diff --git a/src/share/classes/com/sun/tools/hat/internal/server/AllClassesQuery.java b/src/share/classes/com/sun/tools/hat/internal/server/AllClassesQuery.java
index d44a8fc2ecf78f5d39f0fea7d01bd5ed9dec07d7..bdf01b8d5c6748ba92aba14fb3669123fa15d79d 100644
--- a/src/share/classes/com/sun/tools/hat/internal/server/AllClassesQuery.java
+++ b/src/share/classes/com/sun/tools/hat/internal/server/AllClassesQuery.java
@@ -84,7 +84,7 @@ class AllClassesQuery extends QueryHandler {
             lastPackage = pkg;
             printClass(clazz);
             if (clazz.getId() != -1) {
-                out.print(" [" + clazz.getIdString() + "]");
+                print(" [" + clazz.getIdString() + "]");
             }
             out.println("<br>");
         }
diff --git a/src/share/classes/com/sun/tools/hat/internal/server/ClassQuery.java b/src/share/classes/com/sun/tools/hat/internal/server/ClassQuery.java
index 1d5782390ceb430195567af3f781360d92dc6e92..f13572a22cc625e99b97ce8024c1e333ea37484c 100644
--- a/src/share/classes/com/sun/tools/hat/internal/server/ClassQuery.java
+++ b/src/share/classes/com/sun/tools/hat/internal/server/ClassQuery.java
@@ -112,12 +112,12 @@ class ClassQuery extends QueryHandler {
         out.println("<h2>Instances</h2>");
 
         printAnchorStart();
-        out.print("instances/" + encodeForURL(clazz));
+        print("instances/" + encodeForURL(clazz));
         out.print("\">");
         out.println("Exclude subclasses</a><br>");
 
         printAnchorStart();
-        out.print("allInstances/" + encodeForURL(clazz));
+        print("allInstances/" + encodeForURL(clazz));
         out.print("\">");
         out.println("Include subclasses</a><br>");
 
@@ -126,19 +126,19 @@ class ClassQuery extends QueryHandler {
             out.println("<h2>New Instances</h2>");
 
             printAnchorStart();
-            out.print("newInstances/" + encodeForURL(clazz));
+            print("newInstances/" + encodeForURL(clazz));
             out.print("\">");
             out.println("Exclude subclasses</a><br>");
 
             printAnchorStart();
-            out.print("allNewInstances/" + encodeForURL(clazz));
+            print("allNewInstances/" + encodeForURL(clazz));
             out.print("\">");
             out.println("Include subclasses</a><br>");
         }
 
         out.println("<h2>References summary by Type</h2>");
         printAnchorStart();
-        out.print("refsByType/" + encodeForURL(clazz));
+        print("refsByType/" + encodeForURL(clazz));
         out.print("\">");
         out.println("References summary by type</a>");
 
diff --git a/src/share/classes/com/sun/tools/hat/internal/server/HttpReader.java b/src/share/classes/com/sun/tools/hat/internal/server/HttpReader.java
index f86c8caa8e27973efbe7df0569ccf82c2a69dc8a..f08c9875c6700fc7fdd95245ec9c7a723e1fe4de 100644
--- a/src/share/classes/com/sun/tools/hat/internal/server/HttpReader.java
+++ b/src/share/classes/com/sun/tools/hat/internal/server/HttpReader.java
@@ -41,21 +41,17 @@ package com.sun.tools.hat.internal.server;
 
 
 import java.net.Socket;
-import java.net.ServerSocket;
-import java.net.InetAddress;
 
 import java.io.InputStream;
 import java.io.BufferedInputStream;
 import java.io.IOException;
-import java.io.Writer;
 import java.io.BufferedWriter;
 import java.io.PrintWriter;
-import java.io.OutputStream;
 import java.io.OutputStreamWriter;
-import java.io.BufferedOutputStream;
 
 import com.sun.tools.hat.internal.model.Snapshot;
 import com.sun.tools.hat.internal.oql.OQLEngine;
+import com.sun.tools.hat.internal.util.Misc;
 
 public class HttpReader implements Runnable {
 
@@ -87,7 +83,7 @@ public class HttpReader implements Runnable {
                 outputError("Protocol error");
             }
             int data;
-            StringBuffer queryBuf = new StringBuffer();
+            StringBuilder queryBuf = new StringBuilder();
             while ((data = in.read()) != -1 && data != ' ') {
                 char ch = (char) data;
                 queryBuf.append(ch);
@@ -217,7 +213,7 @@ public class HttpReader implements Runnable {
     private void outputError(String msg) {
         out.println();
         out.println("<html><body bgcolor=\"#ffffff\">");
-        out.println(msg);
+        out.println(Misc.encodeHtml(msg));
         out.println("</body></html>");
     }
 
diff --git a/src/share/classes/com/sun/tools/hat/internal/server/InstancesCountQuery.java b/src/share/classes/com/sun/tools/hat/internal/server/InstancesCountQuery.java
index 724b549ca4bd24e2d60fa9d6e7cb6dfd0e455f1d..7e87543ef99a84d5bf46eba573a72f7dffdc276f 100644
--- a/src/share/classes/com/sun/tools/hat/internal/server/InstancesCountQuery.java
+++ b/src/share/classes/com/sun/tools/hat/internal/server/InstancesCountQuery.java
@@ -102,7 +102,7 @@ class InstancesCountQuery extends QueryHandler {
             int count = clazz.getInstancesCount(false);
             print("" + count);
             printAnchorStart();
-            out.print("instances/" + encodeForURL(classes[i]));
+            print("instances/" + encodeForURL(classes[i]));
             out.print("\"> ");
             if (count == 1) {
                 print("instance");
@@ -121,7 +121,7 @@ class InstancesCountQuery extends QueryHandler {
                 }
                 print("(");
                 printAnchorStart();
-                out.print("newInstances/" + encodeForURL(classes[i]));
+                print("newInstances/" + encodeForURL(classes[i]));
                 out.print("\">");
                 print("" + newInst + " new");
                 out.print("</a>) ");
diff --git a/src/share/classes/com/sun/tools/hat/internal/server/OQLHelp.java b/src/share/classes/com/sun/tools/hat/internal/server/OQLHelp.java
index 6aaa909109a4f3eb2eee0c8658e7816a5bf9c9e5..730d2b7672dde1b32c9f156a56a5e4c64def1566 100644
--- a/src/share/classes/com/sun/tools/hat/internal/server/OQLHelp.java
+++ b/src/share/classes/com/sun/tools/hat/internal/server/OQLHelp.java
@@ -54,10 +54,7 @@ class OQLHelp extends QueryHandler {
                 out.print((char)ch);
             }
         } catch (Exception exp) {
-            out.println(exp.getMessage());
-            out.println("<pre>");
-            exp.printStackTrace(out);
-            out.println("</pre>");
+            printException(exp);
         }
     }
 }
diff --git a/src/share/classes/com/sun/tools/hat/internal/server/OQLQuery.java b/src/share/classes/com/sun/tools/hat/internal/server/OQLQuery.java
index 8e5ec5e289468cfa16f5d22ceafa1a55a7de8ba6..3e99bbcbb74103f4fbb2ae6a6ba93095ce2a1c47 100644
--- a/src/share/classes/com/sun/tools/hat/internal/server/OQLQuery.java
+++ b/src/share/classes/com/sun/tools/hat/internal/server/OQLQuery.java
@@ -32,10 +32,7 @@
 
 package com.sun.tools.hat.internal.server;
 
-import com.sun.tools.hat.internal.model.*;
 import com.sun.tools.hat.internal.oql.*;
-import com.sun.tools.hat.internal.util.ArraySorter;
-import com.sun.tools.hat.internal.util.Comparer;
 
 /**
  * This handles Object Query Language (OQL) queries.
@@ -68,7 +65,7 @@ class OQLQuery extends QueryHandler {
         out.println("<p align='center'>");
         out.println("<textarea name='query' cols=80 rows=10>");
         if (oql != null) {
-            out.println(oql);
+            println(oql);
         }
         out.println("</textarea>");
         out.println("</p>");
@@ -91,10 +88,7 @@ class OQLQuery extends QueryHandler {
                          try {
                              out.println(engine.toHtml(o));
                          } catch (Exception e) {
-                             out.println(e.getMessage());
-                             out.println("<pre>");
-                             e.printStackTrace(out);
-                             out.println("</pre>");
+                             printException(e);
                          }
                          out.println("</td></tr>");
                          return false;
@@ -102,10 +96,7 @@ class OQLQuery extends QueryHandler {
                  });
             out.println("</table>");
         } catch (OQLException exp) {
-            out.println(exp.getMessage());
-            out.println("<pre>");
-            exp.printStackTrace(out);
-            out.println("</pre>");
+            printException(exp);
         }
     }
 
diff --git a/src/share/classes/com/sun/tools/hat/internal/server/QueryHandler.java b/src/share/classes/com/sun/tools/hat/internal/server/QueryHandler.java
index deda0f480588c2f00d91eca36404800257a93651..9a6d93de06a186ada757132b217a03fbd0b9baba 100644
--- a/src/share/classes/com/sun/tools/hat/internal/server/QueryHandler.java
+++ b/src/share/classes/com/sun/tools/hat/internal/server/QueryHandler.java
@@ -36,6 +36,7 @@ import java.io.PrintWriter;
 
 import com.sun.tools.hat.internal.model.*;
 import com.sun.tools.hat.internal.util.Misc;
+import java.io.StringWriter;
 
 import java.net.URLEncoder;
 import java.io.UnsupportedEncodingException;
@@ -96,7 +97,7 @@ abstract class QueryHandler {
     }
 
     protected void error(String msg) {
-        out.println(msg);
+        println(msg);
     }
 
     protected void printAnchorStart() {
@@ -160,7 +161,6 @@ abstract class QueryHandler {
             out.println("null");
             return;
         }
-        String name = clazz.getName();
         printAnchorStart();
         out.print("class/");
         print(encodeForURL(clazz));
@@ -208,6 +208,15 @@ abstract class QueryHandler {
         }
     }
 
+    protected void printException(Throwable t) {
+        println(t.getMessage());
+        out.println("<pre>");
+        StringWriter sw = new StringWriter();
+        t.printStackTrace(new PrintWriter(sw));
+        print(sw.toString());
+        out.println("</pre>");
+    }
+
     protected void printHex(long addr) {
         if (snapshot.getIdentifierSize() == 4) {
             out.print(Misc.toHex((int)addr));
@@ -223,4 +232,8 @@ abstract class QueryHandler {
     protected void print(String str) {
         out.print(Misc.encodeHtml(str));
     }
+
+    protected void println(String str) {
+        out.println(Misc.encodeHtml(str));
+    }
 }
diff --git a/src/share/classes/com/sun/tools/hat/internal/server/RefsByTypeQuery.java b/src/share/classes/com/sun/tools/hat/internal/server/RefsByTypeQuery.java
index 5e7de9a8866871b1d9eb08de81a732b7e155a51d..3337b4715903a762a4bd35e3c477a777be47f04f 100644
--- a/src/share/classes/com/sun/tools/hat/internal/server/RefsByTypeQuery.java
+++ b/src/share/classes/com/sun/tools/hat/internal/server/RefsByTypeQuery.java
@@ -89,7 +89,7 @@ public class RefsByTypeQuery extends QueryHandler {
             out.println("<p align='center'>");
             printClass(clazz);
             if (clazz.getId() != -1) {
-                out.println("[" + clazz.getIdString() + "]");
+                println("[" + clazz.getIdString() + "]");
             }
             out.println("</p>");
 
@@ -125,9 +125,9 @@ public class RefsByTypeQuery extends QueryHandler {
             JavaClass clazz = classes[i];
             out.println("<tr><td>");
             out.print("<a href='/refsByType/");
-            out.print(clazz.getIdString());
+            print(clazz.getIdString());
             out.print("'>");
-            out.print(clazz.getName());
+            print(clazz.getName());
             out.println("</a>");
             out.println("</td><td>");
             out.println(map.get(clazz));