Jena 3.0.1 和 3.1.0，RDF/XML 到 JSON-LD 缺少前缀
Jena 3.0.1 and 3.1.0, RDF/XML to JSON-LD missing prefixes
我们最近从 3.0.1 切换到 Jena 3.1.0，发现 Jena 将 JSON-LD 写入字符串格式的方式发生了变化。
下面是 JSON-LD 在 Jena 3.0.1 中的样子：
{
"@graph" : [ {
"@id" : "data:4d1a75b0-484f-4dfa-998f-4382f34e411f",
"@type" : "assertion:assertion",
"data:UUID" : "4d1a75b0-484f-4dfa-998f-4382f34e411f"
}, {
"@id" : "data:UUID",
"@type" : "owl:DatatypeProperty",
"rdfs:label" : {
"@language" : "en",
"@value" : "UUID"
}
}, {
"@id" : "urn:example.data.1.0",
"@type" : "owl:Ontology",
"rdfs:comment" : {
"@language" : "en",
"@value" : "This is an OWL ontology to describe data."
},
"rdfs:label" : {
"@language" : "en",
"@value" : "Data ontology"
},
"owl:versionInfo" : "1.0"
}, {
"@id" : "assertion:assertion",
"@type" : "owl:Class",
"subClassOf" : "data:entity"
} ],
"@context" : {
"comment" : {
"@id" : "http://www.w3.org/2000/01/rdf-schema#comment",
"@type" : "http://www.w3.org/1999/02/22-rdf-syntax-ns#langString"
},
"label" : {
"@id" : "http://www.w3.org/2000/01/rdf-schema#label",
"@type" : "http://www.w3.org/1999/02/22-rdf-syntax-ns#langString"
},
"versionInfo" : {
"@id" : "http://www.w3.org/2002/07/owl#versionInfo",
"@type" : "http://www.w3.org/2001/XMLSchema#string"
},
"UUID" : {
"@id" : "urn:example.data#UUID",
"@type" : "http://www.w3.org/2001/XMLSchema#string"
},
"subClassOf" : {
"@id" : "http://www.w3.org/2000/01/rdf-schema#subClassOf",
"@type" : "@id"
},
"data" : "urn:example.data#",
"rdf" : "http://www.w3.org/1999/02/22-rdf-syntax-ns#",
"owl" : "http://www.w3.org/2002/07/owl#",
"xsd" : "http://www.w3.org/2001/XMLSchema#",
"rdfs" : "http://www.w3.org/2000/01/rdf-schema#",
"assertion" : "urn:example.data.assertion#"
}
}
下面是 JSON-LD 在 Jena 3.1.0 中的样子：
{
"@graph" : [ {
"@id" : "data:4d1a75b0-484f-4dfa-998f-4382f34e411f",
"@type" : "assertion:assertion",
"UUID" : "4d1a75b0-484f-4dfa-998f-4382f34e411f"
}, {
"@id" : "data:UUID",
"@type" : "owl:DatatypeProperty",
"label" : {
"@language" : "en",
"@value" : "UUID"
}
}, {
"@id" : "urn:example.data.1.0",
"@type" : "owl:Ontology",
"comment" : {
"@language" : "en",
"@value" : "This is an OWL ontology to describe data."
},
"label" : {
"@language" : "en",
"@value" : "Data ontology"
},
"versionInfo" : "1.0"
}, {
"@id" : "assertion:assertion",
"@type" : "owl:Class",
"subClassOf" : "data:entity"
} ],
"@context" : {
"comment" : {
"@id" : "http://www.w3.org/2000/01/rdf-schema#comment"
},
"label" : {
"@id" : "http://www.w3.org/2000/01/rdf-schema#label"
},
"versionInfo" : {
"@id" : "http://www.w3.org/2002/07/owl#versionInfo"
},
"UUID" : {
"@id" : "urn:example.data#UUID"
},
"subClassOf" : {
"@id" : "http://www.w3.org/2000/01/rdf-schema#subClassOf",
"@type" : "@id"
},
"data" : "urn:example.data#",
"rdf" : "http://www.w3.org/1999/02/22-rdf-syntax-ns#",
"owl" : "http://www.w3.org/2002/07/owl#",
"xsd" : "http://www.w3.org/2001/XMLSchema#",
"rdfs" : "http://www.w3.org/2000/01/rdf-schema#",
"assertion" : "urn:example.data.assertion#"
}
}
两者的区别在于命名空间前缀data:和rfds:不再出现在UUID和label等标签的旁边。
根据 Jena，JSON-LD 是有效的，但不幸的是我们需要将 JSON-LD 发送到期望这些前缀存在的服务器。
有什么办法可以控制输出吗？我们不是耶拿方面的专家，请谨慎对待我们:(
以下是 XML 格式的原始邮件：
<rdf:RDF
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
xmlns:data="urn:example.data#"
xmlns:assertion="urn:example.data.assertion#"
xmlns:xsd="http://www.w3.org/2001/XMLSchema#"
xmlns:owl="http://www.w3.org/2002/07/owl#">
<owl:Ontology rdf:about="urn:example.data.1.0">
<owl:versionInfo>1.0</owl:versionInfo>
<rdfs:label xml:lang="en">Data ontology</rdfs:label>
<rdfs:comment xml:lang="en">This is an OWL ontology to describe data.</rdfs:comment>
</owl:Ontology>
<owl:Class rdf:about="urn:example.data.assertion#assertion">
<rdfs:subClassOf rdf:resource="urn:example.data#entity"/>
</owl:Class>
<owl:DatatypeProperty rdf:about="urn:example.data#UUID">
<rdfs:label xml:lang="en">UUID</rdfs:label>
</owl:DatatypeProperty>
<assertion:assertion rdf:about="urn:example.data#4d1a75b0-484f-4dfa-998f-4382f34e411f">
<data:UUID>4d1a75b0-484f-4dfa-998f-4382f34e411f</data:UUID>
</assertion:assertion>
</rdf:RDF>
下面是我们的最小代码 运行:
InputStream inputStream = this.getClass().getClassLoader().getResourceAsStream("convert-xml-json-test/temp.xml");
String inputXml = IOUtils.toString(inputStream);
// Convert the XML to RDF model
StringReader stringReader = new StringReader(inputXml);
Model model = ModelFactory.createDefaultModel();
model.read(stringReader, null, RDFLanguages.RDFXML.getLabel());
// Convert the model to JSON String
ByteArrayOutputStream out = new ByteArrayOutputStream();
model.write(out, RDFLanguages.JSONLD.getLabel());
outputJson = out.toString(StandardCharsets.UTF_8.toString());
我们非常有信心这是由于 Jena 的变化，因为我们的最小测试项目仅包括 Jena，如下面的 mvn dependency:tree
+- org.apache.jena:jena-tdb:jar:3.1.0:compile
| +- org.apache.jena:jena-arq:jar:3.1.0:compile
| | +- org.apache.jena:jena-core:jar:3.1.0:compile
| | | +- org.apache.jena:jena-iri:jar:3.1.0:compile
| | | +- xerces:xercesImpl:jar:2.11.0:compile
| | | | \- xml-apis:xml-apis:jar:1.4.01:compile
| | | +- commons-cli:commons-cli:jar:1.3:compile
| | | \- org.apache.jena:jena-base:jar:3.1.0:compile
| | | \- com.github.andrewoma.dexx:collection:jar:0.6:compile
| | +- org.apache.jena:jena-shaded-guava:jar:3.1.0:compile
| | +- org.apache.httpcomponents:httpclient:jar:4.2.6:compile
| | | +- org.apache.httpcomponents:httpcore:jar:4.2.5:compile
| | | \- commons-codec:commons-codec:jar:1.6:compile
| | +- com.github.jsonld-java:jsonld-java:jar:0.7.0:compile
| | | +- com.fasterxml.jackson.core:jackson-core:jar:2.3.3:compile
| | | +- com.fasterxml.jackson.core:jackson-databind:jar:2.3.3:compile
| | | | \- com.fasterxml.jackson.core:jackson-annotations:jar:2.3.0:compile
| | | \- commons-io:commons-io:jar:2.4:compile
| | +- org.apache.httpcomponents:httpclient-cache:jar:4.2.6:compile
| | +- org.apache.thrift:libthrift:jar:0.9.2:compile
| | +- org.slf4j:jcl-over-slf4j:jar:1.7.20:compile
| | +- org.apache.commons:commons-csv:jar:1.0:compile
| | \- org.apache.commons:commons-lang3:jar:3.3.2:compile
| \- org.slf4j:slf4j-api:jar:1.7.20:compile
\- junit:junit:jar:4.11:test
\- org.hamcrest:hamcrest-core:jar:1.3:test
这是我们为解决前缀问题而创建的代码。我们已经发送了 100 多条消息，没有出现任何错误。该代码首先解析 @context 部分中的 OWL ontology 并构建从非前缀到前缀的映射。然后遍历@graph并应用前缀。
package utils.helper;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.node.ObjectNode;
public class ReapplyJenaPrefixes {
public String reapplyPrefixes(String jsonString) throws IOException {
ObjectMapper jacksonParser = new ObjectMapper();
JsonNode jsonNode = jacksonParser.readTree(jsonString);
Map<String, String> prefixMap = buildPrefixedTagMap(jsonNode);
applyPrefixes(jsonNode, prefixMap);
return jacksonParser.writeValueAsString(jsonNode);
}
public void reapplyPrefixes(JsonNode node) {
Map<String, String> prefixMap = buildPrefixedTagMap(node);
applyPrefixes(node, prefixMap);
}
private Map<String, String> buildPrefixedTagMap(JsonNode node) {
Map<String, Boolean> filteredWords = new HashMap<String, Boolean>();
filteredWords.put("subClassOf", true);
JsonNode contextNode = node.get("@context");
List<Entry<String, String>> tagList = new ArrayList<Entry<String, String>>();
Map<String, String> prefixMap = new HashMap<String, String>();
Map<String, String> prefixedTagMap = new HashMap<String, String>();
Iterator<Entry<String, JsonNode>> iterator = contextNode.fields();
JsonNode currentNode;
String currentNodeName;
EntryImpl<String, String> tagEntry;
while(iterator.hasNext()) {
Entry<String, JsonNode> e = iterator.next();
currentNode = e.getValue();
currentNodeName = e.getKey();
if(currentNode.isTextual()) {
prefixMap.put(currentNode.textValue(), currentNodeName);
} else if(!filteredWords.containsKey(currentNodeName)) {
tagEntry = new EntryImpl<String, String>(currentNodeName, currentNode.get("@id").asText());
tagList.add(tagEntry);
}
}
String tagName;
String namespace;
String prefix;
for(Entry<String, String> e : tagList) {
tagName = e.getKey();
namespace = e.getValue();
// strip the tagName
namespace = namespace.substring(0, namespace.length() - tagName.length());
// lookup the prefix
prefix = prefixMap.get(namespace);
prefixedTagMap.put(tagName, prefix+":"+tagName);
}
return prefixedTagMap;
}
private void applyPrefixes(JsonNode node, Map<String, String> prefixMap) {
JsonNode contextNode = node.get("@graph");
ObjectNode currentNode = null;
String prefixedTag = null;
String fieldName = null;
JsonNode topLevelFieldNode = null;
Iterator<String> topLevelFieldNameIterator = null;
List<String> topLevelFieldNameList;
JsonNode subLevelFieldNode = null;
Iterator<String> subLevelFieldNameIterator = null;
List<String> subLevelFieldNameList;
Iterator<JsonNode> arrayIterator = contextNode.elements();
while(arrayIterator.hasNext()) {
currentNode = (ObjectNode)arrayIterator.next();
// Can't modify an iterator while iterating so store the field names in a list first
topLevelFieldNameIterator = currentNode.fieldNames();
topLevelFieldNameList = new ArrayList<String>();
while(topLevelFieldNameIterator.hasNext()) {
fieldName = topLevelFieldNameIterator.next();
if(fieldName.charAt(0) != '@') {
topLevelFieldNameList.add(fieldName);
}
}
for(String topLevelFieldName : topLevelFieldNameList) {
topLevelFieldNode = currentNode.get(topLevelFieldName);
prefixedTag = prefixMap.get(topLevelFieldName);
if(prefixedTag != null
// Data tags don't seem to have prefixes on them
&& (topLevelFieldNode.isTextual()
&& !topLevelFieldNode.textValue().startsWith("data:"))) {
currentNode.remove(topLevelFieldName);
currentNode.set(prefixedTag, topLevelFieldNode);
}
if(topLevelFieldNode.isObject()) {
// Can't modify an iterator while iterating so store the field names in a list first
subLevelFieldNameIterator = topLevelFieldNode.fieldNames();
subLevelFieldNameList = new ArrayList<String>();
while(subLevelFieldNameIterator.hasNext()) {
fieldName = subLevelFieldNameIterator.next();
if(fieldName.charAt(0) != '@') {
subLevelFieldNameList.add(fieldName);
}
}
for(String subLevelFieldName : subLevelFieldNameList) {
subLevelFieldNode = topLevelFieldNode.get(subLevelFieldName);
prefixedTag = prefixMap.get(topLevelFieldName);
if(prefixedTag != null) {
((ObjectNode)topLevelFieldNode).remove(subLevelFieldName);
((ObjectNode)topLevelFieldNode).set(prefixedTag, subLevelFieldNode);
}
}
}
}
}
}
private class EntryImpl<K, V> implements Entry<K, V> {
private K k;
private V v;
public EntryImpl(K k, V v) {
this.k = k;
this.v = v;
}
@Override
public K getKey() {
return k;
}
@Override
public V getValue() {
return v;
}
@Override
public V setValue(V value) {
V oldV = v;
v = value;
return oldV;
}
}
}
我们最近从 3.0.1 切换到 Jena 3.1.0，发现 Jena 将 JSON-LD 写入字符串格式的方式发生了变化。
下面是 JSON-LD 在 Jena 3.0.1 中的样子：
{
"@graph" : [ {
"@id" : "data:4d1a75b0-484f-4dfa-998f-4382f34e411f",
"@type" : "assertion:assertion",
"data:UUID" : "4d1a75b0-484f-4dfa-998f-4382f34e411f"
}, {
"@id" : "data:UUID",
"@type" : "owl:DatatypeProperty",
"rdfs:label" : {
"@language" : "en",
"@value" : "UUID"
}
}, {
"@id" : "urn:example.data.1.0",
"@type" : "owl:Ontology",
"rdfs:comment" : {
"@language" : "en",
"@value" : "This is an OWL ontology to describe data."
},
"rdfs:label" : {
"@language" : "en",
"@value" : "Data ontology"
},
"owl:versionInfo" : "1.0"
}, {
"@id" : "assertion:assertion",
"@type" : "owl:Class",
"subClassOf" : "data:entity"
} ],
"@context" : {
"comment" : {
"@id" : "http://www.w3.org/2000/01/rdf-schema#comment",
"@type" : "http://www.w3.org/1999/02/22-rdf-syntax-ns#langString"
},
"label" : {
"@id" : "http://www.w3.org/2000/01/rdf-schema#label",
"@type" : "http://www.w3.org/1999/02/22-rdf-syntax-ns#langString"
},
"versionInfo" : {
"@id" : "http://www.w3.org/2002/07/owl#versionInfo",
"@type" : "http://www.w3.org/2001/XMLSchema#string"
},
"UUID" : {
"@id" : "urn:example.data#UUID",
"@type" : "http://www.w3.org/2001/XMLSchema#string"
},
"subClassOf" : {
"@id" : "http://www.w3.org/2000/01/rdf-schema#subClassOf",
"@type" : "@id"
},
"data" : "urn:example.data#",
"rdf" : "http://www.w3.org/1999/02/22-rdf-syntax-ns#",
"owl" : "http://www.w3.org/2002/07/owl#",
"xsd" : "http://www.w3.org/2001/XMLSchema#",
"rdfs" : "http://www.w3.org/2000/01/rdf-schema#",
"assertion" : "urn:example.data.assertion#"
}
}
下面是 JSON-LD 在 Jena 3.1.0 中的样子：
{
"@graph" : [ {
"@id" : "data:4d1a75b0-484f-4dfa-998f-4382f34e411f",
"@type" : "assertion:assertion",
"UUID" : "4d1a75b0-484f-4dfa-998f-4382f34e411f"
}, {
"@id" : "data:UUID",
"@type" : "owl:DatatypeProperty",
"label" : {
"@language" : "en",
"@value" : "UUID"
}
}, {
"@id" : "urn:example.data.1.0",
"@type" : "owl:Ontology",
"comment" : {
"@language" : "en",
"@value" : "This is an OWL ontology to describe data."
},
"label" : {
"@language" : "en",
"@value" : "Data ontology"
},
"versionInfo" : "1.0"
}, {
"@id" : "assertion:assertion",
"@type" : "owl:Class",
"subClassOf" : "data:entity"
} ],
"@context" : {
"comment" : {
"@id" : "http://www.w3.org/2000/01/rdf-schema#comment"
},
"label" : {
"@id" : "http://www.w3.org/2000/01/rdf-schema#label"
},
"versionInfo" : {
"@id" : "http://www.w3.org/2002/07/owl#versionInfo"
},
"UUID" : {
"@id" : "urn:example.data#UUID"
},
"subClassOf" : {
"@id" : "http://www.w3.org/2000/01/rdf-schema#subClassOf",
"@type" : "@id"
},
"data" : "urn:example.data#",
"rdf" : "http://www.w3.org/1999/02/22-rdf-syntax-ns#",
"owl" : "http://www.w3.org/2002/07/owl#",
"xsd" : "http://www.w3.org/2001/XMLSchema#",
"rdfs" : "http://www.w3.org/2000/01/rdf-schema#",
"assertion" : "urn:example.data.assertion#"
}
}
两者的区别在于命名空间前缀data:和rfds:不再出现在UUID和label等标签的旁边。
根据 Jena，JSON-LD 是有效的，但不幸的是我们需要将 JSON-LD 发送到期望这些前缀存在的服务器。
有什么办法可以控制输出吗？我们不是耶拿方面的专家，请谨慎对待我们:(
以下是 XML 格式的原始邮件：
<rdf:RDF
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
xmlns:data="urn:example.data#"
xmlns:assertion="urn:example.data.assertion#"
xmlns:xsd="http://www.w3.org/2001/XMLSchema#"
xmlns:owl="http://www.w3.org/2002/07/owl#">
<owl:Ontology rdf:about="urn:example.data.1.0">
<owl:versionInfo>1.0</owl:versionInfo>
<rdfs:label xml:lang="en">Data ontology</rdfs:label>
<rdfs:comment xml:lang="en">This is an OWL ontology to describe data.</rdfs:comment>
</owl:Ontology>
<owl:Class rdf:about="urn:example.data.assertion#assertion">
<rdfs:subClassOf rdf:resource="urn:example.data#entity"/>
</owl:Class>
<owl:DatatypeProperty rdf:about="urn:example.data#UUID">
<rdfs:label xml:lang="en">UUID</rdfs:label>
</owl:DatatypeProperty>
<assertion:assertion rdf:about="urn:example.data#4d1a75b0-484f-4dfa-998f-4382f34e411f">
<data:UUID>4d1a75b0-484f-4dfa-998f-4382f34e411f</data:UUID>
</assertion:assertion>
</rdf:RDF>
下面是我们的最小代码 运行:
InputStream inputStream = this.getClass().getClassLoader().getResourceAsStream("convert-xml-json-test/temp.xml");
String inputXml = IOUtils.toString(inputStream);
// Convert the XML to RDF model
StringReader stringReader = new StringReader(inputXml);
Model model = ModelFactory.createDefaultModel();
model.read(stringReader, null, RDFLanguages.RDFXML.getLabel());
// Convert the model to JSON String
ByteArrayOutputStream out = new ByteArrayOutputStream();
model.write(out, RDFLanguages.JSONLD.getLabel());
outputJson = out.toString(StandardCharsets.UTF_8.toString());
我们非常有信心这是由于 Jena 的变化，因为我们的最小测试项目仅包括 Jena，如下面的 mvn dependency:tree
+- org.apache.jena:jena-tdb:jar:3.1.0:compile
| +- org.apache.jena:jena-arq:jar:3.1.0:compile
| | +- org.apache.jena:jena-core:jar:3.1.0:compile
| | | +- org.apache.jena:jena-iri:jar:3.1.0:compile
| | | +- xerces:xercesImpl:jar:2.11.0:compile
| | | | \- xml-apis:xml-apis:jar:1.4.01:compile
| | | +- commons-cli:commons-cli:jar:1.3:compile
| | | \- org.apache.jena:jena-base:jar:3.1.0:compile
| | | \- com.github.andrewoma.dexx:collection:jar:0.6:compile
| | +- org.apache.jena:jena-shaded-guava:jar:3.1.0:compile
| | +- org.apache.httpcomponents:httpclient:jar:4.2.6:compile
| | | +- org.apache.httpcomponents:httpcore:jar:4.2.5:compile
| | | \- commons-codec:commons-codec:jar:1.6:compile
| | +- com.github.jsonld-java:jsonld-java:jar:0.7.0:compile
| | | +- com.fasterxml.jackson.core:jackson-core:jar:2.3.3:compile
| | | +- com.fasterxml.jackson.core:jackson-databind:jar:2.3.3:compile
| | | | \- com.fasterxml.jackson.core:jackson-annotations:jar:2.3.0:compile
| | | \- commons-io:commons-io:jar:2.4:compile
| | +- org.apache.httpcomponents:httpclient-cache:jar:4.2.6:compile
| | +- org.apache.thrift:libthrift:jar:0.9.2:compile
| | +- org.slf4j:jcl-over-slf4j:jar:1.7.20:compile
| | +- org.apache.commons:commons-csv:jar:1.0:compile
| | \- org.apache.commons:commons-lang3:jar:3.3.2:compile
| \- org.slf4j:slf4j-api:jar:1.7.20:compile
\- junit:junit:jar:4.11:test
\- org.hamcrest:hamcrest-core:jar:1.3:test
这是我们为解决前缀问题而创建的代码。我们已经发送了 100 多条消息，没有出现任何错误。该代码首先解析 @context 部分中的 OWL ontology 并构建从非前缀到前缀的映射。然后遍历@graph并应用前缀。
package utils.helper;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.node.ObjectNode;
public class ReapplyJenaPrefixes {
public String reapplyPrefixes(String jsonString) throws IOException {
ObjectMapper jacksonParser = new ObjectMapper();
JsonNode jsonNode = jacksonParser.readTree(jsonString);
Map<String, String> prefixMap = buildPrefixedTagMap(jsonNode);
applyPrefixes(jsonNode, prefixMap);
return jacksonParser.writeValueAsString(jsonNode);
}
public void reapplyPrefixes(JsonNode node) {
Map<String, String> prefixMap = buildPrefixedTagMap(node);
applyPrefixes(node, prefixMap);
}
private Map<String, String> buildPrefixedTagMap(JsonNode node) {
Map<String, Boolean> filteredWords = new HashMap<String, Boolean>();
filteredWords.put("subClassOf", true);
JsonNode contextNode = node.get("@context");
List<Entry<String, String>> tagList = new ArrayList<Entry<String, String>>();
Map<String, String> prefixMap = new HashMap<String, String>();
Map<String, String> prefixedTagMap = new HashMap<String, String>();
Iterator<Entry<String, JsonNode>> iterator = contextNode.fields();
JsonNode currentNode;
String currentNodeName;
EntryImpl<String, String> tagEntry;
while(iterator.hasNext()) {
Entry<String, JsonNode> e = iterator.next();
currentNode = e.getValue();
currentNodeName = e.getKey();
if(currentNode.isTextual()) {
prefixMap.put(currentNode.textValue(), currentNodeName);
} else if(!filteredWords.containsKey(currentNodeName)) {
tagEntry = new EntryImpl<String, String>(currentNodeName, currentNode.get("@id").asText());
tagList.add(tagEntry);
}
}
String tagName;
String namespace;
String prefix;
for(Entry<String, String> e : tagList) {
tagName = e.getKey();
namespace = e.getValue();
// strip the tagName
namespace = namespace.substring(0, namespace.length() - tagName.length());
// lookup the prefix
prefix = prefixMap.get(namespace);
prefixedTagMap.put(tagName, prefix+":"+tagName);
}
return prefixedTagMap;
}
private void applyPrefixes(JsonNode node, Map<String, String> prefixMap) {
JsonNode contextNode = node.get("@graph");
ObjectNode currentNode = null;
String prefixedTag = null;
String fieldName = null;
JsonNode topLevelFieldNode = null;
Iterator<String> topLevelFieldNameIterator = null;
List<String> topLevelFieldNameList;
JsonNode subLevelFieldNode = null;
Iterator<String> subLevelFieldNameIterator = null;
List<String> subLevelFieldNameList;
Iterator<JsonNode> arrayIterator = contextNode.elements();
while(arrayIterator.hasNext()) {
currentNode = (ObjectNode)arrayIterator.next();
// Can't modify an iterator while iterating so store the field names in a list first
topLevelFieldNameIterator = currentNode.fieldNames();
topLevelFieldNameList = new ArrayList<String>();
while(topLevelFieldNameIterator.hasNext()) {
fieldName = topLevelFieldNameIterator.next();
if(fieldName.charAt(0) != '@') {
topLevelFieldNameList.add(fieldName);
}
}
for(String topLevelFieldName : topLevelFieldNameList) {
topLevelFieldNode = currentNode.get(topLevelFieldName);
prefixedTag = prefixMap.get(topLevelFieldName);
if(prefixedTag != null
// Data tags don't seem to have prefixes on them
&& (topLevelFieldNode.isTextual()
&& !topLevelFieldNode.textValue().startsWith("data:"))) {
currentNode.remove(topLevelFieldName);
currentNode.set(prefixedTag, topLevelFieldNode);
}
if(topLevelFieldNode.isObject()) {
// Can't modify an iterator while iterating so store the field names in a list first
subLevelFieldNameIterator = topLevelFieldNode.fieldNames();
subLevelFieldNameList = new ArrayList<String>();
while(subLevelFieldNameIterator.hasNext()) {
fieldName = subLevelFieldNameIterator.next();
if(fieldName.charAt(0) != '@') {
subLevelFieldNameList.add(fieldName);
}
}
for(String subLevelFieldName : subLevelFieldNameList) {
subLevelFieldNode = topLevelFieldNode.get(subLevelFieldName);
prefixedTag = prefixMap.get(topLevelFieldName);
if(prefixedTag != null) {
((ObjectNode)topLevelFieldNode).remove(subLevelFieldName);
((ObjectNode)topLevelFieldNode).set(prefixedTag, subLevelFieldNode);
}
}
}
}
}
}
private class EntryImpl<K, V> implements Entry<K, V> {
private K k;
private V v;
public EntryImpl(K k, V v) {
this.k = k;
this.v = v;
}
@Override
public K getKey() {
return k;
}
@Override
public V getValue() {
return v;
}
@Override
public V setValue(V value) {
V oldV = v;
v = value;
return oldV;
}
}
}