IntStream filter(IntPredicate predicate)返回一个由与给定谓词匹配的流元素组成的流。这是一个中间操作。这些操作总是很懒惰，即执行诸如filter()之类的中间操作实际上并不执行任何过滤，而是创建一个新的流，该新流在遍历时将包含与给定谓词匹配的初始流的元素。

用法:

IntStream filter(IntPredicate predicate)

Where, IntStream is a sequence of primitive int-valued elements.

IntPredicate represents a predicate (boolean-valued function)

of one int-valued argument and the function returns the new stream.

示例1:IntStream上的filter()方法。

// Java code for IntStream filter

// (IntPredicate predicate) to get a stream

// consisting of the elements of this

// stream that match the given predicate.

import java.util.*;

import java.util.stream.IntStream;

class GFG {

// Driver code

public static void main(String[] args)

{

// Creating an IntStream

IntStream stream = IntStream.of(3, 5, 6, 8, 9);

// Using IntStream filter(IntPredicate predicate)

// to get a stream consisting of the

// elements that gives remainder 2 when

// divided by 3

stream.filter(num -> num % 3 == 2)

.forEach(System.out::println);

}

}

输出：

5

8

示例2:IntStream上的filter()方法。

// Java code for IntStream filter

// (IntPredicate predicate) to get a stream

// consisting of the elements of this

// stream that match the given predicate.

import java.util.*;

import java.util.stream.IntStream;

class GFG {

// Driver code

public static void main(String[] args)

{

// Creating an IntStream

IntStream stream = IntStream.of(-2, -1, 0, 1, 2);

// Using IntStream filter(IntPredicate predicate)

// to get a stream consisting of the

// elements that are greater than 0

stream.filter(num -> num > 0)

.forEach(System.out::println);

}

}

输出：

1

2