Servlet响应的中文字符集问题

在Servlet中利用response向客户端浏览器输出中文时有时会遇到乱码问题，总结如下：

response输出流有两种，一是以字节流输出，一是以字符流输出。

一、以字节流输出：
1.默认编码输出木有乱码
2.通过response的setHeader方法设置编码utf-8，无乱码
3.通过response的setContentType方法设置编码utf-8，无乱码
4.输出数字建议以字符串形式输出

二、以字符流输出：
1.默认查iso-8859-1码表(SUN的Servlet规范要求的) ，客户端显示乱码
2.通过response的setHeader方法设置编码utf-8，无乱码
3.通过response的setContentType方法设置编码utf-8，无乱码

字节流以默认编码输出：

public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        // 以字节流用默认编码向客户端输出中文数据,木有乱码
        response.setContentType("text/html");

        String str = "喔呵呵呵呵";
        OutputStream out = response.getOutputStream();
        out.write("</br></br><div align=\"center\" style=\"font-size:25px; color:red\">".getBytes());

        out.write(str.getBytes());

        out.write("</div>".getBytes());
        out.close();
}

字节流设置编码为utf-8输出：

public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        // 通知客户端查UTF-8码表
        response.setContentType("text/html;charset=utf-8");

        // 或者：
        // response.setHeader("Content-Type","text/html;charset=utf-8");

        String str = "喔哈哈哈哈";
        OutputStream out = response.getOutputStream();
        out.write("</br></br><div align=\"center\" style=\"font-size:25px; color:red\">".getBytes());

        out.write(str.getBytes("utf-8"));

        out.write("</div>".getBytes());
        out.close();
}

字节流输出数字：

public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setHeader("Content-Type", "text/html;charset=utf-8");

        int i = 98;
        OutputStream out = response.getOutputStream();

        out.write("</br></br><div align=\"center\" style=\"font-size:25px; color:red\">"
                .getBytes());

        // out.write(i); 会输出字母b

        // 输出数字98
        out.write((i + "").getBytes());

        out.write("</div>".getBytes());
        out.close();
}

字符流设置编码为utf-8输出：

public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        // 通知客户端查UTF-8码表
        response.setContentType("text/html;charset=utf-8");
        // 或者：
        // response.setHeader("Content-Type", "text/html;charset=utf-8");

        String str = "喔嘿嘿嘿嘿";
        PrintWriter out = response.getWriter();
        out.write("</br></br><div align=\"center\" style=\"font-size:25px; color:red\">");

        out.write(str);

        out.write("</div>");
        out.flush();
        out.close();
}