Apache xmlconfig xpath不是读取元素

时间:2013-11-01 16:09:51

标签: java xml xpath getstring

我想阅读这个xml文件:

<configuration>
 <parameter name="path">C:\Users\bellibot\Desktop</parameter>
 <parameter name="filename">config.xml</parameter>
 <module type="livestatus" id="0001">
   <parameter name="username">nagiosadmin</parameter>
   <parameter name="password">nagiosadmin</parameter>
   <parameter name="hostaddress">127.0.0.1/nagios/live.php?q=</parameter>  
</configuration>   

使用此代码:

class XMLslave {
XMLConfiguration config;
String defval = "DEFAULT";


public XMLslave(){}

public XMLslave(String path, String filename){
    try{
    String str = path + "\\" + filename;
    File file = new File(path, filename); 
    this.config = new XMLConfiguration(file);
    this.config.setExpressionEngine(new XPathExpressionEngine());
    }catch(ConfigurationException e){}
}

public static void main(String[] args) {
    try{
    BufferedReader in = new BufferedReader(
            new InputStreamReader(System.in));
    System.out.println("Insert Path");
    String path = in.readLine();
    System.out.println("Insert Filename");
    String filename = in.readLine();
    XMLslave slave = new XMLslave(path, filename);
    String str = slave.getKey("path");   
    System.out.println(str);    
    }catch (IOException e){}
}

String getKey(String key){
    String result;
    String str = "/configuration/parameter[@name='" + key + "']";
    result = this.config.getString(str);
    if (result==null){
        return this.defval;
    }else{
        return result;}
    }

我不明白为什么返回值是“DEFAULT”而不是“C:\ Users \ bellibot \ Desktop”,我测试了xpath语法并且它是合法的,我相信config.getString()在某种程度上不起作用。 谢谢你的帮助。

1 个答案:

答案 0 :(得分:2)

ExpressionEngine的{​​{1}}实现不需要最顶层的标记(在您的情况下为XMLConfiguration)作为搜索表达式的一部分。用<configuration>替换搜索表达式可以解决您的问题。