Question

我正在研究hashtable。我想在其中形成哈希表但我的外部哈希表的值被替换。

Hashtable1 [键，哈希表[键，值]]

我能够获得outerhashtable密钥而不会覆盖，但内部散列表值会被替换。

 import java.io.*;
 import java.util.*;
 import com.sridhar.util.*;

 public class MyTokenizerDemo 
 {
public static void main(String[] args) throws IOException
{
    Hashtable ht=new Hashtable();
    Hashtable ht1=new Hashtable();
    Hashtable ht2=new Hashtable();
    File f = new File("E:/rum/format.txt");
    FileReader fr = new FileReader(f);
    BufferedReader br = new BufferedReader(fr);
    String s;
    while((s=br.readLine())!=null)
    {
        ArrayList aList = (ArrayList)StringUtils.myTokenizer(s,"~!~");
        for(int i=0;i<aList.size();i++)
        {
            ArrayList aList1 = (ArrayList)StringUtils.myTokenizer((String)aList.get(i),"$#$");
            //System.out.println("==>"+aList1.get(0)+"<==");
            ArrayList aList2 = (ArrayList)StringUtils.myTokenizer((String)aList1.get(1),"~$~");
            //System.out.println("====>"+aList2+"<=====");
            for(int j=0;j<aList2.size();j++)
            {
                ArrayList as = (ArrayList)StringUtils.MyTokenizer((String)aList2.get(j),"#$#");
                if(as!=null)
                {
                String innerkey = (String)as.get(0);
                String innervalue = (String)as.get(1);
                ht2.put(innerkey,innervalue);
                }
            }
        ht1.put(aList1.get(0),ht2);
        }
    }
     System.out.println(ht1);
   }

}

请在我自己的字符串标记实用程序类中进行假设。

我的外部Hashtable值被覆盖。

在这个问题上帮助我。

Answer 1

将此代码ht1.put(aList1.get(0),ht2);修改为ht1.put(aList1.get(i),ht2);

当您调用asList1.get（0）时，始终键将相同，因此您的数据将被覆盖

Answer 2

我在这里犯了一个简单的错误!! for循环中的实例化使值保持活着而不是覆盖!!谢谢大家!!下面是代码！

import java.io.*;
import java.util.*;
import com.sridhar.util.*;

public class MyTokenizerDemo 
{
public static void main(String[] args) throws IOException
{
Hashtable ht=new Hashtable();
Hashtable ht1=new Hashtable();
Hashtable ht2=new Hashtable();
File f = new File("E:/rum/format.txt");
FileReader fr = new FileReader(f);
BufferedReader br = new BufferedReader(fr);
String s;
while((s=br.readLine())!=null)
{
    ArrayList aList = (ArrayList)StringUtils.myTokenizer(s,"~!~");
    for(int i=0;i<aList.size();i++)
    {
        ht2 = new Hashtable();   //Instantiating inside the loop makes to work perfect :)
        ArrayList aList1 = (ArrayList)StringUtils.myTokenizer((String)aList.get(i),"$#$");
        //System.out.println("==>"+aList1.get(0)+"<==");
        ArrayList aList2 = (ArrayList)StringUtils.myTokenizer((String)aList1.get(1),"~$~");
        //System.out.println("====>"+aList2+"<=====");
        for(int j=0;j<aList2.size();j++)
        {
            ArrayList as = (ArrayList)StringUtils.MyTokenizer((String)aList2.get(j),"#$#");
            if(as!=null)
            {
            String innerkey = (String)as.get(0);
            String innervalue = (String)as.get(1);
            ht2.put(innerkey,innervalue);
            }
        }
    ht1.put(aList1.get(0),ht2);
    }
}
 System.out.println(ht1);
}

内部哈希表覆盖

2 个答案: