qq_47988411的博客

原创 jpa Dao层查询语法

原创 java SM4加密报错 No such algorithm: SM4/ECB/PKCS5Padding

import org.apache.commons.codec.binary.Hex;import org.bouncycastle.jce.provider.BouncyCastleProvider;import org.bouncycastle.pqc.math.linearalgebra.ByteUtils;import javax.crypto.Cipher;import javax.crypto.KeyGenerator;import javax.crypto.spec.Secr...

原创 mybatis 一对多 collection标签

<resultMap id="cl" type="com.ding.entity.mysql.TaskComment"> <result property="id" column="id"/> <result property="userName" column="user_name"/> <collection property="taskCommentUserList" ofType="com.ding.entity.mysql.Tas.

原创 java在切面中获取body中的json数据

1.//这是核心的一个类 用来将前端的request复制一份import org.apache.commons.lang3.StringUtils;import javax.servlet.ReadListener;import javax.servlet.ServletInputStream;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletRequestWrapper;imp.

原创 java 将返回前端数据转换null为空字符

@Configurationpublic class JacksonConfig { @Bean @Primary @ConditionalOnMissingBean(ObjectMapper.class) public ObjectMapper jacksonObjectMapper(Jackson2ObjectMapperBuilder builder) { ObjectMapper objectMapper = builder.cr.

原创 OSS将某文件夹下所有文件打包成zip

public static String endpoint = "*"; private static String accessKeyId = "*"; private static String accessKeySecret = "*"; private static String bucketName = "*"; /** * * @param folderPath 某个文件夹下所有 * @param zipName 压缩.

原创 mysql常用函数(持续更新)

substring_index(input,split,index)：input为要截取的字符，split为分隔符，Index为要截取第index个分隔符左（index为正）或右(index为负)的字符串。//一般就是index为1或者-1

原创 easyPOI和导入复杂excel的各种坑

//easyPOI的依赖<dependency> <groupId>cn.afterturn</groupId> <artifactId>easypoi-base</artifactId> <version>4.1.3</version></dependency>//要操作pdf,word还是用原生poi比较好<dependency> <gro..

原创 java集合和数组互相转化

//集合转为数组 直接用toArray方法List<Object> list = new ArrayList();Object[] objects = list.toArray();//数组转为集合 调用Arrays类的asList方法List<Object> objectList = Arrays.asList(objects);