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1
16 package org.apache.cocoon.components.source.impl;
17
18
19 import java.io.InputStream  ;
20 import java.io.IOException ;
21 import java.io.ByteArrayInputStream ;
22 import java.net.MalformedURLException ;
23 import java.util.Map ;
24
25 import org.apache.avalon.framework.configuration.ConfigurationException;
26 import org.apache.avalon.framework.logger.Logger;
27 import org.apache.avalon.framework.service.ServiceException;
28 import org.apache.avalon.framework.service.ServiceManager;
29 import org.apache.avalon.framework.service.ServiceSelector;
30
31 import org.apache.excalibur.source.SourceException;
32 import org.apache.excalibur.source.impl.AbstractSource;
33
34 import org.apache.cocoon.components.modules.input.InputModule;
35
36 import org.apache.commons.jxpath.JXPathContext;
37
38
39
55
56 public class ModuleSource
57 extends AbstractSource {
58
59 private final static String SCHEME = "module";
60 private String attributeType;
61 private String attributeName;
62 private String xPath;
63 private ServiceManager manager;
64 private Map objectModel;
65 private Logger logger;
66
67
71 public ModuleSource( Map objectModel, String uri,
72 ServiceManager manager, Logger logger )
73 throws MalformedURLException {
74
75 this.objectModel = objectModel;
76 this.manager = manager;
77 this.logger = logger;
78
79 setSystemId( uri );
80
81 int start = 0;
83 int end = uri.indexOf( ':' );
84 if ( end == -1 )
85 throw new MalformedURLException ("Malformed uri for module source (cannot find scheme) : " + uri);
86
87 String scheme = uri.substring( start, end );
88 if ( !SCHEME.equals( scheme ) )
89 throw new MalformedURLException ("Malformed uri for a module source : " + uri);
90
91 setScheme( scheme );
92
93 start = end + 1;
95 end = uri.indexOf( ':', start );
96 if ( end == -1 ) {
97 throw new MalformedURLException ("Malformed uri for module source (cannot find attribute type) : " + uri);
98 }
99 this.attributeType = uri.substring( start, end );
100
101 start = end + 1;
103 end = uri.indexOf( '#', start );
104
105 if ( end == -1 )
106 end = uri.length();
107
108 if ( end == start )
109 throw new MalformedURLException ("Malformed uri for module source (cannot find attribute name) : " + uri);
110
111 this.attributeName = uri.substring( start, end );
112
113 start = end + 1;
115 this.xPath = start < uri.length() ? uri.substring( start ) : "";
116 }
117
118
123 public InputStream getInputStream() throws IOException , SourceException {
124 if ( this.logger.isDebugEnabled() ) {
125 this.logger.debug( "Getting InputStream for " + getURI() );
126 }
127
128 Object obj = getInputAttribute( this.attributeType, this.attributeName );
129 if ( obj == null )
130 throw new SourceException( " The attribute: " + this.attributeName +
131 " is empty" );
132
133 if ( !(this.xPath.length() == 0 || this.xPath.equals( "/" )) ) {
134 JXPathContext context = JXPathContext.newContext( obj );
135 obj = context.getValue( this.xPath );
136
137 if ( obj == null )
138 throw new SourceException( "the xpath: " + this.xPath +
139 " applied on the attribute: " +
140 this.attributeName +
141 " returns null");
142 }
143
144 if ( obj instanceof InputStream ) {
145 return (InputStream )obj;
146 } else if ( obj instanceof String ) {
147 return new ByteArrayInputStream ( ((String )obj).getBytes() );
148 } else if (obj instanceof byte[]) {
149 return new ByteArrayInputStream ((byte[]) obj);
150 } else {
151 throw new SourceException( "The object type: " + obj.getClass() +
152 " could not be serialized as a InputStream " + obj );
153 }
154 }
155
156
162 public boolean exists() {
163 boolean exists = false;
164 try {
165 exists = getInputAttribute( this.attributeType, this.attributeName ) != null;
166 } catch ( SourceException e ) {
167 exists = false;
168 }
169 return exists;
170 }
171
172 private Object getInputAttribute( String inputModuleName, String attributeName )
173 throws SourceException {
174 Object obj;
175 ServiceSelector selector = null;
176 InputModule inputModule = null;
177 try {
178 selector = (ServiceSelector) this.manager.lookup( InputModule.ROLE + "Selector" );
179 inputModule = (InputModule) selector.select( inputModuleName );
180 obj = inputModule.getAttribute( attributeName, null, this.objectModel );
181
182 } catch ( ServiceException e ) {
183 throw new SourceException( "Could not find an InputModule of the type " +
184 inputModuleName , e );
185 } catch ( ConfigurationException e ) {
186 throw new SourceException( "Could not find an attribute: " + attributeName +
187 " from the InputModule " + inputModuleName, e );
188 } finally {
189 if ( inputModule != null ) selector.release( inputModule );
190 this.manager.release( selector );
191 }
192
193 return obj;
194 }
195 }
196 |
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