读取xml标记内的值。想要获得<step num =“1”>的值当我尝试阅读时我得到null。使用DOM解析器读取</step>

Question

<step num="1">
  <internalNum>1</internalNum>
  <description>1: Mainframe.IO.Format on [A_DL0_STD_1] -dsname(MMALCHE.CATTMP) </description>
  <autoDesc>true</autoDesc>
  <module>Mainframe</module>
  <submodule>IO</submodule>
  <function>Format</function>
  <devLabel1 idx="0">A_DL0_STD_1</devLabel1>
  <startLoop>false</startLoop>
  <endLoop>false</endLoop>
  <noPoll>false</noPoll>
  <negative>false</negative>
  <option name="dsname">MMALCHE.CATTMP</option>
  <stepOption>1:TEXTFIELD:FALSE:-1:MMALCHE.CATTMP:datasetName:dsname:FALSE</stepOption>
</step>