Servlet资源共享以及Properties配置文件读取

一、Servlet资源共享

1.SetServlet

创建SetServlet类,继承HttpServlet,重写doGet方法

protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    String userName = "无心";	
    resp.setCharacterEncoding("utf-8");	// 设置编码
    resp.setContentType("text/html");	// 指定HTTP响应访问的编码
    resp.getWriter().print("<h1>名字设置成功</h1>");
    ServletContext context = this.getServletContext();
    context.setAttribute("userName",userName);
}

2.GetServlet

创建GetServlet类,继承HttpServlet,重写doGet方法

protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    ServletContext context = this.getServletContext();
    String userName = (String) context.getAttribute("userName");

    resp.setCharacterEncoding("utf-8");	// 设置编码
    resp.setContentType("text/html");	// 指定HTTP响应访问的编码
    PrintWriter writer = resp.getWriter();
    writer.print("<H1>名字:" + userName+"</H1>");
}

3.配置web.xml

配置servlet和servlet-mapping映射

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0">
    <servlet>
      <servlet-name>setc</servlet-name>	<!-- servlet名称 -->
      <servlet-class>com.wuxin.Servlet.SetServlet</servlet-class> <!-- servlet类具体地址 -->
    </servlet>
  <servlet-mapping>	
    <servlet-name>setc</servlet-name>
    <url-pattern>/setc</url-pattern>	<!-- 具体访问关键字 -->
  </servlet-mapping>
  
  <servlet>
    <servlet-name>getc</servlet-name>
    <servlet-class>com.wuxin.Servlet.GetServlet</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>getc</servlet-name>
    <url-pattern>/getc</url-pattern>
  </servlet-mapping>

  <servlet>
    <servlet-name>prop</servlet-name>
    <servlet-class>com.wuxin.Servlet.PropertiesServlet</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>prop</servlet-name>
    <url-pattern>/prop</url-pattern>
  </servlet-mapping>

</web-app>

二、Properties配置文件读取

1.新建配置文件

在resources目录下新建**.Properties配置文件

2.读取

在java目录下新建PropertiesServlet类，继承HttpServlet，并且重写doGet方法

protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    resp.setCharacterEncoding("utf-8");	// 设置编码
    resp.setContentType("text/html");	// 指定HTTP响应访问的编码
    // 获取相对路径下的输入字节流
    InputStream is = this.getServletContext().getResourceAsStream("/WEB-INF/classes/db.properties");
    Properties prop = new Properties();	// 初始化Properties对象
    prop.load(is);	// 读取is字节流
    String user = prop.getProperty("userName");	// 获取键值对
    String pwd = prop.getProperty("PassWord");	// 获取键值对
    resp.getWriter().print("账号：" + user + "密码" + pwd);
}