xref: /AOO41X/main/odk/examples/DevelopersGuide/UCB/MyInputStream.java (revision cdf0e10c4e3984b49a9502b011690b615761d4a3)
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34 
35 // imports
36 import com.sun.star.io.BufferSizeExceededException;
37 import com.sun.star.io.NotConnectedException;
38 import com.sun.star.io.XInputStream;
39 import com.sun.star.io.XSeekable;
40 
41 /**
42  * XInputStream interface implementation.
43  */
44 public class MyInputStream implements XSeekable, XInputStream {
45 
46     /**
47      * Member properties
48      */
49     private int offset = 0;
50 	private int read = offset;
51 	private byte[] bigbuffer;
52 
53     /**
54      * Constructor
55      */
56 	public MyInputStream() {
57 	}
58 
59 	    // XSeekable. Makes it possible to seek to a certain position within a stream.
60 
61     /**
62      *   Returns the length of the stream.
63      *
64      *@return  long  The length of the storage medium on which the stream works.
65      */
66     public synchronized long getLength()
67         throws com.sun.star.io.IOException,com.sun.star.uno.RuntimeException {
68 		if ( bigbuffer != null ) {
69 			return bigbuffer.length - offset;
70 		} else {
71             return 0;
72 		}
73 	}
74 
75     /**
76      *   Returns the current offset of the stream.
77      *
78      *@return  long  The current offset in this stream.
79      */
80 	public synchronized long getPosition()
81         throws com.sun.star.io.IOException,com.sun.star.uno.RuntimeException {
82 		return read - offset ;
83 	}
84 
85     /**
86      *  Changes the seek pointer to a new location relative to the beginning of the stream.
87      *
88      *@param  long
89      */
90 	public synchronized void seek(long p0)
91         throws IllegalArgumentException, com.sun.star.io.IOException,
92             com.sun.star.uno.RuntimeException {
93 		if( bigbuffer != null ) {
94             p0 +=offset;
95             read = ( int ) p0;
96             if( read < offset || read > bigbuffer.length )
97 			    throw new IllegalArgumentException();
98         }
99     }
100 
101 	    // XInputStream. This is the basic interface to read data from a stream.
102 
103     /**
104      *   States how many bytes can be read or skipped without blocking.
105      *
106      *@return  int  If not available, then returned 0
107      */
108     public synchronized int available()
109         throws NotConnectedException, com.sun.star.io.IOException,
110             com.sun.star.uno.RuntimeException {
111 		if( bigbuffer != null )
112 			return ( bigbuffer.length - read );
113 		else
114 			return 0;
115 	}
116 
117 	/**
118      *   Closes the stream. .
119      */
120     public void closeInput()
121 	    throws NotConnectedException,com.sun.star.io.IOException,
122         com.sun.star.uno.RuntimeException {
123 		read = -1;
124     }
125 
126     /**
127      *   Reads the specified number of bytes in the given sequence.
128      *
129      *@param    byte[][]
130      *@param    int
131      *@return   int
132      */
133 	public synchronized int readBytes(byte[][] p0, int p1)
134 		throws NotConnectedException, BufferSizeExceededException,
135             com.sun.star.io.IOException, com.sun.star.uno.RuntimeException {
136 		if( bigbuffer != null ) {
137 			if( read == -1 )
138       		    return 0;
139             int i = 0;
140             int available;
141             if ( p1 > bigbuffer.length - read )
142                 available = bigbuffer.length - read;
143             else
144                 available = p1;
145 
146 			p0[0] = new byte[p1];
147 			while( available != 0 ) {
148 			    p0[0][i++] = bigbuffer[read++];
149 				--available;
150 			}
151 			return i;
152         } else {
153 			p0[0] = new byte[0];
154 			return 0;
155 		}
156     }
157 
158 	/**
159      *  Reads the available number of bytes at maximum  nMaxBytesToRead .
160      *  This method blocks the thread until at least one byte is available.
161      *
162      *@param    byte[][]
163      *@param    int
164      *@return   int
165      */
166     public synchronized int readSomeBytes(byte[][] p0, int p1)
167 		    throws 	NotConnectedException,
168         		    BufferSizeExceededException,
169 		            com.sun.star.io.IOException,
170 		            com.sun.star.uno.RuntimeException {
171 		    return readBytes( p0,p1 );
172 	}
173 
174     /**
175      *  Skips the next nBytesToSkip bytes (must be positive).
176      *  It is up to the implementation whether this method is blocking the thread or not.
177      *
178      *@param    int
179      */
180     public synchronized void skipBytes(int p0)
181         throws 	NotConnectedException, BufferSizeExceededException,
182 		    com.sun.star.io.IOException, com.sun.star.uno.RuntimeException {
183         read += p0;
184 	    if( read > bigbuffer.length )
185     	    read = bigbuffer.length;
186 
187 	    if( read < offset )
188 		    read = offset;
189     }
190 }
191