Groovy基础总结

这里就先整理一下基础的groovy东西

1 字符串类型的方法:

def firstname='Kate'def surname='Bush'//打印字符串的连接println firstname*2def fullname="$firstname $surname"println fullnameprintln fullname-firstname//凑足15个字符,不够就在左边补充空格println fullname.padLeft(15)  //关于字符串的截取println fullname[0..3]println fullname[-4..-1]//下面的方式比较特别,取第5个字符,以及3,2,1位置字符连接起来assert fullname[5,3..1]=='Beta'ff='aaaabbccadvbasd'lines=ff.split('a')//下面assert在后面表达式为false情况下抛出异常assert lines.size()==7//注意字符串中的特殊字符def plain='\n\r\t\b\\\f\$'assert plain.size()==7//关于字符串的闭包(注意下面的括号的使用方法!)fullname="${-> firstname} $surname"println fullnamefirstname = 'li'surname='shuiqing'println fullname//关于字符串的运算符fullname = fullname -'qing'-'l'+' hello world'assert fullname=='i Bush hello world'//字符串替换string = 'hippopotamus'assert string.replace('ppopotam','bisc') == 'hibiscus'//字符串反转,转换为listassert'apple'.toList() == ['a', 'p', 'p', 'l', 'e']//下面把字符串里面去掉重复数字,并排序.string = "an apple a day"assert string.toList().unique().sort().join() == ' adelnpy'//下面方法取出得到字符串里面的各个单词,并进行反转string = 'Yoda said, "can you see this?"'revwords= string.split(' ').toList().reverse().join(' ')assert revwords== 'this?" see you "can said, Yoda'println revwords//对数组进行筛选,找出反转之后还等于原来字符串并且长度大于5的字符串words = ['bob', 'alpha', 'rotator', 'omega', 'reviver']bigPalindromes= words.findAll{w-> w == w.reverse() && w.size() > 5}assert bigPalindromes== ['rotator', 'reviver']println bigPalindromes

数字函数：

def x=3def y=4println x+yprintln x.plus(y)                println x instanceof Integer   //输出truedef a=2/3//进行小数的取三位小数运算.def b = a.setScale(3,BigDecimal.ROUND_HALF_UP)assert b.toString() == '0.667'//进行不等于的比较println 4<=>3     //输出1   4！=3  println 4**3      //4的3次方,等于4.power(3)println 4/3       //输出1.3333333333,等于4.div(3)println 8.intdiv(3)     //输出1println 8%3          //取余,等于8.mod(3)

日期函数：

import static java.util.Calendar.getInstance as nowimport org.codehaus.groovy.runtime.TimeCategoryimport java.text.SimpleDateFormatdef date = new Date()+1println dateinput = '1998-06-03'df1 = new SimpleDateFormat("yyyy-MM-dd")date = df1.parse(input)df2 = new SimpleDateFormat("MMM/dd/yyyy")println 'Date was '+df2.format(date)println now().timeprintln  df1.format(now().time)//进行时间的计算use(TimeCategory){    date3 =  new Date()+1.year+3.hours-2.days    println df1.format(date3)}/*Tue Apr 10 14:59:33 CST 2012Date was 六月/03/1998Mon Apr 09 14:59:33 CST 20122012-04-092013-04-07*/

操作符重载：

//下面演示对字符串实现了操作符++的重载.++对应的方法名是next for ( i='a';i<'d';i++)   print i +", "  println ''    for( i in 'a'..'d')  print i+", "    //下面演示的对于集合，重载了操作符<<,对应的方法名是leftShift()  lst = ['hello']  lst << 'there'  println lst    //下面演示对一个自定义类实现的+的重载。  class ComplexNumber{      def real,imaginary            def plus(other){          new ComplexNumber(real:real+other.real,               imaginary:imaginary+other.imaginary)      }            String toString(){          "$real ${imaginary>0 ? '+':''}${imaginary}i"      }  }    c1 = new ComplexNumber(real:1,imaginary:2)  c2 = new ComplexNumber(real:4,imaginary:-31)    println c1+c2

操作数据库：

import groovy.sql.Sqldef testYear = '2011'//下面的Driver类找不到！修改配置文件就可以了。def sql = Sql.newInstance("jdbc:mysql://localhost:3306/dwz","root","123456"    ,"com.mysql.jdbc.Driver")println '数据库名:'+sql.connection.catalog   sql.execute("delete from testtable where name like ? or name like ? or name like ?",['ls%','lish%','%dataSet%']) println '插入我的数据之前，数据库：'sql.eachRow("select * from testtable"){    println "id = ${it.id}   year = ${it.name}  "+it.name}println '--------------------------------------'wid = 123wname = 'lishuiqing'//下面必须使用双引号！sql.execute("insert into testtable(id,name) values (${wid},${wname})") sql.execute("update testtable set name =? where name = ?",['lsq','lishuiqing'])//下面使用预定义参数的查询语句sql.eachRow("select * from testtable where name like ?",["%a%"]){    println "id = ${it.id}   year = ${it.name}  "+it.name}println '--------------------------------------'println '下面练习使用dataset'testtable = sql.dataSet('testtable')/*def anycity = testtable.findAll{ it.id>1 }anycity.each{    println 1}*/ 2.times{    testtable.add(id:it,name:'使用dataSet添加'+it)}println "testtable.getSql():"+testtable.getSql()println '总行数:'+testtable.rows().size() num = 0testtable.each{     //println it[0]----也可以输出指定位置的元素！！    num = num+1    println it.id+",year="+it.name}//注意要使用${}输出参数的话，必须使用双引号。。。println "${num}"println '--------------------------------------'println "下面显示当前数据库的运行实时状态"sql.eachRow("show status "){    //下面在{}里面定义的变量，在外面也找到，也就是作用域是全部的范围！！    if(it.variable_name=="Uptime")        uptime = it[1]    else if (it.variable_name =='Questions')        questions = it[1]}println "数据库运行时间Uptime for Database:${uptime}"println "数据库查询的条目Number of Queries:${questions}"println "每分钟的查询条目Queties per Minutes = "+Integer.valueOf(questions)/Integer.valueOf(uptime)sql.eachRow("show status like 'Com_%'"){    if(it.variable_name=="Com_insert")        insertnum = Integer.valueOf(it[1])    else if (it.variable_name == "Com_select")        selectnum = Integer.valueOf(it[1])    else if (it.variable_name == "Com_update")        updatenum = Integer.valueOf(it[1])}println "查询语句有${selectnum},百分比："+100*(selectnum/Integer.valueOf(uptime))+"%"println "插入语句有${insertnum},百分比："+100*(insertnum/Integer.valueOf(uptime))+"%"println "更新语句有${updatenum},百分比："+100*(updatenum/Integer.valueOf(uptime))+"%"println '--------------------------------------'println '下面将数据库里面的值保存到xml文件'bldr = new groovy.xml.MarkupBuilder()bldr.testtable{    sql.eachRow('select * from testtable'){        data(id:it.id,name:it.name)    }}println bldr.text()

List 和 Map:

Listassert [1,2,3,4] ==(1..4)//集合是有顺序的！！assert [1,2,3,4] !=[1,2,4,3]assert [1,2,3]+[1] ==[1,2,3,1]//将一个元素添加到已经存在的list中assert [1,2,3]<<1 ==[1,2,3,1]//从已有的list中删除元素assert [1,2,3,1]-[1] ==[2,3]assert [1,2,3]*2 ==[1,2,3,1,2,3]//flatten:扁平的意思assert [1,[2,3]].flatten() ==[1,2,3]assert [1,2,3].reverse()==[3,2,1]//测试两个集合是否有交叉assert [1,2,3].disjoint([4,5,6])//intersect:得到两个集合中的交集assert [1,2,3].intersect([4,3,1]) ==[3,1]//对集合进行循环处理assert [1,2,3].collect{it+3} ==[4,5,6]assert [1,2,3,1].unique().size()==3assert [1,2,3,1].count(1) ==2assert [1,2,3,4].min() ==1assert [1,2,3,4].max() ==4assert [1,2,3,4].sum() ==10assert [4,2,1,3].sort() ==[1,2,3,4]//对集合进行循环处理判断，并返回结果assert [4,2,1,3].findAll{it%2==0} ==[4,2]//对集合的迭代def expected = [1,2,3,'test']expected.each{test -> println test}Map：def map = [a:1,'b':2]println map    //[a:1, b:2]println map.aprintln map['a']println map.keySet()  //[a, b] map = [:]map[1] = 'a';map[2]='b'map[true] = 'p'map[false] = 'q'map[null]='x';map['null'] = 'z'assert map ==[1:'a',2:'b',(true):'p',(false):'q',(null):'x'    ,'null':'z']//下面的例子很有用，对map进行了很快速的循环输出！！def sb = new StringBuffer();[1:'a',2:'b',3:'c'].each{k,v->sb << "$k:$v, "}//下面是输出字符串[1:'a',2:'b',3:'c'].each{k,v-> println "$k:$v, "}assert sb.toString() =='1:a, 2:b, 3:c, '//下面又是一种快速的输出map为字符串形式的方法map = [1:'a',2:'b',3:'c']def string = map.collect{k,v -> "$k:$v"}.join(', ')assert string == '1:a, 2:b, 3:c'   //下面演示一个对city进行分类的例子assert [    [name:'C',city:'London'],    [name:'S',city:'London'],    [name:'M',city:'LA'],    [name:'Z',city:'HK'],    [name:'A',city:'HK']        ].groupBy{it.city}==[    London:[ [name:'C',city:'London'],    [name:'S',city:'London']],    LA:[ [name:'M',city:'LA']],    HK:[ [name:'Z',city:'HK'] ,    [name:'A',city:'HK'] ]]//map中顺序也是有关系的！顺序不对的map也不相等assert [ [name:1,city:'L'],[name:2,city:'H']] != [ [name:2,city:'H'],[name:1,city:'L']]

闭包：

闭包的一个例子：import static java.lang.Math.*//闭包例子1piA = { 22/7 }piB = { 333/106 }piC = { 355/113 }piD = { 0.6*(3+sqrt(5))}piE = { 22/7 +37/47 +888/83}piF = { sqrt(sqrt(2143/22)) }//这里就是闭包的实际算法部分。howCloseToPI = { abs(it.value() - PI) }algorithms = ['piA':piA,'piB':piB,'piC':piC,'piD':piD,'piE':piE,'piF':piF] findBestPI(algorithms)def findBestPI(map){    map.entrySet().sort(howCloseToPI).each{        entry ->//下面调用了闭包的函数        def diff = howCloseToPI(entry)        println "Alorithm $entry.key differs by $diff"    }}doubleNum = {num ->num*2}println doubleNum(3)//闭包例子2//下面的方法定义就是使用了闭包。传入了num，closure，其中closure是函数类型。processThenPrint = {num,closure->  num = closure(num);println "num is $num"}//下面传入了函数名作为第二个参数processThenPrint(3,doubleNum)//下面传入第二个参数是匿名函数processThenPrint(10){it/2}//闭包例子3//下面又是一个闭包的例子def houston(Closure  doit){   (10..1).each{       count -> doit(count)    }}houston{ println it}//闭包例子4,用于迭代3.times{println 'Hi'}[0,1,2].each{number -> println number}//注意下面的it！！[1,3,5].each{ println it}def println = {println it}[4,5,6].each printlnmap = ['a':1,'b':2]map.each{key,value -> map[key]=value*2 }assert map == ['a':2,'b':4]//注意下面的each后面是小括号，不是大括号了！doubler = {key,value -> map[key] = value*2}map.each(doubler)assert map == ['a':4,'b':8]def doubleMethod(entry){    map[entry.key] = entry.value *2;}doubler = this.&doubleMethodmap.each(doubler)assert map == ['a':8,'b':16]//下面对集合的一些操作很容易的结合了闭包方法的使用//查询子元素assert [1,2,3].grep{it<3} ==[1,2]//判断是否有一个满足条件assert [1,2,3].any{ it%2==0 }//判断是否全部满足条件assert [1,2,3].every{ it <4}//将集合中全部元素joinassert (1..9).collect{it}.join() == '123456789'assert (1..4).collect{it*2}.join() == '2468'//闭包例子5：新的函数curry！以及演示一个通过闭包将list进行修改的例子！！def add = {x,y -> x+y}def mult = {x,y -> x*y}assert add(1,3) == 4assert mult(1,3) == 3def min = {x,y -> [x,y].min()}def max = {x,y -> [x,y].max()}def sub = {x,y -> return 'x - y = '+(x-y)}//注意下面的curry函数，意思是默认的传入参数到原有的函数的第一个位置，并将结果返回为一个新的函数//例如下面的triple就是得到一个数值的三倍！！def triple = mult.curry(3);assert triple(2) ==6def atLeastTen = max.curry(10)def subTen = sub.curry(10)assert atLeastTen(5)==10assert atLeastTen(15) == 15assert subTen(13) == 'x - y = -3'//def pairWise(list ,invoke){    if(list.size()<2) return []    def next = invoke(list[0],list[1])    return [next]+pairWise(list[1..-1],invoke)}assert pairWise(1..5,add) == [3,5,7,9]assert pairWise(1..5,mult) == [2,6,12,20]assert pairWise(1..5,min) == [1,2,3,4]assert pairWise(1..5,max) == [2,3,4,5]//inject--参数是初始值，然后放在一个闭包里面对list的每个元素进行迭代操作！assert 'cbaxabc' == ['a','b','c'].inject('x'){    result,item -> item +result+item}

对xml的操作

对xml的解析def CAR_RECORDS = '''<records><car name='HSV Maloo' make='Holden' year='2006'><country>Australia</country><record type='speed'>Production Pickup Truck with speed of 271kph</record></car><car name='P50' make='Peel' year='1962'><country>Isle of Man</country><record type='size'>Smallest Street-Legal Car at 99cm wide and 59 kg in weight</record></car><car name='Royale' make='Bugatti' year='1931'><country>France</country><record type='price'>Most Valuable Car at $15 million</record></car></records>'''//解析xml的第一步，进行分析--注意这里的找到的是根节点<records>，所以后面的car。size（）就有值。def records = new XmlSlurper().parseText(CAR_RECORDS)//得到节点的数目assert 3 == records.car.size()//注意下面的得到car里面的country的条目，而不是直接进行records.country！！assert 3 == records.car.country.size()//depthFirst()：计算全部的节点的数目   assert 10 == records.depthFirst().collect{it}.size()def firstRecord = records.car[0]//得到一个节点里面的属性nameassert 'car' == firstRecord.name()//得到一个节点里面的自定义属性，使用@属性名 assert 'Holden' == [e-mail]()//text():得到节点里面的文本信息！不是属性。assert 'Australia' == firstRecord.country.text()//对节点进行判断，找到make属性含有e的条目数量assert 2 == records.car.findAll {[e-mail]().contains('e')}.size()//使用正则表达式进行节点筛选assert 2 == records.car.findAll{it.@make=~'.*e.*'}.size()//找到全部的国家符合正则表达式的record节点的make属性！assert ['Holden','Peel'] == records.car.findAll{ it.country =~ '.*s.*a.*'}    [e-mail]{it.toString()}    //找到全部的type非空的record节点的type属性！！assert ['speed','size','price'] == records.depthFirst().grep{it.@type!=''}.'@type'*.toString()def countryOne = records.car[1].country//查找父节点的两个方法！parent和使用路径表达式assert 'Peel' == countryOne.parent()[e-mail]()assert 'Peel' == countryOne.'..'[e-mail]()//将所有的节点按照指定顺序排序之后，再按顺序输出name属性！注意后面的一个×号!def names = records.car.list().sort{ [e-mail]()}.'@name'*.toString()assert ['Royale','P50','HSV Maloo'] == names

操作文件，属性文件

myFileDir = "d:\\"myFileName = 'mytest.txt'myFile = new File(myFileDir + myFileName)printFileLine = { println "File line:"+it}myFile.eachLine ( printFileLine )myFile.write('123')myFile.append('123')读取属性文件：Properties properties = new Properties()properties.load(new FileInputStream("d:\\conf.properties"))println properties.getProperty("filename")

正则表达式：

正则表达式：assert 'Hello World!' =~ /Hello/assert 'Hello World!' ==~ /Hello\b.*/def p = ~/Hello\b.*/assert p.class.name == 'java.util.regex.Pattern'//下面的next方法是返回的下一个字符！assert "1.23".replaceAll(/./){ch-> ch.next()}== "2/34"assert "1.23".replaceAll(/\d/){num -> num.toInteger()+1}=='2.34'//下面的 == 不可以换行！否则就是语法错误！！为什么？？因为每一行后面默认就是有一个分号的！！assert "1.23".replaceAll(/\d+/){num -> num.toInteger()+1} == '2.24'