corner.hibernate.JSONStringType.java Source code

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Here is the source code for corner.hibernate.JSONStringType.java

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/* 
 * Copyright 2008 The Corner Team.
 * 
 * Licensed 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.
 */
package corner.hibernate;

import java.io.Serializable;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Types;

import org.apache.tapestry5.json.JSONObject;
import org.hibernate.HibernateException;
import org.hibernate.type.Type;
import org.hibernate.usertype.UserType;
import org.hibernate.util.StringHelper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * JSONHibernate?
 * @author <a href="jun.tsai@ganshane.net">Jun Tsai</a>
 * @version $Revision$
 * @since 0.0.2
 */

public class JSONStringType implements UserType {

    private static final boolean IS_VALUE_TRACING_ENABLED = LoggerFactory
            .getLogger(StringHelper.qualifier(Type.class.getName())).isTraceEnabled();
    private transient Logger log;

    private Logger log() {
        if (log == null) {
            log = LoggerFactory.getLogger(getClass());
        }
        return log;
    }

    public int[] sqlTypes() {
        return new int[] { Types.VARCHAR };
    }

    public Class<?> returnedClass() {
        return JSONObject.class;
    }

    public boolean equals(Object x, Object y) throws HibernateException {
        return (x == y) || (x != null && x.equals(y));
    }

    public int hashCode(Object x) throws HibernateException {
        return x.hashCode();
    }

    public final Object nullSafeGet(ResultSet rs, String[] names, Object owner)
            throws HibernateException, SQLException {
        String name = names[0];
        try {
            Object value = rs.getString(name);
            if (value == null || rs.wasNull()) {
                if (IS_VALUE_TRACING_ENABLED) {
                    log().trace("returning null as column: " + name);
                }
                return null;
            } else {
                if (IS_VALUE_TRACING_ENABLED) {
                    log().trace("returning '" + value + "' as column: " + name);
                }
                return new JSONObject((String) value);
            }
        } catch (RuntimeException re) {
            log().info("could not read column value from result set: " + name + "; " + re.getMessage());
            throw re;
        } catch (SQLException se) {
            log().info("could not read column value from result set: " + name + "; " + se.getMessage());
            throw se;
        }
    }

    public void nullSafeSet(PreparedStatement st, Object value, int index) throws HibernateException, SQLException {
        if (value != null) {
            st.setString(index, value.toString());
        } else {
            st.setNull(index, sqlTypes()[0]);
        }
    }

    public Object deepCopy(Object value) throws HibernateException {
        if (value != null) {
            return new JSONObject(value.toString());
        }
        return value;
    }

    public boolean isMutable() {
        return true;
    }

    public Serializable disassemble(Object value) throws HibernateException {
        return (Serializable) value;
    }

    public Object assemble(Serializable cached, Object owner) throws HibernateException {
        return cached;
    }

    public Object replace(Object original, Object target, Object owner) throws HibernateException {
        return original;
    }

}