如何让Java方法返回多个值？ [英] How can I have a Java method return multiple values?

问题描述

我只是想知道是否有办法让Java方法返回多个值。

I was just wondering whether there's a way to make a Java method return multiple values.

我正在创建一个使用jdbc库来处理a的应用程序数据库。我可以成功地将值输入到数据库中，但我需要一种方法来返回它们，这就是我有点卡住的地方。我创建了一个表单，用户输入一个特定的值（一个ID号），然后由执行我的数据库工作的Database类传递给它。

I'm creating an application that uses the jdbc library to work with a database. I can successfully enter values into the database but I need a way to return them, and this is where I'm a bit stuck. I creating a form into which the user enters a specific value (an ID number) which is then passed to by Database class which carries out my database work.

Database newQuery = new Database();     
newQuery.getCust(c_ID);         //uses the GetCust method in my class,
                                //passing it the ID of the customer.

我的Database类中的getCust（）方法创建以下查询：

The getCust() method in my Database class creates the following query:

ResultSet Customer = stat.executeQuery("SELECT * FROM Persons WHERE Cust_ID=C_ID");

我需要一种方法来返回存储在客户中的结果。任何想法？

I need a way to return the results that are stored in Customer back. Any ideas?

推荐答案

您无法从Java中的方法中返回多个值，但始终可以返回容器对象它有几个值。在您的情况下，最简单的方法是返回ResultSet，Customer。

You can't exactly return multiple values from a method in Java, but you can always return a container object that holds several values. In your case, the easiest thing to do would be to return the ResultSet, Customer.

如果您担心将数据层暴露给UI，则可以复制将ResultSet中的数据转换为不太特定于数据库的结构，可以是List of Maps，也可以是Customer对象List，其中Custom是表示您的业务实体的新类。

If you're concerned about exposing your data layer to your UI, you can copy the data from the ResultSet into a structure that is less specific to the database, either a List of Maps, or perhaps a List of Customer objects, where Custom is a new class that represents your business entity.

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