java 问题求教，急急急！

Question

JAVA:

1、map 存取方法
2、取list所有元素方式
3、是否了解json对象，map怎么转换为jsonobject,java数组和list怎么转换成jsonarray,

下面这段代码的功能：

operAge: function (birth,nowdate){
var age;
var nowDateFormat = nowdate.replace(/-/g,"");
var birthFormat = birth.replace(/-/g,"");
var years = parseInt(nowDateFormat.substr(0,4),10);
var month = parseInt（nowDateFormat.substr(4,2),10）；
var days = parseInt（nowDateFormat.substr(6,2),10）；
var birthYear = parseInt(birthFormat.substr(0,4),10);
var birthMonth = parseInt(birthFormat.substr(4,2),10);
var birthDate = parseInt(birthFormat.substr(6,2),10);

if(month-birthMonth {
age = yeas- birthYear -1;
}
else if(month-birthMonth>0)
{
age = yeas- birthYear;
}
else
{if(days-birthDate>=0)
{age = years - birthYear;}
else
{age = years - birthYear-1;}

}
if (age<0) age = 0;
return age;
}

下面这段代码功能是什么？
publisc final static String TimeUnit_YEAR = "year";
publisc final static String TimeUnit_MONTH = "month";
publisc final static String TimeUnit_DAY = "day";

publisc static Date accountDate(Date givenDate,int amount,String unit)
{
Calendar c = Calendar.getInstance();
c.setTime(giveDate);
if(unit != null && unit.trime().equals(TimeUnit_DAY))
{c.add(Calendar.DATE,amount);
return c.getTime();}
else if(unit != null && unit.trime().equals(TimeUnit_MONTH))
{c.add(Calendar.MONTH,amount);
return c.getTime();}
else if(unit != null && unit.trime().equals(TimeUnit_YEAR))
{c.add(Calendar.YEAR,amount);
return c.getTime();}
else
{return givenDate;}

}

Answer 1

前三个问题google下就有。第四个代码，从字符串中解析生日，并且计算年龄。最后一个代码，给定日期、单位、增量，计算得到另一个日期。