com.ibm.fhir.persistence.jdbc.derby.DerbyParameterNamesDAO Maven / Gradle / Ivy
/*
* (C) Copyright IBM Corp. 2019, 2020
*
* SPDX-License-Identifier: Apache-2.0
*/
package com.ibm.fhir.persistence.jdbc.derby;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import com.ibm.fhir.persistence.jdbc.dao.api.FhirRefSequenceDAO;
import com.ibm.fhir.persistence.jdbc.dao.impl.ParameterNameDAOImpl;
import com.ibm.fhir.persistence.jdbc.exception.FHIRPersistenceDataAccessException;
/**
* For R4 we have replaced the old Derby (Java) stored procedure with
* plain old JDBC statements - much simpler and easier to debug.
*/
public class DerbyParameterNamesDAO extends ParameterNameDAOImpl {
private final FhirRefSequenceDAO fhirRefSequenceDAO;
public DerbyParameterNamesDAO(Connection c, String schemaName) {
super(c, schemaName);
this.fhirRefSequenceDAO = new FhirRefSequenceDAOImpl(c);
}
@Override
public int readOrAddParameterNameId(String parameterName) throws FHIRPersistenceDataAccessException {
// As the system is concurrent, we have to handle cases where another thread
// might create the entry after we selected and found nothing
Integer result = getParameterId(parameterName);
// Create the resource if we don't have it already (set by the continue handler)
if (result == null) {
try {
result = fhirRefSequenceDAO.nextValue();
final String INS = "INSERT INTO parameter_names (parameter_name_id, parameter_name) VALUES (?, ?)";
try (PreparedStatement stmt = getConnection().prepareStatement(INS)) {
// bind parameters
stmt.setInt(1, result);
stmt.setString(2, parameterName);
stmt.executeUpdate();
}
} catch (SQLException e) {
if ("23505".equals(e.getSQLState())) {
// another thread snuck in and created the record, so we need to fetch the correct id
result = getParameterId(parameterName);
if (result == null) {
// would be extremely weird, but good to protect against anyway
throw new IllegalStateException("No parameter id returned after duplicate found!");
}
} else {
throw new FHIRPersistenceDataAccessException("parameterName=" + parameterName, e);
}
}
}
// cannot be null, so safe to return as an int
return result;
}
/**
* Read the id for the named type
* @param parameterName
* @return the database id, or null if the named record is not found
* @throws FHIRPersistenceDataAccessException
*/
protected Integer getParameterId(String parameterName) throws FHIRPersistenceDataAccessException {
Integer result;
String sql1 = "SELECT parameter_name_id FROM parameter_names WHERE parameter_name = ?";
try (PreparedStatement stmt = getConnection().prepareStatement(sql1)) {
stmt.setString(1, parameterName);
ResultSet rs = stmt.executeQuery();
if (rs.next()) {
result = rs.getInt(1);
} else {
result = null;
}
}
catch (SQLException x) {
throw new FHIRPersistenceDataAccessException("parameterName=" + parameterName, x);
}
return result;
}
}