注解使用

一、Springboot中定义注解

1，定义注解类

/**
 * 自定义日志打印
 */
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
public @interface MyLogger {
    String value() default "";
}

2，定义AOP切面

/**
 * 采用aop打印日志
 */
@Component
@Aspect
@Slf4j
public class MyLoggerAspect {

    /**
     * 其中@Pointcut声明了切点（这里的切点是我们自定义的注解类），
     * @Before声明了通知内容，在具体的通知中，我们通过@annotation(logger)拿到了自定义的注解对象， 所以就能够获取我们在使用注解时赋予的值了。
     */
    @Pointcut("@annotation(com.taiji.xhwcb.system.config.ann.MyLogger)")
    private void pointcut() {
    }

    @Before("pointcut() && @annotation(myLogger)")
    public void before(JoinPoint joinPoint, MyLogger myLogger) {
        //类名
        String className = joinPoint.getSignature().getDeclaringType().getSimpleName();
        //方法名
        String methodName = joinPoint.getSignature().getName();
        //获取所有的参数
        Object[] args = joinPoint.getArgs();
        StringBuffer sb = new StringBuffer();
        sb.append("类名:").append(className).append(" - ").append("方法名:").append(methodName);
        for (int i = 0; i < args.length; i++) {
            sb.append(" - ").append("参数" + (i+1) + ":").append(args[i]);
        }
        //登陆用户
        TaijiUser user = SecurityUtils.getUser();
        if (!EmptyUtil.isEmpty(user)) {
            sb.append(" - ").append("用户为:").append(user.getId()).append("-").append(user.getUsername());
        }
        log.info(sb.toString());
    }

}

3，在使用的方法上加上日志

@MyLogger
@ApiOperation(value = "分页查询", notes = "分页查询")
@GetMapping("/page" )
public R getPlayerConfigPage(Page page, PlayerConfig playerConfig) {}

4，打印效果

二、普通类中注解的使用

1，定义注解

//table表注解
@Target({ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
public @interface TableRef {
    String value();
}

//主键注解
@Target({ElementType.FIELD})
@Retention(RetentionPolicy.RUNTIME)
public @interface Rowkey {
}

//普通字段注解
@Target({ElementType.FIELD})
@Retention(RetentionPolicy.RUNTIME)
public @interface Column {
    String family() default "info";
    String column() default  "";
}

2，使用注解

@Data
@TableRef("ct:calllog")
public class Calllog {
    @Rowkey
    private String rowkey;
    @Column(family = "caller")
    private String call1;
    @Column(family = "caller")
    private String call2;
    @Column(family = "caller")
    private String calltime;
    @Column(family = "caller")
    private String duration;
    @Column(family = "caller")
    private String flag = "1";

    public Calllog() {
    }

    public Calllog(String data ) {
        String[] values = data.split("\t");
        call1 = values[0];
        call2 = values[1];
        calltime = values[2];
        duration = values[3];
    }
}

3，注解生效

protected void putData(Object obj) throws Exception {
    //反射
    Class clazz = obj.getClass();
    TableRef tableRef = (TableRef)clazz.getAnnotation(TableRef.class);
    String tableName = tableRef.value();
    //获取所有的字段
    Field[] fs = clazz.getDeclaredFields();
    String stringRowkey = "";
    for (Field f : fs) {
        Rowkey rowkey = f.getAnnotation(Rowkey.class);
        if ( rowkey != null ) {
            f.setAccessible(true);
            //获取属性值
            stringRowkey = (String)f.get(obj);
            break;
        }
    }

    Connection conn = getConnection();
    Table table = conn.getTable(TableName.valueOf(tableName));
    Put put = new Put(Bytes.toBytes(stringRowkey));

    for (Field f : fs) {
        Column column = f.getAnnotation(Column.class);
        if (column != null) {
            String family = column.family();
            String colName = column.column();
            if ( colName == null || "".equals(colName) ) {
                //获取属性名
                colName = f.getName();
            }
            f.setAccessible(true);
            //获取属性值
            String value = (String)f.get(obj);

            put.addColumn(Bytes.toBytes(family), Bytes.toBytes(colName), Bytes.toBytes(value));
        }
    }
    // 增加数据
    table.put(put);
    // 关闭表
    table.close();
}