SpringBoot如何设置404、500返回统一格式json

# 自定义
#出现错误时, 直接抛出异常
spring.mvc.throw-exception-if-no-handler-found=true
#不要为我们工程中的资源文件建立映射
spring.web.resources.add-mappings=false

package com.qykhhr.dujiaoshouservice.exceptionhandler;

import com.qykhhr.dujiaoshouservice.util.r;
import lombok.extern.slf4j.slf4j;
import org.springframework.web.bind.annotation.controlleradvice;
import org.springframework.web.bind.annotation.exceptionhandler;
import org.springframework.web.bind.annotation.responsebody;

import java.sql.sqlintegrityconstraintviolationexception;

/**
 * 异常处理机制
 * 先找到特定异常处理机制，如果没有就会调用exception异常处理机制
 */
@controlleradvice
@slf4j
public class globalexceptionhandler {

    /**
     * 指定出现什么异常来执行这个方法
     * @param e
     * @return
     */
    @exceptionhandler(exception.class)
    @responsebody
    public r error(exception e){
        e.printstacktrace();
        if (e instanceof sqlintegrityconstraintviolationexception){
            return r.error().message("数据库主键冲突，如是本人，请联系管理员");
        }else if (e instanceof org.springframework.web.servlet.nohandlerfoundexception){
            return r.error().message("找不到资源，/(ㄒoㄒ)/~~");
        }
        return r.error().message("内部服务器错误，/(ㄒoㄒ)/~~!");
    }

    /**
     * 自定义异常处理
     * @param e
     * @return
     */
    @exceptionhandler(dujiaoshouexception.class)
    @responsebody
    public r error(dujiaoshouexception e){
        log.error(e.getmessage());
        e.printstacktrace();
        return r.error().code(e.getcode()).message(e.getmsg());
    }
}

package com.qykhhr.dujiaoshouservice.util;

import lombok.data;

import java.util.hashmap;
import java.util.map;

/**
 * 统一返回结果的类
 * @author 雨林
 */
@data
public class r {

    private boolean success;
    private integer code;
    private string message;
    private map<string,object> data = new hashmap<>();

    // 把构造方法私有化，只能使用提供的静态方法
    private r(){

    }

    // 成功静态方法
    public static r ok(){
        r r = new r();

        r.setsuccess(true);
        r.setcode(resultcode.success);
        r.setmessage("成功");
        return r;
    }

    // 失败静态方法
    public static r error(){
        r r = new r();

        r.setsuccess(false);
        r.setcode(resultcode.error);
        r.setmessage("失败");
        return r;
    }

    public r message(string message){
        this.setmessage(message);
        return this;
    }

    public r code(integer code){
        this.setcode(code);
        return this;
    }

    public r data(map<string, object> map){
        this.setdata(map);
        return this;
    }

    public r data(string key, object value){
        this.data.put(key, value);
        return this;
    }
}

upload.image.path=/util/images/
upload.apk.path=/util/apk/
upload.crash.exception.file.path=/util/crash/

/**
 * 资源映射路径，只能配置一个映射
 */
@configuration
public class mywebmvcconfigurer extends webmvcconfigureradapter {
    @value("${upload.file.path}")
    private string uploadpath;

    @value("${upload.image.path}")
    private string uploadimagepath;

    @value("${upload.crash.exception.file.path}")
    private string uploadcrashexceptionfilepath;

    @value("${upload.apk.path}")
    private string uploadapkpath;

    /**
     * 将d:\\upload下的文件映射到当前项目/upload/下
     * @param registry
     */
    @override
    public void addresourcehandlers(resourcehandlerregistry registry) {

        registry.addresourcehandler("/favicon.ico").addresourcelocations("classpath:/static/");

        //addresourcehandler()里配置需要映射的文件夹，此处代表映射文件夹user下的所有资源。
        //addresourcelocations()配置文件夹在系统中的路径，使用绝对路径，格式为“file:你的路径/” 后面的 / 必须加上，否则映射失效
//        registry.addresourcehandler("/upload/**").addresourcelocations("file:d:/dujiaoshouapp/");
//        registry.addresourcehandler("/upload/**").addresourcelocations("file:"+uploadpath);
        registry.addresourcehandler("/upload/images/**").addresourcelocations("file:"+uploadimagepath);
        registry.addresourcehandler("/upload/crash/**").addresourcelocations("file:"+uploadcrashexceptionfilepath);
        registry.addresourcehandler("/upload/apk/**").addresourcelocations("file:"+uploadapkpath);
    }
}

@component
public class exceptioninterceptor implements handlerinterceptor {

    @autowired
    private redistemplate redistemplate;


    @override
    public void posthandle(httpservletrequest request, httpservletresponse response, object handler, modelandview modelandview) throws exception {
        if (modelandview != null){
            // 防止出现空指针
            // 请求转到 / 
            modelandview.setviewname("/");
        }
    }
}

@configuration
public class mywebmvcconfigurer extends webmvcconfigureradapter {
    @autowired
    private exceptioninterceptor exceptioninterceptor;

    @override
    public void addinterceptors(interceptorregistry registry) {
        registry.addinterceptor(exceptioninterceptor);
        super.addinterceptors(registry);
    }

package com.qykhhr.dujiaoshouservice.controller;

import com.qykhhr.dujiaoshouservice.util.r;
import lombok.extern.slf4j.slf4j;
import org.springframework.web.bind.annotation.requestmapping;
import org.springframework.web.bind.annotation.restcontroller;

@restcontroller
@slf4j
public class exceptioncontroller {

    @requestmapping("/")
    public r error() {
        log.info("处理 /error 请求");
        return r.error().message("访问资源无效！");
    }
}