Java 数组到流的转换

使用Arrays.stream()

语法

public static < **T** > Stream< **T** > getStream(T[] arr)
{
  return Arrays.stream(arr);
}

where, **T** represents generic type.

例1： Arrays.stream()将字符串数组转换为流。

// Java code for converting string array
// to stream using Arrays.stream()
import java.util.*;
import java.util.stream.*;
  
class GFG {
  
    public static void main(String[] args)
    {
        // Converting String array to stream
        String[] arr = { "Geeks", "for", "Geeks" };
  
        // Using Arrays.stream to convert an
        // array into Stream
        Stream<String> stm = Arrays.stream(arr);
  
        // Displaying elements in Stream
        stm.forEach(str -> System.out.print(str + " ")); 
    }
}

输出。

Geeks for Geeks

例2： Arrays.stream()将int数组转换为流。

// Java code for converting string array
// to stream using Arrays.stream()
import java.util.*;
import java.util.stream.*;
  
class GFG {
  
    public static void main(String[] args)
    {
        // Converting int array to stream
        int arr[] = { 1, 2, 3, 4, 5 };
  
        IntStream stm = Arrays.stream(arr);
  
        stm.forEach(a -> System.out.print(a + " "));
   }
}

输出。

1 2 3 4 5

例3： Arrays.stream()将长数和双数数组转换为流。

// Java code for converting string array
// to stream using Arrays.stream()
import java.util.*;
import java.util.stream.*;
  
class GFG {
  
    public static void main(String[] args)
    {        // Converting long array to stream
        long[] arrL = { 3L, 5L, 6L, 8L, 9L };
        LongStream stmL = Arrays.stream(arrL);
        stmL.forEach(number -> System.out.print(number + " "));
  
        System.out.println();
  
        // Converting double array to stream
        double[] arrD = { 1, 2, 3, 4, 5 };
        DoubleStream stmD = Arrays.stream(arrD);
        stmD.forEach(d -> System.out.print(d + " "));
    }
}

输出。

3 5 6 8 9 
1.0 2.0 3.0 4.0 5.0

使用Stream.of(), IntStream.of(), LongStream.of() & DoubleStream.of()

语法:

public static < **T** > Stream< **T** > getStream(T[] arr)
{
  return Stream.of(arr);
}

其中，T代表通用类型。

其他函数的语法类似

注：对于对象数组，Stream.of()内部使用Arrays.stream()。

例1： Arrays.stream()将字符串数组转换为流。

// Java code for converting string array
// to stream using Stream.of()
import java.util.*;
import java.util.stream.*;
  
class GFG {
  
    public static void main(String[] args)
    {
        // Converting String array to stream
        String[] arr = { "Geeks", "for", "Geeks" };
  
        // Using Arrays.stream to convert an
        // array into Stream
        Stream<String> stm = Stream.of(arr);
  
        // Displaying elements in Stream
        stm.forEach(str -> System.out.print(str + " ")); 
    }
}

输出。

Geeks for Geeks

例2： Arrays.stream()将int数组转换为流。

// Java code for converting string array
// to stream using IntStream.of()
import java.util.*;
import java.util.stream.*;
  
class GFG {
  
    public static void main(String[] args)
    {
        // Converting int array to stream
        int arr[] = { 1, 2, 3, 4, 5 };
  
        IntStream stm = IntStream.of(arr);
  
        stm.forEach(a -> System.out.print(a + " "));
   }
}

输出。

1 2 3 4 5

例3： Arrays.stream()将长数和双数数组转换为流。

// Java code for converting string array
// to stream using  DoubleStream.of()
import java.util.*;
import java.util.stream.*;
  
class GFG {
  
    public static void main(String[] args)
    {        // Converting long array to stream
        long[] arrL = { 3L, 5L, 6L, 8L, 9L };
        LongStream stmL = LongStream.of(arrL);
        stmL.forEach(number -> System.out.print(number + " "));
  
        System.out.println();
  
        // Converting double array to stream
        double[] arrD = { 1, 2, 3, 4, 5 };
        DoubleStream stmD = DoubleStream.of(arrD);
        stmD.forEach(d -> System.out.print(d + " "));
    }
}