com.fr.data.util.function

接口 DataFunction

所有超级接口:

java.lang.Cloneable, java.io.Serializable

所有已知实现类:

AbstractDataFunction, AverageFunction, CountFunction, DateFunction, MaxFunction, MinFunction, NoneFunction, SumFunction

public interface DataFunction
extends java.lang.Cloneable, java.io.Serializable

The basic function implementation;The normal steps to use it is: invokeaddData(Object) method onec or several times to add data into the function,invoke getResult() method to get the result.

the code below is the source code of (SumFunction) :

 public class SumFunction extends AbstractDataFunction {
     private double sumResult;

     public void reset() {
         sumResult = 0;
     }

     public void addData(Object data) {
         if (data == null) {
             return;
         }

         //number value.
         if (data instanceof Number) {
             sumResult += ((Number) data).doubleValue();
         } else if (data instanceof Boolean) {
             if(((Boolean)data).booleanValue()) {
                 sumResult += 1;
             }
         } else {
             try {
                 sumResult += Double.valueOf(data.toString()).doubleValue();
             } catch (NumberFormatException exp) {
             }
         }
      }

     public Object getResult() {
         return new Double(sumResult);
     }
 }

These code demonstrates how to caculate by using DataFunction:

 DataFunction function = new SumFunction();
 function.addData(new Double(1));
 function.addData(new Double(2));
 function.addData("3");

 //Print the result, 1 + 2 + 3 = 6
 Object result = function.getResult();
 System.out.println("Result=" + result); 

方法概要

方法

限定符和类型	方法和说明
void	addData(java.lang.Object data) Adds data to the function.
void	cal_after_traverse_result(GroupList gl)
void	cal_when_traverse_result(GroupList gl, java.lang.Object value)
java.lang.Object	clone() Clone.
boolean	equals(java.lang.Object obj) Equals.
java.lang.String	getFormula()
java.lang.Object	getResult() Gets the calculated result of the function.
void	reset() Reset the result of DataFunction, restart to add data to DataFunction.

方法详细资料

reset

void reset()

Reset the result of DataFunction, restart to add data to DataFunction.

addData

void addData(java.lang.Object data)

Adds data to the function.

另请参阅:

Object

getResult

java.lang.Object getResult()

Gets the calculated result of the function.

返回:

Returns the calculated result of the function.

另请参阅:

Object

cal_when_traverse_result

void cal_when_traverse_result(GroupList gl,
                            java.lang.Object value)

cal_after_traverse_result

void cal_after_traverse_result(GroupList gl)

equals

boolean equals(java.lang.Object obj)

Equals.

覆盖:

equals 在类中 java.lang.Object

clone

java.lang.Object clone()
                       throws java.lang.CloneNotSupportedException

Clone.

抛出:

java.lang.CloneNotSupportedException

getFormula

java.lang.String getFormula()