一、jwt编写

1.1 pom

• 第二个pom为了生成公私钥

<dependency><groupId>io.jsonwebtoken</groupId><artifactId>jjwt</artifactId><version>0.9.1</version>
</dependency>
<dependency><groupId>cn.hutool</groupId><artifactId>hutool-all</artifactId><version>5.1.0</version></dependency>

1.2 JwtUtils

package org.example.JWT;import cn.hutool.core.io.FileUtil;
import io.jsonwebtoken.*;
import org.example.Entity.User;
import org.springframework.beans.BeanUtils;import java.io.DataInputStream;
import java.io.FileInputStream;
import java.io.InputStream;
import java.lang.reflect.Field;
import java.security.*;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;public class JWTUtil {public static String keyPath = "D:\\";public static int Expire = 1000 * 1000;public static <T> String getToken(String id, T t) throws Exception {HashMap head = new HashMap<>();//添加jwt头head.put("alg",  SignatureAlgorithm.RS256.getValue());//不使用签名算法head.put("typ", "JWT");//JWT体结构HashMap body = new HashMap();Field[] declaredFields = t.getClass().getDeclaredFields();for (Field field: declaredFields){field.setAccessible(true);body.put(field.getName(), field.get(t));System.out.println(field.getName() + " " + field.get(t));}//生成JWTString jwt = Jwts.builder().setHeader(head).setClaims(body).setId(id)//.setExpiration(new Date(System.currentTimeMillis() + Expire)).signWith(SignatureAlgorithm.RS256,getPriKey()).compact();return jwt;}public  static <T> Map<String, Object> parseToken(String jwt, T t) throws Exception {try {Jwt result = Jwts.parser().setSigningKey(getPubKey()).parse(jwt);Header header = result.getHeader();Claims body = (Claims) result.getBody();System.out.println(body);HashMap<String, Object> map = new HashMap<>();String subject = (String)body.get("jti");map.put("id",subject);System.out.println(subject);T o = (T) t.getClass().newInstance();Field[] declaredFields = t.getClass().getDeclaredFields();for(Field field: declaredFields){field.setAccessible(true);field.set(o, body.get(field.getName()));}System.out.println(o);map.put("obj",o);return map;}catch (Exception e){e.getMessage();System.out.println(e.getMessage());return null;}}public static void getKey(String password) throws NoSuchAlgorithmException {KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");SecureRandom secureRandom = new SecureRandom(password.getBytes());keyPairGenerator.initialize(1024, secureRandom);KeyPair keyPair = keyPairGenerator.genKeyPair();byte[] publicKeyBytes = keyPair.getPublic().getEncoded();byte[] privateKeyBytes = keyPair.getPrivate().getEncoded();FileUtil.writeBytes(publicKeyBytes, keyPath +"pub.key");FileUtil.writeBytes(privateKeyBytes, keyPath +"pri.key");}//获取私钥public static PrivateKey getPriKey() throws Exception{InputStream resourceAsStream =new FileInputStream(keyPath +"pri.key");DataInputStream dis = new DataInputStream(resourceAsStream);byte[] keyBytes = new byte[resourceAsStream.available()];dis.readFully(keyBytes);PKCS8EncodedKeySpec spec = new PKCS8EncodedKeySpec(keyBytes);KeyFactory kf = KeyFactory.getInstance("RSA");return kf.generatePrivate(spec);}//获取公钥public static PublicKey getPubKey() throws Exception{InputStream resourceAsStream =new FileInputStream(keyPath + "pub.key");DataInputStream dis = new DataInputStream(resourceAsStream);byte[] keyBytes = new byte[resourceAsStream.available()];dis.readFully(keyBytes);X509EncodedKeySpec spec = new X509EncodedKeySpec(keyBytes);KeyFactory kf = KeyFactory.getInstance("RSA");return kf.generatePublic(spec);}public static void main(String[] args) throws Exception {User user = new User();user.setAge(12);user.setId(1);user.setUserName("jack");String token = getToken("123", user);User user1 = new User();Map<String, Object> map = parseToken(token, new User());User obj = (User)map.get("obj");System.out.println(map.get("sub"));System.out.println(obj);}
}

1.3 注意

• jwt过期会返回null
• 设置jwt过期时间，参数是到期的时间点
• jwt本质上就是将用户的个人信息加密，将加密后的信息通过cookie形式传递。

.setExpiration(new Date(System.currentTimeMillis() + Expire))

1.4 用法

• getKey(“123456”);生成公私钥文件
• getToken(String key,T t):传入对象实例，获得token
• parseToken(String jwt, T t):传入jwt token,得到map,第一个是id,第二个是对象t。

二、过滤器

参考: 拦截器与过滤器详解,使用方式与注意事项,使用场景以及区别与联系

2.1 原理

依赖于servlet容器。在实现上基于函数回调

2.2 使用场景

统一设置编码
过滤敏感字符
登录校验
URL级别的访问权限控制
数据压缩
Filter可以拦截所有请求,包括静态资源

2.3 使用步骤

2.3.1 自定义过滤器类implements Filter

package org.example.Basic;import javax.servlet.*;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;public class myFilter2 implements Filter {@Overridepublic void init(FilterConfig filterConfig) throws ServletException {System.out.println("过滤器2初始化");}@Overridepublic void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {System.out.println("过滤器2前执行");HttpServletRequest request1 = (HttpServletRequest) request;System.out.println(request1.getRequestURI());System.out.println(request1.getRequestURL());chain.doFilter(request,response);System.out.println("过滤器2后执行");}@Overridepublic void destroy() {System.out.println("过滤器2毁灭");}
}

2.3.2 配置类

• 注册过滤器对象，并设置过滤器顺序。

package org.example.Basic;import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;@Configuration
public class MyFilterConfiguration {@Beanpublic FilterRegistrationBean filterRegistrationBean1(){//创建一个注册过滤器对象FilterRegistrationBean registrationBean = new FilterRegistrationBean();//设置自定义过滤器registrationBean.setFilter(new myFilter1());//设置过滤拦截匹配规则,/*是匹配所有
//        registrationBean.addUrlPatterns("/*");//只拦截testController下面的接口registrationBean.addUrlPatterns("/cache/*");//存在多个过滤器时，设置执行顺序，值越大，执行顺序越靠后registrationBean.setOrder(1);//返回这个注册过滤器对象return registrationBean;}@Beanpublic FilterRegistrationBean filterRegistrationBean2(){//创建一个注册过滤器对象FilterRegistrationBean registrationBean1 = new FilterRegistrationBean();//设置自定义过滤器registrationBean1.setFilter(new myFilter2());//设置过滤拦截匹配规则,/*是匹配所有
//        registrationBean.addUrlPatterns("/*");//只拦截testController下面的接口registrationBean1.addUrlPatterns("/cache/*");//存在多个过滤器时，设置执行顺序，值越大，执行顺序越靠后registrationBean1.setOrder(2);//返回这个注册过滤器对象return registrationBean1;}
}

2.3.3 过滤器使用场景

• 过滤参数，参数校验
• 生成日志等等

2.4 问题

• 过滤器的路径如果设置为/*可能会执行2次，有一次会访问/favicon.ico，设置访问路径即可解决。

三、拦截器

3.1 特点

• 拦截器依赖于SpringMvc的,需要导入Mvc的依赖

preHandle() 在目标请求完成之前执行。有返回值Boolean类型，true：表示放行 postHandle()
在目标请求之完成后执行。 afterCompletion() 在整个请求完成之后【modelAndView已被渲染执行】。

• 拦截器只能拦截action请求,不包括静态资源(有待验证)

• 基于java反射机制实现

• 拦截器可以获取IOC容器中的各个bean，而过滤器就不行，这点很重要，在拦截器里注入一个service，可以调用业务逻辑。

3.2 使用

3.2.1 拦截器实现方式

• AOP切面方式实现
• 使用Spring的拦截器相关接口来自定义拦截器

3.3.1 自定义拦截器

3.3.2 拦截器配置信息

package org.example.Intecepter;import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.CorsRegistry;
import org.springframework.web.servlet.config.annotation.InterceptorRegistration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;@Configuration
public class MyInterceptorConfiguration implements WebMvcConfigurer {/*** 重写addCorsMappings()解决跨域问题* 配置：允许http请求进行跨域访问** @param registry* @Author 有梦想的肥宅*/
//    @Override
//    public void addCorsMappings(CorsRegistry registry) {
//        registry.addMapping("/**")//指哪些接口URL需要增加跨域设置
//                .allowedOrigins("*")//指的是前端哪些域名被允许跨域
//                .allowCredentials(true)//需要带cookie等凭证时，设置为true，就会把cookie的相关信息带上
//                .allowedMethods("GET", "HEAD", "POST", "PUT", "DELETE", "OPTIONS")//指的是允许哪些方法
//                .maxAge(3600);//cookie的失效时间，单位为秒（s），若设置为-1，则关闭浏览器就失效
//    }@Overridepublic void addInterceptors(InterceptorRegistry registry) {//注册Interceptor拦截器(Interceptor这个类是我们自己写的拦截器类)InterceptorRegistration registration = registry.addInterceptor(new MyIntercrptor());//addPathPatterns()方法添加需要拦截的路径registration.addPathPatterns("/**");                      //所有路径都被拦截//excludePathPatterns()方法添加不拦截的路径registration.excludePathPatterns(                         //添加不拦截路径"/demo/loginPage",            //登录页面的地址【不拦截】"/**/*.html",            //html静态资源"/**/*.js",              //js静态资源"/**/*.css"              //css静态资源);}
}

3.4 使用场景

• 配置跨域
• 登录校验

3.5 拦截器案例

3.5.1 preHandle方法获取所需参数

• 执行方法名称
• 是否有某个注解
• 方法所需参数名称

package org.example.Intecepter;import lombok.Data;
import org.checkerframework.checker.units.qual.A;
import org.springframework.core.MethodParameter;
import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.lang.invoke.MethodHandle;@Data
public class MyIntercrptor implements HandlerInterceptor {//return true才进行下一步操作@Overridepublic boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {System.out.println("使用拦截器1进行操作");HandlerMethod hand = (HandlerMethod)handler;//执行的方法名称System.out.println(hand.getMethod().getName());//获取执行的参数信息MethodParameter[] methodParameters = hand.getMethodParameters();for(MethodParameter methodParameter : methodParameters){System.out.println(methodParameter.getParameter().getName());System.out.println(methodParameter.getParameter().getType());}//判断类上有没有某个注解GetMapping annotation = hand.getBeanType().getAnnotation(GetMapping.class);boolean annotation1 = hand.getBeanType().isAnnotationPresent(GetMapping.class);//获取方法的注解,判断方法上有没该注解GetMapping annotation2 = hand.getMethod().getAnnotation(GetMapping.class);boolean annotationPresent = hand.getMethod().isAnnotationPresent(GetMapping.class);System.out.println(annotation1 + " " + annotationPresent);return true;}@Overridepublic void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
//        HandlerMethod handler1 = (HandlerMethod) handler;
//        System.out.println(handler1.getReturnType().getMember().getName());
//        String viewName = modelAndView.getViewName();
//        System.out.println(viewName);}@Overridepublic void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {}
}

3.6 执行过程

如果在preHandle()阶段就有某个拦截器校验不通过，会从上一个拦截器开始执行afterCompletion()进行返回

3.7 HandlerMethod类

spring mvc的HandlerMethod简介

四、aop

4.1 区别

Java AOP篇

过滤器，拦截器拦截的是URL。AOP拦截的是类的元数据(包、类、方法名、参数等)。
过滤器并没有定义业务用于执行逻辑前、后等，仅仅是请求到达就执行。
拦截器有三个方法，相对于过滤器更加细致，有被拦截逻辑执行前、后等。
AOP针对具体的代码，能够实现更加复杂的业务逻辑。
三者功能类似，但各有优势，从过滤器 -> 拦截器 -> 切面，拦截规则越来越细致。
执行顺序依次是过滤器、拦截器、切面。

4.2 案例

• 自定义注解

package org.example.AOP;import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
public @interface MyAnn {String value() default "";
}

• aop案例

package org.example.AOP;import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.aspectj.lang.reflect.MethodSignature;
import org.example.Event.OptLogDTO;
import org.example.Event.SysLogEvent;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationEvent;
import org.springframework.stereotype.Component;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.lang.reflect.Method;@Component
@Aspect
public class MyAop {@Autowiredprivate ApplicationContext applicationContext;private static final ThreadLocal<OptLogDTO> THREAD_LOCAL = new ThreadLocal<>();/**** 定义controller切入点拦截规则，拦截SysLog注解的方法*/@Pointcut("@annotation(MyAnn)")public void myAnnTest() {}@Before(value = "myAnnTest()")public void doBefore(JoinPoint joinPoint) {//得到连接点执行的方法对象MethodSignature signature= (MethodSignature) joinPoint.getSignature();Method method = signature.getMethod();//得到方法上的注解MyAnn annotation = method.getAnnotation(MyAnn.class);if (annotation!=null){//获取注解属性的value值String value = annotation.value();System.out.println("自定义注解的值" + " " + value);}}@Around(value = "myAnnTest()")public Object doAround(ProceedingJoinPoint joinPoint) throws Throwable {//HttpServletRequest request = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest();HttpServletResponse response = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getResponse();// 类名String className = joinPoint.getTarget().getClass().getName();System.out.println(className);//获取执行的方法名MethodSignature signature = (MethodSignature) joinPoint.getSignature();String methodName = signature.getMethod().getName();System.out.println(methodName);//方法的返回类型String name = signature.getReturnType().getName();System.out.println(name);//获取方法的参数,这里的参数可能包含有文件Object[] args1 = joinPoint.getArgs();for (int i = 0; i < args1.length; i++) {System.out.println(args1.toString());}Object proceed = joinPoint.proceed();if(proceed instanceof String){System.out.println(proceed.toString());}System.out.println(response.getStatus());return proceed;}
}

package org.example.Service.controller.Aop.OptAop;import com.alibaba.fastjson.JSONObject;
import io.swagger.annotations.ApiOperation;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Pointcut;
import org.aspectj.lang.reflect.MethodSignature;
import org.example.Demo.util.JwtUtils;
import org.example.Demo.util.LoginInfo;
import org.example.Service.Util.DateUtil;
import org.example.Service.entity.PdAuthUser;
import org.example.Service.entity.PdCommonOptLog;
import org.example.Service.service.PdAuthUserService;
import org.example.Service.service.PdCommonLoginLogService;
import org.example.Service.service.impl.PdCommonOptLogServiceImpl;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.annotation.AnnotationUtils;
import org.springframework.stereotype.Component;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.lang.annotation.Annotation;
import java.lang.reflect.Method;
import java.time.LocalDateTime;
import java.util.Date;
import java.util.Map;@Component
@Aspect
public class OptLogAspect {@AutowiredPdCommonOptLogServiceImpl pdCommonOptLogService;@AutowiredPdAuthUserService pdAuthUserService;@Pointcut("@annotation(org.springframework.web.bind.annotation.GetMapping)")public void getOpt(){}@Pointcut("@annotation(org.springframework.web.bind.annotation.PutMapping)")public void putOpt(){}@Pointcut("@annotation(org.springframework.web.bind.annotation.PostMapping)")public void postOpt(){}@Pointcut("@annotation(org.springframework.web.bind.annotation.DeleteMapping)")public void DelOpt(){}@Around(value = "getOpt()||putOpt()||postOpt()||DelOpt()")public Object doAround(ProceedingJoinPoint joinPoint) throws Throwable {LocalDateTime nowStart = LocalDateTime.now();String start = DateUtil.getNowDateStr(nowStart);Long startInstant = DateUtil.getNowInstant(nowStart);Object proceed = joinPoint.proceed();HttpServletRequest request = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest();HttpServletResponse response = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getResponse();if(request.getRequestURL().toString().contains("login")){return proceed;}LocalDateTime nowEnd = LocalDateTime.now();String end = DateUtil.getNowDateStr(nowEnd);Long endInstant = DateUtil.getNowInstant(nowEnd);String token = request.getHeader("token");LoginInfo memberIdByJwtToken = JwtUtils.getMemberIdByJwtToken(token);if(memberIdByJwtToken == null){return proceed;}String account = memberIdByJwtToken.getAccount();System.out.println(account);PdAuthUser user = pdAuthUserService.getByAccout(account);PdCommonOptLog pdCommonOptLog = new PdCommonOptLog();pdCommonOptLog.setRequestIp(request.getRemoteHost());pdCommonOptLog.setUserName(user.getNamed());pdCommonOptLog.setType("OPT");pdCommonOptLog.setRequestUri(request.getRequestURI());Map<String, String[]> parameterMap = request.getParameterMap();StringBuilder param = new StringBuilder();parameterMap.forEach((k,v) -> {param.append(k).append(":").append(v).append(",");});pdCommonOptLog.setParams(new String(param));pdCommonOptLog.setStartTime(nowStart);pdCommonOptLog.setFinishTime(nowEnd);pdCommonOptLog.setConsumingTime(endInstant - startInstant);pdCommonOptLog.setUa(request.getHeader("User-Agent"));pdCommonOptLog.setCreateUser(user.getId());// 类名Class<?> aClass = joinPoint.getTarget().getClass();String className = aClass.getName();System.out.println(className);//获取执行的方法名MethodSignature signature = (MethodSignature) joinPoint.getSignature();Method method = signature.getMethod();//获取注解//Annotation[] annotations = method.getAnnotations();//获取指定注解ApiOperation annotation = method.getAnnotation(ApiOperation.class);//方法的返回类型
//        String name = signature.getReturnType().getName();
//        System.out.println(name);System.out.println(response.getStatus());pdCommonOptLog.setDescription1(annotation.value());pdCommonOptLog.setClassPath(aClass.getName());//方法名称pdCommonOptLog.setActionMethod(signature.getName());//请求类型pdCommonOptLog.setHttpMethod(request.getMethod());//获取方法的参数,这里的参数可能包含有文件Object[] args1 = joinPoint.getArgs();String string = "";System.out.println("返回值的返回类型" + response.getContentType());if(!(response == null) && !(response.getContentType() == null) && !(request.getContentType() == "") && !request.getContentType().contains("multipart/form-data")){string = JSONObject.toJSONString(args1);}pdCommonOptLog.setResult(string);pdCommonOptLog.setExDesc(null);pdCommonOptLogService.save(pdCommonOptLog);return proceed;}
}

五、自定义参数解析器

5.1 自定义注解

@Target({ElementType.PARAMETER})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface CurrentUser {
}

5.2 配置自定义参数构造器

package org.example.Args;import org.springframework.context.annotation.Configuration;
import org.springframework.web.method.support.HandlerMethodArgumentResolver;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;import java.util.List;@Configuration
public class ArgumentResolverConfiguration implements WebMvcConfigurer {@Override//注册自定义参数解析器public void addArgumentResolvers(List<HandlerMethodArgumentResolver> resolvers) {resolvers.add(new CurrentUserMethodArgumentResolver());}
}

5.3 自定义参数解析器类

package org.example.Args;import org.springframework.core.MethodParameter;
import org.springframework.web.bind.support.WebDataBinderFactory;
import org.springframework.web.context.request.NativeWebRequest;
import org.springframework.web.method.support.HandlerMethodArgumentResolver;
import org.springframework.web.method.support.ModelAndViewContainer;public class CurrentUserMethodArgumentResolver implements HandlerMethodArgumentResolver {public CurrentUserMethodArgumentResolver() {System.out.println("CurrentUserMethodArgumentResolver自定义参数解析器初始化...");}//判断自定义注解 注解的参数是否正确@Overridepublic boolean supportsParameter(MethodParameter parameter) {//如果Controller的方法参数类型为User同时还加入了CurrentUser注解，则返回trueif (parameter.getParameterType().equals(User.class) &&parameter.hasParameterAnnotation(CurrentUser.class)) {return true;}return false;}//当supportsParameter方法返回true时执行此方法@Overridepublic Object resolveArgument(MethodParameter parameter,ModelAndViewContainer mavContainer,NativeWebRequest webRequest,WebDataBinderFactory binderFactory) throws Exception {System.out.println("参数解析器...");//此处直接模拟了一个User对象，实际项目中可能需要从请求头中获取登录用户的令牌然后进行解析，//最终封装成User对象返回即可，这样在Controller的方法形参就可以直接引用到User对象了User user = new User("jack","admin");return user;}
}

六、监听器

Spring监听器

6.1 自定义事件源

public class SysLogEvent extends ApplicationEvent {public SysLogEvent(OptLogDTO optLogDTO) {super(optLogDTO);}
}

6.2 自定义事件监听器

• @EventListener(SysLogEvent.class)定义监听的类

@Component
public class SysLogListener {@Async//异步处理@EventListener(SysLogEvent.class)public void saveSysLog(SysLogEvent event) {OptLogDTO sysLog = (OptLogDTO) event.getSource();long id = Thread.currentThread().getId();System.out.println("监听到日志操作事件：" + sysLog + " 线程id：" + id);//将日志信息保存到数据库...}
}

6.3 发布事件

• 可在aop中监听事件

@Autowiredprivate ApplicationContext applicationContext;
//构造事件对象ApplicationEvent event = new SysLogEvent(logInfo);//发布事件applicationContext.publishEvent(event);

七、servlet对象

Servlet基础之HttpServletRequest详解

7.1 request获取参数

7.1.1 获取url上的参数

• getParameter(String name)
• getParameterMap()

http://localhost:9000/cache/hello?name=%22jack%22&&age=12

System.out.println("name参数" + request1.getParameter("name"));System.out.println("param参数");Map<String, String[]> parameterMap = request1.getParameterMap();parameterMap.forEach((k,v)-> {System.out.println(k + " " + v[0]);});

7.1.2 获取请求头参数

• 请求头中会包含cookie信息，cookie : cookie=qwqdqdq; us=qweq

 //获取请求头参数String myHead = request1.getHeader("myHead");System.out.println("请求头参数" + myHead);Enumeration headerNames = request1.getHeaderNames();// 使用循环遍历所有请求头，并通过getHeader()方法获取一个指定名称的头字段while (headerNames.hasMoreElements()) {String headerName = (String) headerNames.nextElement();System.out.println((headerName + " : " + request1.getHeader(headerName)));}

7.1.3 请求体参数

7.1.3.1 form表单key-value数据

• form-data,和获取url上的参数方式一致

  HttpServletRequest request1 = (HttpServletRequest) request;//获取请求体参数System.out.println("----------------------------");System.out.println(request1.getParameter("form2"));String[] form1s = request1.getParameterValues("form1");System.out.println(form1s[0]);Map<String, String[]> parameterMap = request1.getParameterMap();parameterMap.forEach((k,v)-> {System.out.println(k + " " + v[0]);});

7.1.3.1 form表单文件类型数据

HttpServletRequest req = (HttpServletRequest) request;System.out.println(request.getContentType());System.out.println(req.getCharacterEncoding());Collection<Part> parts = req.getParts();for (Part part:parts) {//提交文件添加的名称System.out.println("-----类型名称------->"+part.getName());System.out.println("-----类型------->"+part.getContentType());//文件的原名称System.out.println("-----提交的类型名称------->"+part.getSubmittedFileName());System.out.println("----流-------->"+part.getInputStream());}

7.1.4 获取cookie信息

Cookie[] cookies = request1.getCookies();for (int i = 0; i < cookies.length; i++) {System.out.println(cookies[i].getName() + " " + cookies[i].getValue());}

7.1.5 修改request参数信息

修改request的parameter的几种方式总结

• 自定义MyRequestWrapMapper对象

package org.example.Basic;import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;public class MyRequestWrapMapper extends HttpServletRequestWrapper {/*** Constructs a request object wrapping the given request.** @param request The request to wrap* @throws IllegalArgumentException if the request is null*/public MyRequestWrapMapper(HttpServletRequest request) {super(request);}@Overridepublic String getParameter(String name) {String parameter = super.getParameter(name);if(parameter != null){parameter = parameter + "hahahah";}return parameter;}
}

• 包装原对象即可，原对象是HttpServletRequest

new MyRequestWrapMapper(req)

7.2 response

Servlet之Response

7.2.1 常用方法

• 过滤器前:只是新建了response对象，并赋予初值，经过controller后，才对其中的值进行了赋值。

Collection<String> headerNames1 = rsp.getHeaderNames();headerNames1.forEach(s-> System.out.println(s + " " + rsp.getHeader(s)));System.out.println(rsp.getStatus());System.out.println(rsp.getCharacterEncoding());

7.3 后端参数接收

7.3.1 url参数接收

• @PathVariable url中带{}的参数

@GetMapping("/hello5/{id}")public String hello5(@PathVariable("id")int id){System.out.println(id);return "hello";}

• url上的参数:?name=“xx”

  @GetMapping("/hello1")public String hello(@RequestParam("name")String name, @RequestParam("head")String head){System.out.println(name);System.out.println(head);return "hello";}

7.3.2 请求头参数接收

• @RequestHeader

@GetMapping("/hello2")public String hello1(@RequestHeader("head")String head){System.out.println(head);return "hello";}

7.3.3 请求体参数接收

7.3.3.1 正常类型数据接收

• @RequestParam
  也是上面那个注解

7.3.3.2 文件类型数据接收

SpringBoot项目中使用MultipartFile来上传文件(包含多文件)

• @RequestParam

 @GetMapping("/hello")public String hello(@RequestParam("file") MultipartFile[] file,@RequestParam String body){for (int i = 0; i < file.length; i++) {MultipartFile multipartFile = file[i];System.out.println(multipartFile.getOriginalFilename());System.out.println(multipartFile.getName());}System.out.println(body);return "hello";}

7.3.4 获取cookie

• @CookieValue:获取cookie参数

@GetMapping("/hello1")public String hello1(@CookieValue("name") String name ){System.out.println(name);return "hello";}

7.3.5 自定义传参使用

• @RequestAttribute

@PostMapping("/hello6")public String hello4(@RequestAttribute("num") String num){System.out.println(num);return "hello";}

• request设置值

 req.setAttribute("num",12);

7.4 设置

7.4.1 大文件上传设置

  servlet:multipart:max-file-size: 100MBmax-request-size: 100MB

7.5 seesion和cookie

session和cookie的作用原理和区别
【JavaWeb】Cookie和Session

• session技术就是一种基于后端有别于数据库的临时存储技术
• session是基于cookie实现的，服务器存储每个会话的session信息，如何找到该session的信息呢？session通过cookie保存session的id信息来实现寻找同一个session对象。

7.5.1 区别

• cookie存在浏览器端的浏览器缓存中，session存在服务端，服务端的内存中。
• tomcat默认session的生命周期是20min,一旦session重新活跃，刷新生命周期。关闭浏览器，sessionID就会失效,但是服务器依然会存储session信息，session一般存放在服务器内存，如果服务器重启session则会清空。cookie也可以设置过期时间，但是关闭浏览器，cookie就失效。
• cookie不是很安全，容易被窃取，session存储到服务端，不容易被窃取。

7.5.2 测试

• response添加cookie

 DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH-mm-ss");String format = formatter.format(LocalDateTime.now());String s = format.replaceAll(" ", "");System.out.println("设置cookie的值为" + " " + s);Cookie cookie = new Cookie("sessionID", s);//20s//cookie.setMaxAge(20*60);//cookie.setPath("/*");//response添加cookiersp.addCookie(cookie);

• 关闭浏览器,cookie失效
• 设置session

 HttpServletRequest req = (HttpServletRequest) request;HttpServletResponse rsp = (HttpServletResponse) response;HttpSession session = req.getSession();session.setAttribute("name","jack");System.out.println(session.getId());

7.5.3 重要概念

• 会话:用户打开一个浏览器访问服务器，如果浏览器和服务器有一个关闭则会话结束，否则之间的所有操作都算一次会话。多个浏览器是多个会话。

八、spring mvc

8.1 spring mvc流程

SpringMVC工作流程（超级详细版）

8.1.1 过程

• 用户发送请求，(调度服务器)dispatchServlet接收请求，转发请求到handermapping(处理器映射器),处理器映射器查找对应的handler，返回handler
• dispatchServlet请求执行handler,处理器适配器执行handler，返回Modelandview对象
• dispatchServlet请求解析Modelandview，viewresolver解析视图,返回view对象到dispatchServlet
• dispatchServlet返回view对象

八、总结

8.1 总结

• 过滤器对所有请求做增强，拦截器只对spring mvc的访问做增强
• 过滤器依赖servlet容器，拦截器依赖spring mvc
• 拦截器更强调对controller具体方法的前后做增强