to{}catch{}

 try{}catch{}的流传输

try {
    fis = new FileInputStream("file-APP\\fos.txt");
    fos = new FileOutputStream("fos.txt");
    int a ;
    while ((a= fis.read())!= -1){
        fos.write(a);
    }
    System.out.println(a);
} catch (IOException e) {
    e.printStackTrace();
} finally {
    try {
        if (fis != null) {
            fis.close();
        }
    } catch (IOException e) {
        e.printStackTrace();
    }
}

 try（）{}catch{}的流传输 省略close（）

try{}catch{}finally{}

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finalize（）方法*

Objects的equals()方法*

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抛异常

 自己怎么创建异常 抛异常

 创建异常类  重载所有构造方法

class StudentAgeIllegalException extends Exception {
    public StudentAgeIllegalException() {
    }

    public StudentAgeIllegalException(String message) {
        super(message);
    }

    public StudentAgeIllegalException(String message, Throwable cause) {
        super(message, cause);
    }

    public StudentAgeIllegalException(Throwable cause) {
        super(cause);
    }

    public StudentAgeIllegalException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace) {
        super(message, cause, enableSuppression, writableStackTrace);
    }
}

创建异常类对象

 抛出异常