Servlet类，没有乱码处理
package com.feijian.servlet;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
public class helloServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
resp.getWriter().print("你好，美丽的世界！");
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doGet(req, resp);
}
}写Filter类，需要注意导包为Javax.Servlet
package com.feijian.filter;
import javax.servlet.*;
import java.io.IOException;
public class helloFilter implements Filter {
@Override
public void init(FilterConfig filterConfig) throws ServletException {
}
@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
servletRequest.setCharacterEncoding("utf-8");
servletResponse.setCharacterEncoding("utf-8");
filterChain.doFilter(servletRequest,servletResponse);
}
@Override
public void destroy() {
}
}web.xml中 注册 servlet 和 filter ，servlet有两个mapping, 一个多了一级目录，servlet， 观察在filter 中的mapping 是什么响应路径
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
version="4.0">
<servlet>
<servlet-name>Hello</servlet-name>
<servlet-class>com.feijian.servlet.helloServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>Hello</servlet-name>
<url-pattern>/servlet/hello</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>Hello</servlet-name>
<url-pattern>/hello</url-pattern>
</servlet-mapping>
<filter>
<filter-name>filter01</filter-name>
<filter-class>com.feijian.filter.helloFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>filter01</filter-name>
<url-pattern>/servlet/*</url-pattern>
</filter-mapping>
</web-app>