TemplateMatchCodes (GigaSpaces XAP 7.0 API)

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com.j_spaces.core.client
Class TemplateMatchCodes

java.lang.Object
  com.j_spaces.core.client.TemplateMatchCodes

public class TemplateMatchCodes
extends Object
extends Object

This class provides constants to be used when performing Query using templates.
The extended-indexing space attribute should be defined for templates from classes that use
the GE, LE, LT, GT match codes in order to perform fast search.
The compareTo method MUST be defined for modifiers in order to perform
GE, LE, LT, GT match.

Code example:
The min/max example shows how to query the space to find an entry with min/max attribute value. 
Note the space configuration file should include the following:

 <JavaSpaces>
        <space-config>
                <engine>
                        <extended-match>
                                <enabled-classes>*</enabled-classes> 
                                <min_ext_index_activation_size>1</min_ext_index_activation_size>
                        </extended-match>
                </engine>
        </space-config>
 </JavaSpaces>


import com.j_spaces.core.IJSpace;
import com.j_spaces.core.client.TemplateMatchCodes;
import com.j_spaces.core.client.ExternalEntry;
import com.j_spaces.core.client.SQLQuery;
import com.j_spaces.core.client.SpaceFinder;
import net.jini.core.lease.Lease;
import net.jini.space.JavaSpace;

import java.util.*;

public class MinMax {

    IJSpace space;

    String fields[] = new String [] {"First_Name", "Last_Name", "ID"} ;
    String types[] = new String [] {"java.lang.String", "java.lang.String", "java.lang.Integer"};
    boolean indexes[] = new boolean [] {false, false, true};

    int min = 0;
    int max = 0;

    public void populateSpace(int q) throws Exception {

        Random rnd = new Random();

        Object[] values = new Object[3];
                System.out.println("about to write " + q +" entries to space");
        for (int i = 0; i < q; i++) {
            values[0] = "FirstName"+ i;
            values[1] = "LastName" + i;
            int next = rnd.nextInt();
            if (next < min)
                min = next;
            if (next > max)
                max = next;
            values[2] = new Integer(next);
            ExternalEntry msg = new ExternalEntry("Employee", values, fields, types);
            msg.setIndexIndicators(indexes);
            space.write(msg, null, Lease.FOREVER);
                        if (i%10000==0)
                        {
                        System.out.println( new Date(System.currentTimeMillis()) + " - wrote " + i +" entries to space");
                        }
        }

        System.out.println("Inserted " + q + " entries; range from " + min + " to " + max);
    }

    public void queryMax() throws Exception {
        Object[] values = new Object[3];
        values[0] = null;
        values[1] = null;
        values[2] = new Integer(Integer.MAX_VALUE);
        short[] matchCodes = new short[3];
        matchCodes[2] = TemplateMatchCodes.LE;
        ExternalEntry template = new ExternalEntry("Employee", values);
        template.setExtendedMatchCodes(matchCodes);
        long time = System.currentTimeMillis();
        ExternalEntry result = (ExternalEntry)space.read(template, null, JavaSpace.NO_WAIT);
        time = System.currentTimeMillis() - time;
        Object[] v = result.getFieldsValues();
        System.out.println("Max value for Field ID is : " + v[2] + " ; Query time : " + time + "ms" + " - Entry UID:" + result.m_UID );
                showEntry(result);
    }

    public void queryMin() throws Exception {
        Object[] values = new Object[3];
        values[0] = null;
        values[1] = null;
        values[2] = new Integer(Integer.MIN_VALUE);
        short[] matchCodes = new short[3];
        matchCodes[2] = TemplateMatchCodes.GE;
        ExternalEntry template = new ExternalEntry("Employee", values);
        template.setExtendedMatchCodes(matchCodes);
        long time = System.currentTimeMillis();
        ExternalEntry result = (ExternalEntry)space.read(template, null, JavaSpace.NO_WAIT);
        time = System.currentTimeMillis() - time;
        Object[] v = result.getFieldsValues();
        System.out.println("Min value for Field ID is : " + v[2] + " ; Query time : " + time + "ms"+ " - Entry UID:" + result.m_UID );
                showEntry(result);
}

    public static void main(String[] args) throws Exception {

        System.out.println("Welcome to GigaSpaces min/max demo!");
        MinMax mm = new MinMax();
        System.out.println("About to connect to space " + args[0] +  "..." );
        mm.space = (IJSpace)SpaceFinder.find(args[0]);
        System.out.println("Connect to space " + args[0] +  " OK!" );
        System.out.println("Clean Space");
        mm.space.clean();
        mm.populateSpace(new Integer(args[1]).intValue());
        mm.queryMax();
        mm.queryMin();
    }


        public void showEntry(ExternalEntry entry)
        {
                System.out.println(" ------  ENTRY DATA ---------");  
                System.out.println("First_Name=" + entry.getFieldsValues()[0]);  
                System.out.println("Last_Name=" + entry.getFieldsValues() [1]);  
                System.out.println("ID="+ entry.getFieldsValues() [2]);  

        }
}

Version:: 4.0
Author:: Yechiel Fefer

Field Summary
`static short`	`EQ` equal operation
`static short`	`GE` grater-equal operation
`static short`	`GT` greater than operation
`static short`	`IS_NULL` entry field is null operation (template field not relevant)
`static short`	`LE` less-equal operation
`static short`	`LT` less than operation
`static short`	`NE` not equal operation
`static short`	`NOT_NULL` entry field is not null operation (template field not relevant)
`static short`	`REGEX` regular-expression matching operation (of a string field)