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1
56 package org.objectstyle.cayenne.access.jdbc;
57
58 import java.io.StringReader  ;
59 import java.io.StringWriter ;
60 import java.util.ArrayList ;
61 import java.util.HashMap ;
62 import java.util.List ;
63 import java.util.Map ;
64
65 import org.apache.velocity.VelocityContext;
66 import org.apache.velocity.context.InternalContextAdapterImpl;
67 import org.apache.velocity.exception.ParseErrorException;
68 import org.apache.velocity.runtime.RuntimeConstants;
69 import org.apache.velocity.runtime.RuntimeInstance;
70 import org.apache.velocity.runtime.log.NullLogSystem;
71 import org.apache.velocity.runtime.parser.ParseException;
72 import org.apache.velocity.runtime.parser.node.SimpleNode;
73 import org.objectstyle.cayenne.CayenneRuntimeException;
74
75
82 class SQLTemplateProcessor {
83 private static RuntimeInstance sharedRuntime;
84
85 static final String BINDINGS_LIST_KEY = "bindings";
86 static final String RESULT_COLUMNS_LIST_KEY = "resultColumns";
87 static final String HELPER_KEY = "helper";
88
89 private static final SQLTemplateRenderingUtils sharedUtils =
90 new SQLTemplateRenderingUtils();
91
92 RuntimeInstance velocityRuntime;
93 SQLTemplateRenderingUtils renderingUtils;
94
95 static {
96 initVelocityRuntime();
97 }
98
99 private static void initVelocityRuntime() {
100 sharedRuntime = new RuntimeInstance();
102
103 sharedRuntime.addProperty(RuntimeConstants.RUNTIME_LOG_LOGSYSTEM, new NullLogSystem());
105
106 sharedRuntime.addProperty(
107 RuntimeConstants.RESOURCE_MANAGER_CLASS,
108 SQLTemplateResourceManager.class.getName());
109 sharedRuntime.addProperty("userdirective", BindDirective.class.getName());
110 sharedRuntime.addProperty("userdirective", BindEqualDirective.class.getName());
111 sharedRuntime.addProperty("userdirective", BindNotEqualDirective.class.getName());
112 sharedRuntime.addProperty("userdirective", ResultDirective.class.getName());
113 sharedRuntime.addProperty("userdirective", ChainDirective.class.getName());
114 sharedRuntime.addProperty("userdirective", ChunkDirective.class.getName());
115 try {
116 sharedRuntime.init();
117 }
118 catch (Exception ex) {
119 throw new CayenneRuntimeException(
120 "Error setting up Velocity RuntimeInstance.",
121 ex);
122 }
123 }
124
125 SQLTemplateProcessor() {
126 this.velocityRuntime = sharedRuntime;
127 this.renderingUtils = sharedUtils;
128 }
129
130 SQLTemplateProcessor(
131 RuntimeInstance velocityRuntime,
132 SQLTemplateRenderingUtils renderingUtils) {
133 this.velocityRuntime = velocityRuntime;
134 this.renderingUtils = renderingUtils;
135 }
136
137
143 SQLSelectStatement processSelectTemplate(String template, Map parameters)
144 throws Exception {
145
146 Map internalParameters =
148 (parameters != null && !parameters.isEmpty())
149 ? new HashMap (parameters)
150 : new HashMap (3);
151
152 List bindings = new ArrayList ();
153 List results = new ArrayList ();
154 internalParameters.put(BINDINGS_LIST_KEY, bindings);
155 internalParameters.put(RESULT_COLUMNS_LIST_KEY, results);
156 internalParameters.put(HELPER_KEY, renderingUtils);
157
158 String sql =
159 buildStatement(new VelocityContext(internalParameters), template, parameters);
160
161 ParameterBinding[] bindingsArray = new ParameterBinding[bindings.size()];
162 bindings.toArray(bindingsArray);
163
164 ColumnDescriptor[] resultsArray = new ColumnDescriptor[results.size()];
165 results.toArray(resultsArray);
166 return new SQLSelectStatement(sql, resultsArray, bindingsArray);
167 }
168
169
175 SQLStatement processTemplate(String template, Map parameters) throws Exception {
176 Map internalParameters =
178 (parameters != null && !parameters.isEmpty())
179 ? new HashMap (parameters)
180 : new HashMap (3);
181
182 List bindings = new ArrayList ();
183 internalParameters.put(BINDINGS_LIST_KEY, bindings);
184 internalParameters.put(HELPER_KEY, renderingUtils);
185
186 String sql =
187 buildStatement(new VelocityContext(internalParameters), template, parameters);
188
189 ParameterBinding[] bindingsArray = new ParameterBinding[bindings.size()];
190 bindings.toArray(bindingsArray);
191 return new SQLStatement(sql, bindingsArray);
192 }
193
194 String buildStatement(VelocityContext context, String template, Map parameters)
195 throws Exception {
196
199 StringWriter out = new StringWriter (template.length());
200 SimpleNode nodeTree = null;
201
202 try {
203 nodeTree = velocityRuntime.parse(new StringReader (template), template);
204 }
205 catch (ParseException pex) {
206 throw new ParseErrorException(pex.getMessage());
207 }
208
209 if (nodeTree == null) {
210 throw new CayenneRuntimeException("Error parsing template " + template);
211 }
212
213 InternalContextAdapterImpl ica = new InternalContextAdapterImpl(context);
215 ica.pushCurrentTemplateName(template);
216
217 try {
218 nodeTree.init(ica, velocityRuntime);
219 nodeTree.render(ica, out);
220 return out.toString();
221 }
222 finally {
223 ica.popCurrentTemplateName();
224 }
225 }
226 }
227 |
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