add http admin server

src/main/java/com/alibaba/druid/http/HttpServer.java

@@ -0,0 +1,167 @@
+package com.alibaba.druid.http;
+
+import java.io.IOException;
+import java.net.BindException;
+import java.net.URL;
+import java.util.HashMap;
+import java.util.Map;
+
+import org.mortbay.jetty.Connector;
+import org.mortbay.jetty.Server;
+import org.mortbay.jetty.handler.ContextHandlerCollection;
+import org.mortbay.jetty.nio.SelectChannelConnector;
+import org.mortbay.jetty.servlet.Context;
+import org.mortbay.jetty.servlet.DefaultServlet;
+import org.mortbay.jetty.webapp.WebAppContext;
+import org.mortbay.thread.QueuedThreadPool;
+import org.mortbay.util.MultiException;
+
+import com.alibaba.druid.logging.Log;
+import com.alibaba.druid.logging.LogFactory;
+
+public class HttpServer {
+
+    private final static Log              LOG             = LogFactory.getLog(HttpServer.class);
+
+    protected final Server                webServer;
+    protected final Connector             listener;
+
+    protected final WebAppContext         webAppContext;
+    protected final Map<Context, Boolean> defaultContexts = new HashMap<Context, Boolean>();
+
+    public HttpServer() throws IOException{
+        this("stat", "0.0.0.0", 19790);
+    }
+
+    public HttpServer(String name, String bindAddress, int port) throws IOException{
+        webServer = new Server();
+
+        listener = createBaseListener();
+        listener.setHost(bindAddress);
+        listener.setPort(port);
+
+        webServer.addConnector(listener);
+        webServer.setThreadPool(new QueuedThreadPool());
+
+        final String appDir = getWebAppsPath();
+        ContextHandlerCollection contexts = new ContextHandlerCollection();
+        webServer.setHandler(contexts);
+
+        webAppContext = new WebAppContext();
+        webAppContext.setDisplayName("WepAppsContext");
+        webAppContext.setContextPath("/");
+        webAppContext.setWar(appDir + "/" + name);
+        webServer.addHandler(webAppContext);
+
+        addDefaultApps(contexts, appDir);
+
+        addDefaultServlets();
+    }
+
+    /**
+     * Create a required listener for the Jetty instance listening on the port provided. This wrapper and all subclasses
+     * must create at least one listener.
+     */
+    public Connector createBaseListener() throws IOException {
+        return HttpServer.createDefaultChannelConnector();
+    }
+
+    // LimitedPrivate for creating secure datanodes
+    public static Connector createDefaultChannelConnector() {
+        SelectChannelConnector ret = new SelectChannelConnector();
+        ret.setLowResourceMaxIdleTime(10000);
+        ret.setAcceptQueueSize(128);
+        ret.setResolveNames(false);
+        ret.setUseDirectBuffers(false);
+        return ret;
+    }
+
+    /**
+     * Get the pathname to the webapps files.
+     * 
+     * @return the pathname as a URL
+     * @throws IOException if 'webapps' directory cannot be found on CLASSPATH.
+     */
+    protected String getWebAppsPath() throws IOException {
+        URL url = getClass().getClassLoader().getResource("druid-webapps");
+        if (url == null) throw new IOException("webapps not found in CLASSPATH");
+        return url.toString();
+    }
+
+    /**
+     * stop the server
+     */
+    public void stop() throws Exception {
+        listener.close();
+        webServer.stop();
+    }
+
+    public void join() throws InterruptedException {
+        webServer.join();
+    }
+
+    /**
+     * Start the server. Does not wait for the server to start.
+     */
+    public void start() throws IOException {
+        try {
+            int port = 0;
+            int oriPort = listener.getPort(); // The original requested port
+            while (true) {
+                try {
+                    port = webServer.getConnectors()[0].getLocalPort();
+                    LOG.debug("Port returned by webServer.getConnectors()[0]." + "getLocalPort() before open() is "
+                              + port + ". Opening the listener on " + oriPort);
+                    listener.open();
+                    port = listener.getLocalPort();
+                    LOG.debug("listener.getLocalPort() returned " + listener.getLocalPort()
+                              + " webServer.getConnectors()[0].getLocalPort() returned "
+                              + webServer.getConnectors()[0].getLocalPort());
+                    LOG.debug("Jetty bound to port " + port);
+                    webServer.start();
+                    break;
+                } catch (IOException ex) {
+                    // if this is a bind exception,
+                    // then try the next port number.
+                    if (ex instanceof BindException) {
+                        throw (BindException) ex;
+                    } else {
+                        LOG.debug("HttpServer.start() threw a non Bind IOException");
+                        throw ex;
+                    }
+                } catch (MultiException ex) {
+                    LOG.debug("HttpServer.start() threw a MultiException");
+                    throw ex;
+                }
+            }
+        } catch (IOException ex) {
+            throw ex;
+        } catch (Exception ex) {
+            throw new IOException("Problem starting http server", ex);
+        }
+    }
+
+    /**
+     * Add default apps.
+     * 
+     * @param appDir The application directory
+     * @throws IOException
+     */
+    protected void addDefaultApps(ContextHandlerCollection parent, final String appDir) throws IOException {
+        // set up the context for "/static/*"
+        Context staticContext = new Context(parent, "/static");
+        staticContext.setResourceBase(appDir + "/static");
+        staticContext.addServlet(DefaultServlet.class, "/*");
+        staticContext.setDisplayName("static");
+        setContextAttributes(staticContext);
+        defaultContexts.put(staticContext, true);
+    }
+
+    private void setContextAttributes(Context context) {
+
+    }
+
+    protected void addDefaultServlets() {
+
+    }
+}