版权声明:本文为博主原创文章,未经博主允许不得转载。 https://blog.csdn.net/hju22/article/details/87726744
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。
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
浏览器访问:http://localhost:8081/testFilter
出现了如下结果: