技術標籤：JavaWeb亂碼servlet

看個例子：

在servlet02中設定編碼，可以正常輸出顯示中文。

public class Servlet02 extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.setContentType("text/html");
        resp.setCharacterEncoding
 
("utf-8");
        resp.getWriter().print("你好,Servlet02");
    }
}

此時利用sevlet01轉發到servlet02後編碼失效，出現中文亂碼。

public class Servlet01 extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
       resp.
 
getWriter().print("你好,Servlet01");
       req.getRequestDispatcher("/s02").forward(req,resp);
    }
}

在resp.getWriter().print("你好,Servlet01");前加上resp.setContentType("text/html"); resp.setCharacterEncoding("utf-8");或者將resp.getWriter().print("你好,Servlet01");

public class Servlet01 extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
       resp.setContentType("text/html");
       resp.setCharacterEncoding("utf-8");
       resp.getWriter().print("你好,Servlet01");
       req.getRequestDispatcher("/s02").forward(req,resp);
    }
}

public class Servlet01 extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
       //resp.getWriter().print("你好,Servlet01");
       req.getRequestDispatcher("/s02").forward(req,resp);
    }
}

這樣Servlet01轉發到Servlet02之後就不會顯示中文亂碼了。

原因：servlet在獲取resp的輸出流的時候，首先檢查頭部資訊的編碼方式，然後根據這個編碼來載入資料，所以只要在獲取輸出流之前修改編碼（也就是resp.getWriter();前面）就不會有中文亂碼啦。