全局异常处理器负责将抛出的异常，以统一的格式返给前端。在这里起主要作用的注解是@RestControllerAdvice。
@RestControllerAdvice主要配合@ExceptionHandler使用，统一处理异常情况。
1、@RestControllerAdvice 注解，可以用于定义@ExceptionHandler、@InitBinder、@ModelAttribute，并应用到所有@RequestMapping中。
2、@RestControllerAdvice 是组件注解，他使得其实现类能够被classpath扫描自动发现，如果应用是通过MVC命令空间或MVC Java编程方式配置，那么该特性默认是自动开启的。
例如：
当抛出BizException时，会自动返回ReturnResult.error(...)。这样，在真正的业务中，我们只需要返回ReturnResult.success(...)就可以了。
目录结构：
具体代码：
import com.sugon.cloud.lowcode.result.ReturnResult;import lombok.extern.slf4j.Slf4j;import org.mybatis.spring.MyBatisSystemException;import org.springframework.web.HttpRequestMethodNotSupportedException;import org.springframework.web.bind.annotation.ExceptionHandler;import org.springframework.web.bind.annotation.ResponseBody;import org.springframework.web.bind.annotation.RestControllerAdvice;import javax.naming.AuthenticationException;import javax.servlet.http.HttpServletRequest;import static com.sugon.cloud.lowcode.constants.SplitCharacter.LEFT_PARENTHESES;import static com.sugon.cloud.lowcode.constants.SplitCharacter.RIGHT_PARENTHESES;import static com.sugon.cloud.lowcode.result.CodeMessageEnum.*;@RestControllerAdvice@Slf4jpublic class GlobalExceptionHandler { @ExceptionHandler(value = BizException.class) @ResponseBody public ReturnResult bizExceptionHandler(HttpServletRequest req, BizException e) { log.error("发生业务异常: {}, 请求接口: {}", e.getMessage(), req.getRequestURI()); return ReturnResult.error(e.getCode(), e.getMessage()); } @ExceptionHandler(value = NullPointerException.class) @ResponseBody public ReturnResult exceptionHandler(HttpServletRequest req, NullPointerException e) { log.error("空指针异常信息: {}, 请求接口: {}", e, req.getRequestURI()); return ReturnResult.error( NULL_POINT_ERROR_EXCEPTION.getCode(), NULL_POINT_ERROR_EXCEPTION.getMessage() + RIGHT_PARENTHESES + e.getMessage() + LEFT_PARENTHESES); } @ExceptionHandler(value = HttpRequestMethodNotSupportedException.class) @ResponseBody public ReturnResult methodNotSupportedExceptionHandler(HttpServletRequest req, Exception e) { log.error("请求方法异常信息: {}，请求接口: {}", e, req.getRequestURI()); return ReturnResult.error( REQUEST_METHOD_ERROR.getCode(), REQUEST_METHOD_ERROR.getMessage() + RIGHT_PARENTHESES + e.getMessage() + LEFT_PARENTHESES); } @ExceptionHandler(value = MyBatisSystemException.class) @ResponseBody public ReturnResult sqlSyntaxErrorExceptionHandler(HttpServletRequest req, Exception e) { log.error("MyBatis系统异常信息: {}，请求接口: {}", e, req.getRequestURI()); return ReturnResult.error( INNER_FRAME_EXCEPTION.getCode(), INNER_FRAME_EXCEPTION.getMessage() + RIGHT_PARENTHESES + e.getMessage() + LEFT_PARENTHESES); } @ExceptionHandler(value = AuthenticationException.class) public ReturnResult incorrectCredentialsException( HttpServletRequest request, AuthenticationException e) { log.error("用户名或密码不正确: {}, 请求接口: {}", e, request.getRequestURI()); return ReturnResult.error(USER_CREDENTIALS_ERROR); } @ExceptionHandler(value = UserException.class) public ReturnResult incorrectUserException(HttpServletRequest request, UserException e) { log.error("用户信息异常: {}, 请求接口: {}", e, request.getRequestURI()); return ReturnResult.error(e.getCode(), e.getMessage()); } @ExceptionHandler(value = Exception.class) @ResponseBody public ReturnResult exceptionHandler(HttpServletRequest req, Exception e) { e.printStackTrace(); log.error("未知异常: {}, 请求接口: {}", e, req.getRequestURI()); return ReturnResult.error( INTERNAL_SERVER_ERROR.getCode(), INTERNAL_SERVER_ERROR.getMessage() + RIGHT_PARENTHESES + e.getMessage() + LEFT_PARENTHESES); }}自定义的业务异常类：
import com.sugon.cloud.lowcode.result.BaseResultInterface;import com.sugon.cloud.lowcode.result.CodeMessageEnum;import io.swagger.annotations.ApiModel;import io.swagger.annotations.ApiModelProperty;@ApiModel(description= "业务异常数据")public class BizException extends RuntimeException implements BaseResultInterface { private static final long serialVersionUID = 1L; @ApiModelProperty(value = "错误码") private String code; @ApiModelProperty(value = "错误信息") private String message; public BizException() { super(); } public BizException(CodeMessageEnum codeMessageEnum) { super(codeMessageEnum.getCode()); this.code = codeMessageEnum.getCode(); this.message = codeMessageEnum.getMessage(); } public BizException(CodeMessageEnum codeMessageEnum, Throwable cause) { super(codeMessageEnum.getCode(), cause); this.code = codeMessageEnum.getCode(); this.message = codeMessageEnum.getMessage(); } public BizException(CodeMessageEnum codeMessageEnum, String message, Throwable cause) { super(codeMessageEnum.getCode(), cause); this.code = codeMessageEnum.getCode(); this.message = message; } public BizException(String message) { super(message); this.message = message; } public BizException(String code, String message) { super(code); this.code = code; this.message = message; } public BizException(String code, String message, Throwable cause) { super(code, cause); this.code = code; this.message = message; } @Override public Throwable fillInStackTrace() { return this; } @Override public String getCode() { return this.code; } @Override public String getMessage() { return this.message; }}对象返回到前端以及异常抛出的接口类：
public interface BaseResultInterface { String getCode(); String getMessage();}异常枚举类：
package com.sugon.cloud.lowcode.result;import com.sugon.cloud.lowcode.entity.vo.CodeVo;import io.swagger.annotations.Api;import io.swagger.annotations.ApiModel;import static org.apache.commons.lang3.StringUtils.isBlank;@ApiModel(description = "code码类")@Api(tags = "code码管理")public enum CodeMessageEnum implements BaseResultInterface { SUCCESS("0000", "成功!"), SUCCESS_LOGIN("0001", "用户登录成功"), SUCCESS_LOGOUT("0002", "用户退出成功"), COMMON_FAIL("999", "失败"), SERVER_BUSY("1001", "服务器正忙，请稍后再试!"), INTERNAL_SERVER_ERROR("1002", "服务器内部错误"), NOT_FOUND("1003", "未找到该资源!"), REQUEST_METHOD_ERROR("1004", "接口请求方法异常"), SQL_SYNTAX_ERROR_EXCEPTION("1005", "SQL语法错误异常"), NULL_POINT_ERROR_EXCEPTION("1006", "空指针异常信息"), INNER_FRAME_EXCEPTION("1007", "内部框架执行异常"), PARSE_TOKEN_EXCEPTION("1008", "解析token异常"), TOKEN_NOT_EXIST("1009", "token不存在"), TOKEN_SIGNATURE_EXCEPTION("1010", "token签名异常"), TOKEN_EXPIRE("1011", "token过期，请重新登录"), IMG_TYPE_NOT_CONFIG("1012", "请配置图片类型"), NOT_CONFIG_FILE_DIR("1013", "请配置文件路径"), UPLOAD_FILE_ERROR("1014", "文件上传失败"), FILE_NOT_EXIST("1015", "文件不存在"), FILE_HAS_DELETED("1016", "文件已被删除"), DRIVER_CLASS_NOT_FOUND("1017", "数据库的连接驱动正在加载中..."), TRY_CONNECT_DATABASE_ERROR("1018", "尝试连接数据库失败"), CLOSE_CONNECT_DATABASE_ERROR("1019", "关闭数据库连接失败"), DATABASE_NAME_NOT_EXIST("1020", "数据库名称不存在"), CLOSE_DATASOURCE_ERROR("1021", "释放数据库资源异常"), DRUID_DATASOURCE_ERROR("1022", "数据源创建中..."), CREATE_DATABASE_ERROR("1023", "创建数据库失败"), CREATE_TABLE_ERROR("1024", "创建表失败"), UPDATE_TABLE_FIELD_ERROR("1025", "更新表字段失败"), DELETE_TABLE_FIELD_ERROR("1026", "删除表字段失败"), QUERY_ROLE_ERROR("1027", "查询角色失败"), UPDATE_GROUP_ERROR("1028", "更新接口组失败"), DELETE_GROUP_ERROR("1029", "删除接口组失败"), SAVE_INTERFACE_ERROR("1030", "保存接口信息失败"), BODY_NOT_MATCH("2001", "请求的数据格式不符"), SIGNATURE_NOT_MATCH("2002", "请求的数字签名不匹配!"), REQUEST_PATH_NOT_MATCH("2003", "当前请求路径没有权限!"), NOT_UPLOAD_FILE_NAME_ERROR("2004", "上传的文件名不存在，请重新上传"), NOT_SUPPORT_IMG_TYPE("2005", "图片格式不正确，请重新上传"), NOT_SUPPORT_USERNAME_TYPE("2006", "excel用户名不能为空"), NOT_SUPPORT_ROLE_TYPE("2007", "角色不存在"), NOT_SUPPORT_DEPT_TYPE("2008", "部门不存在"), SQL_INJECT_NOT_ALLOWED("2009", "参数中存在数据库关键字，请修改"), TABLE_FIELD_NOT_EXIST("2010", "表字段不存在"), USER_NOT_LOGIN("3001", "用户未登录"), USER_ACCOUNT_EXPIRED("3002", "账号已过期"), USER_CREDENTIALS_ERROR("3003", "用户名或密码错误"), USER_CREDENTIALS_EXPIRED("3004", "密码过期"), USER_ACCOUNT_NOT_BIND_ENTERPRISE("3005", "当前账号未绑定企业"), USER_ACCOUNT_LOCKED("3006", "账号被锁定"), USER_ACCOUNT_NOT_EXIST("3007", "账号不存在"), USER_ACCOUNT_ALREADY_EXIST("3008", "账号已存在"), USER_ACCOUNT_USE_BY_OTHERS("3009", "账号下线"), USER_NO_PERMISSION("3010", "当前账号没有此权限"), USERNAME_NOT_BLANK("3011", "用户不能为空"), USER_LOGIN_ERROR("3012", "用户登录失败"), USER_LOGOUT_ERROR("3013", "用户退出失败"), USER_ACCOUNT_USE_BY_OTHERS_ERROR("3014", "账号下线异常"), USER_ACCESS_DENIED("3015", "权限认证失败"), USERNAME_EXIST_ERROR("3016", "用户名重名"), ROLE_NAME_ALREADY_EXIST("3101", "角色已存在"), ENTERPRISE_NOT_EXIST("4001", "当前企业不存在"), APP_KEY_EXIST("4002", "应用key已存在"), APP_NOT_EXIST("4003", "应用不存在"), APP_PAGE_NAME_EXIST("4004", "当前页面名称已存在"), APP_PAGE_KEY_EXIST("4005", "当前页面key已存在"), APP_PAGE_NOT_EXIST("4006", "当前页面不存在，或已删除"), APP_PAGE_TYPE_ERROR("4007", "页面类型有误"), APP_PAGE_HOME_IS_NOT_EXIST("4008", "请设置首页"), CAN_NOT_DELETE_HOME_PAGE("4009", "请勿删除首页"), DELETE_PAGE_ERROR("4010", "删除页面失败"), CONFIG_CUSTOM_ERROR("4011", "配置自定义页面失败"), APP_PAGE_PARENT_NOT_EXIST("4012", "当前页面的父级页面不存在，或已删除"), DATASOURCE_NAME_EXIST("4013", "当前数据源名称已经存在，请修改后重试"), DATASOURCE_NOT_EXIST("4014", "当前数据源不存在"), DATASOURCE_HAS_DELETED("4015", "当前数据源已删除"), MODEL_NOT_EXIST("4016", "当前模型不存在"), MODEL_HAS_DELETED("4017", "当前模型已删除"), MODEL_NAME_HAS_EXIST("4018", "当前模型名称已存在"), DATASOURCE_NOT_CONFIG("4019", "数据源配置为空，请联系管理员"), DATASOURCE_NOT_CONFIG_DIALECT("4020", "未配置数据源的类型"), DATASOURCE_NOT_CONFIG_DRIVER_CLASS_NAME("4021", "未配置数据源的驱动"), DEPT_USER_EXIST("4022", "部门下存在用户"), NOT_CONFIG_PAGE_BUTTON_TYPE("4023", "未配置按钮雷星"), MODEL_PAGE_RELATION_MODEL("4024", "已关联当前模型页面"), MODEL_PAGE_NOT_EXIST("4025", "模型页面不存在或已被删除"), MODEL_HAS_RELATION_MODEL_PAGE("4026", "当前模型已关联模型页面，不允许删除"), FORM_NOT_EXIST("4027", "模型表单不存在"), READ_FILE_ERROR("4028", "读取模型页面的模板文件失败"), MODEL_PAGE_CONTENT_NULL("4029", "未配置模型页面的模板文件"), NOT_CONFIG_QUERY_SQL("4030", "未配置查询语句"), APP_PAGE_BUTTON_OPTION_VALUE_ERROR("4031", "未配置接口"), DELETE_COLUMN_ERROR("4032", "删除当前失败"), INSERT_DATA_ERROR("4033", "新建数据失败"), EDIT_DATA_ERROR("4034", "编辑数据失败"), DATASOURCE_HAS_MODELS("4035", "当前数据源存在模型，不允许删除"), NOT_CONFIG_FORM_API("4036", "未配置模型表单页的接口信息"), PLEASE_WRITE_AT_LEAST_DATA("4037", "请至少填写一行数据"), AMIS_PAGE_ERROR("4038", "分页参数异常"), QUERY_APP_PAGE_QUERY_FIELD_ERROR("4039", "查询搜素参数异常"), REQUEST_PARAM_NOT_IN_APP_PAGE_QUERY_FIELD("4040", "请求参数不在查询数据表中"), STYLE_LANGUAGE_ON_CSS("4041", "自定义css中的样式语言不能为空"), APP_CONFIG_TYPE_NOT_EXIST("4042", "不支持当前应用设置的类型"), APP_CONFIG_NOT_EXIST_OR_DELETED("4043", "当前设置不存在或已被删除"), APP_HAS_CONFIG_ON_THIS_TYPE("4044", "当前应用设置的类型已存在，请更新"), NOT_SUPPORT_COMPONENT_FRAME("4045", "不支持当前组件框架"), NOT_SUPPORT_COMPONENT_TYPE("4046", "不支持当前组件类型"), CURRENT_APP_KEY_EXIST("4047", "当前应用的组件key已存在"), CREATE_CUSTOM_COMPONENT_ERROR("4048", "新增自定义组件失败"), APP_CUSTOM_COMPONENT_NOT_EXIST("4049", "当前组件不存在或已被删除"), UPDATE_CUSTOM_COMPONENT_ERROR("4050", "更新自定义组件失败"), DELETED_CUSTOM_COMPONENT_ERROR("4051", "删除自定义组件失败"), INSERT_COMPONENT_DEPENDENCE_ERROR("4052", "新增自定义组件依赖项失败"), DELETE_COMPONENT_DEPENDENCE_ERROR("4053", "删除自定义组件依赖项失败"), CURRENT_COMPONENT_DEPENDENCE_NOT_EXIST("4054", "当前自定义组件依赖项不存在或已被删除"), CURRENT_APP_NAME_EXIST("4055", "当前应用的组件名称已存在"), NOT_SUPPORT_DATASOURCE_FROM("4056", "不支持当前的数据库来源"), JDBC_CONFIG_ERROR("4057", "平台内置的数据源配置有误"), NOT_SUPPORT_MODEL_TYPE("4058", "不支持当前的页面模板"), NOT_SUPPORT_CUSTOM_PAGE("4059", "暂不支持自定义页面"), FORM_PAGE_ON_DEVELOPING("4060", "自定义页面的该功能正在开发中..."), APP_PAGE_QUERY_FIELD_NOT_EXIST("4061", "当前查询条件不存在，或已被删除"), APP_PAGE_BUTTON_NOT_EXIST("4062", "当前页面按钮不存在，或已被删除"), TABLE_KEY_MORE_THEN_ONE("4063", "主键超过一个"), TABLE_KEY_LESS_THEN_ONE("4064", "主键必须存在"), TABLE_KEY_MUST_BE_INT("4065", "主键必须为整数类型"), TABLE_FIELD_MUST_EXIST("4066", "必须存在表字段"), CURRENT_MODEL_PAGE_HAS_CONVERSION_CUSTOM_PAGE("4067", "当前模型页面已转成自定义页面"), NOT_SUPPORT_RELEASE_STATUS("4068", "发布版本状态有误"), APP_FORM_BUTTON_NOT_EXIST("4067", "当前表单按钮不存在，或已被删除"), DATASOURCE_KEY_EXIST_ERROR("4068","数据源key已存在") ; CodeMessageEnum(String code, String message) { this.code = code; this.message = message; } private String code; private String message; @Override public String getCode() { return this.code; } @Override public String getMessage() { return this.message; } public static CodeVo getJsonObjectByCode(String code) { CodeVo codeVo = new CodeVo(); if (isBlank(code)) { return codeVo; } for (CodeMessageEnum enumObj : CodeMessageEnum.values()) { if (enumObj.getCode().equals(code)) { return new CodeVo(code, enumObj.message); } } return codeVo; }}统一给前端的结果格式：
import com.alibaba.fastjson.JSONObject;import io.swagger.annotations.ApiModel;import io.swagger.annotations.ApiModelProperty;import lombok.Getter;import lombok.Setter;import static com.sugon.cloud.lowcode.result.CodeMessageEnum.*;@Setter@Getter@ApiModel(description= "返回响应数据")public class ReturnResult { @ApiModelProperty(value = "状态码") private String code; @ApiModelProperty(value = "响应信息") private String message; @ApiModelProperty(value = "响应对象") private T result; @ApiModelProperty(value = "是否成功") private boolean success = true; public ReturnResult() {} public ReturnResult(CodeMessageEnum codeMessageEnum) { this.code = codeMessageEnum.getCode(); this.message = codeMessageEnum.getMessage(); } public static ReturnResult success() { return success(null); } public static ReturnResult success(T data) { return success(SUCCESS, data); } public static ReturnResult loginSuccess(T data) { return success(SUCCESS_LOGIN, data); } public static ReturnResult loginOutSuccess() { return success(SUCCESS_LOGOUT, null); } private static ReturnResult success(CodeMessageEnum codeMessageEnum, T data) { ReturnResult result = new ReturnResult<>(); result.setCode(codeMessageEnum.getCode()); result.setMessage(codeMessageEnum.getMessage()); result.setResult(data); return result; } public static ReturnResult error(CodeMessageEnum codeMessageEnum) { return error(codeMessageEnum.getCode(), codeMessageEnum.getMessage()); } public static ReturnResult error(CodeMessageEnum codeMessageEnum, String message) { return error(codeMessageEnum.getCode(), message); } public static ReturnResult error(String code, String message) { ReturnResult result = new ReturnResult(); result.setCode(code); result.setMessage(message); result.setSuccess(false); return result; } @Override public String toString() { return JSONObject.toJSONString(this); }} 来源地址：https://blog.csdn.net/qq_44527508/article/details/129684044
