前后端传参中遇见的问题

前后端传参经常容易出错，本文记录开发springBoot+Mybatis-plus+vuecli项目中出现的传参问题及解决办法

1.前后端没有跨域配置，报错

解决方法：后端进行跨域配置，拷贝CorsConfig类

package com.example.xxxx.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.cors.CorsConfiguration;
import org.springframework.web.cors.UrlBasedCorsConfigurationSource;
import org.springframework.web.filter.CorsFilter;

/**
 * 全局配置可跨域访问api接口
 */

@Configuration
public class CorsConfig {
    private CorsConfiguration buildConfig() {
        CorsConfiguration corsConfiguration = new CorsConfiguration();
        corsConfiguration.addAllowedOrigin("*"); //允许任何域名
        corsConfiguration.addAllowedHeader("*"); //允许任何头
        corsConfiguration.addAllowedMethod("*"); //允许任何方法
        return corsConfiguration;
    }

    @Bean
    public CorsFilter corsFilter() {
        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
        source.registerCorsConfiguration("/**", buildConfig()); //注册
        return new CorsFilter(source);
    }
}

2.longtext类型 前端json内容包含转义字符，报错

WARN 9296 --- nio-8090-exec-4 .w.s.m.s.DefaultHandlerExceptionResolver : Resolved org.springframework.http.converter.HttpMessageNotReadableException: JSON parse error: Illegal unquoted character ((CTRL-CHAR, code 10)): has to be escaped using backslash to be included in string value; nested exception is com.fasterxml.jackson.databind.JsonMappingException: Illegal unquoted character ((CTRL-CHAR, code 10)): has to be escaped using backslash to be included in string value\ at \[Source: (org.springframework.util.StreamUtils$NonClosingInputStream); line: 2, column: 15 (through reference chain: com.example.memo.entity.Note"content")]

出现原因：Json 字符中有有些字段比如空格、反斜杠、换行符等一些特殊字符，但是 Json 框架没有对这些字符进行处理，就会导致出现错误。

解决方法：加入 fastjson 依赖

		<dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.78</version>
        </dependency>

在配置文件中加入

spring：
	jackson:
	    parser:
	      allow-unquoted-control-chars: true

重启项目，运行成功！