Question

import java.util.*;
import java.util.ArrayList;
import java.util.List;
import java.util.HashMap;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;
import java.io.File;
import java.io.IOException;
import java.util.List;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

public class MyHandler extends DefaultHandler {

//List to hold Employees object
public HashMap<String,Product> prodList = null;

public Product product = null;

//getter method for employee list
public HashMap<String,Product> getEmpList() {
    return prodList;
}

boolean bImage = false;
boolean bName = false;
boolean bAccessories = false;
boolean bCondition = false;
boolean bPrice = false;

@Override
public void startElement(String uri, String localName, String qName, Attributes attributes)
        throws SAXException {

    if (qName.equalsIgnoreCase("watch" )) {
        //create a new Employee and put it in Map
        String id = attributes.getValue("id");
        //initialize Employee object and set id attribute
        product = new Product();
        product.setId(id);
        String retailer = attributes.getValue("retailer");
        //initialize Employee object and set id attribute
        product.setRetailer(retailer);
        product.setProducttype(qName);
        //initialize list
        if (prodList == null)
            prodList = new HashMap<String,Product>();
    } 
    else if (qName.equalsIgnoreCase("speaker" )) {
        //create a new Employee and put it in Map
        String id = attributes.getValue("id");
        //initialize Employee object and set id attribute
        product = new Product();
        product.setId(id);
        String retailer = attributes.getValue("retailer");
        //initialize Employee object and set id attribute
        product.setRetailer(retailer);
        product.setProducttype(qName);
        //initialize list
        if (prodList == null)
            prodList = new HashMap<String,Product>();
    } 
     else if (qName.equalsIgnoreCase("laptop" )) {
        //create a new Employee and put it in Map
        String id = attributes.getValue("id");
        //initialize Employee object and set id attribute
        product = new Product();
        product.setId(id);
        String retailer = attributes.getValue("retailer");
        //initialize Employee object and set id attribute
        product.setRetailer(retailer);
        product.setProducttype(qName);
        //initialize list
        if (prodList == null)
            prodList = new HashMap<String,Product>();
    } 
      else if (qName.equalsIgnoreCase("headphone" )) {
        //create a new Employee and put it in Map
        String id = attributes.getValue("id");
        //initialize Employee object and set id attribute
        product = new Product();
        product.setId(id);
        String retailer = attributes.getValue("retailer");
        //initialize Employee object and set id attribute
        product.setRetailer(retailer);
        product.setProducttype(qName);
        //initialize list
        if (prodList == null)
            prodList = new HashMap<String,Product>();
    } 
    else if (qName.equalsIgnoreCase("phone" )) {
        //create a new Employee and put it in Map
        String id = attributes.getValue("id");
        //initialize Employee object and set id attribute
        product = new Product();
        product.setId(id);
        String retailer = attributes.getValue("retailer");
        //initialize Employee object and set id attribute
        product.setRetailer(retailer);
        product.setProducttype(qName);
        //initialize list
        if (prodList == null)
            prodList = new HashMap<String,Product>();
    } 
       else if (qName.equalsIgnoreCase("storage" )) {
        //create a new Employee and put it in Map
        String id = attributes.getValue("id");
        //initialize Employee object and set id attribute
        product = new Product();
        product.setId(id);
        String retailer = attributes.getValue("retailer");
        //initialize Employee object and set id attribute
        product.setRetailer(retailer);
        product.setProducttype(qName);
        //initialize list
        if (prodList == null)
            prodList = new HashMap<String,Product>();
    }

    else if (qName.equalsIgnoreCase("name")) {
        //set boolean values for fields, will be used in setting Employee variables
        bName = true;
    } else if (qName.equalsIgnoreCase("image")) {
        bImage = true;
    } else if (qName.equalsIgnoreCase("accessories")) {
        bAccessories = true;
    }else if (qName.equalsIgnoreCase("condition")) {
        bCondition = true;
    } else if (qName.equalsIgnoreCase("price")) {
        bPrice = true;
    } 
     }

@Override
public void endElement(String uri, String localName, String qName) throws SAXException {
    if (qName.equalsIgnoreCase("watch"))
            {
        //add Product object to list
        prodList.put(product.getId(),product);
    }
    else if(qName.equalsIgnoreCase("speaker"))
            {
        //add Product object to list
        prodList.put(product.getId(),product);
            }
             else if(qName.equalsIgnoreCase("laptop"))
            {
        //add Product object to list
        prodList.put(product.getId(),product);
            }
             else if(qName.equalsIgnoreCase("headphone"))
            {
        //add Product object to list
        prodList.put(product.getId(),product);
            }
             else if(qName.equalsIgnoreCase("phone"))
            {
        //add Product object to list
        prodList.put(product.getId(),product);
            }
             else if(qName.equalsIgnoreCase("storage"))
            {
        //add Product object to list
        prodList.put(product.getId(),product);
            }
    }

@Override
public void characters(char ch[], int start, int length) throws SAXException {
    if (bImage) {
        //age element, set Employee age
        product.setImage(new String(ch, start, length));
        bImage = false;
    } else if (bName) {
        product.setName(new String(ch, start, length));
        bName = false;
    } else if (bCondition) {
        product.setCondition(new String(ch, start, length));
        bCondition = false;
    } else if (bPrice) {
        product.setPrice(Double.parseDouble(new String(ch, start, length)));
        bPrice = false;
    }
}
}

Answer 1

问题是Product未被识别为类型。之所以会发生这种情况，是因为class Product很可能与MyHandler类不在同一个包中。所以有两种方法可以解决它：

将Product类放在与MyHandler类
导入Product课程。让我们在mypackage包中说出来。然后你需要添加：

import mypackage.Product;

位于MyHandler类的顶部。

如果同一个包中的Product类，则为e.x. mypackage，然后您需要在MyHandler课程的顶部以及Product课程中添加此行：

package mypackage;

我希望它有所帮助！

Answer 2

看一下你的import语句，没有导入过这样的类。所以首先在MyHandeler中导入Product类。

当我编译它时，它显示有关Product.java的错误。但该文件正在工作和显示

2 个答案: