Parsing 如何在Groovy中解析文本
我需要解析文本(svn命令的输出)以检索数字(svn修订版)。 这是我的密码。注意,我需要以文本形式检索所有输出流以执行其他操作Parsing 如何在Groovy中解析文本,parsing,text,groovy,functional-programming,Parsing,Text,Groovy,Functional Programming,我需要解析文本(svn命令的输出)以检索数字(svn修订版)。 这是我的密码。注意,我需要以文本形式检索所有输出流以执行其他操作 def proc = cmdLine.execute() // Call *execute* on the strin proc.waitFor() // Wait for the command to finish def output = proc.in.text //这
def proc = cmdLine.execute() // Call *execute* on the strin
proc.waitFor() // Wait for the command to finish
def output = proc.in.text
//这里发生的其他事情
output.eachLine {
line ->
def revisionPrefix = "Last Changed Rev: "
if (line.startsWith(revisionPrefix)) res = new Integer(line.substring(revisionPrefix.length()).trim())
}
这段代码运行得很好,但由于我还是Groovy的新手,我想知道是否有更好的惯用方法来避免丑陋的if
svn输出示例(当然问题更一般)
我从下面的答案中得到了灵感,并使用find()解决了这个问题。我的解决办法是:
def revisionPrefix = "Last Changed Rev: "
def line = output.readLines().find { line -> line.startsWith(revisionPrefix) }
def res = new Integer(line?.substring(revisionPrefix.length())?.trim()?:"0")
3行,无if,非常干净一个可能的替代方案是:
def output = cmdLine.execute().text
Integer res = output.readLines().findResult { line ->
(line =~ /^Last Changed Rev: (\d+)$/).with { m ->
if( m.matches() ) {
m[ 0 ][ 1 ] as Integer
}
}
}
不确定是不是更好。我相信其他人会有不同的选择
编辑:
另外,请注意使用proc.text
。如果你的进程输出了很多东西,那么当inputstream满的时候你可能会阻塞
下面是一个有大量注释的备选方案,使用consumeProcessOutput
:
// Run the command
String output = cmdLine.execute().with { proc ->
// Then, with a StringWriter
new StringWriter().with { sw ->
// Consume the output of the process
proc.consumeProcessOutput( sw, System.err )
// Make sure we worked
assert proc.waitFor() == 0
// Return the output (goes into `output` var)
sw.toString()
}
}
// Extract the version from by looking through all the lines
Integer version = output.readLines().findResult { line ->
// Pass the line through a regular expression
(line =~ /Last Changed Rev: (\d+)/).with { m ->
// And if it matches
if( m.matches() ) {
// Return the \d+ part as an Integer
m[ 0 ][ 1 ] as Integer
}
}
}
您考虑过使用Java SVN库吗?是的,但我还需要从命令行启动其他命令。不管怎么说,问题是关于提高我的groovy技能,总的来说,我对这个解决方案非常满意。我标记为解决方案,因为使用readLines让我想到将它与findAll结合起来删除if
// Run the command
String output = cmdLine.execute().with { proc ->
// Then, with a StringWriter
new StringWriter().with { sw ->
// Consume the output of the process
proc.consumeProcessOutput( sw, System.err )
// Make sure we worked
assert proc.waitFor() == 0
// Return the output (goes into `output` var)
sw.toString()
}
}
// Extract the version from by looking through all the lines
Integer version = output.readLines().findResult { line ->
// Pass the line through a regular expression
(line =~ /Last Changed Rev: (\d+)/).with { m ->
// And if it matches
if( m.matches() ) {
// Return the \d+ part as an Integer
m[ 0 ][ 1 ] as Integer
}
}
}