[Java]統計相同對象內容的區別

測試代碼

package main;

import java.lang.reflect.Method;
import java.text.SimpleDateFormat;

import bean.Bird;
import bean.Cat;

public class DiffObjectMainTest {
    private static String FORMAT_PATTERN = "yyyy-MM-dd HH:mm:ss";
    public static void main(String[] args) throws Exception {
        SimpleDateFormat format = new SimpleDateFormat(FORMAT_PATTERN);
        Bird b1 = new Bird();
        b1.setName("Bird11111");
        b1.setAge(20);
        b1.setBirthday(format.parse("2016-10-11 23:45:43"));
        b1.setIsOld(true);
        Bird b2 = new Bird();
        b2.setName("Bird2222222");
        b2.setAge(50);
        b2.setBirthday(format.parse("2014-10-11 23:45:43"));
        b2.setIsOld(true);
        Cat cat = new Cat("cat");
        System.out.println(DiffObject(b1, b2));
        System.out.println(DiffObject(b1, cat));
    }

    /**
     * 比較兩個對象屬性字段內容的變化
     * @param beforeObject 修改前的對象
     * @param afterObject 修改後的對象
     * @return beforeObject,afterObject相同對象則返回修改前後的字段值  否則返回空串
     * @throws Exception
     */
    public static String DiffObject(Object beforeObject,Object afterObject) throws Exception{
        if(!beforeObject.getClass().equals(afterObject.getClass()))
            return "";
        SimpleDateFormat format = new SimpleDateFormat(FORMAT_PATTERN);
        StringBuffer resultBuffer = new StringBuffer();
        Class<?> clazz = beforeObject.getClass();
        Method[] methods = clazz.getDeclaredMethods();
        for(Method method:methods){
            String methodName = method.getName();
            if(methodName.contains("get")){
                Object beforeValue = method.invoke(beforeObject);
                Object afterValue = method.invoke(afterObject);
                if(!beforeValue.equals(afterValue)){
                    StringBuilder methodNameBuilder = new StringBuilder(methodName.substring(3));
                    methodNameBuilder.setCharAt(0, Character.toLowerCase(methodNameBuilder.charAt(0)));
                    String returnType = method.getReturnType().getSimpleName();
                    resultBuffer.append("字段: ").append(methodNameBuilder.toString()).append(":").append(returnType).append(" ");
                    if(returnType.equalsIgnoreCase("Date")){
                        resultBuffer.append(" before: ").append(format.format(beforeValue)).append(" after: ").append(format.format(afterValue)).append(" ");
                    }else{
                        resultBuffer.append(" before: ").append(beforeValue).append(" after: ").append(afterValue).append(" ");
                    }
                }
            }
        }
        return resultBuffer.toString();
    }
}

運行結果

字段: name:String  before: Bird11111 after: Bird2222222 字段: birthday:Date  before: 2016-10-11 23:45:43 after: 2014-10-11 23:45:43 字段: age:Integer  before: 20 after: 50