| 1 | /* |
| 2 | |
| 3 | Derby - Class org.apache.derby.impl.jdbc.ReaderToAscii |
| 4 | |
| 5 | Copyright 2004 The Apache Software Foundation or its licensors, as applicable. |
| 6 | |
| 7 | Licensed under the Apache License, Version 2.0 (the "License"); |
| 8 | you may not use this file except in compliance with the License. |
| 9 | You may obtain a copy of the License at |
| 10 | |
| 11 | http://www.apache.org/licenses/LICENSE-2.0 |
| 12 | |
| 13 | Unless required by applicable law or agreed to in writing, software |
| 14 | distributed under the License is distributed on an "AS IS" BASIS, |
| 15 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 16 | See the License for the specific language governing permissions and |
| 17 | limitations under the License. |
| 18 | |
| 19 | */ |
| 20 | |
| 21 | package org.apache.derby.impl.jdbc; |
| 22 | |
| 23 | import java.io.InputStream; |
| 24 | import java.io.Reader; |
| 25 | import java.io.IOException; |
| 26 | import java.sql.SQLException; |
| 27 | |
| 28 | /** |
| 29 | ReaderToAscii converts Reader (with characters) to a stream of ASCII characters. |
| 30 | */ |
| 31 | public final class ReaderToAscii extends InputStream |
| 32 | { |
| 33 | |
| 34 | private final Reader data; |
| 35 | private char[] conv; |
| 36 | private boolean closed; |
| 37 | |
| 38 | public ReaderToAscii(Reader data) |
| 39 | { |
| 40 | this.data = data; |
| 41 | if (!(data instanceof UTF8Reader)) |
| 42 | conv = new char[256]; |
| 43 | } |
| 44 | |
| 45 | public int read() throws IOException |
| 46 | { |
| 47 | if (closed) |
| 48 | throw new IOException(); |
| 49 | |
| 50 | int c = data.read(); |
| 51 | if (c == -1) |
| 52 | return -1; |
| 53 | |
| 54 | if (c <= 255) |
| 55 | return c & 0xFF; |
| 56 | else |
| 57 | return '?'; // Question mark - out of range character. |
| 58 | } |
| 59 | |
| 60 | public int read(byte[] buf, int off, int len) throws IOException |
| 61 | { |
| 62 | if (closed) |
| 63 | throw new IOException(); |
| 64 | |
| 65 | if (data instanceof UTF8Reader) { |
| 66 | |
| 67 | return ((UTF8Reader) data).readAsciiInto(buf, off, len); |
| 68 | } |
| 69 | |
| 70 | if (len > conv.length) |
| 71 | len = conv.length; |
| 72 | |
| 73 | len = data.read(conv, 0, len); |
| 74 | if (len == -1) |
| 75 | return -1; |
| 76 | |
| 77 | for (int i = 0; i < len; i++) { |
| 78 | char c = conv[i]; |
| 79 | |
| 80 | byte cb; |
| 81 | if (c <= 255) |
| 82 | cb = (byte) c; |
| 83 | else |
| 84 | cb = (byte) '?'; // Question mark - out of range character. |
| 85 | |
| 86 | buf[off++] = cb; |
| 87 | } |
| 88 | |
| 89 | return len; |
| 90 | } |
| 91 | |
| 92 | public long skip(long len) throws IOException { |
| 93 | if (closed) |
| 94 | throw new IOException(); |
| 95 | |
| 96 | return data.skip(len); |
| 97 | } |
| 98 | |
| 99 | public void close() throws IOException |
| 100 | { |
| 101 | if (!closed) { |
| 102 | closed = true; |
| 103 | data.close(); |
| 104 | } |
| 105 | } |
| 106 | } |