nullabletype.java

介绍了hibernate的入门有一些基本常用的事例

//$Id: NullableType.java,v 1.7 2005/02/21 02:08:46 oneovthafew Exp $
package org.hibernate.type;

import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import org.apache.commons.logging.LogFactory;
import org.dom4j.Node;

import org.hibernate.EntityMode;
import org.hibernate.HibernateException;
import org.hibernate.engine.Mapping;
import org.hibernate.engine.SessionFactoryImplementor;
import org.hibernate.engine.SessionImplementor;
import org.hibernate.util.EqualsHelper;
import org.hibernate.util.StringHelper;

/**
 * Superclass of single-column nullable types.
 * @author Gavin King
 */
public abstract class NullableType extends AbstractType {

	private static final boolean IS_TRACE_ENABLED;
	static {
		//cache this, because it was a significant performance cost
		IS_TRACE_ENABLED = LogFactory.getLog( StringHelper.qualifier( Type.class.getName() ) ).isTraceEnabled();
	}

	public abstract Object get(ResultSet rs, String name) throws HibernateException, SQLException;
	public abstract void set(PreparedStatement st, Object value, int index) throws HibernateException, SQLException;
	public abstract int sqlType();
	public abstract String toString(Object value) throws HibernateException;
	public abstract Object fromStringValue(String xml) throws HibernateException;

	public final void nullSafeSet(PreparedStatement st, Object value, int index, boolean[] settable, SessionImplementor session) 
	throws HibernateException, SQLException {
		if ( settable[0] ) nullSafeSet(st, value, index);
	}

	public final void nullSafeSet(PreparedStatement st, Object value, int index, SessionImplementor session) 
	throws HibernateException, SQLException {
		nullSafeSet(st, value, index);
	}

	public final void nullSafeSet(PreparedStatement st, Object value, int index) 
	throws HibernateException, SQLException {

		if (value==null) {
			if (IS_TRACE_ENABLED) {
				LogFactory.getLog( getClass() ).trace("binding null to parameter: " + index);
			}

			st.setNull( index, sqlType() );
		}
		else {
			if (IS_TRACE_ENABLED) {
				LogFactory.getLog( getClass() ).trace("binding '" + toString(value) + "' to parameter: " + index);
			}

			set(st, value, index);
		}
	}

	public final Object nullSafeGet(ResultSet rs, String[] names, SessionImplementor session, Object owner) 
	throws HibernateException, SQLException {
		return nullSafeGet(rs, names[0]);
	}

	public final Object nullSafeGet(ResultSet rs, String[] names) throws HibernateException, SQLException {
		return nullSafeGet(rs, names[0]);
	}

	public final Object nullSafeGet(ResultSet rs, String name) throws HibernateException, SQLException {

		Object value = get(rs, name);
		if ( value==null || rs.wasNull() ) {
			if (IS_TRACE_ENABLED) {
				LogFactory.getLog( getClass() ).trace("returning null as column: " + name);
			}
			return null;
		}
		else {
			if (IS_TRACE_ENABLED) {
				LogFactory.getLog( getClass() ).trace( "returning '" + toString(value) + "' as column: " + name);
			}
			return value;
		}
	}

	public final Object nullSafeGet(ResultSet rs, String name, SessionImplementor session, Object owner) 
	throws HibernateException, SQLException {
		return nullSafeGet(rs, name);
	}

	public final String toXMLString(Object value, SessionFactoryImplementor pc) throws HibernateException {
		return toString(value);
	}

	public final Object fromXMLString(String xml, Mapping factory) throws HibernateException {
		return xml==null || xml.length()==0 ? null : fromStringValue(xml);
	}

	public final int getColumnSpan(Mapping session) {
		return 1;
	}

	public final int[] sqlTypes(Mapping session) {
		return new int[] { sqlType() };
	}
	
	public final boolean isEqual(Object x, Object y, EntityMode entityMode) {
		return isEqual(x, y);
	}
	
	public boolean isEqual(Object x, Object y) {
		return EqualsHelper.equals(x, y);
	}

	public String toLoggableString(Object value, SessionFactoryImplementor factory) {
		return value==null ? "null" : toString(value);
	}

	public Object fromXMLNode(Node xml, Mapping factory) throws HibernateException {
		return fromXMLString( xml.getText(), factory );
	}

	public void setToXMLNode(Node xml, Object value, SessionFactoryImplementor factory) throws HibernateException {
		xml.setText( toXMLString(value, factory) );
	}

}