## 创建web项目
打开netbeans，在菜单栏依次选择“File”、“New Project...”，然后
1、选择java web：
[](https://github.com/someus/another-tutorial-about-java-web/blob/master/img/00-03/01.png)
2、项目名称、路径：
[](https://github.com/someus/another-tutorial-about-java-web/blob/master/img/00-03/02.png)
3、选择使用的web容器，编写ContextPath：
[](https://github.com/someus/another-tutorial-about-java-web/blob/master/img/00-03/03.png)
生成的web项目结构如下：
[](https://github.com/someus/another-tutorial-about-java-web/blob/master/img/00-03/04.png)
index.html的内容如下：
~~~
<!DOCTYPE html>
<!--
To change this license header, choose License Headers in Project Properties.
To change this template file, choose Tools | Templates
and open the template in the editor.
-->
<html>
<head>
<title>TODO supply a title</title>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
</head>
<body>
<div>TODO write content</div>
</body>
</html>
~~~
`context.xml`的内容如下：
~~~
<?xml version="1.0" encoding="UTF-8"?>
<Context antiJARLocking="true" path="/HelloJSP"/>
~~~
`apache-tomcat-8.0.15/conf/server.xml`中关于端口的配置如下：
~~~
<Connector port="8080" protocol="HTTP/1.1"
connectionTimeout="20000"
redirectPort="8443" />
~~~
运行项目后，netbeans的输出信息如下：
~~~
ant -f /data/Code/netbeans/HelloJSP -Dnb.internal.action.name=run -Ddirectory.deployment.supported=true -DforceRedeploy=false -Dnb.wait.for.caches=true -Dbrowser.context=/data/Code/netbeans/HelloJSP run
init:
deps-module-jar:
deps-ear-jar:
deps-jar:
library-inclusion-in-archive:
library-inclusion-in-manifest:
compile:
compile-jsps:
Incrementally deploying http://localhost:8084/HelloJSP
Completed incremental distribution of http://localhost:8084/HelloJSP
run-deploy:
Browsing: http://localhost:8084/HelloJSP
run-display-browser:
run:
~~~
使用浏览器访问`http://localhost:8084/HelloJSP/`，能看到`TODO write content`。
**那么问题来了，为什么配置的是8080,访问时却用8084端口？**
答案是：这个端口是netbeans启动tomcat时配置的。
看一下启动命令：
~~~
$ ps -ef | grep 'tomcat' | grep -v grep
letian 390 24314 0 09:24 ? 00:00:08 /data/Apps/jdk1.8.0_20/bin/java -Djava.util.logging.config.file=/home/letian/.netbeans/8.0.2/apache-tomcat-8.0.15.0_base/conf/logging.properties -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -Dhttp.nonProxyHosts=localhost|127.0.0.1|myhost -Djava.endorsed.dirs=/data/Apps/apache-tomcat-8.0.15/endorsed -classpath /data/Apps/apache-tomcat-8.0.15/bin/bootstrap.jar:/data/Apps/apache-tomcat-8.0.15/bin/tomcat-juli.jar -Dcatalina.base=/home/letian/.netbeans/8.0.2/apache-tomcat-8.0.15.0_base -Dcatalina.home=/data/Apps/apache-tomcat-8.0.15 -Djava.io.tmpdir=/home/letian/.netbeans/8.0.2/apache-tomcat-8.0.15.0_base/temp org.apache.catalina.startup.Bootstrap start
$ grep -r '8084' /home/letian/.netbeans/8.0.2 # 可以看到很多结果
...
~~~
也就是说，实际使用的是`/home/letian/.netbeans/8.0.2/apache-tomcat-8.0.15.0_base/conf` 下的配置。在``/home/letian/.netbeans/8.0.2/apache-tomcat-8.0.15.0_base/conf/Catalina/localhost/HelloJSP.xml`中有以下内容：
~~~
<Context antiJARLocking="true" docBase="/data/Code/netbeans/HelloJSP/build/web" path="/HelloJSP"/>
~~~
这意味着访问`http://localhost:8084/HelloJSP/`时对应的web应用部署在HelloJSP项目 的`build/web/`目录下。
## [](https://github.com/someus/another-tutorial-about-java-web/blob/master/00-03.md#基于jsp的hello-world)基于JSP的hello world
删除index.html，新建index.jsp，内容如下：
~~~
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>JSP Page</title>
</head>
<body>
<%
String data="hello world";
boolean flag=true;
if (flag==true) {
out.println("<h1>" +data.toUpperCase()+ "</h1>");
}
%>
</body>
</html>
~~~
运行项目，访问`http://localhost:8084/HelloJSP/`，可以看到`HELLO WORLD`。
JSP在部署时会被转换成servlet，`/home/letian/.netbeans/8.0.2/apache-tomcat-8.0.15.0_base/work/Catalina/localhost/HelloJSP/org/apache/jsp`中的`index_jsp.java`就是对应的servlet。其内容如下：
~~~
/*
* Generated by the Jasper component of Apache Tomcat
* Version: Apache Tomcat/8.0.15
* Generated at: 2015-09-18 02:43:43 UTC
* Note: The last modified time of this file was set to
* the last modified time of the source file after
* generation to assist with modification tracking.
*/
package org.apache.jsp;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.jsp.*;
public final class index_jsp extends org.apache.jasper.runtime.HttpJspBase
implements org.apache.jasper.runtime.JspSourceDependent {
private static final javax.servlet.jsp.JspFactory _jspxFactory =
javax.servlet.jsp.JspFactory.getDefaultFactory();
private static java.util.Map<java.lang.String,java.lang.Long> _jspx_dependants;
private javax.el.ExpressionFactory _el_expressionfactory;
private org.apache.tomcat.InstanceManager _jsp_instancemanager;
public java.util.Map<java.lang.String,java.lang.Long> getDependants() {
return _jspx_dependants;
}
public void _jspInit() {
_el_expressionfactory = _jspxFactory.getJspApplicationContext(getServletConfig().getServletContext()).getExpressionFactory();
_jsp_instancemanager = org.apache.jasper.runtime.InstanceManagerFactory.getInstanceManager(getServletConfig());
}
public void _jspDestroy() {
}
public void _jspService(final javax.servlet.http.HttpServletRequest request, final javax.servlet.http.HttpServletResponse response)
throws java.io.IOException, javax.servlet.ServletException {
final java.lang.String _jspx_method = request.getMethod();
if (!"GET".equals(_jspx_method) && !"POST".equals(_jspx_method) && !"HEAD".equals(_jspx_method) && !javax.servlet.DispatcherType.ERROR.equals(request.getDispatcherType())) {
response.sendError(HttpServletResponse.SC_METHOD_NOT_ALLOWED, "JSPs only permit GET POST or HEAD");
return;
}
final javax.servlet.jsp.PageContext pageContext;
javax.servlet.http.HttpSession session = null;
final javax.servlet.ServletContext application;
final javax.servlet.ServletConfig config;
javax.servlet.jsp.JspWriter out = null;
final java.lang.Object page = this;
javax.servlet.jsp.JspWriter _jspx_out = null;
javax.servlet.jsp.PageContext _jspx_page_context = null;
try {
response.setContentType("text/html;charset=UTF-8");
pageContext = _jspxFactory.getPageContext(this, request, response,
null, true, 8192, true);
_jspx_page_context = pageContext;
application = pageContext.getServletContext();
config = pageContext.getServletConfig();
session = pageContext.getSession();
out = pageContext.getOut();
_jspx_out = out;
out.write("\n");
out.write("<!DOCTYPE html>\n");
out.write("<html>\n");
out.write(" <head>\n");
out.write(" <meta http-equiv=\"Content-Type\" content=\"text/html; charset=UTF-8\">\n");
out.write(" <title>JSP Page</title>\n");
out.write(" </head>\n");
out.write(" <body>\n");
out.write(" ");
String data="hello world";
boolean flag=true;
if (flag==true) {
out.println("<h1>" +data.toUpperCase()+ "</h1>");
}
out.write("\n");
out.write(" </body>\n");
out.write("</html>\n");
} catch (java.lang.Throwable t) {
if (!(t instanceof javax.servlet.jsp.SkipPageException)){
out = _jspx_out;
if (out != null && out.getBufferSize() != 0)
try {
if (response.isCommitted()) {
out.flush();
} else {
out.clearBuffer();
}
} catch (java.io.IOException e) {}
if (_jspx_page_context != null) _jspx_page_context.handlePageException(t);
else throw new ServletException(t);
}
} finally {
_jspxFactory.releasePageContext(_jspx_page_context);
}
}
}
~~~
感受一下这段代码吧～
关于JSP就介绍这么多。**需要记住的是：JSP最合适的用途是用作MVC中的视图，而不是和HTML一起混合编码 （例如把从数据库拉取数据也放入JSP中写）**
要了解更多，请参考下面的相关资料。
## [](https://github.com/someus/another-tutorial-about-java-web/blob/master/00-03.md#jsp相关资料)JSP相关资料
[JSP 教程](http://www.runoob.com/jsp/jsp-tutorial.html)
- JSP & Servlet
- 00-00、序
- 00-01、相关软件的安装
- 00-02、理解HTTP
- 00-03、从JSP开始
- 00-04、理解Servlet
- 00-05、过滤器与监听器
- 00-06、使用velocity模板引擎
- 00-07、使用数据库连接池
- 00-08、Tomcat的运行机制
- Spring MVC
- 01-00、Spring与依赖注入
- 01-01、Spring与面向切面编程
- 01-02、使用Spring MVC构建Hello World
- 01-03、JdbcTemplate
- 01-04、基于注解的URL映射
- 01-05、JSON
- 01-06、校验器
- 01-07、国际化
- 01-08、拦截器
- 01-09、文件上传
- 01-10、转换器与格式化
- Book
- Online Tutorial
- Q & A
- Learn More
- Supplement