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     17  * under the License.                                           *
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     19 
     20 
     21 package org.apache.james.mime4j.util;
     22 
     23 import java.io.InputStream;
     24 import java.io.IOException;
     25 
     26 public class PartialInputStream extends PositionInputStream {
     27     private final long limit;
     28 
     29     public PartialInputStream(InputStream inputStream, long offset, long length) throws IOException {
     30         super(inputStream);
     31         inputStream.skip(offset);
     32         this.limit = offset + length;
     33     }
     34 
     35     public int available() throws IOException {
     36         return Math.min(super.available(), getBytesLeft());
     37     }
     38 
     39     public int read() throws IOException {
     40         if (limit > position)
     41             return super.read();
     42         else
     43             return -1;
     44     }
     45 
     46     public int read(byte b[]) throws IOException {
     47         return read(b, 0, b.length);
     48     }
     49 
     50     public int read(byte b[], int off, int len) throws IOException {
     51         len = Math.min(len, getBytesLeft());
     52         return super.read(b, off, len);    //To change body of overridden methods use File | Settings | File Templates.
     53     }
     54 
     55     public long skip(long n) throws IOException {
     56         n = Math.min(n, getBytesLeft());
     57         return super.skip(n);    //To change body of overridden methods use File | Settings | File Templates.
     58     }
     59 
     60     private int getBytesLeft() {
     61         return (int)Math.min(Integer.MAX_VALUE, limit - position);
     62     }
     63 }
     64