Groovy XMLSlurper - searching sepecific node

问题

I need to find a specific node with Groovy's XMLSlurper. The condition should be that the text/value of the children nodes have to match. In the following example I want to search for a book node where the year is '2003' and the price is '39.95'.

<bookstore name="Store A">
  <employee>
      <id>546343</id>
      <name>Dustin Brown</name>
  </employee>
  <employee>
      <id>547547</id>
      <name>Lisa Danton</name>
  </employee>
  <book category="cooking">
    <title lang="en">Everyday Italian</title>
    <author>Giada De Laurentiis</author>
    <year>2005</year>
    <price>30.00</price>
  </book>
  <book category="children">
    <title lang="en">Harry Potter</title>
    <author>J K. Rowling</author>
    <year>2005</year>
    <price>29.99</price>
  </book>
  <book category="web">
    <title lang="en">Learning XML</title>
    <author>Erik T. Ray</author>
    <year>2003</year>
    <price>39.95</price>
  </book>
</bookstore>
<bookstore name="Store B">
...
</bookstore>

回答1:

Given:

def xml = '''<stores>
  <bookstore name="Store A">
      <employee>
          <id>546343</id>
          <name>Dustin Brown</name>
      </employee>
      <employee>
          <id>547547</id>
          <name>Lisa Danton</name>
      </employee>
      <book category="cooking">
        <title lang="en">Everyday Italian</title>
        <author>Giada De Laurentiis</author>
        <year>2005</year>
        <price>30.00</price>
      </book>
      <book category="children">
        <title lang="en">Harry Potter</title>
        <author>J K. Rowling</author>
        <year>2005</year>
        <price>29.99</price>
      </book>
      <book category="web">
        <title lang="en">Learning XML</title>
        <author>Erik T. Ray</author>
        <year>2003</year>
        <price>39.95</price>
      </book>
  </bookstore>
  <bookstore name="Store B">
  </bookstore>
</stores>'''

Then

new XmlSlurper().parseText(xml).bookstore.book.findAll { it.year == '2003' && it.price == '39.95' }

回答2:

Here is another way to achieve the same.

Note that user can easily change / add the additional and condition(s) easily by adding as shown below

def queryData = [[<element>, <operator>, <element value>], [<element>, <operator>, <element value>], ...]

Operator can be one the below:

EQ for equals to
LE for less than or equals to
GE for greater than or equals to
GT for greater than
LT for less than
NE for not equals to

For example:

def queryData = [['year','EQ', '2003'], ['price', 'LE', '39.95']]

Basically it creates a closure based on the queryData and pass it to findAll.

getQuery closure builds the query to the above list of condition as

{ it -> it.year.text() == '2003' && it.price.text() <= '39.95' }

I felt that it would be easier for some new folks trying groovy to use above list instead of closure as above which is built dynamically.

Here is the script:

def xml = """<stores>  <bookstore name="Store A">
      <employee>
          <id>546343</id>
          <name>Dustin Brown</name>
      </employee>
      <employee>
          <id>547547</id>
          <name>Lisa Danton</name>
      </employee>
      <book category="cooking">
        <title lang="en">Everyday Italian</title>
        <author>Giada De Laurentiis</author>
        <year>2005</year>
        <price>30.00</price>
      </book>
      <book category="children">
        <title lang="en">Harry Potter</title>
        <author>J K. Rowling</author>
        <year>2005</year>
        <price>29.99</price>
      </book>
      <book category="web">
        <title lang="en">Learning XML</title>
        <author>Erik T. Ray</author>
        <year>2003</year>
        <price>39.95</price>
      </book>
  </bookstore>
  <bookstore name="Store B">
  </bookstore>
</stores>"""

//You may just add additional conditions into below list
def queryData = [['year','EQ', '2003'], ['price', 'LE', '39.95']]

enum Operator {
  EQ('=='), LE('<='), GE('>='), GT('>'), LT('<'), NE('!=')
  def value
  Operator(String value){
    this.value = value
  }

  def getValue(){
    value
  }
}

def getQuery = { list ->
  def sb = new StringBuffer('{ it -> ') 
  list.eachWithIndex { sublist, index ->
   index == 0 ?: sb.append(' && ')
   Operator operator = sublist[1]
   sb.append("it.${sublist[0]}.text() ${operator.value} '${sublist[2]}'")
  }
  def query = sb.append(' }').toString()
  println "Query formed is : ${query}"
  def sh = new GroovyShell()
  sh.evaluate(query)
}

def getBooks = { stores, closure ->
  stores.'**'.findAll { closure(it) } ?: 'Could not find matching book'
}

def stores = new XmlSlurper().parseText(xml)

def result = getBooks(stores, getQuery(queryData))
println result

You may quickly try Demo

Also note that it is currently does only and of conditions, does not support or.

来源：https://stackoverflow.com/questions/42222531/groovy-xmlslurper-searching-sepecific-node

标签

groovy

xml-parsing

xmlslurper