拦截器
1、 鼻祖 HandlerInterceptor
- PreHandle() 执行controller方法之前
- postHandle()执行controller方法之后 DispatCherSevlet视图渲染之前 所以这个方法中有一个modelAndView参数 可以做一些修改
- afterCompletion() 请求处理完成之后（包括DispatCherSevlet视图渲染之后） 有要求：preHandle()被成功执行且返回true
代码实战
1. 创建一个拦截器的类
package com.example.questionlist2.common;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
@Component
@Slf4j
//继承HandlerInterceptor 重新其中的拦截处理防范
public class myInterceptHandle implements HandlerInterceptor {
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
log.info(">>>拦截器>>>>>"+request.getRequestURI());
return HandlerInterceptor.super.preHandle(request, response, handler);
}
@Override
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
HandlerInterceptor.super.postHandle(request, response, handler, modelAndView);
}
@Override
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
HandlerInterceptor.super.afterCompletion(request, response, handler, ex);
}
}
2. 对接口配置拦截
图片.png
package com.example.questionlist2.common;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
@Component
@Slf4j
//继承HandlerInterceptor 重新其中的拦截处理防范
public class myInterceptHandle implements HandlerInterceptor {
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
log.info(">>>>>>>>"+request.getRequestURI());
return false;
}
@Override
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
// HandlerInterceptor.super.postHandle(request, response, handler, modelAndView);
log.info(">>> postHandle <<<");
}
@Override
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
// HandlerInterceptor.super.afterCompletion(request, response, handler, ex);
log.info(">>> afterCompletion <<<");
}
}
postman
log
发现报错：
cannot deserialize from Object value (no delegate- or property-based Creator) at [
这个就是需要对error信息中提到的类 创建一个无参构造器
public questionDto(){
}
正确的拦截
1. 请求如下
curl --location --request POST 'http://localhost:8888/addQuestion3' \
--header 'Content-Type: application/json' \
--data-raw '{
"questionType":"questionType1",
"keyword":"keyword1",
"questionName":"dedede ",
"dependOnQuestion":"dependOnQuestion2",
"book":"book1"
} '
2. 然后结果是包含？？？ 说明响应body有问题
有乱码的结构
3. 对响应结果拦截并处理
这时候去父类中看下 哪个方法可以对响应结果进行配置
package com.example.questionlist2.common;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.StringHttpMessageConverter;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport;
import java.nio.charset.Charset;
import java.util.List;
@Configuration
class myWebMvcConfig extends WebMvcConfigurationSupport {
@Autowired
private myInterceptHandle myInterceptHandle;
@Override
//添加拦截器 先把我们创建的拦截器类加进来
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(myInterceptHandle)
.addPathPatterns("/**");
// .excludePathPatterns("/addQuestion3");
}
@Override
//这时候去父类中看下 哪个方法可以对响应结果进行配置
public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
super.configureMessageConverters(converters);
converters.add(setHttpMessageConverter());
}
public HttpMessageConverter<String> setHttpMessageConverter(){
return new StringHttpMessageConverter(Charset.forName("utf-8"));
}
}
图片.png
