| JDBCDeclaredQueryMetaData.java |
/*
* JBoss, the OpenSource J2EE webOS
*
* Distributable under LGPL license.
* See terms of license at gnu.org.
*/
package org.jboss.ejb.plugins.cmp.jdbc.metadata;
import java.lang.reflect.Method;
import org.w3c.dom.Element;
import org.jboss.deployment.DeploymentException;
import org.jboss.metadata.MetaData;
/**
* Imutable class contains information about a declated query.
*
* @author <a href="mailto:dain@daingroup.com">Dain Sundstrom</a>
* @version $Revision: 1.21 $
*/
public final class JDBCDeclaredQueryMetaData implements JDBCQueryMetaData
{
/**
* The method to which this query is bound.
*/
private final Method method;
/**
* The user specified additional columns to be added to the select clause.
*/
private final String additionalColumns;
/**
* The user specified from clause.
*/
private final String from;
/**
* The user specified where clause.
*/
private final String where;
/**
* The user specified order clause.
*/
private final String order;
/**
* The other clause is appended to the end of the sql. This is useful for
* hints to the query engine.
*/
private final String other;
/**
* Should the select be DISTINCT?
*/
private final boolean distinct;
/**
* The name of the ejb from which the field will be selected.
*/
private final String ejbName;
/**
* The name of the cmp-field to be selected.
*/
private final String fieldName;
/**
* The aliase that is used for the main select table.
*/
private final String alias;
/**
* Read ahead meta data.
*/
private final JDBCReadAheadMetaData readAhead;
/**
* Should the query return Local or Remote beans.
*/
private final boolean resultTypeMappingLocal;
private final Class compiler;
private final boolean lazyResultSetLoading;
/**
* Constructs a JDBCDeclaredQueryMetaData which is defined by the
* declared-sql xml element and is invoked by the specified method.
* Inherits unspecified values from the defaults.
*
* @param defaults the default values to use
* @param readAhead the read-ahead properties for this query
*/
public JDBCDeclaredQueryMetaData(JDBCDeclaredQueryMetaData defaults,
JDBCReadAheadMetaData readAhead,
Class compiler,
boolean lazyResultSetLoading)
throws DeploymentException
{
this.method = defaults.getMethod();
this.readAhead = readAhead;
this.from = defaults.getFrom();
this.where = defaults.getWhere();
this.order = defaults.getOrder();
this.other = defaults.getOther();
this.resultTypeMappingLocal = defaults.isResultTypeMappingLocal();
this.distinct = defaults.isSelectDistinct();
this.ejbName = defaults.getEJBName();
this.fieldName = defaults.getFieldName();
this.alias = defaults.getAlias();
this.additionalColumns = defaults.getAdditionalColumns();
this.compiler = compiler;
this.lazyResultSetLoading = lazyResultSetLoading;
}
/**
* Constructs a JDBCDeclaredQueryMetaData which is defined by the
* declared-sql xml element and is invoked by the specified method.
*
* @param queryElement the xml Element which contains the metadata about
* this query
* @param method the method which invokes this query
* @param readAhead the read-ahead properties for this query
*/
public JDBCDeclaredQueryMetaData(boolean isResultTypeMappingLocal,
Element queryElement,
Method method,
JDBCReadAheadMetaData readAhead,
Class compiler,
boolean lazyResultSetLoading)
throws DeploymentException
{
this.compiler = compiler;
this.lazyResultSetLoading = lazyResultSetLoading;
this.method = method;
this.readAhead = readAhead;
from = nullIfEmpty(MetaData.getOptionalChildContent(queryElement, "from"));
where = nullIfEmpty(MetaData.getOptionalChildContent(queryElement, "where"));
order = nullIfEmpty(MetaData.getOptionalChildContent(queryElement, "order"));
other = nullIfEmpty(MetaData.getOptionalChildContent(queryElement, "other"));
this.resultTypeMappingLocal = isResultTypeMappingLocal;
// load ejbSelect info
Element selectElement =
MetaData.getOptionalChild(queryElement, "select");
if(selectElement != null)
{
// should select use distinct?
distinct =
(MetaData.getOptionalChild(selectElement, "distinct") != null);
if(method.getName().startsWith("ejbSelect"))
{
ejbName = MetaData.getUniqueChildContent(selectElement, "ejb-name");
fieldName = nullIfEmpty(MetaData.getOptionalChildContent(selectElement, "field-name"));
}
else
{
// the ejb-name and field-name elements are not allowed for finders
if(MetaData.getOptionalChild(selectElement, "ejb-name") != null)
{
throw new DeploymentException(
"The ejb-name element of declared-sql select is only " +
"allowed for ejbSelect queries."
);
}
if(MetaData.getOptionalChild(selectElement, "field-name") != null)
{
throw new DeploymentException(
"The field-name element of declared-sql select is only " +
"allowed for ejbSelect queries."
);
}
ejbName = null;
fieldName = null;
}
alias = nullIfEmpty(MetaData.getOptionalChildContent(selectElement, "alias"));
additionalColumns = nullIfEmpty(MetaData.getOptionalChildContent(selectElement, "additional-columns"));
}
else
{
if(method.getName().startsWith("ejbSelect"))
{
throw new DeploymentException(
"The select element of " +
"declared-sql is required for ejbSelect queries."
);
}
distinct = false;
ejbName = null;
fieldName = null;
alias = null;
additionalColumns = null;
}
}
// javadoc in parent class
public Method getMethod()
{
return method;
}
// javadoc in parent class
public boolean isResultTypeMappingLocal()
{
return resultTypeMappingLocal;
}
/**
* Gets the read ahead metadata for the query.
*
* @return the read ahead metadata for the query.
*/
public JDBCReadAheadMetaData getReadAhead()
{
return readAhead;
}
public Class getQLCompilerClass()
{
return compiler;
}
/**
* Gets the sql FROM clause of this query.
*
* @return a String which contains the sql FROM clause
*/
public String getFrom()
{
return from;
}
/**
* Gets the sql WHERE clause of this query.
*
* @return a String which contains the sql WHERE clause
*/
public String getWhere()
{
return where;
}
/**
* Gets the sql ORDER BY clause of this query.
*
* @return a String which contains the sql ORDER BY clause
*/
public String getOrder()
{
return order;
}
/**
* Gets other sql code which is appended to the end of the query.
* This is userful for supplying hints to the query engine.
*
* @return a String which contains additional sql code which is
* appended to the end of the query
*/
public String getOther()
{
return other;
}
/**
* Should the select be DISTINCT?
*
* @return true if the select clause should contain distinct
*/
public boolean isSelectDistinct()
{
return distinct;
}
/**
* The name of the ejb from which the field will be selected.
*
* @return the name of the ejb from which a field will be selected, or null
* if returning a whole ejb
*/
public String getEJBName()
{
return ejbName;
}
/**
* The name of the cmp-field to be selected.
*
* @return the name of the cmp-field to be selected or null if returning a
* whole ejb
*/
public String getFieldName()
{
return fieldName;
}
/**
* The alias that is used for the select table.
*
* @return the alias that is used for the table from which the entity or
* field is selected.
*/
public String getAlias()
{
return alias;
}
/**
* Additional columns that should be added to the select clause. For example,
* columns that are used in an order by clause.
*
* @return additional columns that should be added to the select clause
*/
public String getAdditionalColumns()
{
return additionalColumns;
}
public boolean isLazyResultSetLoading()
{
return lazyResultSetLoading;
}
/**
* Compares this JDBCDeclaredQueryMetaData against the specified object.
* Returns true if the objects are the same. Two JDBCDeclaredQueryMetaData
* are the same if they are both invoked by the same method.
*
* @param o the reference object with which to compare
* @return true if this object is the same as the object argument; false
* otherwise
*/
public boolean equals(Object o)
{
if(o instanceof JDBCDeclaredQueryMetaData)
{
return ((JDBCDeclaredQueryMetaData) o).method.equals(method);
}
return false;
}
/**
* Returns a hashcode for this JDBCDeclaredQueryMetaData. The hashcode is
* computed by the method which invokes this query.
*
* @return a hash code value for this object
*/
public int hashCode()
{
return method.hashCode();
}
/**
* Returns a string describing this JDBCDeclaredQueryMetaData. The exact
* details of the representation are unspecified and subject to change,
* but the following may be regarded as typical:
* <p/>
* "[JDBCDeclaredQueryMetaData: method=public org.foo.User findByName(
* java.lang.String)]"
*
* @return a string representation of the object
*/
public String toString()
{
return "[JDBCDeclaredQueryMetaData : method=" + method + "]";
}
private static String nullIfEmpty(String s)
{
if(s != null && s.trim().length() == 0)
{
s = null;
}
return s;
}
}
| JDBCDeclaredQueryMetaData.java |