Pen questions (b)

1. can not be created through the object's constructor do ()
A. is
B. No
analysis: answer: A
the Java objects created in several ways (Important):
(1) create an object using the new statement, which is most commonly created method of the object.
(2) the use of reflecting means, or call java.lang.Class
newInstance () method java.lang.reflect.Constructor class instance.
(3) call the object's clone () method
(4) the use of anti-serialization means, call the readObject () method java.io.ObjectInputStream object.
(1) and (2) will be clear explicitly call the constructor; (3) is a photocopy of an existing object in memory, it does not call the constructor; (4) reduction of the object from the class file, We will not call the constructor.

2. Which of the following symmetric encryption algorithms ()
A. the DES
B. the MD5
C. the DSA
D. the RSA
Analysis: Answer: A
Analysis: Common symmetric encryption algorithms: DES, 3DES, RC2, RC4 , AES
commonly used asymmetric encryption algorithms: RSA, DSA, ECC
using a one-way hash function encryption algorithm: MD5, SHA