JAVA基础之Optional小窍门 javaoptional

【JAVA基础之Optional小窍门】Optional.ofNullable()可以传入空值，并返回Optional，下面咱们看下这个小窍门挺有意思的

public class FilesTest { private String testName; private String testAge; public Optional getTestName() { return Optional.ofNullable(testName); } public void setTestName(String testName) { this.testName = testName; } public String getTestAge() { return testAge; } public void setTestAge(String testAge) { this.testAge = testAge; } public static void main(String[] args) throws Exception{ FilesTest test = new FilesTest(); test.setTestAge("12"); test.setTestName("123"); String nameResult = test.getTestName().map(testName -> "- " + testName) .orElse("No testName"); System.out.println(nameResult); test.setTestName(null); nameResult = test.getTestName().map(testName -> "- " + testName) .orElse("No testName"); System.out.println(nameResult); } } //输出 - 123 No testName

通过一个orElse就可以使null值输出了一个No testName，是不是挺有意思。