看groovy的时候找资料的时候归纳的
代码测试过都可以执行:
groovy笔记:
XML操作: MarkupBuilder:
def s=new StringWriter()
def builder = new groovy.xml.MarkupBuilder(s)
builder.'web-app' {
'display-name' 'My Web Application'
}
println s.toString()
在里面也可以嵌套写 或者写for等表达式
创建:
groovy.xml.StreamingMarkupBuilder
(http://groovy.codehaus.org/Creating+XML+using+Groovy%27s+StreamingMarkupBuilder)
groovy.xml.MarkupBuilder
解析可以使用XMLParser:
class XmlExample {
static def PERSON =
"""
<person id='2'>
<name>Gweneth</name>
<age>1</age>
</person>
"""
} //?XML作为Groovy源码
class Person {def id; def name; def age} //Groovy中的Person定义
def xmlPerson = new XmlParser().
parseText(XmlExample.PERSON) //?读取XML
Person p = new Person(id: xmlPerson.@id,
name: xmlPerson.name.text(),
age: xmlPerson.age.text()) //?填入GroovyBean Person中
println "${p.id}, ${p.name}, ${p.age}"
生成Json:
和XML的MarkupBuilder传入SW不同 他的输出靠builder本身就可以了
def builder = new groovy.json.JsonBuilder()
def root = builder.people {
person {
firstName 'Guillame'
lastName 'Laforge'
// Named arguments are valid values for objects too
address(
city: 'Paris',
country: 'France',
zip: 12345,
)
married true
// a list of values
conferences 'JavaOne', 'Gr8conf'
}
}
println builder.toString()
println builder.toPrettyString()
def s=new StringWriter()
builder.writeTo(s)
println s.toString()
或者直接传入一个结构:
import groovy.json.JsonBuilder
def tasks = [1, 2, 3]
def data = [ //data是map
success: true,
count: tasks.size(),
data: tasks.collect {[id: it]}
]
def json = new JsonBuilder(data)
println json.toPrettyString()
解析直接使用:JsonSlurper
import groovy.json.JsonBuilder
import groovy.json.JsonSlurper
def builder = new groovy.json.JsonBuilder()
def root = builder.people {
person {
firstName 'Guillame'
lastName 'Laforge'
// Named arguments are valid values for objects too
address(
city: 'Paris',
country: 'France',
zip: 12345,
)
married true
// a list of values
conferences 'JavaOne', 'Gr8conf'
}
}
def result = new JsonSlurper().parseText(builder.toString())
println result.people.person.firstName
集合操作:
集合支持 +(两个集合) -(两个集合) * 的操作
each:遍历集合，对其中的每一项应用函数字面值 //相当于erlang的 lists:foreach操作
collect:收集在集合中每一项上应用函数字面值的返回结果（相当于其他语言map/reduce中的map函数）//相当于erlang的lists:map操作
inject:用函数字面值处理集合并构建返回值（相当于其他语言里map/reduce中的reduce函数）
//相当于erlang中lists:foldl操作
findAll:找到集合中所有与函数字面值匹配的元素 //相当于erlang lists:filter操作
max:返回集合中的最大值
min:返回集合中的最小值
erlang中:
1> A=[1,2,3,4,5,6].
[1,2,3,4,5,6]
2> lists:map(fun(E) -> E*2 end,A).
[2,4,6,8,10,12]
3> lists:foldl(fun(E,Sum) -> Sum+E end,0,A).
21
5> lists:filter(fun(E) -> E rem 2==0 end,A).
[2,4,6]
6> lists:foreach(fun(E) -> io:format("~p~n",[E*2]) end,A).
1
2
3
4
5
6
ok
对应的groovy中:
a=[1,2,3,4,5,6]
println a.collect {i -> i*2}
println a.inject(0, {sum, value -> sum + value })
println a.findAll {i -> i%2==0}
a.each {i -> println(i*2)}
正则表达式
用 def pattern = ~ "正则表达式" //注意 = ~是分开的！！！
然后要match用 def match=("验证的字符串" =~ pattern)就可以了
练习案例:
def begin=System.currentTimeMillis()
def stream=new URL("http://fc.5sing.com/10933160.html###").openStream();
def out=new ByteArrayOutputStream();
def data=new byte[1024];
while((length=stream.read(data))!=-1){
out.write(data,0,length)
}
data=out.toString("utf-8")
def p = ~"songID: SongID, songType: \"fc\", file: \"(.*)\", singerID: UserID"
def matcher=(data =~ p)
for(m in matcher){
result=m.get(1)
}
def end=System.currentTimeMillis()
println "time elasped:${end-begin}ms"
result
此外:
字符串可以直接 进行-操作
"1231"-"1" //等于"231" 这点erlang也是一样的 用--符号
关于闭包:
//转换
interface One{
def drink();
}
def one={ -> println "hello"} as One
one.drink()
//默认是Callable类型的
def closure = {
"called"
}
assert closure instanceof java.util.concurrent.Callable
assert closure() == "called"
//将当前的方法变成一个函数
def modify(item){
"modify_${item}"
}
def fun=this.&modify
def list=[1,2,3,4,5]
list.collect(fun)
fun(45)
//对于静态方法
def s=Math.&sqrt
s(4)
//对于实例方法:
class Mine{
public String sayHello(){
return "hello";
}
}
def m=new Mine()
def hello=m.&sayHello
hello()