jef.database.query.JpqlExpression.java Source code

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Here is the source code for jef.database.query.JpqlExpression.java

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/*
 * JEF - Copyright 2009-2010 Jiyi (mr.jiyi@gmail.com)
 *
 * 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 jef.database.query;

import java.util.Collections;
import java.util.Map;

import jef.common.log.LogUtil;
import jef.database.DbUtils;
import jef.database.Field;
import jef.database.JPQLSelectConvert;
import jef.database.QueryAlias;
import jef.database.dialect.DatabaseDialect;
import jef.database.jsqlparser.SqlFunctionlocalization;
import jef.database.jsqlparser.UndoableVisitor;
import jef.database.jsqlparser.expression.Column;
import jef.database.jsqlparser.expression.JpqlParameter;
import jef.database.jsqlparser.parser.ParseException;
import jef.database.jsqlparser.visitor.Expression;
import jef.database.jsqlparser.visitor.ExpressionType;
import jef.database.jsqlparser.visitor.ExpressionVisitor;
import jef.database.jsqlparser.visitor.VisitorAdapter;
import jef.database.meta.ITableMetadata;
import jef.database.meta.MetaHolder;

import org.apache.commons.lang.ObjectUtils;

public class JpqlExpression implements Expression, LazyQueryBindField {
    protected Query<?> instance;

    protected Expression st;

    // ?
    // ?JEF??SQL??
    public JpqlExpression(String str, Query<?> clz) {
        try {
            this.st = DbUtils.parseExpression(str);
        } catch (ParseException e) {
            LogUtil.exception(e);
            throw new RuntimeException(e.getMessage());
        }
        this.instance = clz;
    }

    public JpqlExpression(Expression exp, Query<?> q) {
        this.st = exp;
        this.instance = q;
    }

    public JpqlExpression(String str) {
        this(str, (Query<?>) null);
    }

    public String toSqlAndBindAttribs(final SqlContext context, final DatabaseDialect profile) {
        //
        st.accept(new SqlFunctionlocalization(profile, null));
        //??
        if (context != null) {
            @SuppressWarnings("unchecked")
            final Map<String, Object> attribs = context.attribute == null ? Collections.EMPTY_MAP
                    : context.attribute;
            st.accept(new VisitorAdapter() {
                @Override
                public void visit(JpqlParameter parameter) {
                    if (parameter.getName() == null)
                        return;
                    Object obj = attribs.get(parameter.getName());
                    if (obj == null) {
                        if (!attribs.containsKey(parameter.getName())) {
                            throw new IllegalArgumentException(
                                    "You have not set the value of param '" + parameter.getName() + "'");
                        } else {
                            parameter.setResolved("null");
                        }
                    } else {
                        if (obj instanceof Number) {
                            parameter.setResolved(String.valueOf(obj));
                        } else {
                            parameter.setResolved("'" + String.valueOf(obj) + "'");
                        }
                    }
                }
            });
        }
        //?
        String result;
        if (instance == null) {
            st.accept(new JPQLSelectConvert(profile));
            result = st.toString();
        } else {
            String alias = context == null ? null : context.getAliasOf(instance);
            ColumnAliasApplier convert = new ColumnAliasApplier(alias, profile);
            st.accept(convert);
            result = st.toString();
            convert.undo();
        }
        return result;
    }

    /**
     * ??????
     * @author Administrator
     *
     */
    private class ColumnAliasApplier extends UndoableVisitor<Column, String[]> {
        private String alias;
        private DatabaseDialect profile;

        public ColumnAliasApplier(String alias, DatabaseDialect profile) {
            this.alias = alias;
            this.profile = profile;
        }

        @Override
        public void visit(Column tableColumn) {
            if (instance == null) {
                return;
            }
            ITableMetadata meta = MetaHolder.getMeta(instance.getInstance());
            Field f = meta.getField(tableColumn.getColumnName());
            String oldAlias = tableColumn.getTableAlias();
            if (f != null) {
                savePoint(tableColumn, new String[] { oldAlias, tableColumn.getColumnName() });
                tableColumn.setTableAlias(alias);
                tableColumn.setColumnName(meta.getColumnName(f, profile, true));
            } else {
                //FIXME ????
            }
        }

        @Override
        protected void undo(Column key, String[] value) {
            key.setTableAlias(value[0]);
            key.setColumnName(value[1]);
        }
    }

    public boolean isBind() {
        return instance != null;
    }

    public ITableMetadata getMeta() {
        if (instance == null)
            return null;
        return MetaHolder.getMeta(instance.getInstance());
    }

    public String toString() {
        return st.toString();
    }

    public void appendTo(StringBuilder sb) {
        st.appendTo(sb);
    }

    public Query<?> getInstanceQuery(AbstractEntityMappingProvider context) {
        if (instance != null) {
            return instance;
        }
        if (context != null && context.getReference().size() == 1) {
            this.instance = ((QueryAlias) context.queries.get(0)).getQuery();
        }
        return instance;
    }

    public void accept(ExpressionVisitor expressionVisitor) {
        throw new UnsupportedOperationException();
    }

    @Override
    public int hashCode() {
        return st.hashCode();
    }

    @Override
    public boolean equals(Object obj) {
        if (obj == null || !JpqlExpression.class.isAssignableFrom(obj.getClass()))
            return false;
        JpqlExpression o = (JpqlExpression) obj;
        if (!ObjectUtils.equals(this.instance, o.instance))
            return false;
        if (!ObjectUtils.equals(this.st, o.st))
            return false;
        return true;
    }

    public JpqlExpression bind(Query<?> query) {
        this.instance = query;
        return this;
    }

    public void setBind(Query<?> query) {
        this.instance = query;
    }

    public ExpressionType getType() {
        return ExpressionType.complex;
    }
}