语源科技BlogJava-liuyf8688

常用软件端口号

liuyf8688 — Wed, 30 Mar 2016 06:59:00 GMT

liuyf8688 2016-03-30 14:59 发表评论

Log4j配置RollingFileAppender

liuyf8688 — Wed, 23 Mar 2016 09:30:00 GMT

log4j.rootLogger=INFO,stdout,wechat

log4j.appender.stdout=org.apache.log4j.ConsoleAppender

log4j.appender.stdout.layout=org.apache.log4j.PatternLayout

log4j.appender.stdout.layout.ConversionPattern=%d [%5p] %l - %m %n

log4j.appender.wechat=org.apache.log4j.RollingFileAppender

log4j.appender.wechat.threshold=debug

log4j.appender.wechat.File=${catalina.base}/logs/wechat.log

log4j.appender.wechat.MaxFileSize=5MB

log4j.appender.wechat.MaxBackupIndex=1

log4j.appender.wechat.layout=org.apache.log4j.PatternLayout

log4j.appender.wechat.layout.ConversionPattern=%d %p [%c] - %m%n

liuyf8688 2016-03-23 17:30 发表评论

Log4j配置DailyRollingFileAppender

liuyf8688 — Wed, 23 Mar 2016 08:12:00 GMT

log4j.rootLogger=INFO,stdout,wechat

log4j.appender.stdout=org.apache.log4j.ConsoleAppender

log4j.appender.stdout.layout=org.apache.log4j.PatternLayout

log4j.appender.stdout.layout.ConversionPattern=%d [%5p] %l - %m %n

log4j.appender.wechat=org.apache.log4j.DailyRollingFileAppender

log4j.appender.wechat.threshold=debug

log4j.appender.wechat.File=${catalina.base}/logs/wechat.log

log4j.appender.wechat.DatePattern='.'yyyy-MM-dd

log4j.appender.wechat.layout=org.apache.log4j.PatternLayout

log4j.appender.wechat.layout.ConversionPattern=%d %p [%c] - %m%n

liuyf8688 2016-03-23 16:12 发表评论

JS中最简单的HashMap实现

liuyf8688 — Wed, 27 Jan 2016 11:00:00 GMT

liuyf8688 2016-01-27 19:00 发表评论

Json String解析

liuyf8688 — Mon, 03 Aug 2015 10:33:00 GMT

背景

1.后台发布API，返回结果为JSON。
2.前端采用AJAX异步请求。

通常我们会碰到后台API返回单个返回值，类型为string的情况。
但是我们查看浏览器控制台或通过alter直接打印结果时，通常该值是被包裹在双引号中。
例如，"http://www.baidu.com"

＝＝＝＝＝＝＝＝＝＝＝＝＝割割割割割割割割===================

我们很困惑，
前端说：后端应该返回string，不带双引号。
后端说：我们返回的是标准JSON格式，不能去掉双引号。
前端说：标准JSON格式为什么不带大括号（{}）。

如果我们细心的去查询JSON官方站点(http://json.org)的话，我们会发现JSON拥有一个单独的类型为String。
定义如下：

A string is a sequence of zero or more Unicode characters, wrapped in double quotes, using backslash escapes. A character is represented as a single character string. A string is very much like a C or Java string

String是由0个或多个Unicode字符组成的序列，被包裹在双引号中。可以使用斜杠（\）来逃逸关键字或特殊字符。字符表示单个的字符串。
字符串与C或JAVA中的字符串非常相似。

现在我们明白了，原来这是一种标准的JSON格式。
那么我们怎么解析他呢。

其实非常简单，我们把他当作普通的JSON来解析就可以了。

liuyf8688 2015-08-03 18:33 发表评论

ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)

liuyf8688 — Sun, 26 Apr 2015 09:44:00 GMT

1. 通过DMG方式，安装完MySQL后，在shell命令行中尝试使用mysql -u root连接MySQL，出现下面提示。

ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)

由于根据本地环境及软件版本，没有统一的解决方案，下面我将说明我的软件环境。

软件说明：

Mac OS - 10.10.2 (OS X Yosemite)

MySQL - Ver 14.14 Distrib 5.7.7-rc, for osx10.8 (x86_64)

解决方案（暂时没有找到理想方案，所以尝试重置root密码：

1. 停止MySQL，使用跳过权限控制方案启动

1.1 使用Preference Pane关闭MySQL

双击MySQL，可能会要求你输入密码，输入密码后，将会打开如下窗口。

点击“Stop MySQL Server”，输入密码后，绿色的“running”将会变成红色的“stopped” ,说明MySQL被正常关闭。

1.2通过跳过权限控制启动

shell命令行输入以下命令回车

sudo mysqld_safe --skip-grant-tables

输入管理员密码后，显示如下提示，说明启动成功

150426 13:32:39 mysqld_safe Logging to '/usr/local/mysql/data/xxxMacBook-Pro.local.err'.

150426 13:32:39 mysqld_safe Starting mysqld daemon with databases from /usr/local/mysql/data

2. 如果以上全部成功，现在可以开始重置root密码了

开启新的shell窗口，输入mysql -u root，现在可以进入mysql了。

今次执行以下命令。

mysql> FLUSH PRIVILEGES;

根据版本不同，请执行不同的命令：

MySQL 5.7.6 and later:

mysql> ALTER USER ‘root’@‘localhost’ IDENTITIED BY ‘123456’;

MySQL 5.7.5 and earlier:

mysql> SET PASSWORD FOR ‘root’@‘localhost’ = PASSWORD(‘123456’);

3. 停止MySQL服务器，正常重启。现在你可以使用新的密码登录root用户了。

liuyf8688 2015-04-26 17:44 发表评论

Copying a Table in MySQL and including the Primary Key

liuyf8688 — Thu, 26 Mar 2015 03:36:00 GMT

CREATE TABLE new_table LIKE old_table;
INSERT INTO new_table SELECT * FROM old_table;

liuyf8688 2015-03-26 11:36 发表评论

DefaultCache in Ehcache

liuyf8688 — Mon, 29 Dec 2014 06:00:00 GMT

Default Cache configuration. These settings will be applied to caches created programmatically using CacheManager.add(String cacheName).

This element is optional, and using CacheManager.add(String cacheName) when its not present will throw CacheException

The defaultCache has an implicit name "default" which is a reserved cache name.

liuyf8688 2014-12-29 14:00 发表评论

Changing the project version

liuyf8688 — Thu, 11 Dec 2014 06:23:00 GMT

mvn versions:set -DnewVersion=XXX-SNAPSHOT

liuyf8688 2014-12-11 14:23 发表评论

Dependency scope In Maven

liuyf8688 — Tue, 09 Dec 2014 08:49:00 GMT

Dependency scope is used to limit the transitivity of a dependency, and also to affect the classpath used for various build tasks.

There are 6 scopes available:

compile
This is the default scope, used if none is specified. Compile dependencies are available in all classpaths of a project. Furthermore, those dependencies are propagated to dependent projects.
provided
This is much like compile, but indicates you expect the JDK or a container to provide the dependency at runtime. For example, when building a web application for the Java Enterprise Edition, you would set the dependency on the Servlet API and related Java EE APIs to scope provided because the web container provides those classes. This scope is only available on the compilation and test classpath, and is not transitive.
runtime
This scope indicates that the dependency is not required for compilation, but is for execution. It is in the runtime and test classpaths, but not the compile classpath.
test
This scope indicates that the dependency is not required for normal use of the application, and is only available for the test compilation and execution phases.
system
This scope is similar to provided except that you have to provide the JAR which contains it explicitly. The artifact is always available and is not looked up in a repository.
import (only available in Maven 2.0.9 or later)
This scope is only used on a dependency of type pom in the section. It indicates that the specified POM should be replaced with the dependencies in that POM's section. Since they are replaced, dependencies with a scope ofimport do not actually participate in limiting the transitivity of a dependency.

Each of the scopes (except for import) affects transitive dependencies in different ways, as is demonstrated in the table below. If a dependency is set to the scope in the left column, transitive dependencies of that dependency with the scope across the top row will result in a dependency in the main project with the scope listed at the intersection. If no scope is listed, it means the dependency will be omitted.

	compile	provided	runtime	test
compile	compile(*)	-	runtime	-
provided	provided	-	provided	-
runtime	runtime	-	runtime	-
test	test	-	test	-

(*) Note: it is intended that this should be runtime scope instead, so that all compile dependencies must be explicitly listed - however, there is the case where the library you depend on extends a class from another library, forcing you to have available at compile time. For this reason, compile time dependencies remain as compile scope even when they are transitive.

liuyf8688 2014-12-09 16:49 发表评论