在Java构造函数中有许多参数。

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在Java构造函数中有许多参数。

我是一个Java初学者。\n在我的图书馆程序中，像这样创建带有多个参数的构造函数是一个好方法吗？\n

public class Book implements Serializable {
private String title;
private String directorName;
private String directorSurname;
private String type;
private int issueYear;
private List actorNames;
private List actorSurnames;
private Tuple directorFullName;
public Book(String title, String directorName, String directorSurname, String type, int issueYear,
            List actorNames, List actorSurnames, Tuple directorFullName){
    this.title = title;
    this.directorName = directorName;
    this.directorSurname = directorSurname;
    this.type = type;
    this.issueYear = issueYear;
    this.actorNames = actorNames;
    this.actorSurnames = actorSurnames;
    this.directorFullName = directorFullName;
}

\n还是有更好的方法来创建这样的构造函数吗？

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2 答案

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在Java中创建一个具有超过3个参数的构造函数不是最佳实践。因为您需要知道每个参数的顺序。我可以建议您在类的title字段中使用getter和setter的方式：

public String getTitle() {
    return title;
}
public Book setTitle(String title) {
    this.title = title;
    return this;
}

通过这种结构，您可以在创建新实例的同时创建一个非常漂亮的构造：

Book book = new Book()
            .setTitle("Book")
            .setType("Comedy")
            .setActorNames(Arrays.asList("Abzal"));

您的类的完整重构版本：

public class Book implements Serializable {
private String title;
private String directorName;
private String directorSurname;
private String type;
private int issueYear;
private List actorNames;
private List actorSurnames;
private Tuple directorFullName;
public Book() {
}
public String getTitle() {
    return title;
}
public Book setTitle(String title) {
    this.title = title;
    return this;
}
public String getDirectorName() {
    return directorName;
}
public Book setDirectorName(String directorName) {
    this.directorName = directorName;
    return this;
}
public String getDirectorSurname() {
    return directorSurname;
}
public Book setDirectorSurname(String directorSurname) {
    this.directorSurname = directorSurname;
    return this;
}
public String getType() {
    return type;
}
public Book setType(String type) {
    this.type = type;
    return this;
}
public int getIssueYear() {
    return issueYear;
}
public Book setIssueYear(int issueYear) {
    this.issueYear = issueYear;
    return this;
}
public List getActorNames() {
    return actorNames;
}
public Book setActorNames(List actorNames) {
    this.actorNames = actorNames;
    return this;
}
public List getActorSurnames() {
    return actorSurnames;
}
public Book setActorSurnames(List actorSurnames) {
    this.actorSurnames = actorSurnames;
    return this;
}
public Tuple getDirectorFullName() {
    return directorFullName;
}
public Book setDirectorFullName(Tuple directorFullName) {
    this.directorFullName = directorFullName;
    return this;
}
}

祝您编码顺利！

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0 Comments

在Java的构造函数中使用过多的参数可能会导致代码混乱和难以维护。为了解决这个问题，可以使用Builder模式。但是，如果不正确地使用Builder模式，会引入创建不完整对象的风险。

除了使用Builder模式，还有其他改进设计的方法。例如，将名字和姓氏（以及导演的全名）作为单独的字符串传递。可以创建一个PersonName类来封装这些不同的命名元素，这样构造函数就变成了：

public Book(String title,

PersonName directorName,

String type,

int issueYear,

List actors) {

...

}

这样看起来更清晰，也使命名更一致。

当然，还应该将该类重命名为Movie而不是Book。

你只是重复了之前的答案。你可以轻松地检查到这一点，因为在你回答之前我已经标记了这个问题。请不要回答明显的重复问题。

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