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/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* License: GNU Lesser General Public License (LGPL), version 2.1 or later.
* See the lgpl.txt file in the root directory or .
*/
package org.hibernate.query.criteria.internal.expression;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
import javax.persistence.criteria.CriteriaBuilder.Coalesce;
import javax.persistence.criteria.Expression;
import org.hibernate.query.criteria.internal.CriteriaBuilderImpl;
import org.hibernate.query.criteria.internal.ParameterRegistry;
import org.hibernate.query.criteria.internal.Renderable;
import org.hibernate.query.criteria.internal.compile.RenderingContext;
/**
* Models an ANSI SQL COALESCE expression. COALESCE is a specialized CASE statement.
*
* @author Steve Ebersole
*/
public class CoalesceExpression extends ExpressionImpl implements Coalesce, Serializable {
private final List> expressions;
private Class javaType;
public CoalesceExpression(CriteriaBuilderImpl criteriaBuilder) {
this( criteriaBuilder, null );
}
public CoalesceExpression(
CriteriaBuilderImpl criteriaBuilder,
Class javaType) {
super( criteriaBuilder, javaType );
this.javaType = javaType;
this.expressions = new ArrayList>();
}
@Override
public Class getJavaType() {
return javaType;
}
public Coalesce value(T value) {
return value( new LiteralExpression( criteriaBuilder(), value ) );
}
@SuppressWarnings({ "unchecked" })
public Coalesce value(Expression value) {
expressions.add( value );
if ( javaType == null ) {
javaType = (Class) value.getJavaType();
}
return this;
}
public List> getExpressions() {
return expressions;
}
public void registerParameters(ParameterRegistry registry) {
for ( Expression expression : getExpressions() ) {
Helper.possibleParameter(expression, registry);
}
}
public String render(RenderingContext renderingContext) {
StringBuilder buffer = new StringBuilder( "coalesce(" );
String sep = "";
for ( Expression expression : getExpressions() ) {
buffer.append( sep )
.append( ( (Renderable) expression ).render( renderingContext ) );
sep = ", ";
}
return buffer.append( ")" ).toString();
}
}