使用vtd-xml解析xml文件

问题描述：

如何在java或C中使用vtd-xml解析xml文件，如下所示：使用vtd-xml解析xml文件

<?xml version="1.0" encoding="utf-8"?> 
<StockReport> 
    <Article Code="027783012" Height="35" Width="36" Length="136" TotalPacks="4" AvailablePacks="4" StockReturnPacks="4" BlockedPacks="0" NextExpiryDate="2015-01-17"> 
     <Machine Number="1" TotalPacks="4" AvailablePacks="4" StockReturnPacks="4" BlockedPacks="0" NextExpiryDate="2015-01-17" /> 
</Article> 
<Article Code="025349109" Height="36" Width="37" Length="129" TotalPacks="6" AvailablePacks="6" StockReturnPacks="6" BlockedPacks="0" NextExpiryDate="2015-01-17"> 
     <Machine Number="1" TotalPacks="6" AvailablePacks="6" StockReturnPacks="6" BlockedPacks="0" NextExpiryDate="2015-01-17" /> 
</Article> 
<Article Code="039154327" Height="0" Width="0" Length="0" TotalPacks="0" AvailablePacks="0" StockReturnPacks="0" BlockedPacks="0" NextExpiryDate="" /> 
<Article Code="932654167" Height="57" Width="99" Length="137" TotalPacks="27" AvailablePacks="27" StockReturnPacks="27" BlockedPacks="0" NextExpiryDate="2014-04-17"> 
    <Machine Number="1" TotalPacks="16" AvailablePacks="16" StockReturnPacks="16" BlockedPacks="0" NextExpiryDate="2015-01-17" /> 
    <Machine Number="2" TotalPacks="11" AvailablePacks="11" StockReturnPacks="11" BlockedPacks="0" NextExpiryDate="2014-04-17" /> 
</Article> 
</StockReport>

任何帮助，将不胜感激。

谢谢

你看过java和C中的教程吗？这应该很容易... –

答

我想这其中的一些取决于你想如何解析文件。

这里有一个“非生产”的例子，它使用一些技术，这是有用的，包括：

XPath的选择（只使用“/ *”这里）
去翻所有兄弟节点
看不起通过子节点
提取节点属性到自动驾驶仪使用一个

希望它可以帮助

package scce; 

import com.ximpleware.AutoPilot; 
import com.ximpleware.NavException; 
import com.ximpleware.VTDGen; 
import com.ximpleware.VTDNav; 
import com.ximpleware.XPathEvalException; 
import com.ximpleware.XPathParseException; 
import java.io.File; 
import java.io.IOException; 
import java.util.LinkedHashMap; 
import java.util.Map; 

/** 
* 
* @author David 
*/ 
public class VTDParserExample { 

    VTDGen vg; 
    VTDNav vn; 

    public VTDParserExample() { 
     vg = new VTDGen();  
    } 

    public void parseAndPrint() throws NavException { 

     int level = 0; 

     for(boolean el = (vn != null); 
        el == true ; 
        el = vn.toElement(VTDNav.NEXT_SIBLING)) { 

      printTag(vn, level); 

      parseAndPrintChildren(level);     
     } 

    } 

    private void parseAndPrintChildren(int level) throws NavException { 

     vn.push(); 

     for(boolean el = vn.toElement(VTDNav.FIRST_CHILD); 
        el == true ; 
        el = vn.toElement(VTDNav.NEXT_SIBLING)) { 

      printTag(vn, level + 1); 

      parseAndPrintChildren(level + 1);     
     } 

     vn.pop(); 

    } 

    public VTDNav loadFile(String filePath) throws IOException { 

     File fDoc = new File(filePath); 

     if (fDoc != null && fDoc.exists()) { 
      System.out.println("loadFile file exists ["+filePath+"]"); 

      vg.clear(); 
      if (vg.parseFile(filePath, true)) { 
       vn = vg.getNav(); 
      } 
     } 
     else { 
      throw new IOException("File ["+filePath+"] invalid"); 
     }    

     if (vn == null) {     
      throw new IOException("Cannot parse file ["+filePath+"]"); 
     } 

     return vn; 
    } 

    public void getElementsByXpath() { 

     AutoPilot ap = new AutoPilot(vn); 

     try 
     { 
      String xpQ = "/*"; 

      ap.selectXPath(xpQ);  
      if (ap.evalXPathToBoolean()) { 
       ap.evalXPath(); 
      } 
      else { 
       System.out.println(this.getClass()+".getAllElements evalXPathToBoolean["+ap.evalXPathToBoolean()+"]"); 
      } 
     } 
     catch(XPathParseException | XPathEvalException | NavException e) { 
      e.printStackTrace(); 
     }    

    } 

    private void loadAttributeMap(VTDNav nav, Map<String, String>amap) {  

     nav.push(); 

     try { 
      AutoPilot apAtt = new AutoPilot(nav); 
      apAtt.selectXPath("@*"); 

      int j=-1; 
      while ((j=apAtt.evalXPath())!=-1) { 
       String name = nav.toString(j); 
       String val = nav.toString(j+1); 

       amap.put(name, val); 
      }      
     } 
     catch(XPathParseException | XPathEvalException | NavException e) { 
      e.printStackTrace(); 
     } 

     nav.pop();   
    }  

    private void printTag(VTDNav vn, int level) throws NavException { 

     String tag = vn.toString(vn.getCurrentIndex()); 
     System.out.print("Level ["+level+"] Tag ["+tag+"]"); 

     Map<String, String>amap = new LinkedHashMap<String, String>(); 

     loadAttributeMap(vn, amap); 

     for (String aname: amap.keySet()) { 
      String aval = amap.get(aname); 

      System.out.print(" @"+aname+"="+aval); 
     } 
     System.out.print("\n"); 
    } 

    public static void main(String[] args) { 

     VTDParserExample vp = new VTDParserExample(); 

     try { 

      vp.loadFile("src/scce/famedoro.xml");          
      vp.getElementsByXpath(); 
      vp.parseAndPrint(); 

     } 
     catch (Exception ex) { 
      ex.printStackTrace(); 
     } 
    } 
}

哪产生以下输出：

loadFile file exists [src/scce/famedoro.xml] 
Level [0] Tag [StockReport] 
Level [1] Tag [Article] @Code=027783012 @Height=35 @Width=36 @Length=136 @TotalPacks=4 @AvailablePacks=4 @StockReturnPacks=4 @BlockedPacks=0 @NextExpiryDate=2015-01-17 
Level [2] Tag [Machine] @Number=1 @TotalPacks=4 @AvailablePacks=4 @StockReturnPacks=4 @BlockedPacks=0 @NextExpiryDate=2015-01-17 
Level [1] Tag [Article] @Code=025349109 @Height=36 @Width=37 @Length=129 @TotalPacks=6 @AvailablePacks=6 @StockReturnPacks=6 @BlockedPacks=0 @NextExpiryDate=2015-01-17 
Level [2] Tag [Machine] @Number=1 @TotalPacks=6 @AvailablePacks=6 @StockReturnPacks=6 @BlockedPacks=0 @NextExpiryDate=2015-01-17 
Level [1] Tag [Article] @Code=039154327 @Height=0 @Width=0 @Length=0 @TotalPacks=0 @AvailablePacks=0 @StockReturnPacks=0 @BlockedPacks=0 @NextExpiryDate= 
Level [1] Tag [Article] @Code=932654167 @Height=57 @Width=99 @Length=137 @TotalPacks=27 @AvailablePacks=27 @StockReturnPacks=27 @BlockedPacks=0 @NextExpiryDate=2014-04-17 
Level [2] Tag [Machine] @Number=1 @TotalPacks=16 @AvailablePacks=16 @StockReturnPacks=16 @BlockedPacks=0 @NextExpiryDate=2015-01-17 
Level [2] Tag [Machine] @Number=2 @TotalPacks=11 @AvailablePacks=11 @StockReturnPacks=11 @BlockedPacks=0 @NextExpiryDate=2014-04-17

添加自动驾驶仪环路示例（而不是基于如上纯粹节点）不混合使用这些很好

package scce; 

import com.ximpleware.AutoPilot; 
import com.ximpleware.NavException; 
import com.ximpleware.VTDGen; 
import com.ximpleware.VTDNav; 
import com.ximpleware.XPathEvalException; 
import com.ximpleware.XPathParseException; 
import java.io.File; 
import java.io.IOException; 
import java.util.LinkedHashMap; 
import java.util.Map; 
import java.util.logging.Level; 
import java.util.logging.Logger; 

/** 
* 
* @author David 
*/ 
public class VTDParserExample { 

    VTDGen vg; 
    VTDNav vn; 
    AutoPilot ap; 

    public VTDParserExample() { 
     vg = new VTDGen();  
    } 

    public void parseAndPrint() throws NavException { 

     int level = 0; 

     for(boolean el = (vn != null); 
        el == true ; 
        el = vn.toElement(VTDNav.NEXT_SIBLING)) { 

      printTag(vn, level); 

      parseAndPrintChildren(level);     
     } 

    } 

    private void parseAndPrintChildren(int level) throws NavException { 

     vn.push(); 

     for(boolean el = vn.toElement(VTDNav.FIRST_CHILD); 
        el == true ; 
        el = vn.toElement(VTDNav.NEXT_SIBLING)) { 

      printTag(vn, level + 1); 

      parseAndPrintChildren(level + 1);     
     } 

     vn.pop(); 

    } 

    private VTDNav loadFile(String filePath) throws IOException { 

     File fDoc = new File(filePath); 

     if (fDoc != null && fDoc.exists()) { 
      System.out.println("loadFile file exists ["+filePath+"]"); 

      vg.clear(); 
      if (vg.parseFile(filePath, true)) { 
       vn = vg.getNav(); 
      } 
     } 
     else { 
      throw new IOException("File ["+filePath+"] invalid"); 
     }    

     if (vn == null) {     
      throw new IOException("Cannot parse file ["+filePath+"]"); 
     } 

     return vn; 
    } 

    public boolean getElementsByXpath() { 
     boolean found = false; 

     ap = new AutoPilot(vn); 

     try 
     { 
      String xpQ = "//Machine"; 

      ap.selectXPath(xpQ);  
      if (ap.evalXPathToBoolean()) { 
       found = true; 
      } 
      else { 
       System.out.println(this.getClass()+".getAllElements evalXPathToBoolean["+ap.evalXPathToBoolean()+"]"); 
      } 
     } 
     catch(XPathParseException e) { 
      e.printStackTrace(); 
     }    

     return found; 
    } 

    private void loadAttributeMap(VTDNav nav, Map<String, String>amap) {  

     nav.push(); 

     try { 
      AutoPilot apAtt = new AutoPilot(nav); 
      apAtt.selectXPath("@*"); 

      int j=-1; 
      while ((j=apAtt.evalXPath())!=-1) { 
       String name = nav.toString(j); 
       String val = nav.toString(j+1); 

       amap.put(name, val); 
      }      
     } 
     catch(XPathParseException | XPathEvalException | NavException e) { 
      e.printStackTrace(); 
     } 

     nav.pop();   
    }  

    private void printTag(VTDNav vn, int level) throws NavException { 

     String tag = vn.toString(vn.getCurrentIndex()); 
     System.out.print("Level ["+level+"] Tag ["+tag+"]"); 

     Map<String, String>amap = new LinkedHashMap<String, String>(); 

     loadAttributeMap(vn, amap); 

     for (String aname: amap.keySet()) { 
      String aval = amap.get(aname); 

      System.out.print(" @"+aname+"="+aval); 
     } 
     System.out.print("\n"); 
    } 

    public static void main(String[] args) { 

     VTDParserExample vp = new VTDParserExample(); 

     try { 

      vp.loadFile("src/scce/famedoro.xml"); 
      if (vp.getElementsByXpath()) { 
       vp.parseAndPrintAP();     
      } 
     } 
     catch (Exception ex) { 
      ex.printStackTrace(); 
     } 
    } 

    private void parseAndPrintAP() { 
     int level = 0; 
     int result = -1; 

     try { 
      while((result = ap.evalXPath())!=-1){ 
       printTag(vn, level); 

       parseAndPrintChildren(level);     

      } 
     } catch (XPathEvalException | NavException ex) { 
      ex.printStackTrace(); 
     } 
    } 

}

这 - 将不同的XPath设置为“// Machine”生成：

loadFile file exists [src/scce/famedoro.xml] 
Level [0] Tag [Machine] @Number=1 @TotalPacks=4 @AvailablePacks=4 @StockReturnPacks=4 @BlockedPacks=0 @NextExpiryDate=2015-01-17 
Level [0] Tag [Machine] @Number=1 @TotalPacks=6 @AvailablePacks=6 @StockReturnPacks=6 @BlockedPacks=0 @NextExpiryDate=2015-01-17 
Level [0] Tag [Machine] @Number=1 @TotalPacks=16 @AvailablePacks=16 @StockReturnPacks=16 @BlockedPacks=0 @NextExpiryDate=2015-01-17 
Level [0] Tag [Machine] @Number=2 @TotalPacks=11 @AvailablePacks=11 @StockReturnPacks=11 @BlockedPacks=0 @NextExpiryDate=2014-04-17

感谢您的友好回应，但我对“public void getAllElements（）”方法有所怀疑，这是正确的吗？什么是xpNum？ – famedoro

是的，再看一遍，有几个问题1）它没有在main中调用，2）它周围不应该有push/pop - 我认为这会抛出xpath输出。我将编辑我的答案 – Dazed

我已将“getAllElements”重命名为“getElementsByXpath”（可能更相关 - 并将“xpNum”引用更改为“evalXPathToBoolean”，这是从另一个示例挂起的。 – Dazed

使用vtd-xml解析xml文件

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