Quick self-level language programming java dry notes - to build Web environment, JSP acquaintance

Build a Web environment, JSP acquaintance

1. master environment to build and use of Tomcat

1.1 understand the mainstream web server

Server (hardware):

在公网上用来运行特别的程序，或者此程序需要的运行环境的，能够给广大用户提供服务的一台计算机。

一般配置比较高，同样也有人专门进行维护(运维)。

Server (software):

如果只有硬件那么用户也是无法访问资源内容，例如使用ServerSocket技术提供接受请求并处理然后响应的能力。

But ServerSocket technology is too close to the bottom, so there are teams and organizations have these things directly to a good package (developed a mature product), we only need to deploy such software on server hardware, the user can then start to provide for the service.

Mainstream server:

• Apache static server
• Static server Nginx
• Jetty
• Jboss
• WebLogic
• Tomcat
• …

Master Tomcat 1.2 environment to build

• Download 8.5 https://tomcat.apache.org/download-80.cgi
• Extract the zip file
• Under the start bin directorystartup.bat
• In the browser address bar enter the localhost:8080Tomcat default port number is 8080
• bin directory shutdown.batoff the server / close the window

Installation Contents Introduction:

• bin can run the batch file
  • startup.bat/sh
  • shutdown.bat/sh
  • catalina.bat/sh
• conf server configuration file
  • server.xml server configuration information
  • Web.xml configuration information in the server project
  • Context.xml configuration information within the server resources
• lib server needs to run a number of related jar library / package
  • el-api.jar
  • jasper.jar
  • jasper-el.jar
  • jsp-api.jar
  • servlet-api.jar
  • tomcat-dbcp.jar
  • tomcat-jni.jar
• logs Server log folder
  • catalina. .log date information about the server is running
  • localhost_access_log. Date .log server access information
• temp server needs at runtime temporary file storage directory
• (Important) webapps : Web store directory project
  • ROOT (root directory /)
• work: it is about and JSP , JSP code will be stored in the translation here

1.3 master common configuration with Tomcat

1. Modify the port number:

   Modify ports server.xml installation directory under the conf (line 69)

   <Connector port="8080" protocol="HTTP/1.1"
                  connectionTimeout="20000"
                  redirectPort="8443" />
   

2. Modify the welcome page:

   The final piece in the web.xml under the conf directory

   <welcome-file-list>
       <welcome-file>index.html</welcome-file>
       <welcome-file>index.htm</welcome-file>
       <welcome-file>index.jsp</welcome-file>
   </welcome-file-list>
   

1.4 Tomcat deployment project

• Find webappsdirectory
• In addition to the ROOT directory, we can create a new folder (in English) in the webapps directory
• Your project will be unified on the resource which can be
• Input will be finished in the browser address bar localhost:8080to continue to write anywhere in the webapps directory of your project is located after
  • If your project is in a directory under the webapps testdirectory, you need to access the localhost:8080/test/prefix
• You can create a new folder within your project files in a WEB-INFdirectory, which can be used to store a new web.xml to configure your specific project application, it has higher priority than the web.xml in the server conf directory.

2. Create a web master Eclipse project

• new -> others -> Search dy ... find a dynamic web project

• According to fill in the content below

  • title
  • Runtime (Java EE Library)
  • Project Templates 2.5 because 2.5 template automatically creates web.xml and 3.

• web 2.5 version of the project directory structure is as follows:

• In order to be able to deploy a web project we created, we need to make some server configurations IDE

  • window -> show view -> servers tab
  • 点击链接创建新的服务器(这个服务器其实是Eclipse基于真实tomcat去创建的临时/镜像服务器，为的是以免影响到真实tomcat目录)

• 为了能够使服务器部署项目时正常被我们所观察，我们需要将其默认的配置目录进行更改，如下。(Ctrl+S)

!

• 接下来可以将我们的项目放到此服务器中了
  • 右键服务器 -> add and remove -> 添加项目
  • 启动服务器(start)

3. 掌握JSP的基本使用

3.0 了解动态网页技术

传统的静态网页技术无法满足动态数据的需求，我们的HTML无法嵌入数据库查询的代码，所以我们需要将HTML结合Java代码进行使用，那么产生了JSP（Java Server Pages）Java服务器页面。 HTML + Java = JSP。

扩展名.jsp，在Eclipse创建JSP小心编码。(window -> 首选项 -> jspfiles -> encoding)

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>

</body>
</html>

3.1 掌握JSP的指令

<!-- page指令是用来配置JSP页面的信息的，它可以出现多次，也可以出现在任意位置，一般放在头部
	language：标识此JSP页面可以嵌套的脚本语言
	contentType：设置响应头信息
	pageEncoding：设置本页面的编码
	import：导入本页面Java代码所需要的包
-->
<%@ page language="java" contentType="text/html; charset=UTF-8"  import=""
    pageEncoding="UTF-8"%>

<%@include %>
<%@taglib %>

3.2 掌握JSP的脚本

<% Java代码 %> 能写一部分Java代码，但是无法定义方法，它可以定义在JSP页面的任意位置。

它的代码是被放到了JSP转成的.java文件的_jspService方法内。

3.3 掌握JSP的表达式

<%=Java代码 %>能写一部分Java代码，但是调用方法时，不能调用无返回值的方法，不能在其中添加;号，当然也不能定义方法等。=号后面的内容，可以在页面输出。

它的代码是被放到了JSP转成的.java文件的_jspService方法内，并且转化为了out.print() 向页面输出的代码。

3.4 掌握JSP的声明

<%! Java代码 %>Write part of Java code, but although the method can be defined, but can not call method .

Its code is placed in the position of a member of the JSP turn into a .java file.

3.5 understand and master the implementation of the principle of JSP

Java code you want to run: .java -> .class to run

The Tomcat work directory (and its related JSP): storing the contents of JSP translation.

JSP at runtime, you need to go through three steps.

1. Translation: the JSP is essentially a template, to Jasper when a program Tomcat in this template will be translated, translated into a Java class. If the content has changed, you need to be translated.
2. Compile: translated Java classes to be compiled
3. Run: compiled byte code file to run