SpringMVC 重写HttpMessageConverter进行Xss过滤

https://my.oschina.net/jayhu/blog/653725

public interface MessageConverterHandler<T, K> {

	/**
	 * 用于在httpMessageConverter read(..)方法完成之后调用
	 * <p>
	 * 1.可以对converter映射出的Object进行处理
	 * </p>
	 */
	public Object readAfter( T obj, K type );
}

 

  2.自定义注解NeedXss

    该注解用于需要xss过滤的字段

@Target( ElementType.FIELD )
@Retention( RetentionPolicy.RUNTIME )
@Documented
public @interface NeedXss {
}

 

//默认会过滤所有请求路径,只会过滤String类型的字段，需要其他类型过滤的请自行完善
public class XssMappingJacksonHttpMessageConverter extends MappingJacksonHttpMessageConverter implements
		MessageConverterHandler<Object, Type> {

	/**
	 * 不需要xss过滤的路径
	 */
	protected static List<String> urls;

	static {
		urls = new ArrayList<String>();
		// for example urls.add("/xxx/xxxxx");
	}
        
        //重写该方法，我们只需要加上Object tempObj = this.process( obj, type, inputMessage );
        //并返回tempObj,process方法里面我们过滤白名单和进行xss处理
	@Override
	public Object read( Type type, Class<?> contextClass, HttpInputMessage inputMessage ) throws IOException,
			HttpMessageNotReadableException {

		JavaType javaType = getJavaType( type, contextClass );

		Object obj = readJavaType( javaType, inputMessage );

		Object tempObj = this.process( obj, type, inputMessage );

		return tempObj;
	}

	//这个就是父类的readJavaType方法，由于父类该方法是private的，所以我们copy一个用
	private Object readJavaType( JavaType javaType, HttpInputMessage inputMessage ) {
		try {
			return super.getObjectMapper().readValue( inputMessage.getBody(), javaType );
		} catch ( IOException ex ) {
			throw new HttpMessageNotReadableException( "Could not read JSON: " + ex.getMessage(), ex );
		}
	}
        
        
	protected Object process( Object obj, Type type, HttpInputMessage inputMessage ) {
		if ( this.isNeedProcess( inputMessage ) ) {
			return this.readAfter( obj, type );
		} else {
			return obj;
		}
	}

	//根据白名单，判断当前请求路径是否需要xss过滤
	protected boolean isNeedProcess( HttpInputMessage inputMessage ) {

		String url = "";

		try {
		        //经过debug发现inputMessage类型为ServletServerHttpRequest，所以进行下类型转换
			ServletServerHttpRequest request = ( ServletServerHttpRequest ) inputMessage;

			url = request.getURI().getPath();

			//根据白名单做下匹配，当然也可以实现正则什么的，代码就不贴了

		} catch ( Exception e ) {
			logger.error( "BACK_ERROR," + this.getClass().getCanonicalName() + ",XSS处理-url处理失败,url=" + url + ",ERROR=", e );
			return true;
		}

		return true;

	}

	//最重要的一步，进行xss过滤
	@Override
	public Object readAfter( Object obj, Type type ) {
		try {
		        //type实际上就是我们需要convert的model，我们通过反射来完成根据NeedXss注解对String
		        //的字段进行xss过滤
			Class clazz = Class.forName( JSON.toJSONString( type ).replace( "\"", "" ) );

			if ( clazz == null ) {
				return obj;
			}

			Field[] fields = clazz.getDeclaredFields();

			if ( fields != null && fields.length > 0 ) {
				// string类型字段名称列表
				List<String> strList = new ArrayList<String>( fields.length );

				// 1. 将需要xss处理的string类型的字段放入strlist
				for ( int i = 0; i < fields.length; i++ ) {

				        // 1.1该属性是否有NeedXss.class注解
					NeedXss needXss = fields[ i ].getAnnotation( NeedXss.class );
					// 1.2如果该没有NeedXss.class注解，则不处理该属性
					if ( needXss == null || !( needXss instanceof NeedXss ) ) {
						continue;
					}

					String mod = Modifier.toString( fields[ i ].getModifiers() );
					if ( mod.indexOf( "static" ) != -1 )
						continue;
					// 得到属性的类名
					String className = fields[ i ].getType().getSimpleName();
					// 得到属性字段名
					if ( className.equalsIgnoreCase( "String" ) ) {

						strList.add( fields[ i ].getName() );
					}

				}

				// 2.将strlist中的字段进行xss处理
				if ( strList.size() > 0 ) {

					Object temp = JSON.toJavaObject( ( JSON ) JSON.toJSON( obj ), clazz );

					for ( int i = 0; i < strList.size(); i++ ) {
						Method set = clazz.getMethod( "set" + strList.get( i ).substring( 0, 1 ).toUpperCase()
								+ strList.get( i ).substring( 1 ), String.class );
						Method get = clazz.getMethod( "get" + strList.get( i ).substring( 0, 1 ).toUpperCase()
								+ strList.get( i ).substring( 1 ) );

						Object tempObj = get.invoke( temp );

						if ( tempObj == null ) {
							break;
						}

						String content = tempObj.toString();

						set.invoke( temp, StringUtils.cleanXss( content ) );
					}

					return temp;
				}

			}

		} catch ( Exception e ) {
			logger.error( "BACK_ERROR," + this.getClass().getCanonicalName() + ",XSS处理失败,obj=" + JSON.toJSONString( obj ) + ",javaType="
					+ JSON.toJSONString( type ) + ",ERROR=", e );
			return obj;
		}

		return obj;
	}

 

 4.配置使用自定义的XssMappingJacksonHttpMessageConverter

    在SpringMVC的配置文件里面加上下面的配置

    <mvc:annotation-driven >
		<mvc:message-converters register-defaults="true">
			<!-- 将StringHttpMessageConverter的默认编码设为UTF-8. -->
			<bean class="org.springframework.http.converter.StringHttpMessageConverter">
				<constructor-arg value="UTF-8" />
			</bean>
			
			<bean class="com.zhubajie.seller.common.converter.XssMappingJacksonHttpMessageConverter">
				<property name="prettyPrint" value="false" />
			</bean>
		</mvc:message-converters>
	</mvc:annotation-driven>