Java Java.lang.String.getByte()用法及代碼示例

java中的getbytes()函數用於將字符串轉換為字節序列並返回字節數組。此函數可以通過兩種方式實現。本文討論了這兩種方式。

1. 語法1-public byte[] getBytes()：此函數不帶參數，並使用默認字符集將字符串編碼為字節。

   // Java code to demonstrate the working of 
   // getByte() 
   public class GetByte { 
     
   public static void main(String args[]) 
       { 
           // Initializing String 
           String gfg = "ASTHA GFG"; 
     
           // Displaying string values before 
           // conversion 
           System.out.println("The String before conversion is : "); 
           System.out.println(gfg); 
     
           // converting the string into byte 
           // using getBytes ( converts into ASCII values ) 
           byte[] b = gfg.getBytes(); 
     
           // Displaying converted string after conversion 
           System.out.println("The String after conversion is : "); 
           for (int i = 0; i < b.length; i++) { 
               System.out.print(b[i]); 
           } 
       } 
   }

   輸出：

   The String before conversion is : 
   ASTHA GFG
   The String after conversion is : 
   658384726532717071
   

2. 語法2：public byte [] getBytes(Charset charset)：此實現接受字符集，根據字符集必須在轉換為字節時對其進行編碼。定義了許多字符集，下麵進行討論。
   • US-ASCII：Seven-bit ASCII，也稱為ISO646-US，也稱為Unicode字符集的基本拉丁語塊
   • ISO-8859-1：ISO拉丁字母1號，又名ISO-LATIN-1
   • UTF-8：Eight-bit UCS轉換格式
   • UTF-16BE：十六位UCS轉換格式，大端字節順序
   • UTF-16LE：十六位UCS轉換格式，低位字節序
   • UTF-16：十六位UCS轉換格式，由可選字節順序標記標識的字節順序。

   // Java code to demonstrate the working of 
   // getByte() using different character sets 
   import java.io.*; 
   public class GetBytecharset { 
     
   public static void main(String args[]) 
       { 
           // Initializing String 
           String gfg = new String("ASTHA GFG"); 
     
           // Displaying string values before 
           // conversion 
           System.out.println("The String before conversion is : "); 
           System.out.println(gfg); 
     
           try { 
     
               // converting the string into byte 
               // using getBytes ( converts into UTF-16 values ) 
               byte[] b = gfg.getBytes("UTF-16"); 
     
               // Displaying converted string after conversion 
               // into UTF-16 
               System.out.println("The String after conversion into UTF-16 is : "); 
               for (int i = 0; i < b.length; i++) { 
                   System.out.print(b[i]); 
               } 
     
               System.out.print("\n"); 
     
               // converting the string into byte 
               // using getBytes ( converts into UTF-16BE values ) 
               byte[] c = gfg.getBytes("UTF-16BE"); 
     
               // Displaying converted string after conversion 
               // into UTF-16BE 
               System.out.println("The String after conversion into UTF-16BE is : "); 
               for (int i = 0; i < c.length; i++) { 
                   System.out.print(c[i]); 
               } 
           } 
           catch (UnsupportedEncodingException g) { 
               System.out.println("Unsupported character set" + g); 
           } 
       } 
   }

   輸出：

   
   

   The String before conversion is : 
   ASTHA GFG
   The String after conversion into UTF-16 is : 
   -2-1065083084072065032071070071
   The String after conversion into UTF-16BE is : 
   065083084072065032071070071