开发一个项目的顺序

目录

1.设计表

2.写好pom.xml和application.yml文件 （设置端口号，配置数据源）

3.引入一个插件，帮助自动生成dao层，model层和mapper目录的代码

4.接着配置mybatis的扫描路径，产生这些文件后，需要让myabtis知道在哪

5.配置好之后，去测试一下，是否能够获取到数据库的数据

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1.设计表

2.写好pom.xml和application.yml文件 （设置端口号，配置数据源）

3.引入一个插件，帮助自动生成dao层，model层和mapper目录的代码

<plugin><groupId>org.mybatis.generator</groupId><artifactId>mybatis-generator-maven-plugin</artifactId><version>${mybatis-generator-plugin-version}</version><executions><execution><id>Generate MyBatis Artifacts</id><phase>deploy</phase><goals><goal>generate</goal></goals></execution></executions><configuration><verbose>true</verbose><overwrite>true</overwrite><configurationFile>src/main/resources/mybatis/generatorConfig.xml</configurationFile></configuration>
</plugin>

接着配置一下这个插件：在resources文件下添加generatorConfig,xml文件：

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE generatorConfigurationPUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN""http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">
<generatorConfiguration><!-- 数据库驱动:选择你的本地硬盘上面的数据库驱动包 --><classPathEntry  location="E:\apache-maven-3.6.1-bin(1)\respository\mysql\mysql-connector-java\5.1.49\mysql-connector-java-5.1.49.jar"/><!-- <classPathEntry  location="D:\maven-warehouse\repository\mysql\mysql-connector-java\8.0.17\mysql-connector-java-8.0.17.jar"/> --><context id="DB2Tables"  targetRuntime="MyBatis3"><!-- 实体类生成序列化属性--><plugin type="org.mybatis.generator.plugins.SerializablePlugin" /><!-- 实体类重写HashCode()和equals()--><plugin type="org.mybatis.generator.plugins.EqualsHashCodePlugin" /><!-- 实体类重写toString() --><plugin type="org.mybatis.generator.plugins.ToStringPlugin" /><commentGenerator><!-- 是否去除自动生成的注释 --><property name="suppressAllComments" value="true"/><!-- 生成注释是否带时间戳--><property name="suppressDate" value="true"/><!-- 生成的Java文件的编码格式 --><property name="javaFileEncoding" value="utf-8"/><!-- 格式化java代码--><property name="javaFormatter" value="org.mybatis.generator.api.dom.DefaultJavaFormatter" /><!-- 格式化XML代码--><property name="xmlFormatter" value="org.mybatis.generator.api.dom.DefaultXmlFormatter" /></commentGenerator><!-- 数据库连接驱动类,URL，用户名、密码 --><jdbcConnection driverClass="com.mysql.jdbc.Driver"connectionURL="jdbc:mysql://127.0.0.1:3306/forum_db?useUnicode=true&amp;characterEncoding=UTF-8"userId="root" password="123456"></jdbcConnection><!-- java类型处理器：处理DB中的类型到Java中的类型 --><javaTypeResolver type="org.mybatis.generator.internal.types.JavaTypeResolverDefaultImpl"><!-- 是否有效识别DB中的BigDecimal类型 --><property name="forceBigDecimals" value="true"/></javaTypeResolver><!-- 生成Domain模型：包名(targetPackage)、位置(targetProject) --><!--<javaModelGenerator targetPackage="com.project.business.domain" targetProject="D:/workSpace/project/src/main/java">&lt;!&ndash; 在targetPackage的基础上，根据数据库的schema再生成一层package，最终生成的类放在这个package下，默认为false &ndash;&gt;<property name="enableSubPackages" value="true"/>&lt;!&ndash; 设置是否在getter方法中，对String类型字段调用trim()方法&ndash;&gt;<property name="trimStrings" value="true"/></javaModelGenerator>--><!--实体类 --><javaModelGenerator targetPackage="com.xiexiangpeng.forum01.model" targetProject="src/main/java"><property name="enableSubPackages" value="true"/><property name="trimStrings" value="true"/></javaModelGenerator><!-- 生成xml映射文件：包名(targetPackage)、位置(targetProject) --><sqlMapGenerator targetPackage="mapper" targetProject="src/main/resources"><property name="enableSubPackages" value="true"/></sqlMapGenerator><!-- 生成DAO接口：包名(targetPackage)、位置(targetProject) --><javaClientGenerator type="XMLMAPPER" targetPackage="com.xiexiangpeng.forum01.dao" targetProject="src/main/java"><property name="enableSubPackages" value="true"/></javaClientGenerator><!-- 要生成的表：tableName - 数据库中的表名或视图名，domainObjectName - 实体类名 --><table tableName="t_article" domainObjectName="Article"enableCountByExample="false"enableUpdateByExample="false"enableDeleteByExample="false"enableSelectByExample="false"selectByExampleQueryId="false"></table><table tableName="t_article_reply" domainObjectName="ArticleReply"enableCountByExample="false"enableUpdateByExample="false"enableDeleteByExample="false"enableSelectByExample="false"selectByExampleQueryId="false"></table><table tableName="t_board" domainObjectName="Board"enableCountByExample="false"enableUpdateByExample="false"enableDeleteByExample="false"enableSelectByExample="false"selectByExampleQueryId="false"></table><table tableName="t_message" domainObjectName="Message"enableCountByExample="false"enableUpdateByExample="false"enableDeleteByExample="false"enableSelectByExample="false"selectByExampleQueryId="false"></table><table tableName="t_user" domainObjectName="User"enableCountByExample="false"enableUpdateByExample="false"enableDeleteByExample="false"enableSelectByExample="false"selectByExampleQueryId="false"></table></context>
</generatorConfiguration>

4.接着配置mybatis的扫描路径，产生这些文件后，需要让myabtis知道在哪

5.配置好之后，去测试一下，是否能够获取到数据库的数据

6.编写公共代码

6.1 对已知的失败和成功的状态进行描述

package com.xiexiangpeng.forum01.common;public enum ResultCode {SUCCESS                     (0, "操作成功"),FAILED                      (1000, "操作失败"),FAILED_UNAUTHORIZED         (1001, "未授权"),FAILED_PARAMS_VALIDATE      (1002, "参数校验失败"),FAILED_FORBIDDEN            (1003, "禁止访问"),FAILED_CREATE               (1004, "新增失败"),FAILED_NOT_EXISTS           (1005, "资源不存在"),// 关于用户的错误描述FAILED_USER_EXISTS          (1101, "用户已存在"),FAILED_USER_NOT_EXISTS      (1102, "用户不存在"),FAILED_LOGIN                (1103, "用户名或密码错误"),FAILED_USER_BANNED          (1104, "您已被禁言, 请联系管理员, 并重新登录."),FAILED_USER_ARTICLE_COUNT   (1105, "更新帖子数量失败"),FAILED_TWO_PWD_NOT_SAME     (1106, "两次输入的密码不一致"),// 关于版块的错误描述FAILED_BOARD_ARTICLE_COUNT  (1201, "更新帖子数量失败"),FAILED_BOARD_BANNED         (1202, "版块状况异常"),FAILED_BOARD_NOT_EXISTS     (1203, "版块不存在"),FAILED_ARTICLE_NOT_EXISTS   (1301, "帖子不存在"),FAILED_ARTICLE_BANNED       (1302, "帖子状况异常"),FAILED_MESSAGE_NOT_EXISTS   (1401, "站内信不存在"),ERROR_SERVICES              (2000, "服务器内部错误"),ERROR_IS_NULL               (2001, "IS NULL.");// 状态码int code;// 描述信息String message;ResultCode(int code, String message) {this.code = code;this.message = message;}@Overridepublic String toString() {return "code = " + code + ", message = " + message + ". ";}public int getCode() {return code;}public String getMessage() {return message;}}

6.2  确定给前端返回的结果的格式

 包含以上三种信息：状态码，描述信息，返回的数据：

提供对外访问的方法：

 

全部代码：

package com.xiexiangpeng.forum01.common;import com.fasterxml.jackson.annotation.JsonInclude;public class AppResult<T> {// 状态码@JsonInclude(JsonInclude.Include.ALWAYS) // 不论任何情况都参与JSON序列化private int code;// 描述信息@JsonInclude(JsonInclude.Include.ALWAYS)private String message;// 具体的数据@JsonInclude(JsonInclude.Include.ALWAYS)private T data;//构造方法public AppResult(int code, String message) {this(code, message, null);}public AppResult(int code, String message, T data) {this.code = code;this.message = message;this.data = data;}//这是对外提供的一些静态方法public static AppResult success () {return new AppResult (ResultCode.SUCCESS.getCode(), ResultCode.SUCCESS.getMessage());}public static AppResult success (String message) {return new AppResult(ResultCode.SUCCESS.getCode(), message);}public static <T> AppResult<T> success (T data) {return new AppResult<>(ResultCode.SUCCESS.getCode(), ResultCode.SUCCESS.getMessage(), data);}public static <T> AppResult<T> success (String message, T data) {return new AppResult<>(ResultCode.SUCCESS.getCode(), message, data);}public static AppResult failed () {return new AppResult(ResultCode.FAILED.getCode(), ResultCode.FAILED.getMessage());}public static AppResult failed (String message) {return new AppResult(ResultCode.FAILED.getCode(), message);}public static AppResult failed (ResultCode resultCode) {return new AppResult(resultCode.getCode(), resultCode.getMessage());}public int getCode() {return code;}public void setCode(int code) {this.code = code;}public void setMessage(String message) {this.message = message;}public T getData() {return data;}public void setData(T data) {this.data = data;}public String getMessage() {return message;}
}

6.3.编写自定义异常

能够让异常被我们精准控制

package com.xiexiangpeng.forum01.exception;import com.xiexiangpeng.forum01.common.AppResult;public class ApplicationException extends RuntimeException{// 在异常中持有一个错误信息对象protected AppResult errorResult;/*** 构造方法* @param errorResult*/public ApplicationException (AppResult errorResult) {super(errorResult.getMessage());this.errorResult = errorResult;}public ApplicationException(String message) {super(message);}public ApplicationException(String message, Throwable cause) {super(message, cause);}public ApplicationException(Throwable cause) {super(cause);}public AppResult getErrorResult() {return errorResult;}}

 6.4全局异常和自定义异常处理

package com.bitejiuyeke.forum.exception;import com.bitejiuyeke.forum.common.AppResult;
import com.bitejiuyeke.forum.common.ResultCode;
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;/*** 全局异常处理** @Author 比特就业课*/
@Slf4j
@ControllerAdvice
public class GlobalExceptionHandler {//捕获自定义异常@ResponseBody@ExceptionHandler(ApplicationException.class)public AppResult applicationExceptionHandler (ApplicationException e) {// 打印异常信息e.printStackTrace(); // 上生产之前要删除// 打印日志log.error(e.getMessage());if (e.getErrorResult() != null) {return e.getErrorResult();}// 非空校验if (e.getMessage() == null || e.getMessage().equals("")) {return AppResult.failed(ResultCode.ERROR_SERVICES);}// 返回具体的异常信息return AppResult.failed(e.getMessage());}//捕获全局异常@ResponseBody@ExceptionHandler(Exception.class)public AppResult exceptionHandler (Exception e) {// 打印异常信息e.printStackTrace();// 打印日志log.error(e.getMessage());// 非空校验if (e.getMessage() == null || e.getMessage().equals("")) {return AppResult.failed(ResultCode.ERROR_SERVICES);}// 返回异常信息return AppResult.failed(e.getMessage());}
}