Initial revision

From-SVN: r26263

libjava/java/io/SequenceInputStream.java

@@ -0,0 +1,112 @@
+/* Copyright (C) 1998, 1999  Cygnus Solutions
+
+   This file is part of libgcj.
+
+This software is copyrighted work licensed under the terms of the
+Libgcj License.  Please consult the file "LIBGCJ_LICENSE" for
+details.  */
+ 
+package java.io;
+
+import java.util.Enumeration;
+
+/**
+ * @author Warren Levy <warrenl@cygnus.com>
+ * @date November 3, 1998.  
+ */
+/* Written using "Java Class Libraries", 2nd edition, ISBN 0-201-31002-3
+ * "The Java Language Specification", ISBN 0-201-63451-1
+ * plus online API docs for JDK 1.2 beta from http://www.javasoft.com.
+ * Status:  Believed complete and correct.
+ */
+ 
+public class SequenceInputStream extends InputStream
+{
+  /* The handle for the current input stream. */
+  private InputStream in;
+
+  /* Secondary input stream; not used if constructed w/ enumeration. */
+  private InputStream in2;
+
+  /* The enum handle; not used if constructed w/ 2 explicit input streams. */
+  private Enumeration enum;
+
+  public SequenceInputStream(Enumeration e)
+  {
+    // FIXME: Assumes that enum contains only InputStreams.
+    enum = e;
+    in = (InputStream) enum.nextElement();
+    in2 = null;
+  }
+
+  public SequenceInputStream(InputStream s1, InputStream s2)
+  {
+    in = s1;
+    in2 = s2;
+  }
+
+  public int available() throws IOException
+  {
+    if (in == null)
+      return 0;
+
+    return in.available();
+  }
+
+  public void close() throws IOException
+  {
+    while (in != null)
+      {
+	in.close();
+	in = getNextStream ();
+      }
+  }
+
+  public int read() throws IOException
+  {
+    int ch = -1;
+
+    while (in != null && (ch = in.read()) < 0)
+      {
+	in.close();
+        in = getNextStream();
+      }
+
+    return ch;
+  }
+
+  public int read(byte[] b, int off, int len) throws IOException
+  {
+    int ch = -1;
+
+    // The validity of the parameters will be checked by in.read so
+    // don't bother doing it here.
+    while (in != null && (ch = in.read(b, off, len)) < 0)
+      {
+	in.close();
+        in = getNextStream();
+      }
+
+    return ch;
+  }
+
+  private InputStream getNextStream()
+  {
+    InputStream nextIn = null;
+
+    // FIXME: Assumes that enum contains only InputStreams.
+    if (enum != null)
+      {
+        if (enum.hasMoreElements())
+	  nextIn = (InputStream) enum.nextElement();
+      }
+    else
+      if (in2 != null)
+	{
+	  nextIn = in2;
+	  in2 = null;
+	}
+
+    return nextIn;
+  }
+}