关于枚举值使用 == 还是 equals 比较

桃扇骨 2023-05-31 07:08 18阅读 0赞

# 关于枚举值使用 == 还是 equals比较 #

### 使用哪一个 ###

== 和 equals 都可以

### 代码 ###

public class MyTest {
        @Test
        public void test03() {
    
            System.out.println(OperatorTypeEnum.ADD == OperatorTypeEnum.ADD);
            System.out.println(OperatorTypeEnum.ADD.equals(OperatorTypeEnum.ADD));
            CustomerDTO customerDTO = new CustomerDTO();
            customerDTO.setName("测试");
            customerDTO.setOperatorTypeEnum(OperatorTypeEnum.ADD);
            System.out.println(customerDTO.getOperatorTypeEnum() == OperatorTypeEnum.ADD);
            System.out.println(customerDTO.getOperatorTypeEnum().equals(OperatorTypeEnum.ADD));
        }
    
    }
    
    enum OperatorTypeEnum {
        ADD(0, "添加"),
        UPDATE(1, "更新");
        private Integer code;
    
        private String message;
    
        OperatorTypeEnum(Integer code, String message) {
            this.code = code;
            this.message = message;
        }
    
        public Integer getCode() {
            return code;
        }
    
        public void setCode(Integer code) {
            this.code = code;
        }
    
        public String getMessage() {
            return message;
        }
    
        public void setMessage(String message) {
            this.message = message;
        }
    }
    
    class CustomerDTO {
    
        private String name;
    
        private OperatorTypeEnum operatorTypeEnum;
    
        public String getName() {
            return name;
        }
    
        public void setName(String name) {
            this.name = name;
        }
    
        public OperatorTypeEnum getOperatorTypeEnum() {
            return operatorTypeEnum;
        }
    
        public void setOperatorTypeEnum(OperatorTypeEnum operatorTypeEnum) {
            this.operatorTypeEnum = operatorTypeEnum;
        }
    }

### 打印结果 ###

true
    true
    true
    true

### 再看下枚举调用equals的实现 ###

/**
         * Returns true if the specified object is equal to this
         * enum constant.
         *
         * @param other the object to be compared for equality with this object.
         * @return  true if the specified object is equal to this
         *          enum constant.
         */
        public final boolean equals(Object other) {
            return this==other;
        }

重写了equals 方法 调用的 还是 == 进行比较

所以效果是一样的