ObjectSimpleComparator.java

package br.com.citframework.comparacao;

import java.io.Serializable;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.math.BigDecimal;
import java.util.Comparator;

import br.com.citframework.excecao.CompareException;
import br.com.citframework.util.Reflexao;
/**
 * Esta classe serve para fazer comparacao entre objetos em caso de utilizacao de Collections.sort(col, Comparator);
 * @author emauri <br><br>
 * Exemplo: <br>
 * 	<code>
 * 		Collections.sort(lst, new ObjectSimpleComparator("getDataInicio", ObjectSimpleComparator.ASC));    //ou
 *      Collections.sort(lst, new ObjectSimpleComparator("getDataInicio", ObjectSimpleComparator.DESC));
 *  </code> <br>
 * 			onde lst � uma collection de beans: PPPBeanRegistroAmbiental, e
 * 			     getDataInicio pertence ao bean PPPBeanRegistroAmbiental, e este ser� utilizado para fazer
 *               comparacao no momento da ordenacao.
 */
public class ObjectSimpleComparator implements Comparator, Serializable {
	
	
	
	/**
	 * 
	 */
	private static final long serialVersionUID = -8866183197604977380L;
	public static String ASC = "ASC";
	public static String DESC = "DESC";
	private String atributo;
	private String ordem;
	public ObjectSimpleComparator(String atributoParm, String ordemParm) throws CompareException{
		if (atributoParm == null){
			throw new CompareException("Informe o atributo no formato (get+<Xxxxx>) para fazer a comparacao!");
		}
		if (ordemParm == null){
			throw new CompareException("Informe o ordem para fazer a comparacao (Utilize: ObjectSimpleComparator.ASC ou ObjectSimpleComparator.DESC)!");
		}		
		this.atributo = atributoParm;
		this.ordem = ordemParm;
	}
	
	public int compare(Object o1, Object o2) {
		if (o1 == null) return 0;
		if (o2 == null) return 0;
		
		Method m1 = Reflexao.findMethod(this.atributo, o1);
		if (m1 == null) return 0;

		Method m2 = Reflexao.findMethod(this.atributo, o2);
        if (m2 == null) return 0;
		
		Object valor1 = null;
		try {
			valor1 = m1.invoke(o1, null);
		} catch (IllegalArgumentException e) {
			System.out.println("            Exception no momento da comparacao (1): " + e.getMessage());
			return 0;
		} catch (IllegalAccessException e) {
			System.out.println("            Exception no momento da comparacao (1): " + e.getMessage());
			return 0;
		} catch (InvocationTargetException e) {
			System.out.println("            Exception no momento da comparacao (1): " + e.getMessage());
			return 0;
		}
		Object valor2 = null;
		try {
			valor2 = m2.invoke(o2, null);
		} catch (IllegalArgumentException e) {
			System.out.println("            Exception no momento da comparacao (2): " + e.getMessage());
			return 0;
		} catch (IllegalAccessException e) {
			System.out.println("            Exception no momento da comparacao (2): " + e.getMessage());
			return 0;
		} catch (InvocationTargetException e) {
			System.out.println("            Exception no momento da comparacao (2): " + e.getMessage());
			return 0;
		}

        try{
        	if(valor1 == null && valor2 == null)
        		  return 0;
        		else if(valor1 == null)
        		  return 1;
        		else if(valor2 == null)
        		  return -1;
            if (valor1 instanceof java.sql.Date) {
                java.sql.Date data1 = (java.sql.Date)valor1;
                java.sql.Date data2 = (java.sql.Date)valor2;
                if (ObjectSimpleComparator.ASC.equalsIgnoreCase(ordem)){
                    return data1.compareTo(data2);
                }else{
                    return data2.compareTo(data1);
                }
            }else if (valor1 instanceof java.sql.Timestamp) {
                java.sql.Timestamp ts1 = (java.sql.Timestamp)valor1;
                java.sql.Timestamp ts2 = (java.sql.Timestamp)valor2;
                if (ObjectSimpleComparator.ASC.equalsIgnoreCase(ordem)){
                    if (ts2 == null)
                        return 1;
                    if (ts1 != null) 
                        return ts1.compareTo(ts2);
                    else
                        return 0;
                }else{
                    if (ts1 == null)
                        return -1;
                    if (ts2 != null)
                        return ts2.compareTo(ts1);
                    else
                        return 0;
                }
            }else if (valor1 instanceof java.util.Date) {
                java.util.Date data1 = (java.util.Date)valor1;
                java.util.Date data2 = (java.util.Date)valor2;
                if (ObjectSimpleComparator.ASC.equalsIgnoreCase(ordem)){
                    if (data2 == null)
                        return 1;
                    if (data1 != null)
                        return data1.compareTo(data2);
                    else 
                        return 0;
                }else{
                    if (data1 == null)
                        return -1;
                    if (data2 != null)
                        return data2.compareTo(data1);
                    else
                        return 0;
                }
            }else if (valor1 instanceof Integer) {
                Integer val1 = (Integer)valor1;
                Integer val2 = (Integer)valor2;
                if (ObjectSimpleComparator.ASC.equalsIgnoreCase(ordem)){
                    return val1.compareTo(val2);
                }else{
                    return val2.compareTo(val1);
                }
            }else if (valor1 instanceof Long) {
                Long val1 = (Long)valor1;
                Long val2 = (Long)valor2;
                if (ObjectSimpleComparator.ASC.equalsIgnoreCase(ordem)){
                    return val1.compareTo(val2);
                }else{
                    return val2.compareTo(val1);
                }
            }else if (valor1 instanceof BigDecimal) {
                BigDecimal val1 = (BigDecimal)valor1;
                BigDecimal val2 = (BigDecimal)valor2;
                if (ObjectSimpleComparator.ASC.equalsIgnoreCase(ordem)){
                    return val1.compareTo(val2);
                }else{
                    return val2.compareTo(val1);
                }
            }else if (valor1 instanceof String) {
                String val1 = (String)valor1;
                String val2 = (String)valor2;
                if (ObjectSimpleComparator.ASC.equalsIgnoreCase(ordem)){
                    return val1.compareTo(val2);
                }else{
                    return val2.compareTo(val1);
                }           
            }
        }catch (Exception e) {
            System.out.println("            Exception no momento da comparacao (2): " + e.getMessage());
            return 0;
        }
		return 0;
	}

}