jOOQ:允许的字符约束?

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问题描述

我正在考虑从Hibernate迁移到jOOQ，但找不到在Hibernate中如何在String上具有模式约束:

I am considering moving from Hibernate to jOOQ but I can't find e.g.how to have Pattern-Constraints on a String like this in Hibernate:

@NotEmpty(message = "Firstname cannot be empty")
@Pattern(regexp = "^[a-zA-Z0-9_]*$", message = "First Name can only contain characters.")
private String firstname;

我将如何在jOOQ中做到这一点?

How would I do that in jOOQ?

"jOOQ方式"

进行此类验证的"jOOQ方法"将是创建以下任一方法:

The "jOOQ way"

The "jOOQ way" to do such validation would be to create either:

数据库中的CHECK约束.
数据库中的触发器.
数据库中的域.

A CHECK constraint in the database.
A trigger in the database.
A domain in the database.

毕竟，如果您要确保数据完整性，那么数据库就是此类约束和完整性检查的来源(可能除了功能上等效的客户端验证之外).想象一下一个批处理作业，一个Perl脚本，甚至是一个绕过JSR-303验证的JDBC语句.您会立即发现数据损坏.

After all, if you want to ensure data integrity, the database is where such constraints and integrity checks belong (possibly in addition to functionally equivalent client-side validation). Imagine a batch job, a Perl script, or even a JDBC statement that bypasses JSR-303 validation. You'll find yourself with corrupt data in no time.

如果确实要实现客户端验证，则仍可以在DTO上使用JSR-303，例如，DTO与UI交互.但是您必须在将数据传递到jOOQ进行存储之前进行验证(如artbristol所述 ).

If you do want to implement client-side validation, you can still use JSR-303 on your DTOs, which interact with your UI, for instance. But you will have to perform validation before passing the data to jOOQ for storage (as artbristol explained).

但是，您可以通过在各个列上声明Converter并通过将这样的Converter注册到源代码生成器中.

You could, however, use your own custom type by declaring a Converter on individual columns and by registering such Converter with the source code generator.

本质上，Converter是:

public interface Converter<T, U> extends Serializable {
    U from(T databaseObject);
    T to(U userObject);
    Class<T> fromType();
    Class<U> toType();
}

在您的情况下，您可以这样实现注释:

In your case, you could implement your annotations as such:

public class NotEmptyAlphaNumericValidator implements Converter<String, String> {

    // Validation
    public String to(String userObject) {
        assertNotEmpty(userObject);
        assertMatches(userObject, "^[a-zA-Z0-9_]*$");
        return userObject;
    }

    // Boilerplate
    public String from(String databaseObject) { return databaseObject; }
    public Class<String> fromType() { return String.class; }
    public Class<String> toType() { return String.class; }
}

请注意，这更像是一种变通方法，因为Converter尚未针对该用例进行设计，即使它可以完美地实现.

Note that this is more of a workaround, as Converter hasn't been designed for this use-case, even if it can perfectly implement it.

还有一个待处理的功能请求#4543 为客户端提供更多支持，侧面验证.从jOOQ 3.7开始，此功能尚未实现.

There's also a pending feature request #4543 to add more support for client-side validation. As of jOOQ 3.7, this is not yet implemented.

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