Guava Longs類

Longs是基本類型long的實用工具類。

類聲明

以下是com.google.common.primitives.Longs類的聲明：

@GwtCompatible
public final class Longs
? ?extends Object

字段

方法

繼承的方法

這個類繼承了以下類方法：java.lang.Object

Longs 示例

使用所選擇的任何編輯器創建下面的java程序 C:/> Guava

GuavaTester.java

import java.util.List;

import com.google.common.primitives.Ints;
import com.google.common.primitives.Longs;

public class GuavaTester {
   public static void main(String args[]){
      GuavaTester tester = new GuavaTester();
      tester.testLongs();
   }

   private void testLongs(){
      long[] longArray = {1,2,3,4,5,6,7,8,9};

      //convert array of primitives to array of objects
      List<Long> objectArray = Longs.asList(longArray);
      System.out.println(objectArray.toString());

      //convert array of objects to array of primitives
      longArray = Longs.toArray(objectArray);
      System.out.print("[ ");
      for(int i = 0; i< longArray.length ; i++){
         System.out.print(longArray[i] + " ");
      }
      System.out.println("]");
      //check if element is present in the list of primitives or not
      System.out.println("5 is in list? "+ Longs.contains(longArray, 5));

      //Returns the minimum		
      System.out.println("Min: " + Longs.min(longArray));

      //Returns the maximum		
      System.out.println("Max: " + Longs.max(longArray));

      //get the byte array from an integer
      byte[] byteArray = Longs.toByteArray(20000);
      for(int i = 0; i< byteArray.length ; i++){
         System.out.print(byteArray[i] + " ");
      }
   }
}

驗證結果

使用javac編譯器編譯如下類

C:\Guava>javac GuavaTester.java

現在運行GuavaTester看到的結果

C:\Guava>java GuavaTester

看到結果

[1, 2, 3, 4, 5, 6, 7, 8, 9]
[ 1 2 3 4 5 6 7 8 9 ]
5 is in list? true
Min: 1
Max: 9
0 0 0 0 0 0 78 32?

 

 

 

 

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