Java Collections synchronizedList()方法及实例

java.util.Collections 类的 synchronizedList() 方法是用来返回一个由指定列表支持的同步（线程安全）列表。为了保证串行访问，对支持列表的所有访问都是通过返回的列表完成的，这一点至关重要。

语法

public static <T> List<T>
  synchronizedList(List<T> list)

参数： 该方法以列表为参数，将其 “包装 “成一个同步列表。

返回值： 该方法返回一个指定列表的同步视图。

下面是说明 synchronizedList() 方法的例子

例子 1 :

// Java program to demonstrate
// synchronizedList() method for String Value
  
import java.util.*;
  
public class GFG1 {
    public static void main(String[] argv) throws Exception
    {
        try {
  
            // creating object of List<String>
            List<String> list = new ArrayList<String>();
  
            // populate the list
            list.add("A");
            list.add("B");
            list.add("C");
            list.add("D");
            list.add("E");
  
            // printing the Collection
            System.out.println("List : " + list);
  
            // create a synchronized list
            List<String> synlist = Collections
                                       .synchronizedList(list);
  
            // printing the Collection
            System.out.println("Synchronized list is : " + synlist);
        }
  
        catch (IllegalArgumentException e) {
            System.out.println("Exception thrown : " + e);
        }
    }
}

输出。

List : [A, B, C, D, E]
Synchronized list is : [A, B, C, D, E]

例2 :

// Java program to demonstrate
// synchronizedList() method for Integer Value
  
import java.util.*;
  
public class GFG1 {
    public static void main(String[] argv)
        throws Exception
    {
  
        try {
  
            // creating object of List<Integer>
            List<Integer> list = new ArrayList<Integer>();
  
            // populate the list
            list.add(20);
            list.add(30);
            list.add(40);
            list.add(50);
            list.add(60);
  
            // printing the Collection
            System.out.println("List : " + list);
  
            // create a synchronized list
            List<Integer> synlist = Collections
                                        .synchronizedList(list);
  
            // printing the Collection
            System.out.println("Synchronized list is : " + synlist);
        }
  
        catch (IllegalArgumentException e) {
            System.out.println("Exception thrown : " + e);
        }
    }
}

输出。

List : [20, 30, 40, 50, 60]
Synchronized list is : [20, 30, 40, 50, 60]