JSP中request与response的用法详解

/** 
 * 获取HTTP请求头 
　*　　　String getHeader(String name)，适用于单值头 
　*　　　int getIntHeader(String name)，适用于单值int类型的请求头 
　*　　　long getDateHeader(String name)，适用于单值毫秒类型的请求头 
　*　　  Enumeration getHeaders(String name)，适用于多值请求头 
 * 
 * 
 */ 
public class CServlet extends HttpServlet { 
 
  public void doGet(HttpServletRequest request, HttpServletResponse response) 
      throws ServletException, IOException { 
 
    String ip = request.getRemoteAddr();//获取IP地址 
    String method = request.getMethod();//获取请求方式 
    System.out.println(ip); 
    System.out.println(method); 
    getLiuLanQi(request); 
    protectMethod(request, response); 
  } 
//防盗链 
  public void protectMethod(HttpServletRequest request, 
      HttpServletResponse response) { 
    String url = request.getHeader("referer"); 
    System.out.println(url); 
    if(url != null && url.equalsIgnoreCase("http://localhost:8080/day10/MyHtml.html") ) { 
      System.out.println("hi"); 
    } 
    else { 
      response.setStatus(302); 
      response.setHeader("Location","/day10/MyHtml.html"); 
      System.out.println("重定向"); 
    } 
  } 
//判断浏览器的类型 
  public void getLiuLanQi(HttpServletRequest request) { 
    String user = request.getHeader("User-Agent"); 
    if(user != null) { 
      String userNoC = user.toLowerCase(); 
      if(userNoC.contains("chrome")) { 
        System.out.println("浏览器类型：谷歌" ); 
      } 
      else if(userNoC.contains("firefox/")) { 
        System.out.println("浏览器类型：火狐"); 
      } 
      else { 
        System.out.println("浏览器类型：IE"); 
      } 
    } 
    else { 
      System.out.println("null"); 
    } 
  } 
} 

/** 
 * 获取请求URL 
  http://localhost:8080/day10_2/AServlet&＃63;username=xxx&password=yyy 
　　　　> String getScheme()：获取协议，http 
　　　　> String getServerName()：获取服务器名，localhost 
　　　　> String getServerPort()：获取服务器端口，8080 
　　　　> *****String getContextPath()：获取项目名，/day10_2 
　　　　> String getServletPath()：获取Servlet路径，/AServlet 
　　　　> String getQueryString()：获取参数部分，即问号后面的部分。username=xxx&password=yyy 
　　　　> String getRequestURI()：获取请求URI，等于项目名+Servlet路径。/day10_2/AServlet 
　　　　> String getRequestURL()：获取请求URL，等于不包含参数的整个请求路径。http://localhost:8080/day10_2/AServlet 
 * 
 * 
 */ 
public class DServlet extends HttpServlet { 
 
  public void doGet(HttpServletRequest request, HttpServletResponse response) 
      throws ServletException, IOException { 
    System.out.println(request.getScheme()); 
    System.out.println(request.getServerName()); 
    System.out.println(request.getServerPort()); 
    System.out.println(request.getContextPath()); 
    System.out.println(request.getServletPath()); 
    System.out.println(request.getQueryString()); 
    System.out.println(request.getRequestURI()); 
    System.out.println(request.getRequestURL()); 
  } 
 
} 

/** 
 * 
 * 请求参数：有一个参数一个值的，还有一个参数多个值！ 
　　　　> *****String getParameter(String name)：获取指定名称的请求参数值，适用于单值请求参数 
　　　　> String[] getParameterValues(String name)：获取指定名称的请求参数值，适用于多值请求参数 
　　　　> Enumeration getParameterNames()：获取所有请求参数名称 
　　　　> *****Map getParameterMap()：获取所有请求参数，其中key为参数名，value为参数值。 
 * 
 */ 
public class EServlet extends HttpServlet { 
 
  public void doGet(HttpServletRequest request, HttpServletResponse response) 
      throws ServletException, IOException { 
    doPost(request,response); 
  } 
 
  public void doPost(HttpServletRequest request, HttpServletResponse response) 
      throws ServletException, IOException { 
    request.setCharacterEncoding("utf-8");//调用他来解决乱码问题的，不会的可以看我写的解决乱码的那一篇 
    String name = request.getParameter("name"); 
    String password = request.getParameter("password"); 
    String[] aihao = request.getParameterValues("aihao"); 
    response.setHeader("content-type", "text/html;charset=utf-8"); 
    PrintWriter pw = response.getWriter(); 
    pw.println("name:" + name + "
"); 
    pw.println("password:" + password + "
"); 
    pw.print("aihao"); 
    for (int i = 0; i 

 
 
  
   
   
  
  
  
   
    姓名:
 
    密码:
 
    爱好：吃饭 
    睡觉 
    打豆豆 
     
   
  
 

/** 
 * 
 ** request域 
　　　　Servlet中三大域对象：request、session、application，都有如下三个方法： 
　　　　> void setAttribute(String name, Object value) 
　　　　> Object getAttribute(String name) 
   > void removeAttribute(String name); 
　　　　> 同一请求范围内使用request.setAttribute()、request.getAttribute()来传值！前一个Servlet调用setAttribute()保存值，后一个Servlet调用getAttribute()获取值。 
 
 * 
 */ 
public class FServlet extends HttpServlet { 
 
  public void doGet(HttpServletRequest request, HttpServletResponse response) 
      throws ServletException, IOException { 
    request.setAttribute("name","weijinhao"); 
    request.setAttribute("password", "123"); 
    RequestDispatcher rd = request.getRequestDispatcher("/GServlet"); 
    rd.forward(request, response); 
  } 
 
} 

public class GServlet extends HttpServlet { 
 
  public void doGet(HttpServletRequest request, HttpServletResponse response) 
      throws ServletException, IOException { 
    String name = (String)request.getAttribute("name"); 
    String password = (String)request.getAttribute("password"); 
    response.setHeader("content-type", "text/html;charset=utf-8"); 
    PrintWriter pw = response.getWriter(); 
    pw.println("name:" + name + "
"); 
    pw.println("password:" + password + "
"); 
    pw.close(); 
  } 
 
} 

/** 
   * response的正文 
   * 1,字符流 
   * 2,字节流 
   */ 
  public void doGet(HttpServletRequest request, HttpServletResponse response) 
      throws ServletException, IOException { 
    //String n = "hello javaweb"; 
    //byte[] b = n.getBytes(); 
    //字节流的使用 
    /*ServletOutputStream outputStream = response.getOutputStream(); 
    outputStream.write(b); 
    outputStream.close();*/ 
     
     
    //字符流的使用 
    /*PrintWriter p = response.getWriter(); 
    p.write(n); 
    p.close();*/ 
     
    //commoms工具包的使用 
    FileInputStream fileInputStream = new FileInputStream("C:/Users/74087/Desktop/6226354_994604.jpg"); 
    byte[] b = IOUtils.toByteArray(fileInputStream); 
    ServletOutputStream outputStream = response.getOutputStream(); 
    outputStream.write(b); 
    outputStream.close(); 
  } 
 
} 

/** 
   *response 的响应码 
   *1, sendError(int sc)//发送错误代码 
   *2, sendError(int sc, java.lang.String msg) //发送错误代码及描述 
   *3, setStatus(int sc) //发送成功响应代码 
   *response 的响应头 
   *1, setDateHeader(java.lang.String name, long date) 
   *2, setHeader(java.lang.String name, java.lang.String value) 
   *3, setIntHeader(java.lang.String name, int value) 
   *  下面的和上面的作用一样但是是为了进行多值的添加 
   *  addDateHeader(java.lang.String name, long date) 
   *  addHeader(java.lang.String name, java.lang.String value) 
   *  addIntHeader(java.lang.String name, int value) 
   */ 
  public void doGet(HttpServletRequest request, HttpServletResponse response) 
      throws ServletException, IOException { 
    //sendNum(response); 
    //sendRe(response); 
    //refresh(response); 
    //noCache(response); 
  } 
  //禁用浏览器缓存 
  public void noCache(HttpServletResponse response) { 
    response.setHeader("Cache-Control","no-cache"); 
    response.setHeader("pragma","0"); 
    response.setHeader("expires","no-cache"); 
  } 
  //自动跳转 
  public void refresh(HttpServletResponse response) { 
    response.setHeader("refresh", "5;url=http://www.baidu.com"); 
  } 
  //重定向的使用 
  public void sendRe(HttpServletResponse response) { 
    response.setStatus(302); 
    response.setHeader("Location", "http://www.baidu.com"); 
  } 
 
  public void sendNum(HttpServletResponse response) throws IOException { 
    response.setStatus(200); 
    response.sendError(404); 
    response.sendError( 404, "ser accept your request but i don't want to you see my web page"); 
  } 
 
}