Filter 过滤器中文乱码

编码过滤器实现

最新推荐文章于 2021-04-29 17:24:53 发布

原创最新推荐文章于 2021-04-29 17:24:53 发布 · 1.1k 阅读

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#filter #encoding #import #servlet #string #jsp

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本文介绍了一个简单的编码过滤器实现，该过滤器默认使用UTF-8编码，并详细解释了如何通过web.xml配置文件来针对不同需求（如所有资源、特定文件类型、指定目录等）进行过滤器映射。

/* EncodeFileter */

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;

/**
* 编码过滤器, 默认UTF-8
*
* @author linde13652
*
*/
public class EncodingFilter implements Filter {

private String encoding = "UTF-8";

public void destroy() {
}

public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
request.setCharacterEncoding(this.encoding);
chain.doFilter(request, response);
}
public void init(FilterConfig config) throws ServletException {
String encoding = config.getInitParameter("encoding");

if (encoding != null && encoding.trim().length() > 0) {
this.encoding = encoding;
}
}

}

web.xml 配置

1。如果要映射过滤应用程序中所有资源：

<filter>
    <filter-name>loggerfilter</filter-name>
    <filter-class>myfilter.LoggerFilter</filter-class>
</filter>
<filter-mapping>
    <filter-name>loggerfilter</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>

2.过滤指定的类型文件资源

<filter>
    <filter-name>loggerfilter</filter-name>
    <filter-class>myfilter.LoggerFilter</filter-class>
</filter>
<filter-mapping>
    <filter-name>loggerfilter</filter-name>
    <url-pattern>*.html</url-pattern>
</filter-mapping>

其中<url-pattern>*.html</url-pattern>要过滤jsp那么就改*.html为*.jsp,但是注意没有“/”斜杠

如果要同时过滤多种类型资源：

<filter>
    <filter-name>loggerfilter</filter-name>
    <filter-class>myfilter.LoggerFilter</filter-class>
</filter>
<filter-mapping>
    <filter-name>loggerfilter</filter-name>
    <url-pattern>*.html</url-pattern>
</filter-mapping>

<filter-mapping>
    <filter-name>loggerfilter</filter-name>
    <url-pattern>*.jsp</url-pattern>
</filter-mapping>

3.过滤指定的目录

<filter>
    <filter-name>loggerfilter</filter-name>
    <filter-class>myfilter.LoggerFilter</filter-class>
</filter>
<filter-mapping>
    <filter-name>loggerfilter</filter-name>
    <url-pattern>/folder_name/*</url-pattern>
</filter-mapping>

4.过滤指定的servlet

<filter>
    <filter-name>loggerfilter</filter-name>
    <filter-class>myfilter.LoggerFilter</filter-class>
</filter>
<filter-mapping>
    <filter-name>loggerfilter</filter-name>
    <servlet-name>loggerservlet</servlet-name>
</filter-mapping>
<servlet>
    <servlet-name>loggerservlet</servlet-name>
    <servlet-class>myfilter.LoggerServlet</servlet-class>
</servlet>

5.过滤指定文件

<filter>
    <filter-name>loggerfilter</filter-name>
    <filter-class>myfilter.LoggerFilter</filter-class>
</filter>
<filter-mapping>
    <filter-name>loggerfilter</filter-name>
    <url-pattern>/simplefilter.html</url-pattern>
</filter-mapping>

以上都要注意是否有斜杠“/”