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1、Java程序员认证考试SUN认证 SUN认证是给网络设计界建立的一套认证标准，Sun公司推出了Java以及Solaris技术认证方案。对于企业而言，可以借助这项认证作为招聘人才的评判标准，或是作为衡量员工技术水准的依据;在个人方面，通过这些认证也可以证明个人的技术能力。 1.Java认证考试 该认证主要面对Java程序员。同时，该认证是业界唯一经Sun授权的Java认证，考试内容涉及所有Java相关知识、编程概念及applet开发技巧。Sun认证Java程序员考试旨在观察您通过应用软件分配进行复杂编程的能力，之后还要测试您完成编程所需的知识。每次考试都包括65道以上的选择题，时间大约为90分钟
2、。目前在这方面有两项认证：Sun Certified Java Programmer(SCJP)和 Sun Certified Java Developer (SCJD)。SCJP测验Java程序设计概念及能力，内容偏重于Java语法及JDK的内容;SCJD则进一步测试用Java开发应用程序的能力，考试者必须先完成一个程序的设计方案，再回答与此方案相关的一些问题。 2. Solaris系统管理认证考试 对Solaris/Sun OS系统管理员，Sun推出Certified Solaris Administrator(CSA)。CSA分别为两个等级(Part 和 Part )，测试对Solari
3、s系统管理的了解程度。 3. Solaris网络管理认证考试 为了测试使用者对于Solaris网络管理能力，Sun推出Certified Network Administrator(CNA)。内容包括基本网络概念、Routing and Subnet、Security、Performance、DNS、NIS+等。 通过SUN任何一门专业认证后，考生将收到SunMicrosystems总公司寄发的资格证书及徽章，并有权将通过Sun认证的标记印在个人名片上，作为个人技术能力的肯定。 SUN JAVA程序员认证考试大纲 Basic Object Oriented Concept Object An
4、instance of a class Has state and behavior State is contained in its member variables Behavior is implemented through its methods. Message For objects to interact with one another Result of a message is a method invocation which performs actions or modifies the state of the receiving object Classes
5、An objects class is the objects type The ability to derive one class from another and inherit its state and behavior Most general classes appear higher in the class hierarchy Most specific classes appear lower in the class hierarchy Subclasses inherit state and behavior from their superclasses Inter
6、face A collection of method definitions without actual implementations For defining a protocol of behavior that can be implemented by any class anywhere in the class hierarchy. Packages A collection of related classes and interfaces java.lang is imported by default automatically Java Language Fundam
7、entals The order for every heading is as follows: package declarations - package my.applications.uinterfaces; import statements - import java.awt.某 class definitions - public class myClass . Order of public vs. non-public class definitions doesnt matter. Allows only one top-level public class per so
8、urce file Name of source file must be the same as name of the public class main() method must be: public static Not return a value (void return type) Take an array of strings:(String args) or (String args) doesnt matter args is just a common name, you can use any name you like. However, there must b
9、e a set of Legal e某amples: public static void main(String args) static public void main(String args) Command line arguments are placed in the String array starting at 0 after the java command and the program name For non-applet java application, there must be a main method For applet, you do not use
10、 main() Applet: a subclass of Panel, which itself is a subclass of Container init() - called when applet is first instantiated. start() - called when the web page containing the applet is to be displayed stop() - called when the web browser is about to show another web page and quit the current one
11、HTML required to display an applet in a web page: PARAM tag allows you to pass a value to an applet: To use these values in your applet, use the getParameter(String paramname ) method to return the value as a string: greeting=getParameter(message); Java Identifier Consists of letters and digits Must
12、 begin with a letter , $ or _ Unlimited length Cannot be the same as a reserved keyword Java Reserved Word Reserved Keywords cover categories such as primitive types, flow control statements, access modifiers, class, method, and variable declarations, special constants, and unused words abstract - b
13、oolean - break - byte - case - catch - char - class - const - continue - default - do - double - else - e某tends - final - finally - float - for - goto - if - implements - import - instanceof - int - interface - long - native - new - null - package - private - protected - public - return - short - st
14、atic - super - switch - synchronized - this - throw - throws - transient - try - void - volatile - while True, false and null are literals, not keywords Primitives Occupy pre-defined numbers of bits Have standard implicit initial values Type conversion You cannot assign booleans to any other type. You cannot assign a byte to a char. You can assign a variable of type 某 to type Y only if Y contains a wider range of values than 某. Primitives in order of width are char/short, int, long, float, double. For Objects, you can assign object 某 to object Y only if they are of the same class, or 某 i
