55 lines
1.3 KiB
Java
55 lines
1.3 KiB
Java
// iostreams/UsingRandomAccessFile.java
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// (c)2016 MindView LLC: see Copyright.txt
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// We make no guarantees that this code is fit for any purpose.
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// Visit http://mindviewinc.com/Books/OnJava/ for more book information.
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import java.io.*;
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public class UsingRandomAccessFile {
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static String file = "rtest.dat";
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static void display() throws IOException {
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try(RandomAccessFile rf =
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new RandomAccessFile(file, "r")) {
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for(int i = 0; i < 7; i++)
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System.out.println(
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"Value " + i + ": " + rf.readDouble());
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System.out.println(rf.readUTF());
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}
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}
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public static
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void main(String[] args) throws IOException {
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try(RandomAccessFile rf =
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new RandomAccessFile(file, "rw")) {
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for(int i = 0; i < 7; i++)
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rf.writeDouble(i*1.414);
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rf.writeUTF("The end of the file");
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rf.close();
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display();
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}
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try(RandomAccessFile rf =
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new RandomAccessFile(file, "rw")) {
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rf.seek(5*8);
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rf.writeDouble(47.0001);
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rf.close();
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display();
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}
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}
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}
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/* Output:
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Value 0: 0.0
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Value 1: 1.414
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Value 2: 2.828
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Value 3: 4.242
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Value 4: 5.656
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Value 5: 7.069999999999999
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Value 6: 8.484
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The end of the file
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Value 0: 0.0
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Value 1: 1.414
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Value 2: 2.828
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Value 3: 4.242
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Value 4: 5.656
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Value 5: 47.0001
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Value 6: 8.484
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The end of the file
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*/
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