摘抄003

CheckParamAssert 类

import org.springframework.util.ObjectUtils;
import java.util.Objects;

/**
 * 检查参数（对象）的断言工具，不满足条件则快速报错
 */
public class CheckParamAssert {
	public static void notEmpty(Object param, String errorMsg) {
		if (ObjectUtils.isEmpty(param)) {
			throw new CheckParamException(errorMsg);
		}
	}
	public static void isTrue(Boolean condition, String errorMsg) {
		if (!condition) {
			throw new CheckParamException(errorMsg);
		}
	}
}

值得注意的是, ObjectUtils.isEmpty() 是导自org.springframework.util.ObjectUtils，几乎涵盖了所有的常见Java对象

下面为这个方法isEmpty的主要代码:

public static boolean isEmpty(@Nullable Object obj) {
        if (obj == null) {
            return true;
        } else if (obj instanceof Optional) {
            return !((Optional)obj).isPresent();
        } else if (obj instanceof CharSequence) {
            return ((CharSequence)obj).length() == 0;
        } else if (obj.getClass().isArray()) {
            return Array.getLength(obj) == 0;
        } else if (obj instanceof Collection) {
            return ((Collection)obj).isEmpty();
        } else {
            return obj instanceof Map ? ((Map)obj).isEmpty() : false;
        }
    }

自定义异常类 CheckParamException

import lombok.Data;
import org.springframework.util.StringUtils;

/**
 * 业务错误自定义异常类，code表示报错编码: 404、500、505之类的, 暂用不到
*/
@Data
public class CheckParamException extends RuntimeException {
	private String message;
	private String code;

	public CheckParamException() {
	}

	public CheckParamException(String message) {
		super(message);
		this.message = message;
	}

	public CheckParamException(String code, String message) {
		super( message);
		this.message = message;
		this.code = code;
	}

	public CheckParamException(Throwable cause, String message) {
		super(message,cause);
		this.message = message;
	}

	private void setErrorMessage(String errorMessage){
		String errDesc = "";

		if(StringUtils.isEmpty(errorMessage)){
			this.message = errDesc;
		}else{
			this.message = errorMessage;
		}
	}
}