使用过滤器解决中文乱码问题

卡尔曼和玻尔兹曼谁曼

发布于 2019-01-25 16:44:07

1.4K0

发布于 2019-01-25 16:44:07

1. 创建字符编码过滤器对象，源码如下：

package com.tzy.filter;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

public class CharacterFilter implements Filter {
	
	String encoding = null;
	
	@Override
	public void destroy() {
		encoding = null;
	}

	@Override
	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException {
		if (encoding != null) {
			request.setCharacterEncoding(encoding);
			response.setContentType("text/html;charset=" + encoding);
		}
		/*
		 * 在过滤器对象的doFilter()方法中，业务逻辑处理完成之后，
		 * 需要通过FilterChain对象的doFilter()方法将请求传递到下一过滤器或目标资源，否则将出现错误。
		 */
		chain.doFilter(request, response);
	}

	@Override
	public void init(FilterConfig filterConfig) throws ServletException {
		encoding = filterConfig.getInitParameter("encoding");
	}

}

2. 在Web.xml文件中对过滤器进行配置，配置如下：

<filter>
  <filter-name>CharacterFilter</filter-name>
  <filter-class>com.tzy.filter.CharacterFilter</filter-class
  <init-param>
    <param-name>encoding</param-name>
    <param-value>UTF-8</param-value>
  </init-param>
</filter>
<filter-mapping>
  <filter-name>CharacterFilter</filter-name>
  <url-pattern>/*</url-pattern>
</filter-mapping>

在Web.xml文件中，配置过滤器，其过滤器的URL映射可以使用正则表达式进行配置，如实例中使用“/*”来匹配所有请求。

3. 我们下面写实例进行测试：

3.1 编写html文件，代码如下：

<!DOCTYPE HTML>
<html>
  <head>
  	<meta charset="utf-8"/>
    <title>注册</title>
  </head>
  
  <body>
  	<div align="center">
  	<form action="servlet/RegisterServlet" method="post">
    	<table>
        	<thead>
            	<tr>
                	<td width="300">个人信息</td>
                </tr>
            </thead>
            <tbody>
            	<tr>
                	<td width="100">姓名：</td>
                    <td width="200"><input type="text" name="name"/></td>
                </tr>
                <tr>
                	<td width="100">性别：</td>
                    <td width="200">
                    	<input type="radio" name="gender" value="男"/>男
                        <input type="radio" name="gender" value="女"/>女
                    </td>
                </tr>
                <tr>
                	<td width="100">联系方式：</td>
                    <td  width="200"><input type="text" name="email"/></td>
                </tr>
                <tr>
                	<td width="100">家庭住址：</td>
                    <td width="200"><input type="text" name="address"/></td>
                </tr>
                <tr>
                	<td width="300">
                	<input type="submit" value="提交"/>
                	</td>
                </tr>
            </tbody>
        </table>
    </form>
  	</div>
  </body>
</html>

3.2 处理请求的Servlet代码如下：

package com.tzy.filter;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class RegisterServlet extends HttpServlet {

	private static final long serialVersionUID = 1L;

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

	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		response.setContentType("text/html");
		PrintWriter out = response.getWriter();
		String name = request.getParameter("name");
		String gender = request.getParameter("gender");
		String email = request.getParameter("email");
		String address = request.getParameter("address");
		out.print("<html>");
		out.print("<h2>个人信息</h2><hr/>");
		out.print("姓名：" + name + "<br/>");
		out.print("性别：" + gender + "<br/>");
		out.print("联系方式：" + email + "<br/>");
		out.print("家庭住址：" + address + "<br/>");
		out.print("</html>");
	}

}

3.3 不要忘了在Web.xml中对Servlet进行配置：

<servlet>
    <description>处理注册信息</description>
    <servlet-name>RegisterServlet</servlet-name>
    <servlet-class>com.tzy.filter.RegisterServlet</servlet-class>
  </servlet>

  <servlet-mapping>
    <servlet-name>RegisterServlet</servlet-name>
    <url-pattern>/servlet/RegisterServlet</url-pattern>
  </servlet-mapping>

OK，大功告成！

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原始发表：2013年12月29日，如有侵权请联系 cloudcommunity@tencent.com 删除

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