spring-boot 自定义xml配置web请求拦截器

spring boo 拦截器教程推荐：http://lihao312.iteye.com/blog/2078139

自定义web请求参数校验拦截器，通过xml（request-validation.xml）配置url对应的字段进行校验，使校验代码通过配置文件分开，保持代码完整，更加符合领域驱动设计模式。

1.配置spring mvc的拦截器WebMvcConfigurerAdapter 

import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;

@Configuration
public class WebMvcConfiguration extends WebMvcConfigurerAdapter {

	/**
	 * 添加拦截器
	 */
	public void addInterceptors(InterceptorRegistry registry) {
		registry.addInterceptor(new ValidationHandlerInterceptor());
    }
}

 2、配置拦截器

import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import com.whtr.nginf.infrastructure.util.JsonUtil;
import com.whtr.nginf.infrastructure.web.validation.DateValidation;
import com.whtr.nginf.infrastructure.web.validation.DatetimeValidation;
import com.whtr.nginf.infrastructure.web.validation.DigitValidation;
import com.whtr.nginf.infrastructure.web.validation.GEValidation;
import com.whtr.nginf.infrastructure.web.validation.GTValidation;
import com.whtr.nginf.infrastructure.web.validation.LEValidation;
import com.whtr.nginf.infrastructure.web.validation.LTValidation;

public class ValidationHandlerInterceptor implements HandlerInterceptor {
	
	public static Map<String, ValidationConfig> vcMap = new ConcurrentHashMap<>();
	
	protected Map<String, ParameterValidation> validationMap = new ConcurrentHashMap<>();
	
	public ValidationHandlerInterceptor() {
                //参数拦截拦截项参考附件
		List<ParameterValidation> list = new ArrayList<>();
		list.add(new StringNotBlankValidation());
		list.add(new StringLengthValidation());
		list.add(new DatetimeValidation());
		list.add(new DateValidation());
		list.add(new DigitValidation());
		list.add(new NumberValidation());
		list.add(new RegexValidation());
		list.add(new GEValidation());
		list.add(new GTValidation());
		list.add(new LEValidation());
		list.add(new LTValidation());
		
		list.forEach((validation) -> validationMap.put(validation.getName(), validation));
		
		if(validationMap.size() != list.size()) {
			throw new RuntimeException("验证器名称有重复，请检查");
		}
	}
	
	/**
	 * 预处理
	 */
	@Override
	public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
		String url = request.getRequestURI();
		ValidationConfig vc = vcMap.get(url);
		if(vc != null) {
			for(ValidationItem item : vc.getItems()) {
				ParameterValidation pv = validationMap.get(item.getType());
				String value = request.getParameter(item.getName());
				boolean result = pv.validation(value, item.getAttach());
				if(!result) {
					/**
					 * 验证失败，直接返回
					 */
					response.setCharacterEncoding("UTF-8");
					response.setContentType("application/json");
					response.getWriter().write(JsonUtil.toJson(new ResponseResult(item.getMsg(), -1)));
					return false;
				}
			}
		}
		return true;
	}

	/**
	 * 
	 */
	@Override
	public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
		//空方法
	}

	/**
	 * 
	 */
	@Override
	public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
		//空方法
	}
}

 3、解析request-validation.xml，并且注册注册到拦截器

package com.whtr.nginf.application.initializer;

import java.io.IOException;
import java.io.InputStream;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;

import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;


public final class ValidationInitializer {
	
	private ValidationInitializer() {
	    throw new IllegalAccessError("Utility class");
	  }
	
	private static final Logger LOG = LoggerFactory.getLogger(ValidationInitializer.class);

	private static boolean initializationed = false;

	/**
	 * doInitialization
	 */
	public static void doInitialization() {
		if (initializationed) {
			throw new RuntimeException("ValidationInitializer 已经初始化了");
		}

		try {
			loadValidationConfig();
		} catch (Exception e) {
			LOG.error(e.getMessage(),e);
			throw new RuntimeException("初始化验证配置出错", e);
		}

		initializationed = true;
	}

	/**
	 * 加载配置
	 * @throws IOException 
	 * @throws ParserConfigurationException 
	 * @throws SAXException 
	 * 
	 * @throws Exception
	 */
	private static void loadValidationConfig() throws IOException, ParserConfigurationException, SAXException {
		try (InputStream input = ClassLoader.getSystemResourceAsStream("request-validation.xml")) {
			int count = 0;

			DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
			DocumentBuilder builder = factory.newDocumentBuilder();
			Document doc = builder.parse(input);
			NodeList nl = doc.getElementsByTagName("validation");

			for (int i = 0; i < nl.getLength(); i++) {
				Element node = (Element) nl.item(i);
				String enable = node.getAttribute("enable");

				if (StringUtils.isBlank(enable) || "true".equals(enable)) {
					NodeList items = node.getElementsByTagName("item");

					if (items.getLength() > 0) {

						ValidationConfig vc = new ValidationConfig();
						vc.setId(node.getAttribute("id"));

						for (int index = 0; index < items.getLength(); index++) {
							Element item = (Element) items.item(index);
							vc.addItem(new ValidationItem(item.getAttribute("name"), item.getAttribute("type"),
									item.getAttribute("msg"), item.getAttribute("attach")));
						}

						count++;
						ValidationHandlerInterceptor.vcMap.put(vc.getId(), vc);
					}
				}
			}

			if (ValidationHandlerInterceptor.vcMap.size() != count) {
				throw new RuntimeException("request-validation.xml 配置重复，请检查是否有相同的ID");
			}

			LOG.info("读取配置成功，总共读取" + count + "个配置项");
		}
	}
}

 4、配置request-validate.xml

<?xml version="1.0" encoding="UTF-8"?>
<validations>

	<validation id="/demo/list" enable="true">
		<item name="orderKey" type="regex" msg="排序key只能是1、2、3" attach="[1|2|3]"/>
		<item name="clientType" type="digit" msg="clientType只能是整数" />
		<item name="endDate" type="date" msg="结束日期错误，正确格式：(yyyy-MM-dd)" />
		<item name="name" type="length" msg="用户名称长度不能超过10" attach="10"/>
		<item name="amount" type="gt" msg="本金必须大于0" attach="0"/>
		<item name="balance" type="number" msg="金额必须是数字" />
		<item name="accountType" type="notBlank" msg="账户类型不能为空" />
	</validation>
	
	<validation id="/demo/xxx" enable="true">
		<item name="age" type="notBlank" msg="数据不能为空" />
	</validation>
</validations>