JAVA 8 ‘::‘ 关键字及在new QueryWrapper“ ::“中的使用说明

Posted 2022-02-02 weixin_40228600

我们可以通过java 8提供的 :: 关键字来快速访问类的构造方法、对象方法、静态方法。
下面例子通过’::'关键字获取SysUserRole对象中的属性值getUserId

@Data
@EqualsAndHashCode(callSuper = false)
@Accessors(chain = true)
public class SysUserRole implements Serializable 

    private static final long serialVersionUID = 1L;

    @TableId(type = IdType.ASSIGN_ID)
    private String id;
    
    /**
     * 用户id
     */
    private String userId;

    /**
     * 角色id
     */
    private String roleId;

	public SysUserRole() 
	

	public SysUserRole(String userId, String roleId) 
		this.userId = userId;
		this.roleId = roleId;
	

    

通过userid赋值getUserId，查询SysUserRole对象list

List<SysUserRole> userRole = sysUserRoleService.list(new QueryWrapper<SysUserRole>().lambda().eq(SysUserRole::getUserId, userid));