金三银四面试题 -java数据结构（二）

public class InterviewBit {
   public static void main(String[] args)
       throws Exception
   {
       try {
           // creating object of ArrayList<String>
           List<String> sample_list = new ArrayList<String>();
           sample_list.add(“practice”);
           sample_list.add(“solve”);
           sample_list.add(“interview”);
           // displaying the initial list
           System.out.println("The initial list is : "
                              + sample_list);
           // using unmodifiableList() method
           List<String>
               read_only_list = Collections
                                   .unmodifiableList(sample_list);
           // displaying the read-only list
           System.out.println("The ReadOnly ArrayList is : "
                              + read_only_list);
           // Trying to add an element to the read-only list
           System.out.println("Trying to modify the ReadOnly ArrayList.");                       
           read_only_list.add(“job”);
       }
       catch (UnsupportedOperationException e) {
           System.out.println("The exception thrown is : " + e);
       }
   }
}

BlockingQueue unbounded_queue = new LinkedBlockingDeque();

BlockingQueue bounded_queue = new LinkedBlockingDeque(10);

Object obj;
for (int i=0, n=list.size(  ); i < n; i++)
 obj = list.get(i);

public class Sample {  
public static void main(String[] args)throws Exception{  
   FileReader reader = new FileReader("info.properties");  
   Properties obj_p = new Properties();  
   obj_p.load(reader);  
   System.out.println(obj_p.getProperty("user"));  
   System.out.println(obj_p.getProperty("password"));  
}  
}

success
determination

class InterviewBit
{
   public static void main (String[] args)
   {
       List<String> synchronized_list =
          Collections.synchronizedList(new ArrayList<String>());
       synchronized_list.add("learn");
       synchronized_list.add("practice");
       synchronized_list.add("solve");
       synchronized_list.add("interview");
       synchronized(synchronized_list)// must be declared
       {
           Iterator it = synchronized_list.iterator();
           while (it.hasNext())
               System.out.println(it.next());
       }
   }
}

CopyOnWriteArrayList<T> list_name = new CopyOnWriteArrayList<T>();

import java.util.Iterator;
import java.util.concurrent.CopyOnWriteArrayList;
class InterviewBit
{
   public static void main (String[] args)
   {
       CopyOnWriteArrayList<String> synchronized_list
           = new CopyOnWriteArrayList<String>();// creating a thread-safe Arraylist.
       // Adding strings to the synchronized ArrayList
       synchronized_list.add("learn");
       synchronized_list.add("practice");
       synchronized_list.add("solve");
       synchronized_list.add("interview");
       System.out.println("The synchronized ArrayList has the following elements :");
       // Iterating on the synchronized ArrayList using an iterator.
       Iterator<String> it = synchronized_list.iterator();
       while (it.hasNext())
           System.out.println(it.next());
   }
}

import java.util.*;
public class Convert_Array_To_Collection {
   public static void main(String args[])
   {
       //creating a sample array
       String sample_array[]
           = { "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday" };
       int length_array = sample_array.length;
       System.out.println("The input elements are as follows : ");
       for(int i = 0; i < length_array; i ++)
       {
           System.out.print(sample_array[i] + " ");
       }
       System.out.println();// setting the print cursor to the next line
       List converted_list = Arrays.asList(sample_array);// converting the array to a list
       // print converted elements
       System.out.println("The converted list is as follows : "
                          + converted_list);
   }
}

import java.util.Enumeration;
import java.util.Hashtable;
public class Iterate_HashTable {
  public static void main(String[] args) {
     Hashtable hash_table = new Hashtable();//creating a hash table
     hash_table.put("1", "Monday");
     hash_table.put("2", "Tuesday");
     hash_table.put("3", "Wednesday");
     hash_table.put("4", "Thursday");
     hash_table.put("5", "Friday");
     hash_table.put("6", "Saturday");
     hash_table.put("7", "Sunday");
     Enumeration enumeration_hash_table = hash_table.elements();//creating an enumeration object
     //while loop runs until the hashtable has more entries in it
     while(enumeration_hash_table.hasMoreElements()) {
        System.out.println(enumeration_hash_table.nextElement());
     }
  }
}

Saturday
Friday
Thursday
Wednesday
Tuesday
Monday
Sunday

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
publicclassShuffle_collection{
  publicstaticvoidmain(String[] argv) throws Exception {
     ArrayList<String> array_list =newArrayList<String>();//creating an arraylist of strings
     array_list.add("Monday");
     array_list.add("Tuesday");
     array_list.add("Wednesday");
     array_list.add("Thursday");
     array_list.add("Friday");
     array_list.add("Saturday");
     array_list.add("Sunday");
     Collections.shuffle(array_list);//shuffling the arraylist
     System.out.println("The shuffled array list is as follows : "+ array_list);//printing the shuffled array list
  }   
}

The shuffled array list is as follows : [Thursday, Friday, Saturday, Wednesday, Tuesday, Sunday, Monday]

import java.util.TreeSet;
import java.util.Iterator;
 public class Clone_Tree_Set {
 public static void main(String[] args) {
     TreeSet<String> tree_set = new TreeSet<String>();//creating an empty tree set
     //adding values in the tree set
     tree_set.add("Monday");
     tree_set.add("Tuesday");
     tree_set.add("Wednesday");
     tree_set.add("Thursday");
     tree_set.add("Friday");
     tree_set.add("Saturday");
     tree_set.add("Sunday");
     //printing the original tree set
     System.out.println("The original tree set is as follows : " + tree_set); 
     //cloning the tree set
     TreeSet<String> cloned_tree_set = (TreeSet<String>)tree_set.clone();
     //printing the cloned tree set
     System.out.println("The cloned tree set is as follows : " + cloned_tree_set);      
    }
}

The original tree set is as follows : [Friday, Monday, Saturday, Sunday, Thursday, Tuesday, Wednesday]
The cloned tree set is as follows : [Friday, Monday, Saturday, Sunday, Thursday, Tuesday, Wednesday]

import java.util.*;  
public class Collection_View {  
   public static void main(String args[]){  
   HashMap<String,String> hash_map = new HashMap<String,String>();//creating an empty hash map
   //adding key values to the hash map
   hash_map.put("1","Monday");
   hash_map.put("2","Tuesday");
   hash_map.put("3","Wednesday");
   hash_map.put("4","Thursday");
   hash_map.put("5","Friday");
   hash_map.put("6","Saturday");
   hash_map.put("7","Sunday");
   //printing the original hash map
   System.out.println("The original hash map is as follows : " + hash_map);
   //printing the collection view of the hash map
   System.out.println("The collection view is as follows : " + hash_map.values());
 }
}

The original hash map is as follows: {1=Monday, 2=Tuesday, 3=Wednesday, 4=Thursday, 5=Friday, 6=Saturday, 7=Sunday}
The collection view is as follows : [Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday]

import java.util.ArrayList;
import java.util.Collections;
 public class Join_Lists {
 public static void main(String[] args) {
       //creating the first array list
       ArrayList<String> list_1 = new ArrayList<String>();
       list_1.add("Monday");
       list_1.add("Tuesday");
       list_1.add("Wednesday");
       list_1.add("Thursday");
       //printing the first array list
       System.out.println("The elements of the first array list is as follows : " + list_1);
       //creating the second array list
       ArrayList<String> list_2 = new ArrayList<String>();
       list_2.add("Friday");
       list_2.add("Saturday");
       list_2.add("Sunday");
       //printing the second array list
       System.out.println("The elements of the second array list is as follows : " + list_2);
       //creating the third array list
       ArrayList<String> joined_list = new ArrayList<String>();
       joined_list.addAll(list_1);//adding the elements of the first array list
       joined_list.addAll(list_2);//adding the elements of the second array list
       System.out.println("The elements of the joined array list is as follows : " + joined_list);
    }
}
输出
The elements of the first array list is as follows : [Monday, Tuesday, Wednesday, Thursday]
The elements of the second array list is as follows : [Friday, Saturday, Sunday]
The elements of the joined array list is as follows : [Monday, Tu
esday, Wednesday, Thursday, Fri