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Cayenne Object Persistence Framework
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* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
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package org.apache.cayenne.dba;
import java.net.URL;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.Collection;
import java.util.Iterator;
import org.apache.cayenne.CayenneRuntimeException;
import org.apache.cayenne.access.DataNode;
import org.apache.cayenne.access.OperationObserver;
import org.apache.cayenne.access.QueryTranslator;
import org.apache.cayenne.access.trans.DeleteTranslator;
import org.apache.cayenne.access.trans.ProcedureTranslator;
import org.apache.cayenne.access.trans.QualifierTranslator;
import org.apache.cayenne.access.trans.QueryAssembler;
import org.apache.cayenne.access.trans.SelectTranslator;
import org.apache.cayenne.access.trans.UpdateTranslator;
import org.apache.cayenne.access.types.BooleanType;
import org.apache.cayenne.access.types.ByteArrayType;
import org.apache.cayenne.access.types.CharType;
import org.apache.cayenne.access.types.ExtendedType;
import org.apache.cayenne.access.types.ExtendedTypeMap;
import org.apache.cayenne.access.types.UtilDateType;
import org.apache.cayenne.map.DbAttribute;
import org.apache.cayenne.map.DbEntity;
import org.apache.cayenne.map.DbJoin;
import org.apache.cayenne.map.DbRelationship;
import org.apache.cayenne.map.DerivedDbEntity;
import org.apache.cayenne.query.BatchQuery;
import org.apache.cayenne.query.DeleteQuery;
import org.apache.cayenne.query.ProcedureQuery;
import org.apache.cayenne.query.Query;
import org.apache.cayenne.query.SQLAction;
import org.apache.cayenne.query.SelectQuery;
import org.apache.cayenne.query.UpdateQuery;
import org.apache.cayenne.util.ResourceLocator;
import org.apache.cayenne.util.Util;
/**
* A generic DbAdapter implementation. Can be used as a default adapter or as a superclass
* of a concrete adapter implementation.
*
* @author Andrei Adamchik
*/
public class JdbcAdapter implements DbAdapter {
protected PkGenerator pkGenerator;
protected TypesHandler typesHandler;
protected ExtendedTypeMap extendedTypes;
protected boolean supportsBatchUpdates;
protected boolean supportsFkConstraints;
protected boolean supportsUniqueConstraints;
protected boolean supportsGeneratedKeys;
/**
* Creates new JdbcAdapter with a set of default parameters.
*/
public JdbcAdapter() {
// init defaults
this.setSupportsBatchUpdates(false);
this.setSupportsUniqueConstraints(true);
this.setSupportsFkConstraints(true);
this.pkGenerator = this.createPkGenerator();
this.typesHandler = TypesHandler.getHandler(findAdapterResource("/types.xml"));
this.extendedTypes = new ExtendedTypeMap();
this.configureExtendedTypes(extendedTypes);
}
/**
* Returns default separator - a semicolon.
*
* @since 1.0.4
*/
public String getBatchTerminator() {
return ";";
}
/**
* Locates and returns a named adapter resource. A resource can be an XML file, etc.
*
* This implementation is based on the premise that each adapter is located in its own
* Java package and all resources are in the same package as well. Resource lookup is
* recursive, so that if DbAdapter is a subclass of another adapter, parent adapter
* package is searched as a failover.
*
*
* @since 1.1
*/
public URL findAdapterResource(String name) {
Class adapterClass = this.getClass();
while (adapterClass != null && JdbcAdapter.class.isAssignableFrom(adapterClass)) {
String path = Util.getPackagePath(adapterClass.getName()) + name;
URL url = ResourceLocator.findURLInClasspath(path);
if (url != null) {
return url;
}
adapterClass = adapterClass.getSuperclass();
}
return null;
}
/**
* Installs appropriate ExtendedTypes as converters for passing values between JDBC
* and Java layers. Called from default constructor.
*/
protected void configureExtendedTypes(ExtendedTypeMap map) {
// use BooleanType to ensure that returned booleans are an enum of Boolean.TRUE
// and Boolean.FALSE
map.registerType(new BooleanType());
// Create a default CHAR handler with some generic settings.
// Subclasses may need to install their own CharType or reconfigure
// this one to work better with the target database.
map.registerType(new CharType(false, true));
// enable java.util.Dates as "persistent" values
map.registerType(new UtilDateType());
// enable "small" BLOBs
map.registerType(new ByteArrayType(false, true));
}
/**
* Creates and returns a primary key generator. This factory method should be
* overriden by JdbcAdapter subclasses to provide custom implementations of
* PKGenerator.
*/
protected PkGenerator createPkGenerator() {
return new JdbcPkGenerator();
}
/**
* Returns primary key generator associated with this DbAdapter.
*/
public PkGenerator getPkGenerator() {
return pkGenerator;
}
/**
* Sets new primary key generator.
*
* @since 1.1
*/
public void setPkGenerator(PkGenerator pkGenerator) {
this.pkGenerator = pkGenerator;
}
/**
* @deprecated since 1.2 this method is unneeded as customizations are done via custom
* SQLActions.
*/
public QueryTranslator getQueryTranslator(Query query) throws Exception {
Class queryClass = queryTranslatorClass(query);
try {
QueryTranslator t = (QueryTranslator) queryClass.newInstance();
t.setQuery(query);
t.setAdapter(this);
return t;
}
catch (Exception ex) {
throw new CayenneRuntimeException("Can't load translator class: "
+ queryClass);
}
}
/**
* Returns a class of the query translator that should be used to translate the query
* q to SQL. Exists mainly for the benefit of subclasses that can
* override this method providing their own translator.
*
* @deprecated since 1.2 this method is unneeded as customizations are done via custom
* SQLActions.
*/
protected Class queryTranslatorClass(Query q) {
if (q == null) {
throw new NullPointerException("Null query.");
}
else if (q instanceof SelectQuery) {
return SelectTranslator.class;
}
else if (q instanceof UpdateQuery) {
return UpdateTranslator.class;
}
else if (q instanceof org.apache.cayenne.query.InsertQuery) {
return org.apache.cayenne.access.trans.InsertTranslator.class;
}
else if (q instanceof DeleteQuery) {
return DeleteTranslator.class;
}
else if (q instanceof ProcedureQuery) {
return ProcedureTranslator.class;
}
else {
throw new CayenneRuntimeException("Unrecognized query class..."
+ q.getClass().getName());
}
}
/**
* Returns true.
*/
public boolean supportsFkConstraints() {
return supportsFkConstraints;
}
/**
* @since 1.1
*/
public void setSupportsFkConstraints(boolean flag) {
this.supportsFkConstraints = flag;
}
/**
* Returns true.
*
* @since 1.1
*/
public boolean supportsUniqueConstraints() {
return supportsUniqueConstraints;
}
/**
* @since 1.1
*/
public void setSupportsUniqueConstraints(boolean flag) {
this.supportsUniqueConstraints = flag;
}
/**
* Returns a SQL string to drop a table corresponding to ent DbEntity.
*/
public String dropTable(DbEntity ent) {
return "DROP TABLE " + ent.getFullyQualifiedName();
}
/**
* Returns a SQL string that can be used to create database table corresponding to
* ent parameter.
*/
public String createTable(DbEntity entity) {
if (entity instanceof DerivedDbEntity) {
throw new CayenneRuntimeException("Can't create table for derived DbEntity '"
+ entity.getName()
+ "'.");
}
StringBuffer sqlBuffer = new StringBuffer();
sqlBuffer.append("CREATE TABLE ").append(entity.getFullyQualifiedName()).append(
" (");
// columns
Iterator it = entity.getAttributes().iterator();
if (it.hasNext()) {
boolean first = true;
while (it.hasNext()) {
if (first) {
first = false;
}
else {
sqlBuffer.append(", ");
}
DbAttribute column = (DbAttribute) it.next();
// attribute may not be fully valid, do a simple check
if (column.getType() == TypesMapping.NOT_DEFINED) {
throw new CayenneRuntimeException("Undefined type for attribute '"
+ entity.getFullyQualifiedName()
+ "."
+ column.getName()
+ "'.");
}
createTableAppendColumn(sqlBuffer, column);
}
createTableAppendPKClause(sqlBuffer, entity);
}
sqlBuffer.append(')');
return sqlBuffer.toString();
}
/**
* @since 1.2
*/
protected void createTableAppendPKClause(StringBuffer sqlBuffer, DbEntity entity) {
Iterator pkit = entity.getPrimaryKey().iterator();
if (pkit.hasNext()) {
sqlBuffer.append(", PRIMARY KEY (");
boolean firstPk = true;
while (pkit.hasNext()) {
if (firstPk)
firstPk = false;
else
sqlBuffer.append(", ");
DbAttribute at = (DbAttribute) pkit.next();
sqlBuffer.append(at.getName());
}
sqlBuffer.append(')');
}
}
/**
* Appends SQL for column creation to CREATE TABLE buffer.
*
* @since 1.2
*/
protected void createTableAppendColumn(StringBuffer sqlBuffer, DbAttribute column) {
String[] types = externalTypesForJdbcType(column.getType());
if (types == null || types.length == 0) {
String entityName = column.getEntity() != null ? ((DbEntity) column
.getEntity()).getFullyQualifiedName() : "";
throw new CayenneRuntimeException("Undefined type for attribute '"
+ entityName
+ "."
+ column.getName()
+ "': "
+ column.getType());
}
String type = types[0];
sqlBuffer.append(column.getName()).append(' ').append(type);
// append size and precision (if applicable)
if (TypesMapping.supportsLength(column.getType())) {
int len = column.getMaxLength();
int prec = TypesMapping.isDecimal(column.getType())
? column.getPrecision()
: -1;
// sanity check
if (prec > len) {
prec = -1;
}
if (len > 0) {
sqlBuffer.append('(').append(len);
if (prec >= 0) {
sqlBuffer.append(", ").append(prec);
}
sqlBuffer.append(')');
}
}
sqlBuffer.append(column.isMandatory() ? " NOT NULL" : " NULL");
}
/**
* Returns a DDL string to create a unique constraint over a set of columns.
*
* @since 1.1
*/
public String createUniqueConstraint(DbEntity source, Collection columns) {
if (columns == null || columns.isEmpty()) {
throw new CayenneRuntimeException(
"Can't create UNIQUE constraint - no columns specified.");
}
StringBuffer buf = new StringBuffer();
buf.append("ALTER TABLE ").append(source.getFullyQualifiedName()).append(
" ADD UNIQUE (");
Iterator it = columns.iterator();
DbAttribute first = (DbAttribute) it.next();
buf.append(first.getName());
while (it.hasNext()) {
DbAttribute next = (DbAttribute) it.next();
buf.append(", ");
buf.append(next.getName());
}
buf.append(")");
return buf.toString();
}
/**
* Returns a SQL string that can be used to create a foreign key constraint for the
* relationship.
*/
public String createFkConstraint(DbRelationship rel) {
StringBuffer buf = new StringBuffer();
StringBuffer refBuf = new StringBuffer();
buf.append("ALTER TABLE ").append(
((DbEntity) rel.getSourceEntity()).getFullyQualifiedName()).append(
" ADD FOREIGN KEY (");
Iterator jit = rel.getJoins().iterator();
boolean first = true;
while (jit.hasNext()) {
DbJoin join = (DbJoin) jit.next();
if (!first) {
buf.append(", ");
refBuf.append(", ");
}
else
first = false;
buf.append(join.getSourceName());
refBuf.append(join.getTargetName());
}
buf
.append(") REFERENCES ")
.append(((DbEntity) rel.getTargetEntity()).getFullyQualifiedName())
.append(" (")
.append(refBuf.toString())
.append(')');
return buf.toString();
}
public String[] externalTypesForJdbcType(int type) {
return typesHandler.externalTypesForJdbcType(type);
}
public ExtendedTypeMap getExtendedTypes() {
return extendedTypes;
}
public DbAttribute buildAttribute(
String name,
String typeName,
int type,
int size,
int precision,
boolean allowNulls) {
DbAttribute attr = new DbAttribute();
attr.setName(name);
attr.setType(type);
attr.setMandatory(!allowNulls);
if (size >= 0) {
attr.setMaxLength(size);
}
if (precision >= 0) {
attr.setPrecision(precision);
}
return attr;
}
public String tableTypeForTable() {
return "TABLE";
}
public String tableTypeForView() {
return "VIEW";
}
/**
* Creates and returns a default implementation of a qualifier translator.
*/
public QualifierTranslator getQualifierTranslator(QueryAssembler queryAssembler) {
return new QualifierTranslator(queryAssembler);
}
/**
* Creates an instance of DataNode class.
*
* @deprecated since 1.2 this method is not used as node behavior customization is
* done via SQLActionVisitor.
*/
public DataNode createDataNode(String name) {
DataNode node = new DataNode(name);
node.setAdapter(this);
return node;
}
/**
* Uses JdbcActionBuilder to create the right action.
*
* @since 1.2
*/
public SQLAction getAction(Query query, DataNode node) {
return query
.createSQLAction(new JdbcActionBuilder(this, node.getEntityResolver()));
}
public void bindParameter(
PreparedStatement statement,
Object object,
int pos,
int sqlType,
int precision) throws SQLException, Exception {
if (object == null) {
statement.setNull(pos, sqlType);
}
else {
ExtendedType typeProcessor = getExtendedTypes().getRegisteredType(
object.getClass());
typeProcessor.setJdbcObject(statement, object, pos, sqlType, precision);
}
}
public boolean supportsBatchUpdates() {
return this.supportsBatchUpdates;
}
public void setSupportsBatchUpdates(boolean flag) {
this.supportsBatchUpdates = flag;
}
/**
* @since 1.2
*/
public boolean supportsGeneratedKeys() {
return supportsGeneratedKeys;
}
/**
* @since 1.2
*/
public void setSupportsGeneratedKeys(boolean flag) {
this.supportsGeneratedKeys = flag;
}
/**
* Always returns true, letting DataNode to handle the query.
*
* @deprecated Since 1.2 this method is obsolete and is ignored across Cayenne.
*/
public boolean shouldRunBatchQuery(
DataNode node,
Connection con,
BatchQuery query,
OperationObserver delegate) throws SQLException, Exception {
return true;
}
}
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