groovy学习6-闭包和数据处理

 

代码

   
     

    
      
    
      

    
      /*
    
      *
 * @author <a href="mailto:[email protected]">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