Java Learning Path process
Each person's study method is different,a person's method suits another person not necessarily,I only can discuss own study method.Because I study Java am study independently completely,has not asked others,therefore the study process basically is completely oneself tries to find out.I did not know whether this method is the quite good method,only could give everybody to provide refers.
Studies Java first step installs good JDK,writes Hello World?Actually the JDK study is not so simple,has two questions about JDK is very easy to puzzle the Java programmer continuously the place:Is the CLASSPATH question, actually said from the principle,is how must make clear JRE ClassLoader increase Class;Another question is package and the import question,how seeks the kind of way question.These two questions tried to find out clear,eliminated has studied Java and uses JDK the biggest barrier.The recommendation looked Wang Sen"the Java Depth Experiences dangers",has carried on the thorough discussion to these two questions
Second step is studies Java the grammar.The Java grammar is kind of C++, the basically mainstream programming language is not kind of C,is kind of C++, does not have what new thing,therefore the grammar study,probably was the quite a while time is enough.Only needs to pay attention is has the key
words usage which several is not easy to make clear,public,protected,private,static, when uses,why has to use,how uses,this possible need some people to direct,I initially was own ponder over completely,has spent the very long time.But afterwards I saw above this book spoke these concepts to"Thinking in Java".
Third step is studies Java the object-oriented programming language characteristic place.For instance inherits,structure,abstract class,the connection,the method are many condition,heavy load,cover,Java exception handling mechanism.Said regarding a not object-oriented language background person that,I thought this process needs to spend the very long very long time, because studies in front of Java does not have C++the experience,only then the C experience,I was have probably spent for a month,all made clear only then thoroughly these concepts,book example above repeatedly estimating,the revision,the attempt,repeatedly looked at that several chapter of contents, looked,looked has not gotten down5,comprehended only then thoroughly. But I thought if has the C++experience,should12days time be enough.Then in this process,may have a look"Thinking in Java"this book,opposite is extremely thorough to the object explanation.What a pity is I studies,has not seen to this book,therefore own have spent the massive time,and estimates through own attempt learns.
Fourth step starts a familiar Java kind of storehouse.The Java foundation class storehouse actually is JDK installs under the table of contents jre\Lib\Rt.Jar this package.The study foundation class storehouse studies rt.Jar. Inside the foundation class storehouse kind are extremely extremely many.It is said some more than3,000,I have not counted.But said the most core truly regarding us only then4,respectively is
Java.Lang.*;
Java.Io.*;
Java.Util.*;
Java.Sql.*;
These four packages study,each package study all may write thick teaching material,but O'reilly also truly is does this.I thought if time quite tight,is impossible through to read four books to study.I thought the quite good study method is such:
First must read through entire package the frame,understood entire package class,interface,the exception constitution,should better be can find the introduction entire package frame the article.These
introduced specially package of books the first several chapters should be these overall frame content introductions.Is not must be familiar with each kind of usage to the package of overall frame assurance,which attributes remembers it have,the method.Wants to record also cannot remember.But is must know which aspects the package does have a kind of constitution,these kind of uses are any,most core several classifications maybe complete any function.I in the time which trains to the human generally is a class speaks a package,therefore not impossible detailed introduction each kind of usage,but I repeatedly stress,how do I speak these packages to you am must tell you a kind of method am transfer,also does not request you to remember the kind of method transfer,but wants you to understand,which kinds Java has provided to us,each kind is uses in any situation,when I meet the question the time,I knew which kind,or which several kind of combinations can solve my problem,That'all!When we write the procedure specifically time,so long as you knew which kind should complete your work with to be enough.Codes,the concrete method transfer,writes the code,Documentation,all things all inside Documentation,will not request you certainly to remember,are actual you also not to be able to remember more than 3,000kinds altogether the nearly100,000methods transfers.Therefore changes
to each package overall frame assurance extremely importantly.
truncated class file翻译
Fifth step,through above study,if study the quite solid speech,built the Java foundation,is left over the work which had to do is sweeps clean inside Documentation besides above4packages other some comparisons to have the use the kind.Believed progressed to this step,Java studies independently the ability already to raise,might to study Documentation directly horizontal. Besides must make the GUI programming,inside JDK other can have the use the package is these:
Java.Text.*;
Java.Net.*;
Javax.Naming.*;
These packages of inside real correct uses quite many kinds very are actually few,only then several,therefore does not need to spend the very much time.
Sixth step,Java Web programming
The Web programming core is the HTTP agreement,the HTTP agreement and Java irrelevant,if not familiar HTTP agreement,although also may learn Servlet/JSP programming,but cannot achieve extrapolates,by knowing one method you will know all boundary.Therefore the HTTP agreement study
is necessary.If has been familiar with HTTP agreement,also had the Java programming good foundation,studies Servlet/JSP is simply easy as pie,I study Servlet/JSP has used not to week-long time,then started with JSP to make the project.In Servlet/In the JSP study,heavy still was Servlet Documentation. Servlet the API most commonly used kind are very few,the flowered quite few time might grasp.These kinds all looked at,writes several examples to try.
Servlet/The JSP programming essence is transferring these kinds to come repeatedly through the HTTP agreement converses between Web Server and Brower.Moreover to JSP,but also needs to be familiar with several commonly used JSP the mark,the concrete mode of writing cannot remember the speech, looks up temporarily and that's the end of.
In addition Java the Web programming study must place Web Application with emphasis in the design pattern,how carries on the service logic the analysis, and carries on the reasonable design,according to the MVC design pattern request,completes the different logical level separately using Servlet and JSP, how grasps carries on the flow between Servlet and JSP the control and data sharing,as well as how Web should Application dispose and the deployment.
Seventh step,J2EE programming
The above study process if is quite smooth,carries on to this step,the difficulty enhances suddenly.Because the above knowledge content all only involves an aspect,but likes EJB,JMS,core the and so on JTA J2EE standard often is several kind of Java technology synthesis utilization crystallization, therefore grasps the difficulty quite to be big.
First certainly must study good JNDI,JNDI is App the Server localization server resources(the EJB module,Datasouce,JMS)searches the method,if to JNDI not familiar,EJB,JMS these things cannot study nearly.JNDI actually is javax.Naming.*This package,utilizes is very simple.The difficulty lies in the server resources document the disposition.Regarding the server resources document disposition,needed to have a look the special documents to be standard,for instance web.Xml mode of writing,ejb-jar.Xml mode of writing and so on.In view of each kind of different App Server,but also has own service

版权声明：本站内容均来自互联网，仅供演示用，请勿用于商业和其他非法用途。如果侵犯了您的权益请与我们联系QQ:729038198，我们将在24小时内删除。