JAVA程序员笔试题目与答案.pdf

1.Given: Integer i = new Integer (42); Long l = new Long (42); Double d = new Double (42.0); Which two expressions evaluate to True? A. (i = 1) B. (i = d) C. (d = 1) D. (i.equals (l) E. (d.equals (l) F. (i.equals (42) G. none of above Answer: 2. Given: public class Foo public static void main (String args) StringBuffer a = new StringBuffer(“A“); StringBuffer b = new StringBuffer (“B“); operate (a,b); System.out.println(a + “,“ +b); static void operate(StringBuffer x, StringBuffer y) x.append(y); y = x; What is the result? A. The code compiles and prints “A,B”. B. The code compiles and prints “A,A”. C. The code compiles and prints “B,B”. D. The code compiles and prints “AB,B”. E. The code compiles and prints “AB,AB”. F. The code does not compile because “+” cannot be overloaded for StringBuffer. Answer: 3.Given: class BaseClass private float x = 1.0f ; protected float getVar() return x; class Subclass extends BaseClass private float x = 2.0f; /insert here Which two are valid examples of method overriding? A. float getVar() return x; B. public float getVar() return x; C. public double getVar() return x; D. protected float getVar() return x; E. public float getVar(float f) return f; Answer: 4. Which of the following are methods of the Runnable interface A) run B) start C) yield D) stop Answer: 5. Which of the following are legal statements? A) float f=1/3; B) int i=1/3; C) float f=1.01; D) double d=999d; Answer: 6. Given: public class test( public static void main(string args) String foo = args1; String baz = args2; String bax = args3; And the command line invocation: Java Test red green blue What is the result? A. baz has the value of “” B. baz has the value of null C. baz has the value of “red” D. baz has the value of “blue” E. bax has the value of “green” F. the code does not compile G. the program throws an exception Answer: 7. Which of the following statements are true? A) The garbage collection algorithm in Java is vendor implemented B) The size of primitives is platform dependent C) The default type for a numerical literal with decimal component is a float. D) You can modify the value in an Instance of the Integer class with the setValue method Answer: 8. Given: int i = 1, j = 10; do if(i+ -j) continue; while(iTOM-eTOM-NGOSS 3什么是数据库系统？列举几个常见数据库系统。 要点： 1)数据库系统是一个实际可运行的存储、维护和应用系统提供数据的软件系统，是存 储介质、处理对象和管理系统的集合体。它通常由软件、数据库和数据管理员组成。其软件 主要包括操作系统、各种宿主语言、实用程序以及数据库管理系统。数据库由数据库管理系 统统一管理，数据的插入、修改和检索均要通过数据库管理系统进行。 2)开源数据库系统有：HSQLDB、MySQL、PostgreSQL 等 3)商业数据库系统包括：Oracle10g、DB2、Sysbase、Informix、MS SQL 等。 4请简单描述软件开发过程的主要阶段。 要点： 计划，分析，设计，编码，测试，维护等。 5请将下面一段文字翻译成中文。 An enterprise service bus (ESB) is a pattern of middleware that unifies and connects services, appl ications and resources within a business. Put another way, it is the framework within which the ca pabilities of a business applications are made available for reuse by other applications throughout the organization and beyond. The ESB is not a new software product its a new way of looking at how to integrate applications, coordinate resources and manipulate information. Unlike many pr evious approaches for connecting distributed applications, for example RPC or distributed objects, the ESB pattern e