java - 为什么是 Class.forName ('database driver' )？

Question

为什么

Class.forName("org.apache.derby.jdbc.EmbeddedDriver");
dbConnection = DriverManager.getConnection(strUrl, props);

代替

dbConnection = EmbeddedDriver.connect(strUrl, props);

?

指定字符串而不是编译器可以检查的类名不是更容易出错吗？我看到一个示例，其中类名是从配置中获取的，但这似乎是无论可用替代方案如何都使用的模式。

Answer 1

使用 JDBC 4.0 驱动程序(及更高版本)，您只需要

dbConnection = DriverManager.getConnection(strUrl, props);

根据 DriverManager java文档，

JDBC 4.0 Drivers must include the file META-INF/services/java.sql.Driver. This file contains the name of the JDBC drivers implementation of java.sql.Driver. For example, to load the my.sql.Driver class, the META-INF/services/java.sql.Driver file would contain the entry:

my.sql.Driver

Applications no longer need to explictly load JDBC drivers using Class.forName(). Existing programs which currently load JDBC drivers using Class.forName() will continue to work without modification.