Class.forName(className)的作用
时间: 2024-05-26 16:12:38 浏览: 181
Class.forName(className)的作用是加载并返回指定类名的Class对象。它会尝试加载指定的类,如果类不存在,则会抛出ClassNotFoundException异常。如果类存在,则会返回该类的Class对象,可以用来创建该类的实例或获取该类的信息。此方法一般用于动态加载类,例如在运行时根据配置文件或用户输入来加载指定的类。
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Class.forName(className);
This method is used in Java to load and initialize a class dynamically during runtime. It takes a string parameter, which is the fully qualified name of the class (including the package name) that needs to be loaded.
The Class.forName() method loads the specified class and returns a Class object that can be used to create instances of the class or to access its static members. If the class is not found, it throws a ClassNotFoundException.
This method is commonly used in database programming to load the JDBC driver, which is a class provided by the database vendor that implements the JDBC API. By using Class.forName() to load the driver class, the application can work with any database that provides a JDBC driver, without having to hard-code the driver class name in the code.
class.forname
`Class.forName()`是Java中的一个方法,用于加载并返回指定类名的类对象。它接受一个字符串参数,该参数是完全限定的类名(包括包名)。当调用该方法时,JVM会查找并加载指定名称的类。如果找到了该类,则返回其类对象;否则,将抛出ClassNotFoundException异常。
例如,以下代码将加载并返回java.lang.String类的类对象:
```
Class stringClass = Class.forName("java.lang.String");
```
需要注意的是,当使用`Class.forName()`方法加载一个类时,该类的静态代码块会在加载时被执行。因此,如果你只是想获取一个类的类对象而不需要执行其静态代码块,可以使用`Class.forName(className, false, classLoader)`方法,并将第三个参数设置为`null`。
```
Class stringClass = Class.forName("java.lang.String", false, null);
```
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