在Java中测试不可变类(Immutable Class)时,我们需要确保类的实例在创建后不能被修改。下面是一个详细的步骤指南,包括如何创建一个不可变类、编写测试用例,并验证不可变类的行为。 1. 创建一个不可变类 首先,我们需要一个不可变类的示例。以下是一个简单的不可变类Person的实现: java public final class Person { pr
How do you create an immutable class in Java?如何在Java中创建一个不可变类? 相关知识点: 试题来源: 解析 1. 将类声明为final以防止继承。2. 所有成员变量声明为private final。3. 不提供setter方法。4. 通过构造函数初始化所有字段。5. 返回可变对象的深拷贝,而非直接引用。6. 不暴露成员变量的可变对象...
2.1. With Java 9 Since Java 9, we can use aList<E>.of(E… elements)static factory method to create an immutable list: @Test(expected = UnsupportedOperationException.class)publicfinalvoidgivenUsingTheJava9_whenUnmodifiableListIsCreated_thenNotModifiable(){finalList<String> list =newArrayList<>(...
Take the example ofjava.lang.Stringclass which is an immutable class. Once a String is created, there is no way we can change the content of that String. Every public API inStringclass returns a new String with the modified content. The originalStringalways remains the same. Stringstring="t...
不可变对象的类即为不可变类(Immutable Class)。Java平台类库中包含许多不可变类,如String、基本类型的包装类、BigInteger和BigDecimal等。 对于String和StringBuilder,String是immutable的,每次对String对象的修改都将产生一个新的String对象,而原来的对象保持不变。而StringBuilder是mutable,因为每次对于它的对象的修改都作用...
Stringis an immutable class in Java. An immutable class is simply a class whose instances cannot be modified. All information in an instance is initialized when the instance is created and the information can not be modified. There are many advantages of immutable classes. This article summarizes...
Java. The concept of immutability has always been important in all programming languages, including Java. With the release of Java 8 however, immutables have become even more important. This version introduced functional programming, as well as the new java.time api. Both rely heavily on ...
publicfinalclassStringimplementsjava.io.Serializable,Comparable<String>,CharSequence{/** The value is used for character storage. */privatefinal char value[];/** The offset is the first index of the storage that is used. */privatefinal int offset;/** The count is the number of characters ...
Let’s explore some examples of built-in immutable classes in Java. 2.1.StringClass The immutability ofStringsin Javaensures thread safety, enhances security, and helps with the efficient use of memory through theStringPoolmechanism. @TestpublicvoidgivenImmutableString_whenConcatString_thenNotSameAndCor...
Java public class Product { private long id; private String name; private String description; public Product(long id, String name, String description) { this.id = id; this.name = name; this.description = description; } public long getId() { ...