线程“主”java.lang.IndexOutOfBoundsException 中的异常：索引：11，大小：11

Question

这个爬虫程序出现越界异常 如何解决？

线程“主”java.lang.IndexOutOfBoundsException 中的异常：索引： 11，大小：11 在 java.util.ArrayList.rangeCheck(ArrayList.java:653) 在 java.util.ArrayList.get(ArrayList.java:429) 在 Glowship_inv_battery.main(Glowship_inv_battery.java:68)

代码：

import java.util.ArrayList;

import com.webscrap4j.WebScrap;
import com.webscrap4j.WebScrapException;

import java.io.FileOutputStream;
import java.io.IOException;

import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.Row;
  
public class letsbuybattery_inverterbattery 
{
    @SuppressWarnings("resource")
    public static void main(String[] args) throws IOException {
    
        ArrayList<String> al = new ArrayList<String>();
        ArrayList<String> bl = new ArrayList<String>();
        ArrayList<String> cl = new ArrayList<String>();
        WebScrap ws = new WebScrap();
        
        ws.setUrl("http://letsbuybattery.com/inverters/");
        try
        {               
            ws.startWebScrap();
            
            al = ws.getSingleHTMLScriptData("<h5>", "</h5>");
            //mrp
            bl = ws.getSingleHTMLScriptData("<div class='clearfix'> ", "</div>");
            //selling price
            cl = ws.getSingleHTMLScriptData("<div class='item-price pull-left'>", "</div>");                
            
            HSSFWorkbook workBook = new HSSFWorkbook();
             FileOutputStream fos = new FileOutputStream("/Users/parthpatil/Documents/Abm Technologies/Crawl/letbuybattery_battery.xls"); 
             {

            // Create the Sheet
            HSSFSheet Sheet = workBook.createSheet("products");

            // Create the first row corresponding to the header
            Row header = Sheet.createRow(0);
            header.createCell(0).setCellValue("Product Name");
            header.createCell(1).setCellValue("Product Price");
            header.createCell(2).setCellValue("Product MRP");

            // Ensure that all the List have the same size otherwise throw an exception
            //  if (al.size() != bl.size() || al.size() != cl.size())
            //    throw new IllegalStateException("Some data is missing");

            // Iterate over all the list an create the rows of data
            for(int i = 0; i < al.size(); i++){
                // Create the current starting from 1 to al.size()
                HSSFRow row = Sheet.createRow((short) i + 1);
                // Cell of the Product Name
                row.createCell(0).setCellValue(al.get(i));
                // Cell of the Product Price
                row.createCell(1).setCellValue(cl.get(i));
                // Cell of the Product MRP
                row.createCell(2).setCellValue(bl.get(i));
                
            }
            // Write the result into the file
            workBook.write(fos);
            
            for (String adata : al)
            {    
                System.out.println("the product are:- " + adata);    
            }

            for (String bdata : bl)
            {
                System.out.println("the MRp are:- " + bdata);    
            }

            for (String cdata : cl)
            {    
                System.out.println("the selling price is:- " + cdata);    
            }               
        }
             }catch (WebScrapException e) {
            
            e.printStackTrace(System.out);
        }
        }
    }

Answer 1

a1,b1,c1 您必须确保 b1,c1 和 a1.size() 的大小至少相同或大于 a1.size().adjust your logic accrodingly.means 迭代语句应该在三个中的最小值arraylists.use 类似下面的东西来找到数组列表中的最小大小并使用该值来启动你的循环。你得到的错误是在下面的代码中产生的，你将 indexout of bound 因为显然 b1 和 c1 小于 a1 并且你的 i index 将尝试获取 b1.get(2),c2.get(2) 显然没有任何价值

    int d = c1.size() < (a1.size()< b1.size() ? a1.size() : b1.size()) ? c1.size() : ((a1.size() < b1.size()) ? a1.size() : b1.size());

public class TestArrayList {

    public static void main(String[] args) {
        // TODO Auto-generated method stub

        
        ArrayList<String> a1=new ArrayList<>();
        ArrayList<String> b1=new ArrayList<>();
        ArrayList<String> c1=new ArrayList<>();
        a1.add("a1");
        a1.add("a2");
        a1.add("a3");
        
        b1.add("b1");
        b1.add("b2");
        
        c1.add("c1");
        c1.add("c2");
        
        for(int j=0;j<a1.size();j++)
        {
            System.out.println("finding thestuuf from arralist to use in your excel cells"+">>>"+a1.get(j)+">>>"+b1.get(j)+">>>"+c1.get(j));
        }
        
    }

}

Answer 2

这里是代码爆炸发生的：

 for(int i = 0; i < al.size(); i++){
                // Create the current starting from 1 to al.size()
                HSSFRow row = Sheet.createRow((short) i + 1);
                // Cell of the Product Name
                row.createCell(0).setCellValue(al.get(i));
                // Cell of the Product Price
                row.createCell(1).setCellValue(cl.get(i));
                // Cell of the Product MRP
                row.createCell(2).setCellValue(bl.get(i));
            }

您正在循环使用 al 的大小，但没有检查 bl 或 cl 的大小...

Answer 3

Exception in thread "main" java.lang.IndexOutOfBoundsException: Index: 11, Size: 11 
at java.util.ArrayList.rangeCheck(ArrayList.java:653) 
at java.util.ArrayList.get(ArrayList.java:429) 
at Glowship_inv_battery.main(Glowship_inv_battery.java:68)

让我们把它翻译成简单的英语：

There was an Exception thrown because of accessing notexisting index which is 11 
    on an object which has size 11, so has indexes from 0 to 10.
It has occured on line 653 of ArrayList.java, in method rangeCheck,
    which was invoked from:
line 429 of ArrayList.java, in method get
    which was invoked from
line 68 of Glowship_inv_battery.java in method main

可能的解决方案。在Glowship_inv_battery.java 文件的第 68 行设置断点并进行调试。您的调试器肯定有可能在运行时查找所有值。