自定义TypeHandler中的Mybatis null配置对象

public class NullTypeHandler implements TypeHandler<Object> {
    
    private final Object nullValue; // 自定义的null配置对象
    
    public NullTypeHandler(Object nullValue) {
        this.nullValue = nullValue;
    }
    
    @Override
    public void setParameter(PreparedStatement ps, int i, Object parameter, JdbcType jdbcType) throws SQLException {
        if (parameter == null) {
            ps.setObject(i, nullValue);
        } else {
            // 处理非null值的逻辑
            // ...
        }
    }
    
    @Override
    public Object getResult(ResultSet rs, String columnName) throws SQLException {
        Object value = rs.getObject(columnName);
        if (value == null || value.equals(nullValue)) {
            return null;
        } else {
            // 处理非null值的逻辑
            // ...
        }
    }
    
    @Override
    public Object getResult(ResultSet rs, int columnIndex) throws SQLException {
        Object value = rs.getObject(columnIndex);
        if (value == null || value.equals(nullValue)) {
            return null;
        } else {
            // 处理非null值的逻辑
            // ...
        }
    }
    
    @Override
    public Object getResult(CallableStatement cs, int columnIndex) throws SQLException {
        Object value = cs.getObject(columnIndex);
        if (value == null || value.equals(nullValue)) {
            return null;
        } else {
            // 处理非null值的逻辑
            // ...
        }
    }
}

<typeHandlers>
    <typeHandler handler="com.example.NullTypeHandler">
        <property name="nullValue" value="NULL" />
    </typeHandler>
</typeHandlers>