package liquibase.parser.core.xml;
import liquibase.parser.LiquibaseParser;
import liquibase.parser.NamespaceDetails;
import liquibase.parser.NamespaceDetailsFactory;
import liquibase.serializer.LiquibaseSerializer;
import liquibase.util.StreamUtil;
import org.xml.sax.InputSource;
import java.io.IOException;
import java.io.InputStream;
import liquibase.logging.LogFactory;
import liquibase.logging.Logger;
import liquibase.resource.ResourceAccessor;
import liquibase.util.file.FilenameUtils;
import org.xml.sax.SAXException;
import org.xml.sax.ext.EntityResolver2;
/**
* Finds the Liquibase schema from the classpath rather than fetching it over the Internet.
* Also resolve external entities using a resourceAccessor if it's provided
*/
public class LiquibaseEntityResolver implements EntityResolver2 {
private LiquibaseParser parser;
private LiquibaseSerializer serializer;
private ResourceAccessor resourceAccessor;
private String basePath;
private Logger log=LogFactory.getLogger();
public LiquibaseEntityResolver(LiquibaseSerializer serializer) {
this.serializer = serializer;
}
public LiquibaseEntityResolver(LiquibaseParser parser) {
this.parser = parser;
}
/**
* Use the resource accessor to resolve external entities
* @param resourceAccessor Resource accessor to use
* @param basePath Base path to use in the resourceAccessor
*/
public void useResoureAccessor(ResourceAccessor resourceAccessor,String basePath) {
this.resourceAccessor=resourceAccessor;
this.basePath=basePath;
}
@Override
public InputSource resolveEntity(String name, String publicId, String baseURI, String systemId) throws SAXException, IOException {
log.debug("Resolving XML entity name='" + name + "', publicId='" + publicId + "', baseURI='" + baseURI + "', systemId='" + systemId + "'");
InputSource resolved=null;
if(systemId!=null && systemId.toLowerCase().endsWith(".xsd")) {
if (systemId.startsWith("http://www.liquibase.org/xml/ns/migrator/")) {
systemId = systemId.replace("http://www.liquibase.org/xml/ns/migrator/", "http://www.liquibase.org/xml/ns/dbchangelog/");
}
resolved=tryResolveLiquibaseSchema(systemId, publicId);
}
if(resolved==null && resourceAccessor!=null && basePath!=null && systemId!=null) {
resolved=tryResolveFromResourceAccessor(systemId);
}
if (resolved == null) {
log.debug("Unable to resolve XML entity locally. Will load from network.");
}
return resolved;
}
private InputSource tryResolveLiquibaseSchema(String systemId, String publicId) {
if (systemId != null) {
NamespaceDetails namespaceDetails;
if (serializer != null) {
namespaceDetails = NamespaceDetailsFactory.getInstance().getNamespaceDetails(serializer, systemId);
} else {
namespaceDetails = NamespaceDetailsFactory.getInstance().getNamespaceDetails(parser, systemId);
}
if (namespaceDetails == null) {
log.debug("Found no namespace details class "+namespaceDetails.getClass().getName()+" for "+systemId);
return null;
}
log.debug("Found namespace details class "+namespaceDetails.getClass().getName()+" for "+systemId);
String xsdFile = namespaceDetails.getLocalPath(systemId);
log.debug("Local path for "+systemId+" is "+xsdFile);
if (xsdFile == null) {
return null;
}
try {
InputStream resourceAsStream = StreamUtil.singleInputStream(xsdFile, resourceAccessor);
if (resourceAsStream == null) {
log.debug("Could not load "+xsdFile+" with the standard resource accessor. Trying context classloader...");
if (Thread.currentThread().getContextClassLoader() != null) {
resourceAsStream = Thread.currentThread().getContextClassLoader().getResourceAsStream(xsdFile);
}
if (resourceAsStream == null) {
log.debug("Could not load "+xsdFile+" with the standard resource accessor. Trying class classloader...");
resourceAsStream = this.getClass().getClassLoader().getResourceAsStream(xsdFile);
}
}
if (resourceAsStream == null) {
log.debug("Could not find "+xsdFile+" locally");
return null;
}
log.debug("Successfully loaded XSD from "+xsdFile);
InputSource source = new InputSource(resourceAsStream);
source.setPublicId(publicId);
source.setSystemId(systemId);
return source;
} catch (Exception ex) {
return null; // We don't have the schema, try the network
}
}
return null;
}
private InputSource tryResolveFromResourceAccessor(String systemId) {
String path=FilenameUtils.concat(basePath, systemId);
log.debug("Attempting to load "+systemId+" from resourceAccessor as "+path);
try {
InputStream resourceAsStream = StreamUtil.singleInputStream(path, resourceAccessor);
if (resourceAsStream == null) {
log.debug("Could not load "+systemId+" from resourceAccessor as "+path);
return null;
}
return new InputSource(resourceAsStream);
}catch(Exception ex) {
return null;
}
}
@Override
public InputSource getExternalSubset(String name, String baseURI) throws SAXException, IOException {
return null;
}
@Override
public InputSource resolveEntity(String publicId, String systemId) throws SAXException, IOException {
log.warning("Current XML parsers seems to not support EntityResolver2. External entities won't be correctly loaded");
return tryResolveLiquibaseSchema(systemId, publicId);
}
}