Remove stringutils and add simple escaper (#34)

pom.xml

@@ -52,11 +52,6 @@
             <version>1.3</version>
             <scope>test</scope>
         </dependency>
-        <dependency>
-            <groupId>org.apache.commons</groupId>
-            <artifactId>commons-lang3</artifactId>
-            <version>3.4</version>
-        </dependency>
     </dependencies>
 
     <packaging>jar</packaging>

src/main/java/j2html/attributes/Attribute.java

@@ -1,6 +1,7 @@
 package j2html.attributes;
 
-import static org.apache.commons.lang3.StringEscapeUtils.escapeHtml4;
+
+import j2html.utils.SimpleEscaper;
 
 public class Attribute {
     private String name;
@@ -8,7 +9,7 @@ public class Attribute {
 
     public Attribute(String name, String value) {
         this.name = name;
-        this.value = escapeHtml4(value);
+        this.value = SimpleEscaper.escape(value);
     }
 
     public Attribute(String name) {

src/main/java/j2html/tags/Text.java

@@ -1,6 +1,6 @@
 package j2html.tags;
 
-import static org.apache.commons.lang3.StringEscapeUtils.escapeHtml4;
+import j2html.utils.SimpleEscaper;
 
 public class Text extends DomContent {
 
@@ -12,7 +12,7 @@ public class Text extends DomContent {
 
     @Override
     public String render() {
-        return escapeHtml4(text);
+        return SimpleEscaper.escape(text);
     }
 
 }

src/main/java/j2html/utils/SimpleEscaper.java

@@ -0,0 +1,28 @@
+package j2html.utils;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class SimpleEscaper {
+
+    private static Map<Character, String> map = new HashMap<Character, String>() {{
+        put('&', "&amp;");
+        put('<', "&lt;");
+        put('>', "&gt;");
+        put('"', "&quot;");
+        put('\'', "&#x27;");
+    }};
+
+    public static String escape(String s) {
+        if(s == null) {
+            return null;
+        }
+        String escapedString = "";
+        for(char c : s.toCharArray()) {
+            String escaped = map.get(c);
+            escapedString += escaped != null ? escaped : c;
+        }
+        return escapedString;
+    }
+
+}