Hbase-2.0.0_02_常用操作
主要是常用的hbase shell命令，包括表的创建与删除，表数据的增删查【hbase没有修改】；以及hbase的导出与导入。
参考教程：HBase教程
参考博客：hbase shell基础和常用命令详解
参考博客：hbase导入导出数据
1. hbase命令
1.1. 命令的登录与退出
1.1. 命令的登录与退出
[yun@mini03 ~]$ hbase shell # 登录hbase
SLF4J: Class path contains multiple SLF4J bindings.
………………
Version 2.0., r7483b111e4da77adbfc8062b3b22cbe7c2cb91c1, Sun Apr :: PDT
Took 0.0126 seconds
hbase(main)::> quit # 退出hbase
[yun@mini03 ~]$
1.2. 常用命令
|
名称 |
命令表达式 |
|
创建表 |
create '表名', '列族名1','列族名2','列族名N' |
|
查看所有表 |
list |
|
描述表 |
describe ‘表名’ |
|
判断表存在 |
exists '表名' |
|
判断是否禁用启用表 |
is_enabled '表名' is_disabled ‘表名’ |
|
添加记录 |
put ‘表名’, ‘rowKey’, ‘列族 : 列‘ , '值' |
|
查看记录rowkey下的所有数据 |
get '表名' , 'rowKey' |
|
查看表中的记录总数 |
count '表名' |
|
获取某个列族 |
get '表名','rowkey','列族' |
|
获取某个列族的某个列 |
get '表名','rowkey','列族：列’ |
|
删除记录 |
delete ‘表名’ ,‘行名’ , ‘列族：列' |
|
删除整行 |
deleteall '表名','rowkey' |
|
删除一张表 |
先要屏蔽该表，才能对该表进行删除 第一步 disable ‘表名’ ，第二步 drop '表名' |
|
清空表 |
truncate '表名' |
|
查看所有记录 |
scan "表名" |
|
查看某个表某个列中所有数据 |
scan "表名" , {COLUMNS=>'列族名:列名'} |
|
更新记录 |
就是重写一遍，进行覆盖，hbase没有修改，都是追加 |
说明：
1、列族里边可以自由添加子列很方便。如果列族下没有子列，加不加冒号都是可以的。
hbase> put 't1', 'r1', 'c1', 'value', ts1
2、t1指表名，r1指行键名，c1指列名，value指单元格值。ts1指时间戳，一般都省略掉了。
1.3. 示例1-建表，查看表结构信息，删表
hbase(main):006:0* create 'user','info1','info2','info3' # 创建表
Created table user
Took 2.9927 seconds
=> Hbase::Table - user
hbase(main):007:0> list # 查看所有表
TABLE
user
1 row(s)
Took 0.0468 seconds
=> ["user"]
hbase(main):008:0> describe 'user' # 描述表
Table user is ENABLED ##### 当前表可用
user
COLUMN FAMILIES DESCRIPTION
{NAME => 'info1', VERSIONS => '1', EVICT_BLOCKS_ON_CLOSE => 'false', NEW_VERSION_BEHAVIOR => 'false', KEEP_DELETED_CELLS => 'FALSE', CACHE_DATA_ON_WRITE => 'false', DATA_BLOCK_ENCODING => 'NONE', TTL => 'FOREVER', MIN_VERSIONS => '0', REPLICATION_SCOPE => '0', BLOOMFILTER => 'ROW', CACHE_INDEX_ON_WRITE => 'false', IN_MEMORY => 'false', CACHE_BLOOMS_ON_WRITE => 'false', PREFETCH_BLOCKS_ON_OPEN => 'false', COMPRESSION => 'NONE', BLOCKCACHE => 'true', BLOCKSIZE => '65536'}
{NAME => 'info2', VERSIONS => '1', EVICT_BLOCKS_ON_CLOSE => 'false', NEW_VERSION_BEHAVIOR => 'false', KEEP_DELETED_CELLS => 'FALSE', CACHE_DATA_ON_WRITE => 'false', DATA_BLOCK_ENCODING => 'NONE', TTL => 'FOREVER', MIN_VERSIONS => '0', REPLICATION_SCOPE => '0', BLOOMFILTER => 'ROW', CACHE_INDEX_ON_WRITE => 'false', IN_MEMORY => 'false', CACHE_BLOOMS_ON_WRITE => 'false', PREFETCH_BLOCKS_ON_OPEN => 'false', COMPRESSION => 'NONE', BLOCKCACHE => 'true', BLOCKSIZE => '65536'}
{NAME => 'info3', VERSIONS => '1', EVICT_BLOCKS_ON_CLOSE => 'false', NEW_VERSION_BEHAVIOR => 'false', KEEP_DELETED_CELLS => 'FALSE', CACHE_DATA_ON_WRITE => 'false', DATA_BLOCK_ENCODING => 'NONE', TTL => 'FOREVER', MIN_VERSIONS => '0', REPLICATION_SCOPE => '0', BLOOMFILTER => 'ROW', CACHE_INDEX_ON_WRITE => 'false', IN_MEMORY => 'false', CACHE_BLOOMS_ON_WRITE => 'false', PREFETCH_BLOCKS_ON_OPEN => 'false', COMPRESSION => 'NONE', BLOCKCACHE => 'true', BLOCKSIZE => '65536'}
3 row(s)
Took 0.1933 seconds
hbase(main):011:0* exists 'user' # 判断表是否存在
Table user does exist
Took 0.0398 seconds
=> true
hbase(main):026:0> is_enabled 'user' # 判断表是否可用
true
Took 0.0149 seconds
=> true
hbase(main):027:0> is_disabled 'user' # 判断表是否不可用
false
Took 0.0148 seconds
=> 1
hbase(main):015:0> drop 'user' # 删除表【必须先将表置为不可用】 ERROR: Table user is enabled. Disable it first. Drop the named table. Table must first be disabled:
hbase> drop 't1'
hbase> drop 'ns1:t1' Took 0.0342 seconds
hbase(main):018:0* disable 'user' # 将表置为不可用
Took 0.5544 seconds
hbase(main):019:0> drop 'user' # 之后删除表
Took 0.5143 seconds
hbase(main):020:0> list
TABLE
0 row(s)
Took 0.0687 seconds
=> []
1.4. 示例2-添加表数据和查询表数据
hbase(main):024:0> create 'user','info1','info2','info3' # 创建表
Created table user
Took 1.2717 seconds
=> Hbase::Table - user
hbase(main):025:0> list # 查看所有表信息
TABLE
user
1 row(s)
Took 0.0466 seconds
=> ["user"]
hbase(main):042:0* put 'user','1234','info1:name','zhang' # 添加数据
Took 0.0634 seconds
hbase(main):043:0> scan 'user' # 查看所有记录
ROW COLUMN+CELL
1234 column=info1:name, timestamp=1533740907054, value=zhang
1 row(s)
Took 0.0776 seconds
hbase(main):044:0> put 'user','1234','info1:name','zhangsan' # 再次添加【实际类似修改】
Took 0.0055 seconds
hbase(main):045:0> scan 'user'
ROW COLUMN+CELL
1234 column=info1:name, timestamp=1533740935956, value=zhangsan
1 row(s)
Took 0.0160 seconds
hbase(main):046:0> put 'user','1234','info2:name','zhang' # 在另一个列族添加数据
Took 0.0160 seconds
hbase(main):047:0> put 'user','1234','info2:age','23' # 在另一个列族的另外一个列添加数据
Took 0.0133 seconds
hbase(main):048:0> scan 'user'
ROW COLUMN+CELL
1234 column=info1:name, timestamp=1533740935956, value=zhangsan
1234 column=info2:age, timestamp=1533741066465, value=23
1234 column=info2:name, timestamp=1533741052169, value=zhang
1 row(s)
Took 0.0171 seconds
hbase(main):050:0* put 'user','12345','info1:name','lisi'
Took 0.0125 seconds
hbase(main):051:0> put 'user','12345','info2:age','25'
Took 0.0143 seconds
hbase(main):052:0> scan 'user'
ROW COLUMN+CELL
1234 column=info1:name, timestamp=1533740935956, value=zhangsan
1234 column=info2:age, timestamp=1533741066465, value=23
1234 column=info2:name, timestamp=1533741052169, value=zhang
12345 column=info1:name, timestamp=1533741585906, value=lisi
12345 column=info2:age, timestamp=1533741595725, value=25
2 row(s)
Took 0.0179 seconds
hbase(main):058:0* count 'user' # 查看表中的记录总数【根据 row keys 判断】
2 row(s)
Took 0.1065 seconds
=> 2
hbase(main):053:0> get 'user','1234' # 查看记录rowkey下的所有数据
COLUMN CELL
info1:name timestamp=1533740935956, value=zhangsan
info2:age timestamp=1533741066465, value=23
info2:name timestamp=1533741052169, value=zhang
1 row(s)
Took 0.0371 seconds
hbase(main):067:0* get 'user','1234','info2' # 获取某个列族
COLUMN CELL
info2:age timestamp=1533741066465, value=23
info2:name timestamp=1533741052169, value=zhang
1 row(s)
Took 0.0305 seconds
hbase(main):068:0> get 'user','1234','info2:name' # 获取某个列族的某个列
COLUMN CELL
info2:name timestamp=1533741052169, value=zhang
1 row(s)
Took 0.0182 seconds
1.5. 示例3-删除行数据
hbase(main):072:0> get 'user','1234'
COLUMN CELL
info1:name timestamp=1533740935956, value=zhangsan
info2:address timestamp=1533742368985, value=China
info2:age timestamp=1533741066465, value=23
info2:name timestamp=1533741052169, value=zhang
1 row(s)
Took 0.0146 seconds
hbase(main):073:0> delete 'user','1234','info2:age' # 删除指定行，指定列记录
#### 注意其中： delete 'user','1234','info2' 是无效的 ★★★
Took 0.0288 seconds
hbase(main):074:0> get 'user','1234'
COLUMN CELL
info1:name timestamp=1533740935956, value=zhangsan
info2:address timestamp=1533742368985, value=China
info2:name timestamp=1533741052169, value=zhang
1 row(s)
Took 0.0140 seconds
hbase(main):100:0* deleteall 'user','1234' # 删除整行
Took 0.0119 seconds
hbase(main):101:0> get 'user','1234'
COLUMN CELL
0 row(s)
Took 0.0145 seconds
1.6. 示例4-条件scan和truncate
hbase(main):122:0* scan 'user'
ROW COLUMN+CELL
1234 column=info2:address, timestamp=1533743416815, value=CN
1234 column=info2:age, timestamp=1533743407616, value=20
1234 column=info2:name, timestamp=1533743396872, value=wangwu
12345 column=info1:name, timestamp=1533741585906, value=lisi
12345 column=info2:age, timestamp=1533741595725, value=25
2 row(s)
Took 0.0241 seconds
hbase(main):123:0> scan 'user',{COLUMNS => 'info2'}
ROW COLUMN+CELL
1234 column=info2:address, timestamp=1533743416815, value=CN
1234 column=info2:age, timestamp=1533743407616, value=20
1234 column=info2:name, timestamp=1533743396872, value=wangwu
12345 column=info2:age, timestamp=1533741595725, value=25
2 row(s)
Took 0.0161 seconds
hbase(main):124:0> scan 'user',{COLUMNS => 'info2:age'}
ROW COLUMN+CELL
1234 column=info2:age, timestamp=1533743407616, value=20
12345 column=info2:age, timestamp=1533741595725, value=25
2 row(s)
Took 0.0158 seconds
hbase(main):128:0* truncate
truncate truncate_preserve
hbase(main):128:0* truncate 'user' # 截断表
Truncating 'user' table (it may take a while):
Disabling table...
Truncating table...
Took 2.6156 seconds
hbase(main):129:0> scan 'user'
ROW COLUMN+CELL
0 row(s)
Took 0.1305 seconds
2. hbase导入导出数据
在实际应用HBase过程中，经常需要将生产环境中的数据备份，或者需要在开发环境中利用生产环境的数据（更加符合实际情况），因此HBase存储的数据的导入导出必不可少。
2.1. 表信息准备
hbase(main):002:0> create 'zhang','userinfo','baseinfo','eduinfo','workinfo'
Created table zhang
Took 1.4311 seconds
=> Hbase::Table - zhang
hbase(main):005:0* put 'zhang','12345','userinfo:username','zhangsan'
Took 0.3751 seconds
hbase(main):006:0> put 'zhang','12345','userinfo:password','111111'
Took 0.0220 seconds
hbase(main):007:0> put 'zhang','12345','baseinfo:name','zhangsan'
Took 0.0136 seconds
hbase(main):008:0> put 'zhang','12345','baseinfo:age','22'
Took 0.0136 seconds
hbase(main):009:0> put 'zhang','12345','baseinfo:name','zhangnew'
Took 0.0106 seconds
hbase(main):010:0> put 'zhang','12345','baseinfo:age','25'
Took 0.0138 seconds
hbase(main):013:0> put 'zhang','12345','eduinfo:pri_school','star school'
Took 0.0106 seconds
hbase(main):014:0> scan 'zhang'
ROW COLUMN+CELL
12345 column=baseinfo:age, timestamp=1533884261796, value=25
12345 column=baseinfo:name, timestamp=1533884258020, value=zhangnew
12345 column=eduinfo:pri_school, timestamp=1533884297216, value=star school
12345 column=userinfo:password, timestamp=1533884246132, value=111111
12345 column=userinfo:username, timestamp=1533884241334, value=zhangsan
1 row(s)
Took 0.0179 seconds
2.2. hbase表导出到HDFS
[yun@mini02 ~]$ hbase org.apache.hadoop.hbase.mapreduce.Export zhang /zhang/hbase/zhang_tab
……………………
2018-08-10 15:01:27,354 INFO [main] mapreduce.Job: The url to track the job: http://mini02:8088/proxy/application_1533865678790_0001/
2018-08-10 15:01:27,355 INFO [main] mapreduce.Job: Running job: job_1533865678790_0001
2018-08-10 15:01:39,564 INFO [main] mapreduce.Job: Job job_1533865678790_0001 running in uber mode : false
2018-08-10 15:01:39,566 INFO [main] mapreduce.Job: map 0% reduce 0%
2018-08-10 15:01:52,384 INFO [main] mapreduce.Job: map 100% reduce 0%
2018-08-10 15:01:53,416 INFO [main] mapreduce.Job: Job job_1533865678790_0001 completed successfully
2018-08-10 15:01:53,554 INFO [main] mapreduce.Job: ps in occupied slots (ms)=9661
Total time spent by all reduces in occupied slots (ms)=0
Total time spent by all map tasks (ms)=9661
Total vcore-milliseconds taken by all map tasks=9661
Total megabyte-milliseconds taken by all map tasks=9892864
Map-Reduce Framework
Map input records=1
Map output records=1
Input split bytes=124
Spilled Records=0
Failed Shuffles=0
Merged Map outputs=0
GC time elapsed (ms)=493
CPU time spent (ms)=7670
Physical memory (bytes) snapshot=259244032
Virtual memory (bytes) snapshot=2178433024
Total committed heap usage (bytes)=89653248
HBase Counters
BYTES_IN_REMOTE_RESULTS=252
BYTES_IN_RESULTS=252
MILLIS_BETWEEN_NEXTS=1258
NOT_SERVING_REGION_EXCEPTION=0
NUM_SCANNER_RESTARTS=0
NUM_SCAN_RESULTS_STALE=0
REGIONS_SCANNED=1
REMOTE_RPC_CALLS=1
REMOTE_RPC_RETRIES=0
ROWS_FILTERED=0
ROWS_SCANNED=1
RPC_CALLS=1
RPC_RETRIES=0
File Input Format Counters
Bytes Read=0
File Output Format Counters
Bytes Written=364
HDFS查看
[yun@mini03 ~]$ hadoop fs -ls /zhang/hbase/zhang_tab
Found items
-rw-r--r-- yun supergroup -- : /zhang/hbase/zhang_tab/_SUCCESS
-rw-r--r-- yun supergroup -- : /zhang/hbase/zhang_tab/part-m-
2.3. hbase表导出到本地集群系统
具体导出到哪台机器，需要自己去查找
[yun@mini02 hbase_data]$ hbase org.apache.hadoop.hbase.mapreduce.Export zhang file:///app/software/hbase_data/zhang_tab
……………………
2018-08-10 16:14:17,619 INFO [main] mapreduce.JobSubmitter: Submitting tokens for job: job_1533865678790_0003
2018-08-10 16:14:18,249 INFO [main] impl.YarnClientImpl: Submitted application application_1533865678790_0003
2018-08-10 16:14:18,290 INFO [main] mapreduce.Job: The url to track the job: http://mini02:8088/proxy/application_1533865678790_0003/
2018-08-10 16:14:18,290 INFO [main] mapreduce.Job: Running job: job_1533865678790_0003
2018-08-10 16:14:29,932 INFO [main] mapreduce.Job: Job job_1533865678790_0003 running in uber mode : false
2018-08-10 16:14:29,935 INFO [main] mapreduce.Job: map 0% reduce 0%
2018-08-10 16:14:39,958 INFO [main] mapreduce.Job: map 100% reduce 0%
2018-08-10 16:14:40,984 INFO [main] mapreduce.Job: Job job_1533865678790_0003 completed successfully
2018-08-10 16:14:41,131 INFO [main] mapreduce.Job: aps in occupied slots (ms)=7246
Total time spent by all reduces in occupied slots (ms)=0
Total time spent by all map tasks (ms)=7246
Total vcore-milliseconds taken by all map tasks=7246
Total megabyte-milliseconds taken by all map tasks=7419904
Map-Reduce Framework
Map input records=1
Map output records=1
Input split bytes=124
Spilled Records=0
Failed Shuffles=0
Merged Map outputs=0
GC time elapsed (ms)=242
CPU time spent (ms)=5580
Physical memory (bytes) snapshot=263946240
Virtual memory (bytes) snapshot=2176024576
Total committed heap usage (bytes)=94896128
HBase Counters
BYTES_IN_REMOTE_RESULTS=252
BYTES_IN_RESULTS=252
MILLIS_BETWEEN_NEXTS=959
NOT_SERVING_REGION_EXCEPTION=0
NUM_SCANNER_RESTARTS=0
NUM_SCAN_RESULTS_STALE=0
REGIONS_SCANNED=1
REMOTE_RPC_CALLS=1
REMOTE_RPC_RETRIES=0
ROWS_FILTERED=0
ROWS_SCANNED=1
RPC_CALLS=1
RPC_RETRIES=0
File Input Format Counters
Bytes Read=0
File Output Format Counters
Bytes Written=376
导出到本地的文件
[yun@mini04 task_1533865678790_0003_m_000000]$ pwd
/app/software/hbase_data/zhang_tb/_temporary//task_1533865678790_0003_m_000000
[yun@mini04 task_1533865678790_0003_m_000000]$ ll
total
-rw-r--r-- yun yun Aug : part-m-
2.4. 导入数据到hbase
把刚才导出的数据，导入到hbase。
方式1【该方式导入失败】
# 把 hbase 中表 zhang 的数据给删掉，然后导入
hbase(main)::* deleteall 'zhang',''
Took 0.0541 seconds \
hbase(main)::> scan 'zhang'
ROW COLUMN+CELL
row(s)
Took 0.0247 seconds
结果导入时死活没数据。。。
方式2【导入正常】
# 对表 zhang 进行truncate，然后导入数据 或者 删除表 zhang，再重建该表
hbase(main)::* truncate 'zhang'
Truncating 'zhang' table (it may take a while):
Disabling table...
Truncating table...
Took 1.8954 seconds
hbase(main)::> scan 'zhang'
ROW COLUMN+CELL
row(s)
Took 1.4118 seconds
导入数据命令
[yun@mini04 task_1533865678790_0003_m_000000]$ hbase org.apache.hadoop.hbase.mapreduce.Import zhang file:///app/software/hbase_data/zhang_tb/_temporary/1/task_1533865678790_0003_m_000000/part-m-00000
……………………
导入后查看
hbase(main):023:0* scan 'zhang'
ROW COLUMN+CELL
12345 column=baseinfo:age, timestamp=1533884261796, value=25
12345 column=baseinfo:name, timestamp=1533884258020, value=zhangnew
12345 column=eduinfo:pri_school, timestamp=1533884297216, value=star school
12345 column=userinfo:password, timestamp=1533884246132, value=111111
12345 column=userinfo:username, timestamp=1533884241334, value=zhangsan
1 row(s)
Took 0.0439 seconds
方式3【导入正常】
# 新建表导入 要求：表结构一样
hbase(main)::* create 'zhang_test','userinfo','baseinfo','eduinfo','workinfo'
Created table zhang_test
Took 0.7815 seconds \
=> Hbase::Table - zhang_test
hbase(main)::> list # 查看所有表
TABLE
scores
user
zhang
zhang_test
row(s)
Took 0.0280 seconds
=> ["scores", "user", "zhang", "zhang_test"]
导入数据命令
[yun@mini04 task_1533865678790_0003_m_000000]$ hbase org.apache.hadoop.hbase.mapreduce.Import zhang_test file:///app/software/hbase_data/zhang_tb/_temporary/1/task_1533865678790_0003_m_000000/part-m-00000
………………
导入后查看
hbase(main)::* scan 'zhang_test'
ROW COLUMN+CELL
column=baseinfo:age, timestamp=, value=
column=baseinfo:name, timestamp=, value=zhangnew
column=eduinfo:pri_school, timestamp=, value=star school
column=userinfo:password, timestamp=, value=
column=userinfo:username, timestamp=, value=zhangsan
row(s)
Took 0.0544 seconds
Hbase-2.0.0_02_常用操作的更多相关文章
- Hbase到Solr同步常用操作
Hbase到Solr同步常用操作 1. 整体流程 2. 常用操作 Hbase常用操作 Solr常用操作 hbase-index常用操作 3. 其他资料 Lily HBase Indexer使用整理 h ...
- kafka_2.11-2.0.0_常用操作
参考博文:Kafka消费组(consumer group) 参考博文:kafka 1.0 中文文档(九):操作 参考博文:kafka集群管理工具kafka-manager部署安装 以下操作可以在min ...
- Hbase常用操作(增删改查)
Hbase常用操作(增删改查) [日期:2014-01-03] 来源:Linux社区 作者:net19880504 [字体:大 中 小] 运行Eclipse,创建一个新的Java工程“HBa ...
- Hbase常用操作记录
Hbase常用操作记录 Hbase 创建表 查看表结构 修改表结构 删除表 创建表 语法:create <table>, {NAME => <family>, VERSI ...
- HBase常用操作之namespace
1.介绍 在HBase中,namespace命名空间指对一组表的逻辑分组,类似RDBMS中的database,方便对表在业务上划分.Apache HBase从0.98.0, 0.95.2两个版本开始支 ...
- C# 字符串常用操作 分类： C# 2014-08-22 15:07 238人阅读 评论(0) 收藏
string str1 = "C#操作字符串<几种常见方式>如下"; string str2 = "C#操作字符串"; //比较字符串 Co ...
- 『心善渊』Selenium3.0基础 — 11、Selenium对元素常用操作
目录 1.Selenium对元素常用操作 2.Selenium对元素的其他操作 1.Selenium对元素常用操作 操作 说明 click() 单击元素 send_keys() 模拟输入 clear( ...
- Hbase深入学习(六) Java操作HBase
Hbase深入学习(六) ―― Java操作HBase 本文讲述如何用hbase shell命令和hbase java api对hbase服务器进行操作. 先看以下读取一行记录hbase是如何进行工作 ...
- Oracle常用操作——创建表空间、临时表空间、创建表分区、创建索引、锁表处理
摘要:Oracle数据库的库表常用操作:创建与添加表空间.临时表空间.创建表分区.创建索引.锁表处理 1.表空间 ■ 详细查看表空间使用状况,包括总大小,使用空间,使用率,剩余空间 --详细查看表空 ...
随机推荐
- 从零开始学 Web 之 JavaScript（四）数组
大家好,这里是「 Daotin的梦呓 」从零开始学 Web 系列教程.此文首发于「 Daotin的梦呓 」公众号,欢迎大家订阅关注.在这里我会从 Web 前端零基础开始,一步步学习 Web 相关的知识 ...
- golang逃逸分析和竞争检测
最近在线上发现一块代码逻辑在执行N次耗时波动很大1ms~800ms,最开始以为是gc的问题,对代码进行逃逸分析,看哪些变量被分配到堆上了,后来发现是并发编程时对一个切片并发的写,导致存在竞争,类似下面 ...
- AI时代的OCR识别技术浅析
人工智能这个词可谓是耳熟能详,近几年人工智能热潮再次席卷而来,引起轰动的要数google的AlphaGo,相继打败了围棋界的韩国选手李世石以及世界冠军柯洁,见证了人工智能发展的里程碑式的变革,人工智能 ...
- 类Exception_A继承Exception，类Exception_B继承Exception_A，请问执行此段代码的输出是什么？
@Test public void Test_Exception() { try { throw new ExceptionB("A"); } catch (ExceptionA ...
- 如何将一个HTML页面嵌套在另一个页面中
一 在原页面嵌入其他页面 1.使用iframe框架 客户端页面嵌套可以使用iframe的方法,弊端是必须事先想好被嵌套的页面在首页中要占多大的位置. 如果被嵌套页面太大,超过事先定义的宽度或高度,则首 ...
- JavaSE Map集合
Map集合 在Map集合中保存的数据为一组数据,其中:一个数据为key,另外一个数据为value.而key和value具备对应的关系,在集合中它们属于一组(一对)数据.而每个key只能对应唯一的一个v ...
- Spring容器的创建刷新过程
Spring容器的创建刷新过程 以AnnotionConfigApplicationContext为例,在new一个AnnotionConfigApplicationContext的时候,其构造函数内 ...
- FIFO、LRU、LFU的含义和原理
含义: FIFO:First In First Out,先进先出LRU:Least Recently Used,最近最少使用 LFU:Least Frequently Used,最不经常使用 以上三者 ...
- css3 Box model 与 Box-sizing
1.Box Model(盒模型) CSS中的Box Model分为两种:第一种是W3C的标准模型,另一种是IE的传统模型.它们的相同之处是对元素的width.height.padding.border ...
- 《AngularJS入门与进阶》图书简介
一.图书封面 二.图书CIP信息 图书在版编目(CIP)数据 AngularJS入门与进阶 / 江荣波著. – 北京 : 清华大学出版社, 2017 ISBN 978-7-302-46074-9 Ⅰ. ...