Learn Groovy

Quick Start

1. download groovy-binary-1.7.3.zip,and unzip into,for example,d:groovy-binary-1.7.3
2. add d:groovy-binary-1.7.3bin into Window PATH
3. Write file of test1.g,the content is "println new Date()"
4. Make sure you have installed JDK,run command groovy test1.g,you will get date string,? "Tue Jul 17 09:59:49 CST 2012"

http://groovy.codehaus.org/ http://groovy.codehaus.org/User+Guide http://groovy.codehaus.org/groovy-jdk/ http://blog.csdn.net/hivon/article/details/4256296

Java中的equals方法对应Groovy中的==,而Java中的==（判断是否引用同一对象）对应Groovy中的is方法。 ======File Operation ---transfer file character encoding new FileOutputStream("out.txt").withWriter("UTF-8") { writer -> ??? new FileInputStream("in.txt").withReader("ISO-8859-1") { reader -> ??????? writer << reader ??? } } def f=new File("c:/data/myiso88591.xml").getText("ISO-8859-1") new File("c:/data/myutf8.xml").write(f,"utf-8") def writer=new File("FileWrite.out").newWriter() writer.writeLine("contents") writer.close() file.eachLine ("utf8") { println it} new File("test").eachFile() { file->? println file.getName() new File("test").eachDirRecurse() { dir ->? println dir.getPath()} } ? ======Collection ---Map def map = [:] def map=[name:"Gromit",likes:"cheese",id:1234] map.each{key,value -> print key} map.keySet().each{print it} assert map.get("name") == "Gromit" map.put("foo",5) assert map.size() == 1 map['name'] //Result: "Bruce" map[a]????? //Result: "Bruce" map[3]????? //Result: 56 map.containsKey('name')?? //Result: true ---List assert [1,3,5] == ['a','few','words']*.size() def words = ['ant','buffalo','cat','dinosaur'] assert words.collect{ it[0] } == ['a','b','c','d'] list + [6,7]?? //Result: [1,2,4,5,6,7] list << 6????? //Result: [1,6] list << [6,7]? //Result: [1,[6,7]] [2,7].remove(1)????????? //Result: 5; list = [2,7] [2,5].isEmpty()??????????? //Result: false [2,5].get(1)?????????????? //Result: 5 [2,5].size()?????????????? //Result: 2 [2,5].add(7)?????????????? //Result: true; list = [2,7] def a1=(1..10).grep{it<5 && it>3} //[4] a1=(1..10).collect{it<2} //[true,false,false] a1=(1..10).every{it>2}??? //false a1=(1..10).find{it>2} //3,it is first matched list.eachWithIndex { elem,i ->println "$i : $elem"} def list = [2007,8,26] list.sort { e1,e2 ->return e1 - e2} 'a1/b2/c3/d4'.tokenize('/') /["a1","b2","c3","d4"] def list = ['a','ab','a'] list.count('a') def list = [1,3] list.sum() // 6 ======String def str2 = 'hello world it is a groovy world'.split(' ').collect{it[0].toUpperCase()+(it.size()>1?it[1..-1]:'')}.join(' ') //Hello World It Is A Groovy World propName.substring(1,propName.length()) propName.substring(0,1).toUpperCase() println str[1..-2] //获取从下标1开始，到倒数第二位的子串 println str[1..2]//下标为1和2处的子串 包含一个最简单正则表达式的表达式是用==~. "beijing" ==~ /beijing/ check("I love beijing?",/[^/?]+/?/) //必须在?前面加'/'进行转义 locationData = "Liverpool,England: 53° 25? 0? N 3° 0? 0?" --> myRegularExpression = /([a-zA-Z]+),([a-zA-Z]+): ([0-9]+). ([0-9]+). ([0-9]+). ([A-Z]) ([0-9]+). ([0-9]+). ([0-9]+)./ matcher = ( locationData =~ myRegularExpression ) for(int i = 0;i < matcher[0].size; i ++)?? {????? println(matcher[0][i])? } 就用到了非俘获组．表示方法就是用?: 加上你要过滤的正则前面． myMatcher = (it =~ /(.*?)(?:?? .+)+ (.*)/) --> "ZDW?? love beijing",matcher = (it =~ /(.*?)(?: .+)+ (.*)/);? --> "Graham James Edward Miller",m="10.128.12.16" =~ /(/d.*?)/./ --> //星号加个问题，表示非贪婪匹配，输出为 10 ======database import groovy.sql.Sql; sql = Sql.newInstance("jdbc:jtds:sqlserver://localhost/pubs","sa","","net.sourceforge.jtds.jdbc.Driver"); sql.eachRow("select * from person",{? println it.id + "-- ${it.username} -- ${it.password} -- ${it.age}"}); row = sql.firstRow("select username,password from person"); println "Row: username = ${row.username} and password = ${row.password}"; sql.execute("insert into person (username,password) values (${username},${password})") sql.execute("insert into person values ('admin','admin',99)"); sql.execute("insert into person (username,password) values (?,?)",[username,password]); sql.execute("update person set username = 'dddd' where id = ?",[id]); sql.execute("delete from person where id = ?",[2]) =======多线程 t = new Thread() {println "a"}; t.start(); Thread.start { println "a"}; Thread.startDaemon { println "a"}; new Timer().runAfter(1000) { println "a"} ======swing import groovy.swing.SwingBuilder import javax.swing.* import java.awt.* def swing = new SwingBuilder() def swing_count = 0 def sharedPanel = {swing.panel() {label("??Panel")}} def textlabel def frame = ??? swing.frame(title:'??Panel??',size:[600,600],defaultCloSEOperation:JFrame.EXIT_ON_CLOSE,pack:true,show:true) ??? { ?? ???? boxLayout(axis:BoxLayout.Y_AXIS) ?? ???? textlabel = label(text:"???${swing_count}?.",constraints: BorderLayout.NORTH) ?? ???? button(text:'???',actionPerformed: {swing_count++; textlabel.text = "???${swing_count}?"; println "clicked"},constraints:BorderLayout.SOUTH) ?? ???? widget(sharedPanel()) ?? ???? widget(sharedPanel()) ?? } frame.pack() frame.show() ======class class Person {String name1;String m1(String v1){return v1+v1};def m2(v1){return v1+v1}} Person.metaClass.introduce << {println "I'm $name1"} Person.metaClass.constructor << { name,sex ->new Person(name:name,sex:sex)} ======闭包 将代码块作为方法参数进行传递，这种机制就叫做闭包 默认的闭包带一个参数"it",你也能创建闭包用自命名参数.例如方法Map.each() 如果是多个参数的闭包，则在闭包中用 "->" 把参数列表和实现隔开，如：(当然一个参数也可以这么方式定义的) square = {it * it} [ 1,4 ].collect(square) // [ 1,9,16 ] printMapClosure = { key,value -> println key + "=" + value } [ "yue" : "wu","lane" : "burks","sudha" : "saseethiaseeleethialeselan" ].each(printMapClosure) myMap.keySet().each( { result+= myMap[it] } ) //匿名闭包 ====== utils ---?? Groovy File and URL MD5 import java.security.MessageDigest def generateMD5(final file) { ? MessageDigest digest = MessageDigest.getInstance("MD5") ? file.withInputStream(){is-> ??? byte[] buffer = new byte[8192] ??? int read = 0 ??? while( (read = is.read(buffer)) > 0) {?? digest.update(buffer,read);} ? } ? byte[] md5sum = digest.digest() ? BigInteger bigInt = new BigInteger(1,md5sum) ? return bigInt.toString(16) } ---listAllFiles import groovy.io.FileType def list = [] new File(path_to_parent_dir).eachFileRecurse (FileType.FILES) { file ->? list << file}