branch-0.23.1/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/ServletUtil.java - hadoop - Git at Google

 /**
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
  * distributed with this work for additional information
  * regarding copyright ownership.  The ASF licenses this file
  * to you 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 org.apache.hadoop.util;

 import java.io.*;
 import java.util.Calendar;

 import javax.servlet.*;
 import javax.servlet.http.HttpServletRequest;

 import org.apache.commons.httpclient.URIException;
 import org.apache.commons.httpclient.util.URIUtil;
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.classification.InterfaceStability;

 import com.google.common.base.Preconditions;

 @InterfaceAudience.Private
 @InterfaceStability.Unstable
 public class ServletUtil {
   /**
    * Initial HTML header
    */
   public static PrintWriter initHTML(ServletResponse response, String title
       ) throws IOException {
     response.setContentType("text/html");
     PrintWriter out = response.getWriter();
     out.println("<html>\n"
         + "<link rel='stylesheet' type='text/css' href='/static/hadoop.css'>\n"
         + "<title>" + title + "</title>\n"
         + "<body>\n"
         + "<h1>" + title + "</h1>\n");
     return out;
   }

   /**
    * Get a parameter from a ServletRequest.
    * Return null if the parameter contains only white spaces.
    */
   public static String getParameter(ServletRequest request, String name) {
     String s = request.getParameter(name);
     if (s == null) {
       return null;
     }
     s = s.trim();
     return s.length() == 0? null: s;
   }

   public static final String HTML_TAIL = "<hr />\n"
     + "<a href='http://hadoop.apache.org/core'>Hadoop</a>, "
     + Calendar.getInstance().get(Calendar.YEAR) + ".\n"
     + "</body></html>";

   /**
    * HTML footer to be added in the jsps.
    * @return the HTML footer.
    */
   public static String htmlFooter() {
     return HTML_TAIL;
   }

   /**
    * Generate the percentage graph and returns HTML representation string
    * of the same.
    *
    * @param perc The percentage value for which graph is to be generated
    * @param width The width of the display table
    * @return HTML String representation of the percentage graph
    * @throws IOException
    */
   public static String percentageGraph(int perc, int width) throws IOException {
     assert perc >= 0; assert perc <= 100;

     StringBuilder builder = new StringBuilder();

     builder.append("<table border=\"1px\" width=\""); builder.append(width);
     builder.append("px\"><tr>");
     if(perc > 0) {
       builder.append("<td cellspacing=\"0\" class=\"perc_filled\" width=\"");
       builder.append(perc); builder.append("%\"></td>");
     }if(perc < 100) {
       builder.append("<td cellspacing=\"0\" class=\"perc_nonfilled\" width=\"");
       builder.append(100 - perc); builder.append("%\"></td>");
     }
     builder.append("</tr></table>");
     return builder.toString();
   }

   /**
    * Generate the percentage graph and returns HTML representation string
    * of the same.
    * @param perc The percentage value for which graph is to be generated
    * @param width The width of the display table
    * @return HTML String representation of the percentage graph
    * @throws IOException
    */
   public static String percentageGraph(float perc, int width) throws IOException {
     return percentageGraph((int)perc, width);
   }

   /**
    * Escape and encode a string regarded as within the query component of an URI.
    * @param value the value to encode
    * @return encoded query, null if the default charset is not supported
    */
   public static String encodeQueryValue(final String value) {
     try {
       return URIUtil.encodeWithinQuery(value, "UTF-8");
     } catch (URIException e) {
       throw new AssertionError("JVM does not support UTF-8"); // should never happen!
     }
   }

   /**
    * Escape and encode a string regarded as the path component of an URI.
    * @param path the path component to encode
    * @return encoded path, null if UTF-8 is not supported
    */
   public static String encodePath(final String path) {
     try {
       return URIUtil.encodePath(path, "UTF-8");
     } catch (URIException e) {
       throw new AssertionError("JVM does not support UTF-8"); // should never happen!
     }
   }

   /**
    * Parse and decode the path component from the given request.
    * @param request Http request to parse
    * @param servletName the name of servlet that precedes the path
    * @return decoded path component, null if UTF-8 is not supported
    */
   public static String getDecodedPath(final HttpServletRequest request, String servletName) {
     try {
       return URIUtil.decode(getRawPath(request, servletName), "UTF-8");
     } catch (URIException e) {
       throw new AssertionError("JVM does not support UTF-8"); // should never happen!
     }
   }

   /**
    * Parse the path component from the given request and return w/o decoding.
    * @param request Http request to parse
    * @param servletName the name of servlet that precedes the path
    * @return path component, null if the default charset is not supported
    */
   public static String getRawPath(final HttpServletRequest request, String servletName) {
     Preconditions.checkArgument(request.getRequestURI().startsWith(servletName+"/"));
     return request.getRequestURI().substring(servletName.length());
   }
 }
	/**
	* Licensed to the Apache Software Foundation (ASF) under one
	* or more contributor license agreements. See the NOTICE file
	* distributed with this work for additional information
	* regarding copyright ownership. The ASF licenses this file
	* to you 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 org.apache.hadoop.util;

	import java.io.*;
	import java.util.Calendar;

	import javax.servlet.*;
	import javax.servlet.http.HttpServletRequest;

	import org.apache.commons.httpclient.URIException;
	import org.apache.commons.httpclient.util.URIUtil;
	import org.apache.hadoop.classification.InterfaceAudience;
	import org.apache.hadoop.classification.InterfaceStability;

	import com.google.common.base.Preconditions;

	@InterfaceAudience.Private
	@InterfaceStability.Unstable
	public class ServletUtil {
	/**
	* Initial HTML header
	*/
	public static PrintWriter initHTML(ServletResponse response, String title
	) throws IOException {
	response.setContentType("text/html");
	PrintWriter out = response.getWriter();
	out.println("<html>\n"
	+ "<link rel='stylesheet' type='text/css' href='/static/hadoop.css'>\n"
	+ "<title>" + title + "</title>\n"
	+ "<body>\n"
	+ "<h1>" + title + "</h1>\n");
	return out;
	}

	/**
	* Get a parameter from a ServletRequest.
	* Return null if the parameter contains only white spaces.
	*/
	public static String getParameter(ServletRequest request, String name) {
	String s = request.getParameter(name);
	if (s == null) {
	return null;
	}
	s = s.trim();
	return s.length() == 0? null: s;
	}

	public static final String HTML_TAIL = "<hr />\n"
	+ "<a href='http://hadoop.apache.org/core'>Hadoop</a>, "
	+ Calendar.getInstance().get(Calendar.YEAR) + ".\n"
	+ "</body></html>";

	/**
	* HTML footer to be added in the jsps.
	* @return the HTML footer.
	*/
	public static String htmlFooter() {
	return HTML_TAIL;
	}

	/**
	* Generate the percentage graph and returns HTML representation string
	* of the same.
	*
	* @param perc The percentage value for which graph is to be generated
	* @param width The width of the display table
	* @return HTML String representation of the percentage graph
	* @throws IOException
	*/
	public static String percentageGraph(int perc, int width) throws IOException {
	assert perc >= 0; assert perc <= 100;

	StringBuilder builder = new StringBuilder();

	builder.append("<table border=\"1px\" width=\""); builder.append(width);
	builder.append("px\"><tr>");
	if(perc > 0) {
	builder.append("<td cellspacing=\"0\" class=\"perc_filled\" width=\"");
	builder.append(perc); builder.append("%\"></td>");
	}if(perc < 100) {
	builder.append("<td cellspacing=\"0\" class=\"perc_nonfilled\" width=\"");
	builder.append(100 - perc); builder.append("%\"></td>");
	}
	builder.append("</tr></table>");
	return builder.toString();
	}

	/**
	* Generate the percentage graph and returns HTML representation string
	* of the same.
	* @param perc The percentage value for which graph is to be generated
	* @param width The width of the display table
	* @return HTML String representation of the percentage graph
	* @throws IOException
	*/
	public static String percentageGraph(float perc, int width) throws IOException {
	return percentageGraph((int)perc, width);
	}

	/**
	* Escape and encode a string regarded as within the query component of an URI.
	* @param value the value to encode
	* @return encoded query, null if the default charset is not supported
	*/
	public static String encodeQueryValue(final String value) {
	try {
	return URIUtil.encodeWithinQuery(value, "UTF-8");
	} catch (URIException e) {
	throw new AssertionError("JVM does not support UTF-8"); // should never happen!
	}
	}

	/**
	* Escape and encode a string regarded as the path component of an URI.
	* @param path the path component to encode
	* @return encoded path, null if UTF-8 is not supported
	*/
	public static String encodePath(final String path) {
	try {
	return URIUtil.encodePath(path, "UTF-8");
	} catch (URIException e) {
	throw new AssertionError("JVM does not support UTF-8"); // should never happen!
	}
	}

	/**
	* Parse and decode the path component from the given request.
	* @param request Http request to parse
	* @param servletName the name of servlet that precedes the path
	* @return decoded path component, null if UTF-8 is not supported
	*/
	public static String getDecodedPath(final HttpServletRequest request, String servletName) {
	try {
	return URIUtil.decode(getRawPath(request, servletName), "UTF-8");
	} catch (URIException e) {
	throw new AssertionError("JVM does not support UTF-8"); // should never happen!
	}
	}

	/**
	* Parse the path component from the given request and return w/o decoding.
	* @param request Http request to parse
	* @param servletName the name of servlet that precedes the path
	* @return path component, null if the default charset is not supported
	*/
	public static String getRawPath(final HttpServletRequest request, String servletName) {
	Preconditions.checkArgument(request.getRequestURI().startsWith(servletName+"/"));
	return request.getRequestURI().substring(servletName.length());
	}
	}