HADOOP-3854. Add some files that I missed.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/core/trunk@688923 13f79535-47bb-0310-9956-ffa450edef68

src/core/org/apache/hadoop/http/FilterContainer.java

@@ -0,0 +1,33 @@
+/**
+ * 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.http;
+
+import java.util.Map;
+
+/**
+ * A container class for javax.servlet.Filter. 
+ */
+public interface FilterContainer {
+  /**
+   * Add a filter to the container.
+   * @param name Filter name
+   * @param classname Filter class name
+   * @param parameters a map from parameter names to initial values
+   */
+  void addFilter(String name, String classname, Map<String, String> parameters);
+}

src/core/org/apache/hadoop/http/FilterInitializer.java

@@ -0,0 +1,29 @@
+/**
+ * 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.http;
+
+/**
+ * Initialize a javax.servlet.Filter. 
+ */
+public abstract class FilterInitializer {
+  /**
+   * Initialize a Filter to a FilterContainer.
+   * @param container The filter container
+   */
+  abstract void initFilter(FilterContainer container);
+}

src/test/org/apache/hadoop/http/TestServletFilter.java

@@ -0,0 +1,148 @@
+/**
+ * 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.http;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.net.URL;
+import java.net.URLConnection;
+import java.util.Map;
+import java.util.Random;
+import java.util.TreeMap;
+
+import javax.servlet.Filter;
+import javax.servlet.FilterChain;
+import javax.servlet.FilterConfig;
+import javax.servlet.ServletException;
+import javax.servlet.ServletRequest;
+import javax.servlet.ServletResponse;
+import javax.servlet.http.HttpServletRequest;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.conf.Configuration;
+
+public class TestServletFilter extends junit.framework.TestCase {
+  static final Log LOG = LogFactory.getLog(HttpServer.class);
+  static final Map<String, Integer> COUNTS = new TreeMap<String, Integer>(); 
+
+  /** A very simple filter which count number of access for each uri */
+  static public class CountingFilter implements Filter {
+    private FilterConfig filterConfig = null;
+
+    public void init(FilterConfig filterConfig) {
+      this.filterConfig = filterConfig;
+    }
+
+    public void destroy() {
+      this.filterConfig = null;
+    }
+
+    public void doFilter(ServletRequest request, ServletResponse response,
+        FilterChain chain) throws IOException, ServletException {
+      if (filterConfig == null)
+         return;
+
+      String uri = ((HttpServletRequest)request).getRequestURI();
+      LOG.info("filtering " + uri);
+      Integer value = COUNTS.get(uri);
+      value = value == null? 1: value + 1;
+      COUNTS.put(uri, value);
+      chain.doFilter(request, response);
+    }
+
+    /** Configuration for CountingFilter */
+    static public class Initializer extends FilterInitializer {
+      public Initializer() {}
+
+      void initFilter(FilterContainer container) {
+        container.addFilter("counting", CountingFilter.class.getName(), null);
+      }
+    }
+  }
+  
+  
+  /** access a url, ignoring some IOException such as the page does not exist */
+  static void access(String urlstring) throws IOException {
+    LOG.warn("access " + urlstring);
+    URL url = new URL(urlstring);
+    URLConnection connection = url.openConnection();
+    connection.connect();
+    
+    try {
+      BufferedReader in = new BufferedReader(new InputStreamReader(
+          connection.getInputStream()));
+      try {
+        for(; in.readLine() != null; );
+      } finally {
+        in.close();
+      }
+    } catch(IOException ioe) {
+      LOG.warn("urlstring=" + urlstring, ioe);
+    }
+  }
+
+  public void testServletFilter() throws Exception {
+    Configuration conf = new Configuration();
+    
+    //start a http server with CountingFilter
+    conf.set(HttpServer.FILTER_INITIALIZER_PROPERTY,
+        CountingFilter.Initializer.class.getName());
+    HttpServer http = new HttpServer("datanode", "localhost", 0, true, conf);
+    http.start();
+
+    final String fsckURL = "/fsck";
+    final String stacksURL = "/stacks";
+    final String ajspURL = "/a.jsp";
+    final String[] urls = {fsckURL, stacksURL, ajspURL};
+    final Random ran = new Random();
+    final int[] sequence = new int[20];
+    final int[] counts = new int[urls.length]; 
+
+    //generate a random sequence and update counts 
+    for(int i = 0; i < sequence.length; i++) {
+      sequence[i] = ran.nextInt(urls.length);
+      counts[sequence[i]]++;
+    }
+
+    //access the urls as the sequence
+    final String prefix = "http://localhost:" + http.getPort();
+    try {
+      for(int i = 0; i < sequence.length; i++) {
+        access(prefix + urls[sequence[i]]);
+      }
+    } finally {
+      http.stop();
+    }
+
+    LOG.info("COUNTS = " + COUNTS);
+    //make sure fsck not get filtered
+    assertFalse(COUNTS.containsKey(fsckURL));
+    
+    //verify other counts
+    for(int i = 1; i < urls.length; i++) {
+      if (counts[i] == 0) {
+        assertFalse(COUNTS.containsKey(urls[i]));
+      } else {
+        assertEquals(counts[i], COUNTS.remove(urls[i]).intValue());
+      }
+    }
+    assertTrue(COUNTS.isEmpty());
+  }
+}