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;}@Beanpublic 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<EOL> 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！