环境配置

JDK:1.8 MAVEN:3.6.1 IDE:19.3 TOMCAT:8 MYSQL:5.7 swagger-ui2

基本框架搭建

可参考本人博客地址
基本SSM框架搭建

https://blog.csdn.net/qq_41998978/article/details/103362147

SSM前后分离配置

https://blog.csdn.net/qq_41998978/article/details/104248826

解决SSM+VUE跨域问题

配置过滤器

在WEB.XML文件中加入一个过滤器

<filter>
    <filter-name>SimpleCORSFilter</filter-name>
    <!-- 指向自己的类-->
    <filter-class>com.item.utile.SimpleCORSFilter</filter-class>
    <init-param>
      <param-name>IsCross</param-name>
      <param-value>true</param-value>
    </init-param>
  </filter>
  <filter-mapping>
    <filter-name>SimpleCORSFilter</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>

创建SimpleCORSFilter，过滤器指向文件

package com.item.utile;

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

public class SimpleCORSFilter implements Filter {
    private boolean isCross = false;

    @Override
    public void destroy() {
        isCross = false;
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
            throws IOException, ServletException {
        if (isCross) {
            HttpServletRequest httpServletRequest = (HttpServletRequest) request;
            HttpServletResponse httpServletResponse = (HttpServletResponse) response;
            System.out.println("拦截请求: " + httpServletRequest.getServletPath());
            httpServletResponse.setHeader("Access-Control-Allow-Origin", "*");
            httpServletResponse.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE");
            httpServletResponse.setHeader("Access-Control-Max-Age", "0");
            httpServletResponse.setHeader("Access-Control-Allow-Headers",
                    "Origin, No-Cache, X-Requested-With, If-Modified-Since, Pragma, Last-Modified, Cache-Control, Expires, Content-Type, X-E4M-With,userId,token");
            httpServletResponse.setHeader("Access-Control-Allow-Credentials", "true");
            httpServletResponse.setHeader("XDomainRequestAllowed", "1");
        }
        chain.doFilter(request, response);
    }

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        String isCrossStr = filterConfig.getInitParameter("IsCross");
        isCross = isCrossStr.equals("true") ? true : false;
        System.out.println(isCrossStr);
    }

}

spring-mvc文件加入，spring版本4.0以上

<mvc:cors>
        <mvc:mapping path="/**"
                     allowed-origins="*"
                     allowed-methods="POST, GET, OPTIONS, DELETE, PUT"
                     allowed-headers="Content-Type, Access-Control-Allow-Headers, Authorization, X-Requested-With"
                     allow-credentials="true" />
    </mvc:cors>

若出现问题

Controller文件加入注解

@RestController
@CrossOrigin

接口加入，返回json

@ResponseBody

解决返回json时，是格式的问题

pom.xml文件加入

    <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-databind</artifactId>
      <version>2.9.2</version>
    </dependency>

实体类时间属性加入注解

    /**
     * 创建时间
     */
    @JsonFormat(pattern="yyyy-MM-dd HH:mm:ss",timezone="GMT+8")
    private Date creationtime;