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<title>The Java Language Specification The Package java.io </title>
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<a name="28230"></a>
<center><h1>22.4 The Class <code>java.io.FileInputStream</code></h1></center>
<a name="33503"></a>
A file input stream obtains input bytes from a file in a file system. What files are
available depends on the host environment.
<p><pre><a name="28231"></a>public class <code><b>FileInputStream</b></code> extends InputStream {
<a name="28232"></a> public <code><b>FileInputStream</b></code>(String path)
<a name="28233"></a> throws SecurityException, FileNotFoundException;
<a name="28234"></a> public <code><b>FileInputStream</b></code>(File file)
<a name="28235"></a> throws SecurityException, FileNotFoundException;
<a name="28236"></a> public <code><b>FileInputStream</b></code>(FileDescriptor fdObj)
<a name="30480"></a> throws SecurityException;
<a name="28237"></a> public native int <code><b>read</b></code>() throws IOException;
<a name="28238"></a> public int <code><b>read</b></code>(byte[] b)
<a name="32297"></a> throws IOException, NullPointerException;
<a name="28239"></a> public int <code><b>read</b></code>(byte[] b, int off, int len)
<a name="28240"></a> throws IOException, NullPointerException,
<a name="32300"></a> IndexOutOfBoundsException;
<a name="28241"></a> public native long <code><b>skip</b></code>(long n) throws IOException;
<a name="28242"></a> public native int <code><b>available</b></code>() throws IOException;
<a name="28243"></a> public native void <code><b>close</b></code>() throws IOException;
<a name="28244"></a> public final FileDescriptor <code><b>getFD</b></code>() throws IOException;
<a name="28245"></a> protected void <code><b>finalize</b></code>() throws IOException;
<a name="28246"></a>}
</pre><a name="28248"></a>
<p><font size=+1><strong>22.4.1 </strong> <code>public <code><b>FileInputStream</b></code>(String path)<br>throws SecurityException, FileNotFoundException</code></font>
<p>
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This constructor initializes a newly created <code>FileInputStream</code> by opening a connection
to an actual file, the file named by the path name <code>path</code> in the file system.
A new <code>FileDescriptor</code> object is created to represent this file connection.
<p><a name="28253"></a>
First, if there is a security manager, its <code>checkRead</code> method <a href="javalang.doc16.html#14115">(§20.17.19)</a> is called with the <code>path</code> argument as its argument.<p>
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If the actual file cannot be opened, a <code>FileNotFoundException</code> is thrown.<p>
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<p><font size=+1><strong>22.4.2 </strong> <code>public <code><b>FileInputStream</b></code>(File file)<br>throws SecurityException, FileNotFoundException</code></font>
<p>
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This constructor initializes a newly created <code>FileInputStream</code> by opening a connection
to an actual file, the file named by the <code>File</code> object <code>file</code> in the file system.
A new <code>FileDescriptor</code> object is created to represent this file connection.
<p><a name="28261"></a>
First, if there is a security manager, its <code>checkRead</code> method <a href="javalang.doc16.html#14115">(§20.17.19)</a> is called with the path represented by the <code>file</code> argument as its argument.<p>
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If the actual file cannot be opened, a <code>FileNotFoundException</code> is thrown.<p>
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<p><font size=+1><strong>22.4.3 </strong> <code>public <code><b>FileInputStream</b></code>(FileDescriptor fdObj)<br>throws SecurityException</code></font>
<p>
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This constructor initializes a newly created <code>FileInputStream</code> by using the file
descriptor <code>fdObj</code>, which represents an existing connection to an actual file in the
file system.
<p><a name="30448"></a>
First, if there is a security manager, its <code>checkRead</code> method <a href="javalang.doc16.html#14114">(§20.17.18)</a> is called with the file descriptor <code>fdObj</code> as its argument.<p>
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<p><font size=+1><strong>22.4.4 </strong> <code>public final FileDescriptor <code><b>getFD</b></code>() throws IOException</code></font>
<p>
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This method returns the <code>FileDescriptor</code> object <a href="javaio.doc23.html#29890">(§22.26)</a> that represents the connection
to the actual file in the file system being used by this <code>FileInputStream</code>.
<p><a name="28265"></a>
<p><font size=+1><strong>22.4.5 </strong> <code>public int <code><b>read</b></code>() throws IOException;</code></font>
<p>
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The byte for this operation is read from the actual file with which this file input
stream is connected.
<p><a name="28270"></a>
Implements the <code>read</code> method of <code>InputStream</code> <a href="javaio.doc1.html#28142">(§22.3.1)</a>.<p>
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<p><font size=+1><strong>22.4.6 </strong> <code>public int <code><b>read</b></code>(byte[] b)<br>throws IOException, NullPointerException</code></font>
<p>
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Bytes for this operation are read from the actual file with which this file input
stream is connected.
<p><a name="28276"></a>
Overrides the <code>read</code> method of <code>InputStream</code> <a href="javaio.doc1.html#28150">(§22.3.2)</a>.<p>
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<p><font size=+1><strong>22.4.7 </strong> <code>public int <code><b>read</b></code>(byte[] b, int off, int len)<br>throws IOException, NullPointerException,      IndexOutOfBoundsException</code></font>
<p>
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Bytes for this operation are read from the actual file with which this file input
stream is connected.
<p><a name="28282"></a>
Overrides the <code>read</code> method of <code>InputStream</code> <a href="javaio.doc1.html#28164">(§22.3.3)</a>.<p>
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<p><font size=+1><strong>22.4.8 </strong> <code>public long <code><b>skip</b></code>(long n) throws IOException</code></font>
<p>
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Bytes for this operation are read from the actual file with which this file input
stream is connected.
<p><a name="28288"></a>
Overrides the <code>skip</code> method of <code>InputStream</code> <a href="javaio.doc1.html#28178">(§22.3.4)</a>.<p>
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<p><font size=+1><strong>22.4.9 </strong> <code>public int <code><b>available</b></code>() throws IOException</code></font>
<p>
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Overrides the <code>available</code> method of <code>InputStream</code> <a href="javaio.doc1.html#28182">(§22.3.5)</a>.
<p><a name="28294"></a>
<p><font size=+1><strong>22.4.10 </strong> <code>public void <code><b>close</b></code>() throws IOException</code></font>
<p>
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This file input stream is closed and may no longer be used for reading bytes.
<p><a name="28299"></a>
Overrides the <code>close</code> method of <code>InputStream</code> <a href="javaio.doc1.html#28187">(§22.3.6)</a>.<p>
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<p><font size=+1><strong>22.4.11 </strong> <code>protected void <code><b>finalize</b></code>() throws IOException</code></font>
<p>
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A <code>FileInputStream</code> uses finalization to clean up the connection to the actual
file.
<p>
<hr>
<!-- This inserts footnotes--><p>
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<p>
<font size=-1>Java Language Specification (HTML generated by Suzette Pelouch on February 24, 1998)<br>
<i><a href="jcopyright.doc.html">Copyright © 1996 Sun Microsystems, Inc.</a>
All rights reserved</i>
<br>
Please send any comments or corrections to <a href="mailto:doug.kramer@sun.com">doug.kramer@sun.com</a>
</font>
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