java.util.zip.GZIPInputStream;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 
 import javax.net.ssl.HostnameVerifier;
 import javax.net.ssl.SSLContext;
@@ -64,7 +66,6 @@ import org.apache.http.impl.client.HttpClientBuilder;
 import org.apache.http.impl.client.HttpClients;
 import org.apache.http.impl.client.LaxRedirectStrategy;
 import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
-import org.apache.log4j.Logger;
 
 import org.xml.sax.EntityResolver;
 import org.xml.sax.ErrorHandler;
@@ -83,7 +84,7 @@ import io.mola.galimatias.GalimatiasParseException;
 @SuppressWarnings("deprecation") public class PrudentHttpEntityResolver
         implements EntityResolver {
 
-    private static final Logger log4j = Logger.getLogger(PrudentHttpEntityResolver.class);
+    private static final Logger log4j = Logger.getLogger(PrudentHttpEntityResolver.class.getName());
 
     private static HttpClient client;
 
@@ -380,14 +381,15 @@ import io.mola.galimatias.GalimatiasParseException;
 
                         @Override
                         public void closeCalled() {
-                            log4j.debug("closeCalled");
+                            log4j.fine("closeCalled");
                             if (!released) {
-                                log4j.debug("closeCalled, not yet released");
+                                log4j.fine("closeCalled, not yet released");
                                 released = true;
                                 try {
                                     meth.releaseConnection();
                                 } catch (Exception e) {
-                                    log4j.debug(
+                                    log4j.log(
+                                            Level.FINE,
                                             "closeCalled, releaseConnection", e);
                                 }
                             }
@@ -401,12 +403,13 @@ import io.mola.galimatias.GalimatiasParseException;
                                 try {
                                     meth.abort();
                                 } catch (Exception e) {
-                                    log4j.debug("exceptionOccurred, abort", e);
+                                    log4j.log(Level.FINE, "exceptionOccurred, abort", e);
                                 } finally {
                                     try {
                                         meth.releaseConnection();
                                     } catch (Exception e) {
-                                        log4j.debug(
+                                        log4j.log(
+                                                Level.FINE,
                                                 "exceptionOccurred, releaseConnection",
                                                 e);
                                     }
@@ -434,12 +437,12 @@ import io.mola.galimatias.GalimatiasParseException;
                                 try {
                                     meth.abort();
                                 } catch (Exception e) {
-                                    log4j.debug("finalizerCalled, abort", e);
+                                    log4j.log(Level.FINE, "finalizerCalled, abort", e);
                                 } finally {
                                     try {
                                         meth.releaseConnection();
                                     } catch (Exception e) {
-                                        log4j.debug(
+                                        log4j.log(Level.FINE,
                                                 "finalizerCalled, releaseConnection",
                                                 e);
                                     }
@@ -454,12 +457,12 @@ import io.mola.galimatias.GalimatiasParseException;
                 try {
                     m.abort();
                 } catch (Exception ex) {
-                    log4j.debug("abort", ex);
+                    log4j.log(Level.FINE, "abort", ex);
                 } finally {
                     try {
                         m.releaseConnection();
                     } catch (Exception ex) {
-                        log4j.debug("releaseConnection", ex);
+                        log4j.log(Level.FINE, "releaseConnection", ex);
                     }
                 }
             }
-- 
2.37.2