#21 Übergabe von Fehlerinformation in der API

src/main/java/de/kosit/validationtool/impl/HtmlExtraction.java

@@ -0,0 +1,49 @@
+package de.kosit.validationtool.impl;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+import lombok.RequiredArgsConstructor;
+
+import net.sf.saxon.s9api.SaxonApiException;
+import net.sf.saxon.s9api.XPathExecutable;
+import net.sf.saxon.s9api.XPathSelector;
+import net.sf.saxon.s9api.XdmItem;
+import net.sf.saxon.s9api.XdmNode;
+
+/**
+ * @author Andreas Penski
+ */
+@RequiredArgsConstructor
+public class HtmlExtraction {
+
+    private final ContentRepository repository;
+
+    private XPathExecutable executable;
+
+    public List<XdmNode> extract(XdmNode xdmSource) {
+        try {
+            final XPathSelector selector = getSelector();
+            selector.setContextItem(xdmSource);
+            return selector.stream().map(this::castToNode).collect(Collectors.toList());
+
+        } catch (SaxonApiException e) {
+            throw new IllegalStateException("Can not extract html content", e);
+        }
+    }
+
+    private XdmNode castToNode(final XdmItem xdmItem) {
+        return (XdmNode) xdmItem;
+    }
+
+    private XPathSelector getSelector() {
+        if (executable == null) {
+            Map<String, String> ns = new HashMap<>();
+            ns.put("html", "http://www.w3.org/1999/xhtml");
+            executable = repository.createXPath("//html:html", ns);
+        }
+        return executable.load();
+    }
+}