[英]Java: How do I iterate through a file with multiple lines, then extract specific lines after filtering delimiters?
[英]Iterate through String with multiple lines
我得到了一些數據:
def data = "# some useless text\n"+
"# even more\n"+
"finally interesting text"
我怎樣才能得到那個“有趣的部分”? 所以基本上所有的行,不是以#開頭。
一個Groovy選項是:
def data = '''# some useless text
|# even more
|finally interesting text'''.stripMargin()
List lines = data.split( '\n' ).findAll { !it.startsWith( '#' ) }
assert lines == [ 'finally interesting text' ]
使用split方法獲取子字符串然后檢查每個以“#”開頭的字符串。 例如:
String[] splitData = data.split("\n");
for (String eachSplit : splitData) {
if (!eachSplit.startWith("#")) {
print(eachSplit);
}
}
data.eachLine {
if (!it.startsWith( '#' )
println it
}
這是一個使用Groovy的元編程功能( http://groovy.codehaus.org/JN3525-MetaClasses )的解決方案:
def data = "# some useless text\n"+
"# even more\n"+
"finally interesting text"
String.metaClass.collectLines = { it ->
delegate.split('\n').findAll it
}
def result = data.collectLines{ !it.startsWith( '#' )}
assert result == ["finally interesting text"]
我會根據換行符(\\ n)拆分字符串,然后忽略以“#”開頭的行。
String[] lines = data.split("\n");
for (String line : lines) {
if (line.startsWith("#") {
continue;
}
//Do stuff with the important part
}
請注意,這是純Java。
不需要將輸入字符串轉換為列表的基於正則表達式的解決方案是:
def data = '''\
# some useless text
# even more
finally interesting text'''
assert data.replaceAll(/#.*\n/, '') == 'finally interesting text'
如果你需要將輸入拆分成行,你仍然可以使用regexp,使用Collection#grep
方法:
assert data.split('\n').grep(~/[^#].*/) == ['finally interesting text']
PS:Regexps FTW! = P
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