1 files changed, 245 insertions, 0 deletions
diff --git a/gerrit-httpd/src/main/java/com/google/gerrit/httpd/HtmlDomUtil.java b/gerrit-httpd/src/main/java/com/google/gerrit/httpd/HtmlDomUtil.java
new file mode 100644
index 0000000000..a675e4f917
--- /dev/null
+++ b/gerrit-httpd/src/main/java/com/google/gerrit/httpd/HtmlDomUtil.java
@@ -0,0 +1,245 @@
+// Copyright (C) 2008 The Android Open Source Project
+//
+// Licensed 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.
+
+package com.google.gerrit.httpd;
+
+import org.w3c.dom.Document;
+import org.w3c.dom.Element;
+import org.w3c.dom.Node;
+import org.w3c.dom.NodeList;
+import org.xml.sax.SAXException;
+
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.StringWriter;
+import java.io.UnsupportedEncodingException;
+import java.util.zip.GZIPOutputStream;
+
+import javax.xml.parsers.DocumentBuilder;
+import javax.xml.parsers.DocumentBuilderFactory;
+import javax.xml.parsers.ParserConfigurationException;
+import javax.xml.transform.OutputKeys;
+import javax.xml.transform.Transformer;
+import javax.xml.transform.TransformerConfigurationException;
+import javax.xml.transform.TransformerException;
+import javax.xml.transform.TransformerFactory;
+import javax.xml.transform.dom.DOMSource;
+import javax.xml.transform.stream.StreamResult;
+
+/** Utility functions to deal with HTML using W3C DOM operations. */
+public class HtmlDomUtil {
+  /** Standard character encoding we prefer (UTF-8). */
+  public static final String ENC = "UTF-8";
+
+  /** DOCTYPE for a standards mode HTML document. */
+  public static final String HTML_STRICT =
+      "-//W3C//DTD HTML 4.01//EN\" \"http://www.w3.org/TR/REC-html40/strict.dtd";
+
+  /** Convert a document to a UTF-8 byte sequence. */
+  public static byte[] toUTF8(final Document hostDoc) throws IOException {
+    return toString(hostDoc).getBytes(ENC);
+  }
+
+  /** Compress the document. */
+  public static byte[] compress(final byte[] raw) throws IOException {
+    final ByteArrayOutputStream out = new ByteArrayOutputStream();
+    final GZIPOutputStream gz = new GZIPOutputStream(out);
+    gz.write(raw);
+    gz.finish();
+    gz.flush();
+    return out.toByteArray();
+  }
+
+  /** Convert a document to a String, assuming later encoding to UTF-8. */
+  public static String toString(final Document hostDoc) throws IOException {
+    try {
+      final StringWriter out = new StringWriter();
+      final DOMSource domSource = new DOMSource(hostDoc);
+      final StreamResult streamResult = new StreamResult(out);
+      final TransformerFactory tf = TransformerFactory.newInstance();
+      final Transformer serializer = tf.newTransformer();
+      serializer.setOutputProperty(OutputKeys.ENCODING, ENC);
+      serializer.setOutputProperty(OutputKeys.METHOD, "html");
+      serializer.setOutputProperty(OutputKeys.INDENT, "no");
+      serializer.setOutputProperty(OutputKeys.DOCTYPE_PUBLIC,
+          HtmlDomUtil.HTML_STRICT);
+      serializer.transform(domSource, streamResult);
+      return out.toString();
+    } catch (TransformerConfigurationException e) {
+      final IOException r = new IOException("Error transforming page");
+      r.initCause(e);
+      throw r;
+    } catch (TransformerException e) {
+      final IOException r = new IOException("Error transforming page");
+      r.initCause(e);
+      throw r;
+    }
+  }
+
+  /** Find an element by its "id" attribute; null if no element is found. */
+  public static Element find(final Node parent, final String name) {
+    final NodeList list = parent.getChildNodes();
+    for (int i = 0; i < list.getLength(); i++) {
+      final Node n = list.item(i);
+      if (n instanceof Element) {
+        final Element e = (Element) n;
+        if (name.equals(e.getAttribute("id"))) {
+          return e;
+        }
+      }
+      final Element r = find(n, name);
+      if (r != null) {
+        return r;
+      }
+    }
+    return null;
+  }
+
+  /** Append an HTML &lt;input type="hidden"&gt; to the form. */
+  public static void addHidden(final Element form, final String name,
+      final String value) {
+    final Element in = form.getOwnerDocument().createElement("input");
+    in.setAttribute("type", "hidden");
+    in.setAttribute("name", name);
+    in.setAttribute("value", value);
+    form.appendChild(in);
+  }
+
+  /** Clone a document so it can be safely modified on a per-request basis. */
+  public static Document clone(final Document doc) throws IOException {
+    final Document d;
+    try {
+      d = newBuilder().newDocument();
+    } catch (ParserConfigurationException e) {
+      throw new IOException("Cannot clone document");
+    }
+    final Node n = d.importNode(doc.getDocumentElement(), true);
+    d.appendChild(n);
+    return d;
+  }
+
+  /** Parse an XHTML file from our CLASSPATH and return the instance. */
+  public static Document parseFile(final Class<?> context, final String name)
+      throws IOException {
+    final InputStream in;
+
+    in = context.getResourceAsStream(name);
+    if (in == null) {
+      return null;
+    }
+    try {
+      try {
+        try {
+          return newBuilder().parse(in);
+        } catch (SAXException e) {
+          throw new IOException("Error reading " + name, e);
+        } catch (ParserConfigurationException e) {
+          throw new IOException("Error reading " + name, e);
+        }
+      } finally {
+        in.close();
+      }
+    } catch (IOException e) {
+      throw new IOException("Error reading " + name, e);
+    }
+  }
+
+  /** Read a Read a UTF-8 text file from our CLASSPATH and return it. */
+  public static String readFile(final Class<?> context, final String name)
+      throws IOException {
+    final InputStream in = context.getResourceAsStream(name);
+    if (in == null) {
+      return null;
+    }
+    try {
+      return asString(in);
+    } catch (IOException e) {
+      throw new IOException("Error reading " + name, e);
+    }
+  }
+
+  /** Parse an XHTML file from the local drive and return the instance. */
+  public static Document parseFile(final File parentDir, final String name)
+      throws IOException {
+    if (parentDir == null) {
+      return null;
+    }
+    final File path = new File(parentDir, name);
+    try {
+      final InputStream in = new FileInputStream(path);
+      try {
+        try {
+          return newBuilder().parse(in);
+        } catch (SAXException e) {
+          throw new IOException("Error reading " + path, e);
+        } catch (ParserConfigurationException e) {
+          throw new IOException("Error reading " + path, e);
+        }
+      } finally {
+        in.close();
+      }
+    } catch (FileNotFoundException e) {
+      return null;
+    } catch (IOException e) {
+      throw new IOException("Error reading " + path, e);
+    }
+  }
+
+  /** Read a UTF-8 text file from the local drive. */
+  public static String readFile(final File parentDir, final String name)
+      throws IOException {
+    if (parentDir == null) {
+      return null;
+    }
+    final File path = new File(parentDir, name);
+    try {
+      return asString(new FileInputStream(path));
+    } catch (FileNotFoundException e) {
+      return null;
+    } catch (IOException e) {
+      throw new IOException("Error reading " + path, e);
+    }
+  }
+
+  private static String asString(final InputStream in)
+      throws UnsupportedEncodingException, IOException {
+    try {
+      final StringBuilder w = new StringBuilder();
+      final InputStreamReader r = new InputStreamReader(in, ENC);
+      final char[] buf = new char[512];
+      int n;
+      while ((n = r.read(buf)) > 0) {
+        w.append(buf, 0, n);
+      }
+      return w.toString();
+    } finally {
+      in.close();
+    }
+  }
+
+  private static DocumentBuilder newBuilder()
+      throws ParserConfigurationException {
+    final DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
+    factory.setValidating(false);
+    factory.setExpandEntityReferences(false);
+    factory.setIgnoringComments(true);
+    final DocumentBuilder parser = factory.newDocumentBuilder();
+    return parser;
+  }
+}