java - XML SAX 解析

Question

我必须打印此 XML 文件示例中每个客户的订单总额。

<OrderID id="10248">
<CustomerID>VINET</CustomerID>
<ProductName>Queso Cabrales</ProductName>
<UnitPrice>14.0000</UnitPrice>
<Quantity>12</Quantity>
<Freight>32.3800</Freight>
</OrderID>
<OrderID id="10248">
<CustomerID>VINET</CustomerID>
<ProductName>Singaporean Hokkien Fried Mee</ProductName>
<UnitPrice>9.8000</UnitPrice>
<Quantity>10</Quantity>
<Freight>32.3800</Freight>
</OrderID>
<OrderID id="10248">
<CustomerID>VINET</CustomerID>
<ProductName>Mozzarella di Giovanni</ProductName>
<UnitPrice>34.8000</UnitPrice>
<Quantity>5</Quantity>
<Freight>32.3800</Freight>
</OrderID>
<OrderID id="10249">
<CustomerID>TOMSP</CustomerID>
<ProductName>Tofu</ProductName>
<UnitPrice>18.6000</UnitPrice>
<Quantity>9</Quantity>
<Freight>11.6100</Freight>
</OrderID>
<OrderID id="10249">
<CustomerID>TOMSP</CustomerID>
<ProductName>Manjimup Dried Apples</ProductName>
<UnitPrice>42.4000</UnitPrice>
<Quantity>40</Quantity>
<Freight>11.6100</Freight>
</OrderID>

我想要的结果是这样的:

VINET:537.14

TOMSP:1886.62

等等

这些总计是根据结果建议的单价 * 数量 + 运费得出的。如果我给您 XML 的其余部分，您可以更清楚地看到它，但为了节省时间，我将其缩小了。我还得到一个错误，为这三个变量设置十进制格式，我不知道为什么。

public class DataProcessor2 extends DefaultHandler {

    boolean unitPrice = false;
    boolean collectCount = false;
    boolean freight = false;;
    boolean quantity = false;
    boolean customer = false;

    float currentCount = 0;
    float totalCount = 0;
    float unitPriceCount = 0;
    float freightCount = 0;
    float quantityCount = 0;

    //unitprice, freight, quantity

    public DataProcessor2(){
        super();
    }

    public void startDocument()  {
        // TODO Auto-generated method stub
        System.out.println("Order Totals Per Customer");
    }

    public void endDocument()  {
        // TODO Auto-generated method stub

        System.out.println("Document END");
    }

    public void startElement(String namespaceUri, String localName,
            String qualifiedName, Attributes attributes) {

        DecimalFormat df = new DecimalFormat("0.00");
        df.setMaximumFractionDigits(2);
        if (qualifiedName.equals("CustomerID")){
            customer = true;
        }
        if(qualifiedName.equals("UnitPrice")){
            unitPrice = true;
            //unitPriceCount = Float.parseFloat((qualifiedName));
        }
        if(qualifiedName.equalsIgnoreCase("Freight")){
            freight = true;
            //freightCount = Float.parseFloat(df.format(qualifiedName));
        }
        if(qualifiedName.equalsIgnoreCase("Quantity")){
            quantity = true;
            //quantityCount = Float.parseFloat(df.format(qualifiedName));
        }
        if(unitPrice & freight & quantity){
            collectCount = true;
            //currentCount = unitPriceCount * quantityCount + freightCount;
        }

    }
    public void endElement(String namespaceUri, String localName,
            String qualifiedName, Attributes attributes) {
        //System.out.println("End Element "+ qualifiedName);
    }
    public void characters (char[] ch, int start, int length) throws SAXException{

         if (customer) {
             System.out.println(new String(ch, start, length)); 
             customer = false;
            }
         if(unitPrice){
            // System.out.println(new String(ch, start, length));
             unitPrice = false;
         }
         if(freight){
             //System.out.println(new String(ch, start, length));
             freight = false;
         }
         if(quantity){
             //System.out.println(new String(ch, start, length));
             quantity = false;
         }
         if(collectCount){
             //System.out.println("Amount"+new String(ch, start, length));
             collectCount = false;
         }
         if(unitPrice & freight & quantity){
                collectCount = true;
                //currentCount = unitPriceCount * quantityCount + freightCount;
            }

    }

}

错误:

Exception in thread "main" java.lang.NumberFormatException: For input string: "UnitPrice"
    at sun.misc.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:2043)
    at sun.misc.FloatingDecimal.parseFloat(FloatingDecimal.java:122)
    at java.lang.Float.parseFloat(Float.java:451)
    at DataProcessor2.startElement(DataProcessor2.java:50)
    at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.startElement(AbstractSAXParser.java:509)
    at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.scanStartElement(XMLNSDocumentScannerImpl.java:379)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScannerImpl.java:2786)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:606)
    at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.next(XMLNSDocumentScannerImpl.java:117)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:510)
    at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:848)
    at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:777)
    at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:141)
    at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1213)
    at One.main(One.java:19)

Answer 1

下面是在 VTD-XML 中执行此操作的代码

import com.ximpleware.*;

public class xpathSearch {
    private static  double compute(VTDNav vn) throws VTDException{
        double d1=0,d2=0;
        if (vn.toElement(VTDNav.NEXT_SIBLING,"UnitPrice")){
            int i=vn.getText();
            if (i!=-1)
            d1 = vn.parseDouble(i);
        }
        if (vn.toElement(VTDNav.NEXT_SIBLING,"Quantity")){
            int i=vn.getText();
            if (i!=-1)
            d2 = vn.parseDouble(i);
        }
        return d1*d2;
    }
    public static void main(String s[])throws VTDException{
        VTDGen vg = new VTDGen();
        if (!vg.parseFile("d:\\xml\\input2.txt", false))
                return;
        VTDNav vn = vg.getNav();
        AutoPilot ap = new AutoPilot(vn);
        ap.selectXPath("/root/OrderID");
        int i;
        double p1=0,p2 = 0;
        while ((i=ap.evalXPath())!=-1){
            if (vn.toElement(VTDNav.FIRST_CHILD,"CustomerID")){
                i = vn.getText();
                if (i!=-1) {
                    if(vn.matchTokenString(i, "TOMSP")){
                        p1 += compute(vn);
                    }
                    else if (vn.matchTokenString(i, "VINET")){

                        p2 += compute(vn);
                    }
                }  
                vn.toElement(VTDNav.P);
            }
        }

        System.out.println(" TOMSP "+p1);
        System.out.println(" VINET "+p2);

    }
}