27
28 import java.io.InputStream;
29 import java.util.Enumeration;
30 import java.util.Vector;
31
32 /**
33 * A <code>SequenceInputStream</code> represents
34 * the logical concatenation of other input
35 * streams. It starts out with an ordered
36 * collection of input streams and reads from
37 * the first one until end of file is reached,
38 * whereupon it reads from the second one,
39 * and so on, until end of file is reached
40 * on the last of the contained input streams.
41 *
42 * @author Author van Hoff
43 * @since JDK1.0
44 */
45 public
46 class SequenceInputStream extends InputStream {
47 Enumeration e;
48 InputStream in;
49
50 /**
51 * Initializes a newly created <code>SequenceInputStream</code>
52 * by remembering the argument, which must
53 * be an <code>Enumeration</code> that produces
54 * objects whose run-time type is <code>InputStream</code>.
55 * The input streams that are produced by
56 * the enumeration will be read, in order,
57 * to provide the bytes to be read from this
58 * <code>SequenceInputStream</code>. After
59 * each input stream from the enumeration
60 * is exhausted, it is closed by calling its
61 * <code>close</code> method.
62 *
63 * @param e an enumeration of input streams.
64 * @see java.util.Enumeration
65 */
66 public SequenceInputStream(Enumeration<? extends InputStream> e) {
67 this.e = e;
68 try {
69 nextStream();
70 } catch (IOException ex) {
71 // This should never happen
72 throw new Error("panic");
73 }
74 }
75
76 /**
77 * Initializes a newly
78 * created <code>SequenceInputStream</code>
79 * by remembering the two arguments, which
80 * will be read in order, first <code>s1</code>
81 * and then <code>s2</code>, to provide the
82 * bytes to be read from this <code>SequenceInputStream</code>.
83 *
84 * @param s1 the first input stream to read.
85 * @param s2 the second input stream to read.
86 */
87 public SequenceInputStream(InputStream s1, InputStream s2) {
88 Vector v = new Vector(2);
89
90 v.addElement(s1);
91 v.addElement(s2);
92 e = v.elements();
93 try {
94 nextStream();
95 } catch (IOException ex) {
96 // This should never happen
97 throw new Error("panic");
98 }
99 }
100
101 /**
102 * Continues reading in the next stream if an EOF is reached.
103 */
104 final void nextStream() throws IOException {
105 if (in != null) {
106 in.close();
107 }
108
|
27
28 import java.io.InputStream;
29 import java.util.Enumeration;
30 import java.util.Vector;
31
32 /**
33 * A <code>SequenceInputStream</code> represents
34 * the logical concatenation of other input
35 * streams. It starts out with an ordered
36 * collection of input streams and reads from
37 * the first one until end of file is reached,
38 * whereupon it reads from the second one,
39 * and so on, until end of file is reached
40 * on the last of the contained input streams.
41 *
42 * @author Author van Hoff
43 * @since JDK1.0
44 */
45 public
46 class SequenceInputStream extends InputStream {
47 Enumeration<? extends InputStream> e;
48 InputStream in;
49
50 /**
51 * Initializes a newly created <code>SequenceInputStream</code>
52 * by remembering the argument, which must
53 * be an <code>Enumeration</code> that produces
54 * objects whose run-time type is <code>InputStream</code>.
55 * The input streams that are produced by
56 * the enumeration will be read, in order,
57 * to provide the bytes to be read from this
58 * <code>SequenceInputStream</code>. After
59 * each input stream from the enumeration
60 * is exhausted, it is closed by calling its
61 * <code>close</code> method.
62 *
63 * @param e an enumeration of input streams.
64 * @see java.util.Enumeration
65 */
66 public SequenceInputStream(Enumeration<? extends InputStream> e) {
67 this.e = e;
68 try {
69 nextStream();
70 } catch (IOException ex) {
71 // This should never happen
72 throw new Error("panic");
73 }
74 }
75
76 /**
77 * Initializes a newly
78 * created <code>SequenceInputStream</code>
79 * by remembering the two arguments, which
80 * will be read in order, first <code>s1</code>
81 * and then <code>s2</code>, to provide the
82 * bytes to be read from this <code>SequenceInputStream</code>.
83 *
84 * @param s1 the first input stream to read.
85 * @param s2 the second input stream to read.
86 */
87 public SequenceInputStream(InputStream s1, InputStream s2) {
88 Vector<InputStream> v = new Vector<>(2);
89
90 v.addElement(s1);
91 v.addElement(s2);
92 e = v.elements();
93 try {
94 nextStream();
95 } catch (IOException ex) {
96 // This should never happen
97 throw new Error("panic");
98 }
99 }
100
101 /**
102 * Continues reading in the next stream if an EOF is reached.
103 */
104 final void nextStream() throws IOException {
105 if (in != null) {
106 in.close();
107 }
108
|