Application: gvSIG desktop

import org.gvsig.expressionevaluator.impl.function.string.ReverseFunction;

import org.gvsig.expressionevaluator.impl.function.string.ReverseInStrFunction;

        this.addFunction(new ReverseInStrFunction());

        this.addFunction(new ReverseFunction());

package org.gvsig.expressionevaluator.impl.function.string;

import org.apache.commons.lang3.Range;

import org.apache.commons.lang3.StringUtils;

import org.gvsig.expressionevaluator.Interpreter;

import org.gvsig.expressionevaluator.spi.AbstractFunction;

public class ReverseFunction extends AbstractFunction {

    public ReverseFunction() {

        super(

                "String", "REVERSE", Range.is(1),

                "reverses a string and returns the result.",

                "REVERSE"+"({{string}})",

                new String[]{

                    "string - String to reverse."

                },

                "String",

                true

        );        

        // Nota: 

        // Parece ser que no habria falta poner un formatter, H2 es la unica que no 

        // tiene esta funcion y sl proveedor de gvSIG para h2 se la a?ade.

    }

    @Override

    public boolean allowConstantFolding() {

        return true;

    }

    @Override

    public Object call(Interpreter interpreter, Object[] args) throws Exception {

        String string = getStr(args, 0);

        return StringUtils.reverse(string);

    }

}

package org.gvsig.expressionevaluator.impl.function.string;

import org.apache.commons.lang3.Range;

import org.gvsig.expressionevaluator.Interpreter;

import org.gvsig.expressionevaluator.spi.AbstractFunction;

public class ReverseInStrFunction extends AbstractFunction {

    public ReverseInStrFunction() {

        super(

                "String", "REVERSEINSTR", Range.is(2),

                "Returns the index (position) of the last occurrence of a specified substring in a string.",

                "REVERSEINSTR"+"({{string}}, substring)",

                new String[]{

                    "string - String in which to perform the search. ",

                    "substring - String to search"

                },

                "Integer",

                true

        );        

        // Nota: 

        // Habria que poner un formatter. Para REVERSEINSTR(string, substring):

        //   En H2: INSTR(string,substring, -1)

        //   En PostgreSQL: LENGTH(string)-STRPOS(REVERSE(string), substring)

        //   En Oracle: LEN(string)-INSTR(REVERSE(string), substring)

        //   En SQL Server: LEN(string)-CHARINDEX(substring, REVERSE(string))

    }

    @Override

    public boolean allowConstantFolding() {

        return true;

    }

    @Override

    public Object call(Interpreter interpreter, Object[] args) throws Exception {

        String string = getStr(args, 0);

        String substring = getStr(args, 1);

        if( string == null || substring == null ) {

            return null;

        }

        int n = string.lastIndexOf(substring);

        if( n<0 ) {

            return 0;

        }

        return n+1;

    }

}

        super(

                "String", "INSTR", Range.is(2),

                "The functions search string for substring. The function returns "

                        + "an integer indicating the position of the character "

                        + "in string that is the first character of this occurrence.\n"

                        + "The function returns a numeric value. The first position "

                        + "in the string is 1. If substring is not found in string, "

                        + "then the function will return 0",

                "INSTR"+"({{string}}, substring)",

                new String[]{

                    "string - String in which to perform the search.  ",

                    "substring - String to search"

                },

                "Integer",

                true

        );        

        // Nota: 

        // En SQL Server: CHARINDEX(substring, string)

        // En PostgreSQL: STRPOS(string,substring) o POSITION(substring in string)

        // En Oracle: INSTR(string,substring)

        // En H2: INSTR(string,substring)

        if( str==null || search==null ) {

            return null;

        int n = str.indexOf(search);

        if( n<0 ) {

            return 0;

        }

        return n+1;

import org.gvsig.fmap.dal.store.h2.functions.Json_value;

import org.gvsig.fmap.dal.store.h2.functions.Reverse;

import org.gvsig.fmap.dal.store.h2.functions.Reverseinstr;

            String[] sqls = new String[] {

                "CREATE SCHEMA IF NOT EXISTS PUBLIC;SET SCHEMA PUBLIC",

                Json_value.getSQL(),

                Reverse.getSQL(),

                Reverseinstr.getSQL()

            };

            for (String sql : sqls) {

                try {

                    conn.createStatement().execute(sql);

                } catch(SQLException ex) {

                    LOGGER.debug("Can't configure gvsig tables.",ex);

                    LOGGER.warn("Can't configure gvsig tables. "+sql);

                    // Ignore this error.

                }

                    String[] sqls2 = new String[] {

                        "ALTER TABLE PUBLIC.\""+TABLE_CONFIGURATION_NAME+"\" ADD CONSTRAINT PUBLIC.CONSTRAINT_2 PRIMARY KEY(\""+FIELD_CONFIGURATION_NAME+"\")",

                    for (String sql : sqls2) {

/*

 * gvSIG. Desktop Geographic Information System.

 * 

 * Copyright (C) 2007-2020 gvSIG Association.

 * 

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version 3

 * of the License, or (at your option) any later version.

 * 

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 * 

 * You should have received a copy of the GNU General Public License 

 * along with this program. If not, see <https://www.gnu.org/licenses/>. 

 * 

 * For any additional information, do not hesitate to contact us

 * at info AT gvsig.com, or visit our website www.gvsig.com.

 */

package org.gvsig.fmap.dal.store.h2.functions;

import org.apache.commons.lang3.StringUtils;

/**

 *

 * @author gvSIG Team

 */

public class Reverse {

    public static String getSQL() {

        return "CREATE ALIAS REVERSE  FOR \"org.gvsig.fmap.dal.store.h2.functions.Reverse.reverse\"";

    }

    public static Object reverse(String s) {

        return StringUtils.reverse(s);

    }

}

/*

 * gvSIG. Desktop Geographic Information System.

 * 

 * Copyright (C) 2007-2020 gvSIG Association.

 * 

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version 3

 * of the License, or (at your option) any later version.

 * 

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 * 

 * You should have received a copy of the GNU General Public License 

 * along with this program. If not, see <https://www.gnu.org/licenses/>. 

 * 

 * For any additional information, do not hesitate to contact us

 * at info AT gvsig.com, or visit our website www.gvsig.com.

 */

package org.gvsig.fmap.dal.store.h2.functions;

import org.apache.commons.lang3.StringUtils;

/**

 *

 * @author gvSIG Team

 */

public class Reverseinstr {

    public static String getSQL() {

        return "CREATE ALIAS REVERSE FOR \"org.gvsig.fmap.dal.store.h2.functions.Reverseinstr.reverseinstr\"";

    }

    public static Object reverseinstr(String string, String substring) {

        if( string == null || substring == null ) {

            return null;

        }

        int n = string.lastIndexOf(substring);

        if( n<0 ) {

            return 0;

        }

        return n+1;

    }

}

        return "CREATE ALIAS JSON_VALUE  FOR \"org.gvsig.fmap.dal.store.h2.functions.Json_value.json_value\"";