javaEE ##

字符编码过滤器 SetEncodingFilter.java

SetEncodingFilter.java

package com.testdemo.analysis.tool;

import javax.servlet.*;
import java.io.*;

public class SetEncodingFilter implements Filter {
    protected String encoding = null;// 定义缺省字符编码方式
    protected boolean ignore = true;// 定义客户端指定的编码方式是否应被忽略
    protected FilterConfig filterConfig = null;// 定义过滤器配置对象,若为null,则说明过滤器未配置

    public void destroy()// 停止过滤器的工作
    {
        this.encoding = null;
        this.filterConfig = null;
    }

    // 设置字符编码
    public void doFilter(ServletRequest req, ServletResponse res,
            FilterChain chain) throws IOException, ServletException {
        if (ignore || (req.getCharacterEncoding() == null)) {
            req.setCharacterEncoding(selectEncoding(req));
        }
        chain.doFilter(req, res);
    }

    // 启动过滤器
    public void init(FilterConfig filterConfig) throws ServletException {
        this.filterConfig = filterConfig;
        this.encoding = filterConfig.getInitParameter("encoding");
        String value = filterConfig.getInitParameter("ignore");
        if (value == null)
            this.ignore = true;
        else if (value.equalsIgnoreCase("true")
                || value.equalsIgnoreCase("yes"))
            this.ignore = true;
        else
            this.ignore = false;
    }

    // 选择合适的字符编码方式
    protected String selectEncoding(ServletRequest req) {
        return this.encoding;
    }

    // 返回filterConfig对象
    public FilterConfig getFilterConfig() {
        return filterConfig;
    }

    // 设置filterConfig对象
    public void setFilterConfig(FilterConfig filterConfig) {
        this.filterConfig = filterConfig;
    }
}

 

web.xml

<filter>
        <filter-name>CharacterFilter</filter-name>
        <filter-class>com.testdemo.analysis.tool.SetEncodingFilter</filter-class>
        <init-param>
            <param-name>encoding</param-name>
            <param-value>UTF-8</param-value>
        </init-param>
        <init-param>
            <param-name>ignore</param-name>
            <param-value>false</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>CharacterFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>