groovy学习6-闭包和数据处理

 

/**
 * @author <a href="mailto:zhangting@taobao.com">张挺</a>
 * @since 2010-4-2 13:06:00
 *
 */

//定义一个闭包，By default closures take 1 parameter called "it"
square = { it * it }
//像调用函数一样调用
println square(9)

//使用collection.collection方法对list里的每一个数据进行操作
println ([ 1, 2, 3, 4 ].collect({it*5+10}))

//使用each遍历map，闭包里有2个参数
printMapClosure = {key, value -> println key + "=" + value }
["yue": "wu", "lane": "burks", "sudha": "saseethiaseeleethialeselan"].each(printMapClosure)

//匿名闭包，省略了()
fullString = ""
orderParts = ["BUY", 200, "Hot Dogs", "1"]
orderParts.each {
  fullString += it + " "
}

println fullString

//另一个匿名闭包，循环map的keyset
myMap = ["asdf": 1 , "qwer" : 2, "sdfg" : 10]

result = 0
myMap.keySet().each( { result+= myMap[it] } )
println result

//使用闭包打印文件内容
myFileDirectory = "C:/"
myFileName = "1.txt"
myFile = new File(myFileDirectory + myFileName)

printFileLine = { println "File line: " + it }

myFile.eachLine( printFileLine )

//字符串处理,字符串可以调toInteger()转成integer
stringDate = "2005-07-04"
dateArray = stringDate.split("-")    // split() uses regEx's, so you need to escape chars such as a "." -> "\\."
year = dateArray[0].toInteger()
year = year + 1
newDate = year + "-" + dateArray[1] + "-" + dateArray[2]
println newDate