标签：point you ... cond mutable tab copy [] instance
Mutable objects are those whose state can be changed. For instance, an array is mutable, but a String is not. Mutable class members should never be returned to a caller or accepted and stored directly. Doing so leaves you vulnerable to unexpected changes in your class state.
Instead use an unmodifiable
Collection(viaCollections.unmodifiableCollection,Collections.unmodifiableList, ...) or make a copy of the mutable object, and store or return copy instead.This rule checks that arrays, collections and Dates are not stored or returned directly.
可变对象是那些状态可以改变的对象。
例如，数组是可变的，但String不是。 永远不应将可变类成员返回给调用者或直接接受和存储。 这样做会使您容易受到类状态的意外更改的影响。
而是使用不可修改的Collection（通过Collections.unmodifiableCollection，Collections.unmodifiableList，...）或制作可变对象的副本，然后存储或返回副本。
此规则检查是否未直接存储或返回数组，集合和日期。
不合格的代码如下：
class A { private String [] strings; public A () { strings = new String[]{"first", "second"}; } public String [] getStrings() { return strings; // Noncompliant } public void setStrings(String [] strings) { this.strings = strings; // Noncompliant } } public class B { private A a = new A(); // At this point a.strings = {"first", "second"}; public void wreakHavoc() { a.getStrings()[0] = "yellow"; // a.strings = {"yellow", "second"}; } }
合格代码解决方案
class A { private String [] strings; public A () { strings = new String[]{"first", "second"}; } public String [] getStrings() { return strings.clone(); } public void setStrings(String [] strings) { this.strings = strings.clone(); } } public class B { private A a = new A(); // At this point a.strings = {"first", "second"}; public void wreakHavoc() { a.getStrings()[0] = "yellow"; // a.strings = {"first", "second"}; } }
不应直接存储或返回可变成员 Mutable members should not be stored or returned directly
标签：point you ... cond mutable tab copy [] instance
原文地址：https://www.cnblogs.com/xingyunblog/p/9506534.html
