jdk/test/java/io/BufferedInputStream/SkipTest.java
changeset 2 90ce3da70b43
child 5506 202f599c92aa
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/java/io/BufferedInputStream/SkipTest.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,97 @@
+/*
+ * Copyright 1998 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code 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 License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+/*
+ * @test 1.1 98/01/12
+ * @bug 4022294
+ * @summary Test bufferedinputstream for data loss during skip
+ *
+ */
+
+import java.io.*;
+import java.util.*;
+
+/**
+ * This class tests to see if bufferinputstream can be reset
+ * to recover data that was skipped over when the buffer did
+ * not contain all the bytes to be skipped
+ */
+public class SkipTest {
+
+    public static void main(String[] args) throws Exception {
+        long skipped = 0;
+
+        // Create a tiny buffered stream so it can be easily
+        // set up to contain only some of the bytes to skip
+        DataSupplier source = new DataSupplier();
+        BufferedInputStream in = new BufferedInputStream(source, 4);
+
+        // Set up data to be skipped and recovered
+        // the skip must be longer than the buffer size
+        in.mark(30);
+        while (skipped < 15) {
+            skipped += in.skip(15-skipped);
+        }
+        int nextint = in.read();
+        in.reset();
+
+        // Resume reading and see if data was lost
+        nextint = in.read();
+
+        if (nextint != 'a')
+            throw new RuntimeException("BufferedInputStream skip lost data");
+    }
+}
+
+
+class DataSupplier extends InputStream {
+
+    private int aposition=0;
+
+    public int read() {
+        return 'x';
+    }
+
+    public long skip(long n) {
+        aposition += (int) n;
+        return n;
+    }
+
+    public static final byte[] buffer = {(byte)'a',(byte)'b',(byte)'c',
+(byte)'d',(byte)'e',(byte)'f',(byte)'g',(byte)'h',(byte)'i',
+(byte)'j',(byte)'k',(byte)'l',(byte)'m',(byte)'n',(byte)'o',
+(byte)'p',(byte)'q',(byte)'r',(byte)'s',(byte)'t',(byte)'u',
+(byte)'v',(byte)'w',(byte)'x',(byte)'y',(byte)'z'
+                                         };
+
+    public int read(byte b[]) throws IOException {
+        return read(b, 0, b.length);
+    }
+
+    public int read(byte b[], int off, int len) throws IOException {
+        if (len > buffer.length) len = buffer.length;
+        System.arraycopy(buffer, aposition, b, off, len);
+        return len;
+    }
+
+}