一段关于信息过滤的java代码有谁能解释下？

来源：百度知道 编辑：UC知道 时间：2024/06/25 21:22:35
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;
import javax.servlet.UnavailableException;
public class CodeFilter implements Filter {
protected String encoding = null;
protected FilterConfig filterConfig = null;
protected boolean ignore = true;
public void destroy() {
this.encoding = null;
this.filterConfig = null;
}

public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
if (ignore || (request.getCharacterEncoding() == null)) {
String encoding = selectEncoding(request);
if (encoding != null)
request.setCharacterE

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 CodeFilter implements Filter {
//可以理解为默认编码，在web.xml中配置后读取存入
protected String encoding = null;
protected FilterConfig filterConfig = null;
protected boolean ignore = true;

public void destroy() {
this.encoding = null;
this.filterConfig = null;
}

public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
//如果被忽略或者请求未设置编码，为了防止乱码，进行编码过滤
if (ignore || (request.getCharacterEncoding() == null)) {
String encoding = selectEncoding(request);
if (encoding != null)
//设置请求编码为web.xml中配置的编码类型
request.setCharacterEncodi