From f59cbbb5adcd012e180e139aa03665ff840f4fb4 Mon Sep 17 00:00:00 2001
From: Arndt Brenschede <Arndt.Brenschede@web.de>
Date: Sat, 2 Nov 2019 18:27:32 +0100
Subject: [PATCH] StringUtils escape xml/json

---
 .../main/java/btools/util/StringUtils.java    | 37 ++++++++++++++++++-
 .../java/btools/util/StringUtilsTest.java     | 29 +++++++++++++++
 2 files changed, 64 insertions(+), 2 deletions(-)
 create mode 100644 brouter-util/src/test/java/btools/util/StringUtilsTest.java

diff --git a/brouter-util/src/main/java/btools/util/StringUtils.java b/brouter-util/src/main/java/btools/util/StringUtils.java
index f2f299b..3e8c7f8 100644
--- a/brouter-util/src/main/java/btools/util/StringUtils.java
+++ b/brouter-util/src/main/java/btools/util/StringUtils.java
@@ -5,12 +5,18 @@ package btools.util;
  */
 public class StringUtils
 {
+  private static char[]   xmlChr = new char[]  { '&',     '<',    '>',    '\'',     '"',      '\t',    '\n',    '\r' };
+  private static String[] xmlEsc = new String[]{ "&amp;", "&lt;", "&gt;", "&apos;", "&quot;", "&#x9;", "&#xA;", "&#xD;" };
+
+  private static char[]   jsnChr = new char[]  { '\'',  '"',    '\\',   '/' };
+  private static String[] jsnEsc = new String[]{ "\\'", "\\\"", "\\\\", "\\/" };
+
   /**
    * Escape a literal to put into a json document
    */
   public static String escapeJson( String s )
   {
-    return s;
+    return escape( s, jsnChr, jsnEsc );
   }
 
   /**
@@ -18,7 +24,34 @@ public class StringUtils
    */
   public static String escapeXml10( String s )
   {
-    return s;
+    return escape( s, xmlChr, xmlEsc );
   }
 
+  private static String escape( String s, char[] chr, String[] esc )
+  {
+    StringBuilder sb = null;
+    for( int i=0; i<s.length(); i++ )
+    {
+      char c = s.charAt( i );
+      int j = 0;
+      while( j<chr.length )
+      {
+         if (c == chr[j])
+         {
+           if ( sb == null )
+           {
+             sb = new StringBuilder( s.substring( 0, i ) );
+           }
+           sb.append( esc[j] );
+           break;
+         }
+         j++;
+      }
+      if ( sb != null && j==chr.length )
+      {
+        sb.append( c );
+      }
+    }
+    return sb == null ? s : sb.toString();
+  }
 }
diff --git a/brouter-util/src/test/java/btools/util/StringUtilsTest.java b/brouter-util/src/test/java/btools/util/StringUtilsTest.java
new file mode 100644
index 0000000..118116f
--- /dev/null
+++ b/brouter-util/src/test/java/btools/util/StringUtilsTest.java
@@ -0,0 +1,29 @@
+package btools.util;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class StringUtilsTest
+{
+  private static String[] raw = new String[] { "hallo", "is 1<2 ?", "or 4>5 ?", "or 1<>2 ?", "\"hi\" 'there'" };
+  private static String[] xml = new String[] { "hallo", "is 1&lt;2 ?", "or 4&gt;5 ?", "or 1&lt;&gt;2 ?", "&quot;hi&quot; &apos;there&apos;" };
+  private static String[] jsn = new String[] { "hallo", "is 1<2 ?", "or 4>5 ?", "or 1<>2 ?", "\\\"hi\\\" \\'there\\'" };
+
+  @Test
+  public void xmlEncodingTest()
+  {
+    for( int i=0; i<raw.length; i++ )
+    {
+		  Assert.assertEquals( "xml encoding mismatch for raw: " + raw[i], xml[i], StringUtils.escapeXml10( raw[i] ) );
+	  }
+  }
+
+  @Test
+  public void jsonEncodingTest()
+  {
+    for( int i=0; i<raw.length; i++ )
+    {
+      Assert.assertEquals( "json encoding mismatch for raw: " + raw[i], jsn[i], StringUtils.escapeJson( raw[i] ) );
+    }
+  }
+}