/*
* Copyright (c) 2008, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.wso2.carbon.governance.api.schema;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.*;
import org.apache.axiom.om.OMAttribute;
import org.apache.axiom.om.OMElement;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.jaxen.JaxenException;
import org.wso2.carbon.governance.api.common.dataobjects.GovernanceArtifact;
import org.wso2.carbon.governance.api.exception.GovernanceException;
import org.wso2.carbon.governance.api.schema.dataobjects.Schema;
import org.wso2.carbon.governance.api.util.GovernanceConstants;
import org.wso2.carbon.governance.api.util.GovernanceUtils;
import org.wso2.carbon.registry.core.Registry;
import org.wso2.carbon.registry.core.Resource;
import org.wso2.carbon.registry.core.exceptions.RegistryException;
import org.wso2.carbon.registry.core.utils.RegistryUtils;
import javax.xml.namespace.QName;
/**
* This provides the management functionality for schema artifacts stored on the
* registry.
*/
public class SchemaManager {
private static final Log log = LogFactory.getLog(SchemaManager.class);
private Registry registry;
/**
* Constructor accepting an instance of the registry to use.
*
* @param registry the instance of the registry.
*/
public SchemaManager(Registry registry) {
this.registry = registry;
}
/**
* Creates a new schema artifact from the given URL.
*
* @param url the given URL.
*
* @return the artifact added.
* @throws GovernanceException if the operation failed.
*/
public Schema newSchema(String url) throws GovernanceException {
String schemaId = UUID.randomUUID().toString();
Schema schema = new Schema(schemaId, url);
schema.associateRegistry(registry);
return schema;
}
/**
* Adds the given schema artifact to the registry.
*
* @param schema the schema artifact.
*
* @throws GovernanceException if the operation failed.
*/
public void addSchema(Schema schema) throws GovernanceException {
boolean succeeded = false;
try {
registry.beginTransaction();
String url = schema.getUrl();
Resource schemaResource = registry.newResource();
schemaResource.setMediaType(GovernanceConstants.SCHEMA_MEDIA_TYPE);
// setting the schema content
setContent(schema, schemaResource);
String tmpPath;
if (schema.getQName() != null) {
tmpPath = "/" + schema.getQName().getLocalPart();
} else {
tmpPath = RegistryUtils.getResourceName(new URL(url).getFile().replace("~", ""));
}
registry.importResource(tmpPath, url, schemaResource);
schema.updatePath();
schema.loadSchemaDetails();
succeeded = true;
} catch (RegistryException e) {
String msg = "Error in adding the Schema. schema id: " + schema.getId() + ".";
log.error(msg, e);
throw new GovernanceException(msg, e);
} catch (MalformedURLException e) {
String msg = "Malformed schema url provided. url: " + schema.getUrl() + ".";
log.error(msg, e);
throw new GovernanceException(msg, e);
} finally {
if (succeeded) {
try {
registry.commitTransaction();
} catch (RegistryException e) {
String msg =
"Error in committing transactions. Add schema failed: schema id: " +
schema.getId() + ", path: " + schema.getPath() + ".";
log.error(msg, e);
}
} else {
try {
registry.rollbackTransaction();
} catch (RegistryException e) {
String msg =
"Error in rolling back transactions. Add schema failed: schema id: " +
schema.getId() + ", path: " + schema.getPath() + ".";
log.error(msg, e);
}
}
}
}
/**
* Updates the given schema artifact on the registry.
*
* @param schema the schema artifact.
*
* @throws GovernanceException if the operation failed.
*/
public void updateSchema(Schema schema) throws GovernanceException {
if (schema.getSchemaElement() == null) {
// there won't be any updates
String msg =
"Updates are only accepted if the schemeElement is available. " +
"So no updates will be done. " + "schema id: " + schema.getId() +
", schema path: " + schema.getPath() + ".";
log.error(msg);
throw new GovernanceException(msg);
}
boolean succeeded = false;
try {
registry.beginTransaction();
// getting the old schema.
Schema oldSchema = getSchema(schema.getId());
if (oldSchema == null) {
addSchema(schema);
return;
}
// we are expecting only the OMElement to be different.
Resource schemaResource = registry.newResource();
schemaResource.setMediaType(GovernanceConstants.SCHEMA_MEDIA_TYPE);
// setting the schema content
setContent(schema, schemaResource);
registry.put(oldSchema.getPath(), schemaResource);
schema.updatePath();
schema.loadSchemaDetails();
succeeded = true;
} catch (RegistryException e) {
String msg =
"Error in updating the schema, schema id: " + schema.getId() +
", schema path: " + schema.getPath() + ".";
log.error(msg, e);
throw new GovernanceException(msg, e);
} finally {
if (succeeded) {
try {
registry.commitTransaction();
} catch (RegistryException e) {
String msg =
"Error in committing transactions. Update schema failed: " +
"schema id: " + schema.getId() + ", path: " + schema.getPath() +
".";
log.error(msg, e);
}
} else {
try {
registry.rollbackTransaction();
} catch (RegistryException e) {
String msg =
"Error in rolling back transactions. Update schema failed: " +
"schema id: " + schema.getId() + ", path: " + schema.getPath() +
".";
log.error(msg, e);
}
}
}
}
/**
* Fetches the given schema artifact on the registry.
*
* @param schemaId the identifier of the schema artifact.
*
* @return the schema artifact.
* @throws GovernanceException if the operation failed.
*/
public Schema getSchema(String schemaId) throws GovernanceException {
GovernanceArtifact artifact =
GovernanceUtils.retrieveGovernanceArtifactById(registry, schemaId);
if (artifact != null && !(artifact instanceof Schema)) {
String msg = "The artifact request is not a Schema. id: " + schemaId + ".";
log.error(msg);
throw new GovernanceException(msg);
}
return (Schema) artifact;
}
/**
* Removes the given schema artifact from the registry.
*
* @param schemaId the identifier of the schema artifact.
*
* @throws GovernanceException if the operation failed.
*/
public void removeSchema(String schemaId) throws GovernanceException {
GovernanceUtils.removeArtifact(registry, schemaId);
}
/**
* Sets content of the given schema artifact to the given resource on the
* registry.
*
* @param schema the schema artifact.
* @param schemaResource the content resource.
*
* @throws GovernanceException if the operation failed.
*/
protected void setContent(Schema schema, Resource schemaResource) throws GovernanceException {
if (schema.getSchemaElement() != null) {
OMElement contentElement = schema.getSchemaElement().cloneOMElement();
try {
for (String importType : new String[] {"import", "include", "redefine"}) {
List<OMElement> schemaImports =
GovernanceUtils.evaluateXPathToElements("//xsd:" + importType,
contentElement);
for (OMElement schemaImport : schemaImports) {
OMAttribute location = schemaImport.getAttribute(
new QName("schemaLocation"));
if (location != null) {
String path = location.getAttributeValue();
if (path.indexOf(";version:") > 0) {
location.setAttributeValue(path.substring(0,
path.lastIndexOf(";version:")));
}
}
}
}
} catch (JaxenException ignore) { }
String schemaContent = contentElement.toString();
try {
schemaResource.setContent(schemaContent);
} catch (RegistryException e) {
String msg =
"Error in setting the content from schema, schema id: " + schema.getId() +
", schema path: " + schema.getPath() + ".";
log.error(msg, e);
throw new GovernanceException(msg, e);
}
}
// and set all the attributes as properties.
String[] attributeKeys = schema.getAttributeKeys();
if (attributeKeys != null) {
Properties properties = new Properties();
for (String attributeKey : attributeKeys) {
String[] attributeValues = schema.getAttributes(attributeKey);
if (attributeValues != null) {
// The list obtained from the Arrays#asList method is
// immutable. Therefore,
// we create a mutable object out of it before adding it as
// a property.
properties.put(attributeKey,
new ArrayList<String>(Arrays.asList(attributeValues)));
}
}
schemaResource.setProperties(properties);
}
schemaResource.addProperty(GovernanceConstants.ARTIFACT_ID_PROP_KEY, schema.getId());
}
/**
* Finds all schema artifacts matching the given filter criteria.
*
* @param criteria the filter criteria to be matched.
*
* @return the schema artifacts that match.
* @throws GovernanceException if the operation failed.
*/
public Schema[] findSchemas(SchemaFilter criteria) throws GovernanceException {
List<Schema> schemas = new ArrayList<Schema>();
for (Schema schema : getAllSchemas()) {
if (schema != null) {
if (criteria.matches(schema)) {
schemas.add(schema);
}
}
}
return schemas.toArray(new Schema[schemas.size()]);
}
/**
* Finds all schema artifacts on the registry.
*
* @return all schema artifacts on the registry.
* @throws GovernanceException if the operation failed.
*/
public Schema[] getAllSchemas() throws GovernanceException {
List<String> schemaPaths =
Arrays.asList(GovernanceUtils.getResultPaths(registry,
GovernanceConstants.SCHEMA_MEDIA_TYPE));
Collections.sort(schemaPaths, new Comparator<String>() {
public int compare(String o1, String o2) {
// First order by name
int result = RegistryUtils.getResourceName(o1).compareToIgnoreCase(
RegistryUtils.getResourceName(o2));
if (result != 0) {
return result;
}
// Then order by namespace
return o1.compareToIgnoreCase(o2);
}
});
List<Schema> schemas = new ArrayList<Schema>();
for (String schemaPath : schemaPaths) {
GovernanceArtifact artifact =
GovernanceUtils.retrieveGovernanceArtifactByPath(registry, schemaPath);
schemas.add((Schema) artifact);
}
return schemas.toArray(new Schema[schemas.size()]);
}
}