| 1 | /* |
| 2 | * $Id: Template.java,v 1.4 2004/11/04 19:27:37 hastings Exp $ |
| 3 | * |
| 4 | * Copyright (c) 2004, Moebius Solutions, Inc. |
| 5 | * All rights reserved. |
| 6 | * |
| 7 | * Redistribution and use in source and binary forms, with or without |
| 8 | * modification, are permitted provided that the following conditions |
| 9 | * are met: |
| 10 | * |
| 11 | * Redistributions of source code must retain the above copyright |
| 12 | * notice, this list of conditions and the following disclaimer. |
| 13 | * |
| 14 | * Redistributions in binary form must reproduce the above |
| 15 | * copyright notice, this list of conditions and the following |
| 16 | * disclaimer in the documentation and/or other materials provided |
| 17 | * with the distribution. |
| 18 | * |
| 19 | * Neither the name of Moebius Solutions, Inc. nor the names of |
| 20 | * its contributors may be used to endorse or promote products |
| 21 | * derived from this software without specific prior written |
| 22 | * permission. |
| 23 | * |
| 24 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 25 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 26 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
| 27 | * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
| 28 | * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 29 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
| 30 | * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR |
| 31 | * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 32 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
| 33 | * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 34 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED |
| 35 | * OF THE POSSIBILITY OF SUCH DAMAGE. |
| 36 | */ |
| 37 | |
| 38 | package com.moesol.generator.core; |
| 39 | |
| 40 | import java.io.*; |
| 41 | import java.util.*; |
| 42 | import java.lang.reflect.*; |
| 43 | |
| 44 | |
| 45 | interface NameParsedListener { |
| 46 | public String nameParsed(String name) throws ApplyException; |
| 47 | } |
| 48 | |
| 49 | /** |
| 50 | * Process a template file and replace occurances of ${foo} with the |
| 51 | * value of the property foo. |
| 52 | */ |
| 53 | public class Template { |
| 54 | public Template(InputStream is) { |
| 55 | in = new LineNumberReader(new InputStreamReader(is)); |
| 56 | } |
| 57 | public Template(Reader r) { |
| 58 | in = new LineNumberReader(r); |
| 59 | } |
| 60 | public Template(String t) { |
| 61 | in = new LineNumberReader(new StringReader(t)); |
| 62 | } |
| 63 | public void setInput(Reader r) { |
| 64 | in = new LineNumberReader(r); |
| 65 | } |
| 66 | /** |
| 67 | * @return the input reader used for the source of the template. |
| 68 | * Note that input reader set by the constructor and setInput is |
| 69 | * wrapped by a LineNumberReader, which this method returns. |
| 70 | */ |
| 71 | public Reader getInput() { |
| 72 | return in; |
| 73 | } |
| 74 | public void setObject(Object o) { |
| 75 | object = o; |
| 76 | } |
| 77 | public Object getObject() { |
| 78 | return object; |
| 79 | } |
| 80 | /** |
| 81 | * Message to prepend to thrown error messages. |
| 82 | */ |
| 83 | public void setErrorPrefix(String info) { |
| 84 | error_info = info; |
| 85 | } |
| 86 | public String getErrorPrefix() { |
| 87 | return error_info; |
| 88 | } |
| 89 | public void apply(Properties p, Writer out) |
| 90 | throws ApplyException |
| 91 | { |
| 92 | try { |
| 93 | int c; |
| 94 | while ((c = in.read()) != -1) { |
| 95 | if (c == '$') { |
| 96 | replaceName(p, out, '$'); |
| 97 | } else if (c == '#') { |
| 98 | callName(p, out); |
| 99 | } else if (c == '\\') { |
| 100 | escapeSeen(out); |
| 101 | } else if (c == '"') { |
| 102 | writeChar(out, c); |
| 103 | // Do not treat quotes specially. |
| 104 | // Replace ${xx} inside of quotes. |
| 105 | // quoteSeen(out); |
| 106 | } else { |
| 107 | writeChar(out, c); |
| 108 | } |
| 109 | } |
| 110 | } catch (IOException e) { |
| 111 | throw new ApplyException(error_info + "io error at: " + in.getLineNumber(), e); |
| 112 | } |
| 113 | } |
| 114 | |
| 115 | private void replaceName(final Properties p, Writer out, char cause) |
| 116 | throws ApplyException, IOException |
| 117 | { |
| 118 | NameParsedListener l = new NameParsedListener() { |
| 119 | public String nameParsed(String name) throws ApplyException { |
| 120 | String replace = p.getProperty(name.toString()); |
| 121 | if (null == replace) { |
| 122 | throw new ApplyException(error_info + "line: " |
| 123 | + in.getLineNumber() |
| 124 | + ": No property for ${"+name+"}"); |
| 125 | } |
| 126 | return replace; |
| 127 | } |
| 128 | }; |
| 129 | String replacement = needOpenBrace(p, l, cause); |
| 130 | |
| 131 | Template t = new Template(new StringReader(replacement)); |
| 132 | t.setObject(t.getObject()); |
| 133 | t.apply(p, out); |
| 134 | } |
| 135 | private void callName(final Properties p, final Writer out) |
| 136 | throws ApplyException, IOException |
| 137 | { |
| 138 | NameParsedListener l = new NameParsedListener() { |
| 139 | public String nameParsed(String name) throws ApplyException { |
| 140 | // TODO better arg parsing |
| 141 | int left = name.indexOf('('); |
| 142 | int right = name.lastIndexOf(')'); |
| 143 | if (left > 0 && right > left) { |
| 144 | callWithArg(name.substring(0,left), name.substring(left+1, right)); |
| 145 | } else { |
| 146 | callSimple(name); |
| 147 | } |
| 148 | return ""; |
| 149 | } |
| 150 | private void callSimple(String name) throws ApplyException { |
| 151 | Class c = object.getClass(); |
| 152 | Class param_types[] = { Writer.class }; |
| 153 | Object params[] = { out }; |
| 154 | try { |
| 155 | Method m = c.getMethod(name, param_types); |
| 156 | m.invoke(object, params); |
| 157 | } catch (InvocationTargetException e) { |
| 158 | throwUnwrappedException(e); |
| 159 | throw new ApplyException(error_info + "error: " + in.getLineNumber(), e); |
| 160 | } catch (Exception e) { |
| 161 | throw new ApplyException(error_info + "error: " + in.getLineNumber(), e); |
| 162 | } |
| 163 | } |
| 164 | private void callWithArg(String name, String arg) throws ApplyException { |
| 165 | Class c = object.getClass(); |
| 166 | Class param_types[] = { Writer.class, String.class }; |
| 167 | Object params[] = { out, arg }; |
| 168 | try { |
| 169 | Method m = c.getMethod(name, param_types); |
| 170 | m.invoke(object, params); |
| 171 | } catch (InvocationTargetException e) { |
| 172 | throwUnwrappedException(e); |
| 173 | throw new ApplyException(error_info + "error: " + in.getLineNumber(), e); |
| 174 | } catch (Exception e) { |
| 175 | throw new ApplyException(error_info + "error: " + in.getLineNumber(), e); |
| 176 | } |
| 177 | } |
| 178 | }; |
| 179 | needOpenBrace(p, l, '#'); |
| 180 | } |
| 181 | private void throwUnwrappedException(InvocationTargetException e) |
| 182 | throws ApplyException |
| 183 | { |
| 184 | if (e.getCause() != null) { |
| 185 | if (e.getCause() instanceof ApplyException) { |
| 186 | throw (ApplyException)e.getCause(); |
| 187 | } |
| 188 | } |
| 189 | } |
| 190 | private void escapeSeen(Writer out) throws IOException { |
| 191 | int c; |
| 192 | if ((c = in.read()) == -1) { |
| 193 | return; |
| 194 | } |
| 195 | writeChar(out, c); |
| 196 | } |
| 197 | private void quoteSeen(Writer out) throws IOException { |
| 198 | int c; |
| 199 | while ((c = in.read()) != -1) { |
| 200 | if (c == '\\') { |
| 201 | escapeSeen(out); |
| 202 | } else if (c == '"') { |
| 203 | writeChar(out, c); |
| 204 | return; |
| 205 | } else { |
| 206 | writeChar(out, c); |
| 207 | } |
| 208 | } |
| 209 | } |
| 210 | |
| 211 | private String needOpenBrace(Properties p, NameParsedListener l, char cause) |
| 212 | throws ApplyException, IOException |
| 213 | { |
| 214 | int c; |
| 215 | if ((c = in.read()) == -1) { |
| 216 | // Caused by "foo$" or "bar#" input escape the cause and |
| 217 | // return |
| 218 | return "\\" + cause; |
| 219 | } |
| 220 | if (c == '{') { |
| 221 | return scanName(p, l); |
| 222 | } |
| 223 | // Caused by "foo$bar" input, just give up on the |
| 224 | // replacement and return the escaped cause plus bad char. |
| 225 | return "\\" + cause + (char)c; |
| 226 | } |
| 227 | private String scanName(Properties p, NameParsedListener l) |
| 228 | throws IOException, ApplyException |
| 229 | { |
| 230 | StringBuffer name = new StringBuffer(); |
| 231 | |
| 232 | int c; |
| 233 | while ((c = in.read()) != -1) { |
| 234 | if (c == '}') { |
| 235 | return l.nameParsed(name.toString()); |
| 236 | } else if (c == '$') { |
| 237 | name.append(needOpenBrace(p, l, '$')); |
| 238 | } else if (c == '\\') { |
| 239 | StringWriter sw = new StringWriter(1); |
| 240 | escapeSeen(sw); |
| 241 | name.append(sw.getBuffer()); |
| 242 | } else if (c == '#') { |
| 243 | throw new ApplyException(error_info + "parse error at: " |
| 244 | + in.getLineNumber() |
| 245 | + ", nested calls not allowed in ${" |
| 246 | + name.toString()); |
| 247 | } else if (c == '\n') { |
| 248 | throw new ApplyException(error_info + "parse error at: " |
| 249 | + in.getLineNumber() |
| 250 | + ", newline embedded in ${" |
| 251 | + name.toString()); |
| 252 | } else { |
| 253 | name.append((char)c); |
| 254 | } |
| 255 | } |
| 256 | throw new ApplyException("at: " + in.getLineNumber() + " EOF looking for } "); |
| 257 | } |
| 258 | |
| 259 | /** |
| 260 | * Write c to out, but skipping CR characters. |
| 261 | */ |
| 262 | private void writeChar(Writer out, int c) throws IOException { |
| 263 | if (c == '\r') { |
| 264 | return; |
| 265 | } |
| 266 | out.write(c); |
| 267 | } |
| 268 | |
| 269 | private String error_info = ""; |
| 270 | private LineNumberReader in; |
| 271 | private Object object; |
| 272 | } |