97 lines
5.5 KiB
HTML
97 lines
5.5 KiB
HTML
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<?xml version="1.0" encoding="UTF-8"?>
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<!DOCTYPE html
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PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
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<html lang="en-us" xml:lang="en-us">
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<head>
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<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
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<meta name="security" content="public" />
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<meta name="Robots" content="index,follow" />
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<meta http-equiv="PICS-Label" content='(PICS-1.1 "http://www.icra.org/ratingsv02.html" l gen true r (cz 1 lz 1 nz 1 oz 1 vz 1) "http://www.rsac.org/ratingsv01.html" l gen true r (n 0 s 0 v 0 l 0) "http://www.classify.org/safesurf/" l gen true r (SS~~000 1))' />
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<meta name="DC.Type" content="reference" />
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<meta name="DC.Title" content="IFSRandomAccessFile" />
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<meta name="abstract" content="The IFSRandomAccessFile class represents a file on the server for reading and writing data." />
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<meta name="description" content="The IFSRandomAccessFile class represents a file on the server for reading and writing data." />
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<meta name="copyright" content="(C) Copyright IBM Corporation 2006" />
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<meta name="DC.Rights.Owner" content="(C) Copyright IBM Corporation 2006" />
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<meta name="DC.Format" content="XHTML" />
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<meta name="DC.Identifier" content="ifsraf" />
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<meta name="DC.Language" content="en-us" />
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<!-- All rights reserved. Licensed Materials Property of IBM -->
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<!-- US Government Users Restricted Rights -->
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<!-- Use, duplication or disclosure restricted by -->
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<!-- GSA ADP Schedule Contract with IBM Corp. -->
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<link rel="stylesheet" type="text/css" href="./ibmdita.css" />
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<link rel="stylesheet" type="text/css" href="./ic.css" />
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<title>IFSRandomAccessFile</title>
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</head>
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<body id="ifsraf"><a name="ifsraf"><!-- --></a>
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<!-- Java sync-link --><script language="Javascript" src="../rzahg/synch.js" type="text/javascript"></script>
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<h1 class="topictitle1">IFSRandomAccessFile</h1>
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<div><p>The IFSRandomAccessFile class represents a file on the server for
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reading and writing data. </p>
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<div class="section"><p><a href="javadoc/com/ibm/as400/access/IFSRandomAccessFile.html#NAVBAR_TOP"> IFSRandomAccessFile</a> </p>
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<p>The Java™ program
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can read and write data sequentially or randomly. As in IFSFile, methods exist
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in IFSRandomAccessFile that duplicate the methods in RandomAccessFile from
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the java.io package. In addition to these methods, IFSRandomAccessFile has
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additional methods specific to the iSeries™ server. Through IFSRandomAccessFile,
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a Java program
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can do the following:</p>
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<ul><li><a href="javadoc/com/ibm/as400/access/IFSRandomAccessFile.html#CONSTRUCTOR_DETAIL"> Open</a> a file for read, write, or read/write access. The Java program
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can optionally specify the file sharing mode and the existence option.</li>
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<li><a href="javadoc/com/ibm/as400/access/IFSRandomAccessFile.html#READ()"> Read</a> data at the current offset from the file.</li>
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<li><a href="javadoc/com/ibm/as400/access/IFSRandomAccessFile.html#WRITE(INT)"> Write</a> data at the current offset to the file.</li>
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<li><a href="javadoc/com/ibm/as400/access/IFSRandomAccessFile.html#GETFILEPOINTER()"> Get</a> or <a href="javadoc/com/ibm/as400/access/IFSRandomAccessFile.html#SEEK(LONG)"> set</a> the current offset of the file.</li>
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<li><a href="javadoc/com/ibm/as400/access/IFSRandomAccessFile.html#CLOSE()"> Close</a> the file.</li>
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</ul>
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<p>In addition to the methods in java.io RandomAccessFile, IFSRandomAccessFile
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gives the Java program the following options:</p>
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<ul><li><a href="javadoc/com/ibm/as400/access/IFSRandomAccessFile.html#FLUSH()"> Committing</a> to disk bytes written.</li>
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<li><a href="javadoc/com/ibm/as400/access/IFSRandomAccessFile.html#LOCK(INT, INT)"> Locking</a> or <a href="javadoc/com/ibm/as400/access/IFSRandomAccessFile.html#UNLOCK(COM.IBM.AS400.ACCESS.IFSKEY)"> unlocking</a> bytes in the file.</li>
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<li>Locking and unlocking bytes in the stream. See <a href="ifskey.htm#ifskey">IFSKey</a> for
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more information.</li>
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<li>Specifying a sharing mode when the file is opened. See <a href="ifsmode.htm#ifsmode">sharing
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modes</a> for more information.</li>
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<li>Specify the existence option when a file is opened. The Java program
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can choose one of the following: <ul><li>Open the file if it exists; create the file if it does not.</li>
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<li>Replace the file if it exists; create the file if it does not.</li>
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<li>Fail the open if the file exists; create the file if it does not.</li>
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<li>Open the file if it exists; fail the open if it does not.</li>
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<li>Replace the file if it exists; fail the open if it does not.</li>
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</ul>
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</li>
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</ul>
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</div>
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<div class="section"><h4 class="sectiontitle">Example: Using IFSRandomAccessFile</h4><p>The following
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example shows how to use the IFSRandomAccessFile class to write four bytes
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at 1K intervals to a file.</p>
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<pre> // Create an AS400 object.
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AS400 sys = new AS400("mySystem.myCompany.com");
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// Open a file object that represents
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// the file.
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IFSRandomAccessFile aFile = new IFSRandomAccessFile(sys,"/mydir1/myfile", "rw");
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// Establish the data to write.
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byte i = 123;
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// Write to the file 10 times at 1K
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// intervals.
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for (int j=0; j<10; j++)
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{
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// Move the current offset.
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aFile.seek(j * 1024);
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// Write to the file. The current
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// offset advances by the size of
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// the write.
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aFile.write(i);
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}
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// Close the file.
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aFile.close();</pre>
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</div>
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</div>
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</body>
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</html>
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