add the Java Client from M0AZM

[spider.git] / SpiderConsole / src / PipedInputMUX.java

diff --git a/SpiderConsole/src/PipedInputMUX.java b/SpiderConsole/src/PipedInputMUX.java
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+++ b/SpiderConsole/src/PipedInputMUX.java
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+/**
+ * InputStreamMultiplexor 
+ * This takes multiple input streams and sends them to one input stream.
+ * @author Ian Norton
+ * @version 1.00 - 20010418.
+ *
+ * Copyright (C) 2001 Ian Norton.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public Licence as published by
+ * the Free Software Foundation; either version 2 of the Licence, or
+ * (at your option) any later version.
+ *
+ * This program 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 Licence for more details.
+ *
+ * You should have received a copy of the GNU General Public Licence
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * Contacting the author :
+ * Ian Norton
+ * i.norton@lancaster.ac.uk
+ * http://www.lancs.ac.uk/~norton/
+ **/
+
+import java.io.* ;
+import java.util.Vector ;
+import java.util.Enumeration ;
+import java.util.Calendar ;
+
+class PipedInputMUX implements Runnable
+    {
+    public static final boolean DEBUG = false ;
+    public static final String encoding = "latin1"; // "ISO8859_1";
+
+    private PipedOutputStream pos ;
+    private Vector streams ;
+
+    private Thread t ;
+    
+    /**
+     * PipedInputMUX initialiser.
+     * @param PipedOutputStream - target stream.
+     **/
+    public PipedInputMUX(PipedOutputStream o)
+        {
+        pos = o ;
+
+        // Streams Vector holds all the InputStreams we know about.
+        streams = new Vector() ;
+
+        // Initialise and start the thread.
+        t = new Thread(this, "InputMultiplexor") ;
+        t.start() ;
+        }
+
+    /**
+     * addInputStream
+     * @param PipedInputStream pi - add a stream get input from.
+     **/
+    public void addInputStream(PipedInputStream pi)
+        {
+        // Add the supplied stream to the vector of streams.
+        streams.addElement(pi) ;
+        }
+
+    /**
+     * run - Thread run method.
+     **/
+    public void run()
+        {
+        // Loop continually reading from the input streams
+        while(true)
+            {
+            // Enumeration thing here.
+            Enumeration e = streams.elements() ;
+ 
+            byte[] b = new byte[16];
+
+            while(e.hasMoreElements())
+                {
+                PipedInputStream is = (PipedInputStream)e.nextElement() ;
+                
+                try
+                    {
+                    // Read a line and see if it has any data in it.
+                    int n = 0;
+
+                    // While there is non-blocking data available to read
+                    while(is.available() > 0)
+                        {
+                        // find out how many bytes we can read without blocking
+                        int rdb = is.available() ;
+                        if(rdb > 16) rdb = 16 ;
+                        
+                        // Read that many bytes and return.
+                        n = is.read(b, 0, rdb);
+                        if(n > 0)
+                            {
+                            String output = new String(b, 0, n, encoding) ;
+                            send(output) ;
+                            }
+                        }
+     
+                    if(DEBUG) System.out.println("After reading a line.") ;
+                    }
+                catch(IOException ex)
+                    {
+                    // If we get an IO exception, then the other end of the pipe
+                    // has been closed.  We need to remove this stream.
+                    streams.removeElement(is) ;
+                    System.out.println("IOException - stream removed.") ;
+                    }
+                                                                                
+                } // End of while(e.hasMoreElements())
+            } // End of while(true)
+        } // End of run()
+
+    /**
+     * send
+     * @param String s - string to send to destination stream.
+     **/
+    private void send(String s)
+        {
+        // Calendar cal = Calendar.getInstance() ;
+        // if(DEBUG) System.out.println("PipedInputMUX: " + cal.getTime() + " Send called with : " + s) ;
+
+        try
+            {
+            // Write the data to the stream.
+            for(int i=0;i<s.length();i++)
+                {
+                pos.write(s.charAt(i)) ;
+                pos.flush() ;
+                }
+            }
+        catch(IOException ex)
+            {
+            System.out.println("PipedInputMUX: IOException on destination stream.") ;
+            }
+        }
+    } // End of class.