运行hashtable,内存不足怎么办?

Question

我写了个程序,用哈舌鳎罢了做搜索,运行是说内存不足,怎么办?

Answer 1

说清楚点,就这么谁知道你用hashtable做哪个部分啊?
存放结果?

Answer 2

内存不足就说明你创建了太多的对象呗，要解决这个问题，就不要创建太多的对象呗。hehe

Answer 3

方式1：加大JVM内存（当然前提是你真的有那么多内存）
方式2：改变算法

Answer 4

我把数据库中的一个表的内容放到了hashtable中，在程序里有对数据表的更新和添加。程序是先看table里面有没有程序新生成的对象，如果有就更新，没有就添加！我添加到大概5万个对象的时候就内存不足了。有没有什么好办法解决这个问题啊！

Answer 5

private static Hashtable W_table = new Hashtable();
    
    private static Hashtable P_table = new Hashtable();
    
    //construct the hash table
    private static void ConstructTable(){
        String word = new String();
        byte Aword[] = null;  
        ResultSet rs = null;
        Statement stm1 = null;
        Connection con1 = null;
        
        int t = 0;
        String JDBC_DRIVER = "com.mysql.jdbc.Driver";
        String DATABASE_URL = "jdbc:mysql://localhost/wordbase"; 
       int c = 0;
        
        try{
           
           Class.forName(JDBC_DRIVER);
           con1 = DriverManager.getConnection(DATABASE_URL, "root", "root");
           stm1 = con1.createStatement();
           
           //construct w_table
           rs = stm1.executeQuery("SELECT *  FROM worddatas");
           rs.beforeFirst();
           while(rs.next()){
               
                t = rs.getInt(4);         
               //System.out.println(Aword);
               W_table.put(rs.getString(3), new Integer(t));
               //System.out.println((String)W_table.get(Aword));
               //i++;
               
           }
           System.out.println(c);
           System.out.println(W_table.size());
           rs = stm1.executeQuery("SELECT * FROM Probability_c");
           rs.beforeFirst();
           while(rs.next()){
               Vector vc = new Vector();
               vc.add(0, (String)rs.getString(1));
               vc.add(1, (String)rs.getString(2));
               vc.add(2, new Integer(rs.getInt(4)));
               vc.add(3, new Integer(0));
               P_table.put(rs.getString(3), vc);
               //P_table.put(rs.getString(3), new Integer(t));
           }
                    
           //System.out.println(i);
           con1.close();
       }
       
       catch(Exception e){
           System.out.println(e+"in table construct");
           System.exit(1);
       }      }

Answer 6

private static void CollectWordPair(String artical, String Char8xxFile){
        int i, j, k;
        int l = 0;
        int j1, j2, j3;
        int flag = 0;
        char Char8xx[] = new char[1000];
        
        int NumberOfRead = -1;
        File InputFile = new File(artical);
        FileReader InWord = null;
        File CharFile = new File(Char8xxFile);
        FileReader InChar = null;
        char Line[] = new char[8192];
        String Sentence = new String();
        StringBuffer Sen_NoString = new StringBuffer();
        
StringBuffer Sen = new StringBuffer();
        String[] phrase = new String[8192];
        String CharNoString = new String();
        
       
//read in char file      
       try {
            InChar = new FileReader(CharFile);
            InChar.read(Char8xx);
            //System.out.println("read char file success");
           
       }
        catch(FileNotFoundException e){
            System.out.println("Char File Not Found");
            System.exit(1);
        }
        catch(Exception e){
                System.out.println("error during read char file");
                System.exit(1);
            }
        
       try
{
 InWord = new FileReader(InputFile); 

       }

       catch(FileNotFoundException e){
 System.out.println(e);

       }
  
int a = 0;
      //read in passage line by line to check, till it is over! 
      do{
               //read in a line
               try{
                   //System.out.println("read artical file success");
   NumberOfRead = InWord.read(Line);
                }
               catch(Exception e){
                    System.out.println("error during read char file");
                    System.exit(1);
                } 
               
              
                for(i=0; i<8192; i++){
                   if((Line[i] != '\n') ){
                       Sen.append(Line[i]);
                       
                   }
                   
                   else{
                      
                      //System.out.println("sentence contrust success");
                      //change the sentence char to no_string for the ease of sql process
                       l = 0;
                       for(k=0; k<Sen.length(); k++){
                          for(j=0; j<1000; j++){
                              if(Sen.charAt(k) == Char8xx[j]){
                                  //System.out.println(Sen.charAt(k));
                                  j1 = j/100;
                                  j2 = (j - 100 * j1)/10;
                                  j3 = j - 100 * j1 - 10 * j2;
                                  Sen_NoString.append(j1);
                                  Sen_NoString.append(j2);
                                  Sen_NoString.append(j3);
                                  Sen_NoString.append('$');
                                  break;
                              }
                              
                          }
                          if(j == 1000)Sen_NoString.append("###$");
                      }
                     // System.out.println(Sen_NoString.toString());
                     // System.out.println(Sen_NoString.length());
                      k = 0;
                      while( k<Sen_NoString.length()){
                          CharNoString = Sen_NoString.substring(k, k+4); 
                          if( CharNoString.equalsIgnoreCase( "###$")){
                              
                              k = k + 4;
                              
                          }
                          else{
                             
                              for(j=k+4; j<Sen_NoString.length(); j=j+4){
                                  CharNoString = Sen_NoString.substring(j, j+4);
                                  if( CharNoString.equalsIgnoreCase( "###$")){
                                     
                                      phrase[l++] = Sen_NoString.substring(k, j);
                                      //System.out.println(phrase[l-1]);
                                      //System.out.println(l-1);
                                      k = j + 4;
                                      
                                      break;
                                  }
                                  
                              }
                          }
                         
                      }
                     // System.out.println("change to NoString success");
                      Sen.delete(0, Sen.length());
                      Sen_NoString.delete(0, Sen_NoString.length());
                      
                      //Start collect word-pairs
                      for(j=0; j<l; j++){
                          //System.out.println(phrase[j]);
                          doCollectProcess(phrase[j]);
                      }
                      System.out.println(a++);
                   }
                         
            }
           
        }while(NumberOfRead == 8192);
            
      }

Answer 7

放太多可能会导致内存溢出的,如果真的考虑用这种方法,
可以考虑加个算发,比如hashTable里先放1000行表数据
,算法就多了,比如最近最多使用,最近使用等