JSP中文乱码

JSP中文乱码

所有乱码出现的原因都是：前后编码不一致。

URL中文乱码： 示例1：前端encode后端decode

• 前端代码

  
  
  
  
      login
      
  
  
  	'>URL中文
  
  
  

• 后端相关代码

  @WebServlet(urlPatterns = "/demoServlet")
  public class DemoServlet extends HttpServlet {
      @Override
      protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
          request.setCharacterEncoding("UTF-8");
          String queryString = request.getQueryString();
          String res = URLDecoder.decode(queryString, "UTF-8");
          System.out.println(res);
  
          String k1 = request.getParameter("k1");
          System.out.println(k1);
          String k2 = request.getParameter("k2");
          res = URLDecoder.decode(k2, "UTF-8");
          System.out.println(res);
      }
  }
  

备注：本示例在本地tomcat中测试结果正确

示例2：前端URL的参数没有使用编码

• 前端代码

  
  
  
  
      login
      
  
  
  	URL中文
  
  
  

• 后端相关代码

  @WebServlet(urlPatterns = "/demoServlet")
  public class DemoServlet extends HttpServlet {
      @Override
      protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
          doGet(req,resp);
      }
      @Override
      protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
          request.setCharacterEncoding("UTF-8");
          String k1 = request.getParameter("k1");
          System.out.println(k1);
          String k2 = request.getParameter("k2");
          String res = new String(k2.getBytes("UTF-8"), "UTF-8");
          System.out.println(res);
      }
  }
  

备注：本示例在本地tomcat中测试结果正确

Post乱码

post乱码包含包括post请求乱码、post输出乱码两种情况，解决方案。

• n前端代码

  
  
  
      login
      
  
  
      
          用户名：
          
      
  
  
  

• 后端代码

  @WebServlet(urlPatterns = "/demoServlet")
  public class DemoServlet extends HttpServlet {
      @Override
      protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
          request.setCharacterEncoding("UTF-8");
          response.setCharacterEncoding("UTF-8");
          response.setContentType("text/html;charset=utf-8");
  
          String uname = request.getParameter("uname");
          System.out.println(uname);
          PrintWriter out = response.getWriter();
          out.write("欢迎您：" + uname);
          out.flush();
          out.close();
      }
  
  }
  

• 运行

• 控制台输出结果： 页面结果：