spring项目结构设计-错误和异常

error and exception

结构说明：提供错误信息接口ErrorIntf，具体的实现类为BasicError，异常类BasicException被设计为继承自RuntimeException并拥有自己的属性error，实例化时将ErrorIntf当作参数传入。

• 优点：

1. 规范错误码（限制再枚举类中取值）
2. 可以附带错误信息（通过BasicException的desc属性）
3. spring全局统一异常处理（可以包装其他异常，通过BasicException的throwable属性

• 缺点：

1. spring全局异常处理不能很方便的根据异常类型来处理返回值，需要将错误实例中的error取出来根据errCode来处理

• 示例：

new BasicException(BasicError.METHOD_NOT_IMPLEMENTATION, "method name: mergeEntity")

• 错误类标准接口ErrorIntf

/**
* 标准错误接口
*/
public interface ErrorIntf {

   /**
    * 获取错误代码
    */
   Integer getErrorCode();

   /**
    * 获取错误信息
    */
   String getErrorMessage();
   
}

• 标准错误类BasicError

public enum BasicError implements ErrorIntf {
    
    /** 一般错误 **/
    BAD_PARAM(100000, "BAD_PARAM"),
    CONVERT_FAILED(100001, "CONVERT_FAILED"),
    NUMBER_FORMAT_ERROR(100002, "NUMBER_FORMAT_ERROR"),
    LOST_PRECISION_FAILED(100003, "LOST_PRECISION_FAILED"),
    BEAN_BIND_FAILED(100004, "BEAN_BIND_FAILED"),
    PERMISSION_DENIED(100005, "PERMISSION_DENIED"),
    INVALID_ENUM_TYPE(100006, "INVALID_ENUM_TYPE"),
    METHOD_NOT_IMPLEMENTATION(100007, "METHOD_NOT_IMPLEMENTATION"),
    FIELD_NOT_FOUND(100008, "FIELD_NOT_FOUND"),
    METHOD_NOT_FOUND(100009, "METHOD_NOT_FOUND"),
    PARAM_NOT_FOUND(100010, "PARAM_NOT_FOUND"),
    CLASS_NOT_FOUND(100011, "CLASS_NOT_FOUND"),
    INTF_NOT_FOUND(100012, "INTF_NOT_FOUND"),
    ENUM_NOT_FOUND(100013, "ENUM_NOT_FOUND"),
    CLASS_TYPE_NOT_SUPPORT(100014, "CLASS_TYPE_NOT_SUPPORT"),
    METHOD_TYPE_NOT_SUPPORT(100015, "METHOD_TYPE_NOT_SUPPORT"),
    OBJECT_TYPE_NOT_SUPPORT(100016, "OBJECT_TYPE_NOT_SUPPORT"),
    BAD_REQUEST(100017, "BAD_REQUEST"),
    UNSUPPORTED_MEDIA_TYPE(100018, "UNSUPPORTED_MEDIA_TYPE"),
    INTERNAL_SERVER_ERROR(100019, "INTERNAL_SERVER_ERROR"),

    /** 数据错误 **/
    DATA_INSERT_FAILED(200000, "DATA_INSERT_FAILED"),
    DATA_DELETE_FAILED(200001, "DATA_DELETE_FAILED"),
    DATA_UPDATE_FAILED(200002, "DATA_UPDATE_FAILED"),
    DATA_QUERY_FAILED(200003, "DATA_QUERY_FAILED"),
    DATA_NOT_EXIST(200004, "DATA_NOT_EXIST"),
    DATA_ALREADY_EXIST(200005, "DATA_ALREADY_EXIST"),
    DATA_NOT_UNIQUE_EXIST(200006, "DATA_NOT_UNIQUE_EXIST"),


    /** 文件错误 **/
    FILE_NOT_EXIST(300000, "FILE_NOT_EXIST"),
    FILE_ALREADY_EXIST(300001, "FILE_ALREADY_EXIST"),
    FILE_NOT_READABLE(300002, "FILE_NOT_READABLE"),
    FILE_NOT_WRITEABLE(300003, "FILE_NOT_WRITEABLE"),
    FILE_PERMISSION_DENIED(300004, "FILE_PERMISSION_DENIED"),
    DIRECTORY_NOT_EXIST(300005, "DIRECTORY_NOT_EXIST"),
    DIRECTORY_ALREADY_EXIST(300006, "DIRECTORY_ALREADY_EXIST"),
    DIRECTORY_NOT_READABLE(300007, "DIRECTORY_NOT_READABLE"),
    DIRECTORY_NOT_WRITEABLE(300008, "DIRECTORY_NOT_WRITEABLE"),
    DIRECTORY_PERMISSION_DENIED(300009, "DIRECTORY_PERMISSION_DENIED"),
    DIRECTORY_OPERATION_FAILED(300010, "DIRECTORY_OPERATION_FAILED"),
    DIRECTORY_CREATE_FAILED(300011, "DIRECTORY_CREATE_FAILED"),
    DIRECTORY_DELETE_FAILED(300012, "DIRECTORY_DELETE_FAILED"),
    DIRECTORY_UPDATE_FAILED(300013, "DIRECTORY_UPDATE_FAILED"),
    FILE_CREATE_FAILED(300014, "FILE_CREATE_FAILED"),
    FILE_DELETE_FAILED(300015, "FILE_DELETE_FAILED"),
    FILE_UPDATE_FAILED(300016, "FILE_UPDATE_FAILED"),
    FILE_READ_FAILED(300017, "FILE_READ_FAILED"),
    FILE_WRITE_FAILED(300018, "FILE_WRITE_FAILED"),
    FILE_OPERATION_FAILED(300019, "FILE_OPERATION_FAILED"),

    /** 网络错误 **/
    HTTP_OPERATION_FAILED(900050, "HTTP_OPERATION_FAILED"),

    /** 默认错误 **/
    UNKNOWN_ERROR(999999, "UNKNOWN_ERROR");

    private Integer errorCode;
    private String errorMessage;

    private BassError(Integer errorCode, String errorMessage){
        this.errorCode = errorCode;
        this.errorMessage = errorMessage;
    }

    @Override
    public Integer getErrorCode() {
        return this.errorCode;
    }

    @Override
    public String getErrorMessage() {
        return this.errorMessage;
    }
    
}

• 异常类的设计

public class BasicException extends RuntimeException {
    private static final long serialVersionUID = 1046400807995227718L;
    private ErrorIntf error;

    public ErrorIntf getError() {
        return error;
    }

    public BasicException(ErrorIntf error) {
        super(error.getErrCode() + " " + error.getErrMsg());
        this.error = error;
    }

    public BasicException(ErrorIntf error, String message) {
        super(message);
        this.error = error;
    }

    public BasicException(ErrorIntf error, Throwable throwable) {
        super(throwable);
        this.error = error;
    }

    public BasicException(ErrorIntf error, Throwable throwable, String message) {
        super(message, throwable);
        this.error = error;
    }

    public BasicException(ErrorIntf error, Throwable throwable, String message, boolean enableSuppression, boolean writableStackTrace) {
        super(message, throwable, enableSuppression, writableStackTrace);
        this.error = error;
    }

}