filter替换(过滤)非法字符

功用： 如果用户提交(POST或PUT)的文本中含有定义的关键词(字)时，将其转义

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一个关健词文件keywords.properties：

<=*
>=*
'=*

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RequestWrapper

import java.util.Enumeration;
import java.util.Iterator;
import java.util.Map;
import java.util.Properties;
import java.util.Set;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;

import org.apache.cxf.common.util.StringUtils;

public class KeyWordRequestWrapper extends HttpServletRequestWrapper {

	private Properties props;

	public KeyWordRequestWrapper(HttpServletRequest request, Properties props) {
		super(request);
		this.props = props;
	}

	@Override
	public Map getParameterMap() {
		super.getContextPath();
		Map<String, String[]> map = super.getParameterMap();
		if (!map.isEmpty()) {
			Set<String> keySet = map.keySet();
			Iterator<String> keyIt = keySet.iterator();
			while (keyIt.hasNext()) {
				String key = keyIt.next();
				String[] values = map.get(key);
				for (int i = 0; i < values.length; i++) {
					map.get(key)[i] = this.replaceParam(values[i]);
				}
			}
		}
		return map;
	}

	@Override
	public String getParameter(String str) {
		String s = super.getParameter(str);
		return replaceParam(s);
	}

	@Override
	public String[] getParameterValues(String str) {
		String[] ss = super.getParameterValues(str);
		if (ss == null || ss.length == 0) {
			return ss;
		}
		String[] ss2 = new String[ss.length];
		for (int i = 0; i < ss2.length; i++) {
			ss2[i] = replaceParam(ss[i]);
		}
		return ss2;
	}

	private String replaceParam(String string) {
		if (StringUtils.isEmpty(string)) {
			return string;
		}
		String sb = new String(string);
		Enumeration en = props.propertyNames();
		while (en.hasMoreElements()) {
			String s = en.nextElement().toString();
			if (string.contains(s)) {
				sb = sb.replaceAll(s, props.getProperty(s));
			}
		}
		return sb;
	}

}

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filter:

import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;

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.http.HttpServletRequest;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class CharacterReplaceFilter implements Filter {

	private final Logger LOG = LoggerFactory.getLogger(CharacterReplaceFilter.class);
	private final static String KEY = "filePath";

	private FilterConfig filterConfig = null;

	private static Properties props = new Properties();

	public void init(FilterConfig filterConfig) throws ServletException {
		this.filterConfig = filterConfig;
		String value = this.filterConfig.getInitParameter(KEY);
		InputStream ins = CharacterReplaceFilter.class.getClassLoader().getResourceAsStream(value);
		try {
			props.load(ins);
			LOG.info("敏感词文件加载成功");
		} catch (IOException e) {
			LOG.error("加载敏感词文件时发生错误", e);
		}
	}

	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException,
			ServletException {
		HttpServletRequest httpReq = (HttpServletRequest) request;
		final String method = httpReq.getMethod();
		if (method.equalsIgnoreCase("POST") || method.equalsIgnoreCase("PUT")) {
			KeyWordRequestWrapper wrapper = new KeyWordRequestWrapper((HttpServletRequest) request, props);
			chain.doFilter(wrapper, response);
		} else {
			chain.doFilter(request, response);
		}
	}

	public void destroy() {
		filterConfig = null;
		props = null;
	}

}

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web.xml:

<!-- 处理敏感字符 -->
	<filter>
		<filter-name>keywordFilter</filter-name>
		<filter-class>com.xxx.wdss.web.filter.CharacterReplaceFilter</filter-class>
		<init-param>
			<param-name>filePath</param-name>
			<param-value>properties/keywords.properties</param-value>
		</init-param>
	</filter>
	<filter-mapping>
		<filter-name>keywordFilter</filter-name>
		<url-pattern>/*</url-pattern>
	</filter-mapping>
<!-- / 处理敏感字符 -->