在Java中处理数组中的空值,你可以采用以下几种方法:
1. 使用Java 8的流API(Streams):
import java.util.Arrays;
import java.util.stream.IntStream;
public class Main {
public static void main(String[] args) {
Integer[] arrayWithNulls = {1, null, 3, null, 5};
Integer[] filteredArray = Arrays.stream(arrayWithNulls)
.filter(e -> e != null)
.toArray(Integer[]::new);
System.out.println(Arrays.toString(filteredArray));
}
}
2. 使用Guava库的`Collections2.filter()`方法:
import com.google.common.collect.Collections2;
public class Main {
public static void main(String[] args) {
Integer[] arrayWithNulls = {1, null, 3, null, 5};
Integer[] filteredArray = Collections2.filter(Arrays.asList(arrayWithNulls), e -> e != null);
System.out.println(Arrays.toString(filteredArray));
}
}
3. 使用循环和`ArrayList`:
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
public class Main {
public static void main(String[] args) {
Integer[] arrayWithNulls = {1, null, 3, null, 5};
List
list = new ArrayList<>(Arrays.asList(arrayWithNulls)); list.removeIf(e -> e == null);
Integer[] filteredArray = list.toArray(new Integer);
System.out.println(Arrays.toString(filteredArray));
}
}
4. 使用`Arrays.asList()`和`Collections.addAll()`:
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
public class Main {
public static void main(String[] args) {
Integer[] arrayWithNulls = {1, null, 3, null, 5};
List
list = new ArrayList<>(Arrays.asList(arrayWithNulls)); list.removeAll(Collections.singleton(null));
Integer[] filteredArray = list.toArray(new Integer);
System.out.println(Arrays.toString(filteredArray));
}
}
5. 使用`Arrays.asList()`和`Iterator`:
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
public class Main {
public static void main(String[] args) {
Integer[] arrayWithNulls = {1, null, 3, null, 5};
List
list = new ArrayList<>(Arrays.asList(arrayWithNulls)); Iterator
iterator = list.iterator(); while (iterator.hasNext()) {
if (iterator.next() == null) {
iterator.remove();
}
}
Integer[] filteredArray = list.toArray(new Integer);
System.out.println(Arrays.toString(filteredArray));
}
}
以上方法都可以用来处理Java数组中的空值。选择哪一种方法取决于你的具体需求和偏好。