javaweb中用过滤器Filter处理所有页面中文乱码问题

冷不防 2022-03-18 06:38 258阅读 0赞

### 文章目录 ###

*   *   *   *  一、项目结构
             *  二、过滤器—处理字符编码
             *  三、测试servlet
             *  四、部署及运行

#### 一、项目结构 ####

写一个过滤器，处理所有页面的字符编码；  
写一个servlet，测试过滤器的功能。  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hqdTIy_size_16_color_FFFFFF_t_70]

#### 二、过滤器—处理字符编码 ####

CharacterFilter.java

package net.test.filter;
    
    import javax.servlet.*;
    import javax.servlet.annotation.WebFilter;
    import javax.servlet.annotation.WebInitParam;
    import java.io.IOException;
    
    // url映射/*，给所有页面处理中文乱码
    @WebFilter(filterName = "CharacterFilter",urlPatterns = "/*",initParams = {@WebInitParam(name="encoding",value = "utf-8")})
    public class CharacterFilter implements Filter {//实现filter接口
        //字符编码
        private String encoding;
    
        @Override
        public void init(FilterConfig filterConfig) throws ServletException {
            //获取初始化参数
            encoding = filterConfig.getInitParameter("encoding");
        }
    
        @Override
        public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
            if (encoding!=null) {
                //设置request字符编码
                servletRequest.setCharacterEncoding(encoding);
                //设置response字符编码
                servletResponse.setContentType("text/html;charset="+encoding);
            }
            //传递给下一个过滤器
            filterChain.doFilter(servletRequest,servletResponse);
        }
    
        @Override
        public void destroy() {
            encoding=null;
        }
    }

#### 三、测试servlet ####

TestFilterServlet.java

package net.test.servlet;
    
    import javax.servlet.ServletException;
    import javax.servlet.annotation.WebServlet;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    import java.io.IOException;
    
    @WebServlet(name = "TestFilterServlet",urlPatterns = "/testFilter")
    public class TestFilterServlet extends HttpServlet {
        protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    
        }
    
        protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            response.getWriter().write("testFilter被访问了");
        }
    }

#### 四、部署及运行 ####

部署  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hqdTIy_size_16_color_FFFFFF_t_70 1]  
浏览器访问：[http://localhost:8081/testFilter][http_localhost_8081_testFilter]  
出现了如下结果：  
![在这里插入图片描述][20190219190204182.]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hqdTIy_size_16_color_FFFFFF_t_70]: /images/20220318/93395afffcf747bbaf1aea0ee1017831.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hqdTIy_size_16_color_FFFFFF_t_70 1]: /images/20220318/3a09bca180ca45b696b96fdf4bf8e7f0.png
[http_localhost_8081_testFilter]: http://localhost:8081/testFilter
[20190219190204182.]: /images/20220318/8499bb3ecf5e4ff68c80e0668aac1bad.png