JavaOperator小框架制作【精品博客】

以下是运算小框架的制作过程，以及核心代码，完成（计算，监听，回馈等）：

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package com.demo2.operator;

/**
 * 运算标准接口
 * @author Liudeli
 */
public interface IOperator {

    /**
     * 设置第一个数
     * @param number1
     * @return
     */
    public Operator setNumber1(double number1);

    /**
     * 设置运算符
     * @param operator
     * @return
     */
    public Operator setOperator(String operator);

    /**
     * 设置第二个数
     * @param number2
     * @return
     */
    public Operator setNumber2(double number2);


    /**
     * 设置运算结果
     * @param onResult
     * @return
     */
    public Operator setOnResultListener(OnResult onResult);

    /**
     * 设置运算出错
     * @param onError
     * @return
     */
    public Operator setOnErrorListener(OnError onError);

    /**
     * 次方法为最后提交的方法(必须最后提交调用)
     */
    public void operatorCommit();
}

package com.demo2.operator;

/**
 * 运算配置类
 * @author Liudeli
 */
public class OperatorConfig {

    /**
     * 定义返回错误码（运算符输入错误）
     */
    public static final int ERROR_CODE_INPUT = 4004;

    /**
     * 定义返回错误码（运算发生异常）
     */
    public static final int ERROR_CODE_EX = 4005;

    /**
     * 运算默认值
     */
    public static final double RESULT_DEFAUTL = 0.0;

}

package com.demo2.operator;

/**
 * 运算结果接口
 * @author Liudeli
 */
public interface OnResult {

    /**
     * 获取得到运算结果
     * @param result
     */
    public void result(double result);

}

package com.demo2.operator;

/**
 * 次接口为运算出错接口
 * @author Liudeli
 *
 */
public interface OnError {

    /**
     * 错误码方法
     * @param error
     */
    public void error(int error);

}

package com.demo2.operator;

/**
 * 此类为运算类的具体实现
 * @author Liudeli
 */
public class Operator implements IOperator {

    /**
     * 定义单例模式
     */
    private static Operator mOperator = null;

    public static Operator getInstance() {
        if (null == mOperator) {
            synchronized (Operator.class) {
                mOperator = new Operator();
            }
        }
        return mOperator;
    }

    /**
     * 此方法的用于计算两个数的值
     * @param figure1   第一个数值
     * @param figure2   第二个数值
     * @param operator  传入运算符
     * @return
     */
    private double getOperatorResult(double figure1,
            double figure2, String operator) {

        double resultOperator = OperatorConfig.RESULT_DEFAUTL;

        try {
            if ("+".equals(operator)) {
                resultOperator = figure1 + figure2;
            } else if ("-".equals(operator)) {
                resultOperator = figure1 - figure2;
            } else if ("*".equals(operator)) {
                resultOperator = figure1 * figure2;
            } else if ("/".equals(operator)) {
                resultOperator = figure1 / figure2;
            } else {
                onError.error(OperatorConfig.ERROR_CODE_INPUT);
            }
        } catch (Exception e) {
            e.printStackTrace();
            onError.error(OperatorConfig.ERROR_CODE_EX);
        }
        return resultOperator;

    }

    private double number1;

    public Operator setNumber1(double number1) {
        this.number1 = number1;
        return this;
    }

    private String operator;

    public Operator setOperator(String operator) {
        this.operator = operator;
        return this;
    }

    private double number2;

    public Operator setNumber2(double number2) {
        this.number2 = number2;
        return this;
    }

    private OnResult  onResult;

    public Operator setOnResultListener(OnResult onResult) {
        this.onResult = onResult;
        return this;
    }

    private OnError onError;

    public Operator setOnErrorListener(OnError onError) {
        this.onError = onError;
        return this;
    }

    public void operatorCommit() {
        double operatorResult = getOperatorResult(number1, number2, operator);
        if (OperatorConfig.RESULT_DEFAUTL != operatorResult) {
            onResult.result(operatorResult);
        }
    }

}

---

使用方式，非常灵活，可以设置监听提交结合一体：

模拟客户端程序使用：

方式一：

package com.demo2.client;

import java.util.Scanner;

import com.demo2.operator.OnError;
import com.demo2.operator.OnResult;
import com.demo2.operator.Operator;

/**
 * 模拟客户端程序
 * @author Liudeli
 */
public class Client {

    public static void main(String [] srgs) {

        Scanner scanner = new Scanner(System.in);

        System.out.println("请输入第一个数");
        double number1 = Double.parseDouble(scanner.nextLine());

        System.out.println("请输入运算符  ( + - * /)");
        String operator = scanner.nextLine();

        System.out.println("请输入第二数");
        double number2 = Double.parseDouble(scanner.nextLine());

        // 第一种用法
        Operator.getInstance()
        .setNumber1(number1)
        .setNumber2(number2)
        .setOperator(operator)
        .setOnErrorListener(new OnError() {

            public void error(int error) {
                System.out.println("运算过程出错，错误码是：" + error);
            }
        })
        .setOnResultListener(new OnResult() {

            public void result(double result) {
                System.out.println("运算结果是：" + result);
            }
        })
        .operatorCommit();
    }

}

方式二：

package com.demo2.client;

import java.util.Scanner;

import com.demo2.operator.OnError;
import com.demo2.operator.OnResult;
import com.demo2.operator.Operator;

/**
 * 模拟客户端程序
 * @author Liudeli
 */
public class Client2 {

    public static void main(String [] srgs) {

        Scanner scanner = new Scanner(System.in);

        System.out.println("请输入第一个数");
        double number1 = Double.parseDouble(scanner.nextLine());

        System.out.println("请输入运算符   (+ - * /)");
        String operator = scanner.nextLine();

        System.out.println("请输入第二数");
        double number2 = Double.parseDouble(scanner.nextLine());

        // 第二种用法
        Operator.getInstance()
        .setNumber1(number1)
        .setNumber2(number2)
        .setOperator(operator)
        .setOnErrorListener(onError)
        .setOnResultListener(onResult)
        .operatorCommit();
    }

    private static OnError onError = new OnError() {

        public void error(int error) {
            System.out.println("运算过程出错，错误码是：" + error);
        }
    };

    private static OnResult onResult = new OnResult() {

        public void result(double result) {
            System.out.println("运算结果是：" + result);
        }

    };

}

方式三：

package com.demo2.client;

import java.util.Scanner;

import com.demo2.operator.OnError;
import com.demo2.operator.OnResult;
import com.demo2.operator.Operator;

/**
 * 模拟客户端程序
 * @author Liudeli
 */
public class Client3 {

    public static void main(String [] srgs) {

        Scanner scanner = new Scanner(System.in);

        System.out.println("请输入第一个数");
        double number1 = Double.parseDouble(scanner.nextLine());

        System.out.println("请输入运算符   (+ - * /)");
        String operator = scanner.nextLine();

        System.out.println("请输入第二数");
        double number2 = Double.parseDouble(scanner.nextLine());

        // 第三种用法
        Operator instance = Operator.getInstance();

        instance.setNumber1(number1);
        instance.setNumber2(number2);
        instance.setOperator(operator);

        instance.setOnErrorListener(new OnError() {

            public void error(int error) {
                System.out.println("运算过程出错，错误码是：" + error);
            }
        });

        instance.setOnResultListener(new OnResult() {

            public void result(double result) {
                System.out.println("运算结果是：" + result);
            }
        });

        instance.operatorCommit();
    }
}

运行结果：

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Project结构：

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谢谢大家的观看，更多精彩技术博客，会不断的更新，请大家访问，
刘德利CSDN博客， http://blog.csdn.net/u011967006