1 files changed, 207 insertions, 0 deletions
diff --git a/subsonic-main/src/main/java/net/sourceforge/subsonic/taglib/UrlTag.java b/subsonic-main/src/main/java/net/sourceforge/subsonic/taglib/UrlTag.java
new file mode 100644
index 00000000..141ba847
--- /dev/null
+++ b/subsonic-main/src/main/java/net/sourceforge/subsonic/taglib/UrlTag.java
@@ -0,0 +1,207 @@
+/*
+ This file is part of Subsonic.
+
+ Subsonic is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ Subsonic is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with Subsonic.  If not, see <http://www.gnu.org/licenses/>.
+
+ Copyright 2009 (C) Sindre Mehus
+ */
+package net.sourceforge.subsonic.taglib;
+
+import net.sourceforge.subsonic.Logger;
+import net.sourceforge.subsonic.filter.ParameterDecodingFilter;
+import net.sourceforge.subsonic.util.StringUtil;
+import org.apache.taglibs.standard.tag.common.core.UrlSupport;
+import org.apache.commons.lang.CharUtils;
+
+import javax.servlet.jsp.JspException;
+import javax.servlet.jsp.JspTagException;
+import javax.servlet.jsp.PageContext;
+import javax.servlet.jsp.tagext.BodyTagSupport;
+import java.io.IOException;
+import java.io.UnsupportedEncodingException;
+import java.net.URLEncoder;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Creates a URL with optional query parameters. Similar to 'c:url', but
+ * you may specify which character encoding to use for the URL query
+ * parameters. If no encoding is specified, the following steps are performed:
+ * <ul>
+ * <li>Parameter values are encoded as the hexadecimal representation of the UTF-8 bytes of the original string.</li>
+ * <li>Parameter names are prepended with the suffix "Utf8Hex"</li>
+ * <li>Note: Nothing is done with the parameter name or value if the value only contains ASCII alphanumeric characters.</li>
+ * </ul>
+ * <p/>
+ * (The problem with c:url is that is uses the same encoding as the http response,
+ * but most(?) servlet container assumes that ISO-8859-1 is used.)
+ *
+ * @author Sindre Mehus
+ */
+public class UrlTag extends BodyTagSupport {
+
+    private String DEFAULT_ENCODING = "Utf8Hex";
+    private static final Logger LOG = Logger.getLogger(UrlTag.class);
+
+    private String var;
+    private String value;
+    private String encoding = DEFAULT_ENCODING;
+    private List<Parameter> parameters = new ArrayList<Parameter>();
+
+    public int doStartTag() throws JspException {
+        parameters.clear();
+        return EVAL_BODY_BUFFERED;
+    }
+
+    public int doEndTag() throws JspException {
+
+        // Rewrite and encode the url.
+        String result = formatUrl();
+
+        // Store or print the output
+        if (var != null)
+            pageContext.setAttribute(var, result, PageContext.PAGE_SCOPE);
+        else {
+            try {
+                pageContext.getOut().print(result);
+            } catch (IOException x) {
+                throw new JspTagException(x);
+            }
+        }
+        return EVAL_PAGE;
+    }
+
+    private String formatUrl() throws JspException {
+        String baseUrl = UrlSupport.resolveUrl(value, null, pageContext);
+
+        StringBuffer result = new StringBuffer();
+        result.append(baseUrl);
+        if (!parameters.isEmpty()) {
+            result.append('?');
+
+            for (int i = 0; i < parameters.size(); i++) {
+                Parameter parameter = parameters.get(i);
+                try {
+                    result.append(parameter.getName());
+                    if (isUtf8Hex() && !isAsciiAlphaNumeric(parameter.getValue())) {
+                        result.append(ParameterDecodingFilter.PARAM_SUFFIX);
+                    }
+
+                    result.append('=');
+                    if (parameter.getValue() != null) {
+                        result.append(encode(parameter.getValue()));
+                    }
+                    if (i < parameters.size() - 1) {
+                        result.append("&");
+                    }
+
+                } catch (UnsupportedEncodingException x) {
+                    throw new JspTagException(x);
+                }
+            }
+        }
+        return result.toString();
+    }
+
+    private String encode(String s) throws UnsupportedEncodingException {
+        if (isUtf8Hex()) {
+            if (isAsciiAlphaNumeric(s)) {
+                return s;
+            }
+
+            try {
+                return StringUtil.utf8HexEncode(s);
+            } catch (Exception x) {
+                LOG.error("Failed to utf8hex-encode the string '" + s + "'.", x);
+                return s;
+            }
+        }
+
+        return URLEncoder.encode(s, encoding);
+    }
+
+    private boolean isUtf8Hex() {
+        return DEFAULT_ENCODING.equals(encoding);
+    }
+
+    private boolean isAsciiAlphaNumeric(String s) {
+        if (s == null) {
+            return true;
+        }
+
+        for (int i = 0; i < s.length(); i++) {
+            if (!CharUtils.isAsciiAlphanumeric(s.charAt(i))) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    public void release() {
+        var = null;
+        value = null;
+        encoding = DEFAULT_ENCODING;
+        parameters.clear();
+        super.release();
+    }
+
+    public void addParameter(String name, String value) {
+        parameters.add(new Parameter(name, value));
+    }
+
+    public String getVar() {
+        return var;
+    }
+
+    public void setVar(String var) {
+        this.var = var;
+    }
+
+    public String getValue() {
+        return value;
+    }
+
+    public void setValue(String value) {
+        this.value = value;
+    }
+
+    public String getEncoding() {
+        return encoding;
+    }
+
+    public void setEncoding(String encoding) {
+        this.encoding = encoding;
+    }
+
+    /**
+     * A URL query parameter.
+     */
+    private static class Parameter {
+        private String name;
+        private String value;
+
+        private Parameter(String name, String value) {
+            this.name = name;
+            this.value = value;
+        }
+
+        private String getName() {
+            return name;
+        }
+
+        private String getValue() {
+            return value;
+        }
+    }
+}