j2ee基础知识点笔记（三） - 15841333625/Java GitHub Wiki

将应用程序发布到tomcat上

/abc/hello/  
       WEB-INF  
             classes  
             lib  
             web.xml

  1.    META-INF
         context.xml
             <Context path="/xyz" />
  2. copy hello folder to tomcat_installation\webapps
    hello
  3. config/server.xml
    <Context path="/hello"(服务器上的路径, 如果是"", 则发布到根路径上) docBase="c:\abc\hello"(本地路径)/>

打包

jar cvf hello.war -C c:\abc\hello 创建打包文件

MVC

// 猜字游戏
public class NumberGuessBean {
  private int answer;
  private int count;
  private String hint;

  private boolean success;

  public int getCount() {return count;}
  public String getHint() {return hint;}
  public NumberGuessBean() {reset();}

  public void reset() {
    answer = (int) (Math.random()*100 + 1);
    count = 0;
  }
  public void setSuccess(String guess) {
    count ++;
    try {
      int g = Integer.parseInt(guess);
    } catch (Exception e) {
      g = -1;
    }

    if( g == -1) {
      hint = "请输入数字！";
    }
  }
}
public class NumberGuessServlet extends HttpServlet {
  public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException {
    HttpSession session = request.getSession();

    response.setContextType("text/html");
    PrintWriter out = response.getWriter();

    NumberGuessBean bean = null;
    Object o = session.getAttribute("bean");
    if(o == null) {
      bean = new NumberGuessBean();
      session.setAttribute("bean", bean);
    }  else {
      bean = (NumberGuessBean) o;
    }

    String guess = request.getParameter("guess");
    if(guess != null) {
      bean.setGuess(guess);
    }

    if(bean.getSuccess()) {
      out.println("成功");
      bean.reset();
    } else if(bean.getCount() != 0) {
      out.println("继续");
    } else {
      out.println("<form action=\"\" method = \"get\"/>");
      out.println("<input type = \"text\" name = \"guess\" />");
    }
  }
}

JSP

jsp 从本质上讲就是 servlet
<> html
<% %> 合法的java程序
<%@ %> jsp指令
<%= %> 合法的java表达式
<%! %> 声明

<h1>now: <%= new java.util.Date() %> </h1>

jsp 指令

  1. page
<%@ page import="java.util.*, java.io.*"
    pageEncoding="utf-8"
    // contentType="text/html; charset=utf-8"
    // session="true"
    // isErrorPage ="false"   
    errorPage="/error.html"   //重定向
    buffer="8kb"              //缓冲区，默认值8kb
 %>
  1. include
// 发生在jsp文件转化为java文件的过程中
<%@ include file="a.jsp" %>
⚠️ **GitHub.com Fallback** ⚠️