摘要: Atomic从JDK5开始, java.util.concurrent包里提供了很多面向并发编程的类. 使用这些类在多核CPU的机器上会有比较好的性能.
主要原因是这些类里面大多使用(失败-重试方式的)乐观锁而不是synchronized方式的悲观锁.

今天有时间跟踪了一下AtomicInteger的incrementAndGet的实现.
本人对并发编程也不是特别了解, 在这里就是做个笔记, 方便以后再深入研究.  阅读全文

     摘要: 概述
Apache MINA 是一个网络应用框架， 它可以帮助你简单容易的开发高性能，高可扩展性的网络应用程序。Apache MINA底层利用Java NIO实现，在TCP/IP和UPD/IP等传输层上提供一个抽象的基于事件驱动的异步API。  阅读全文

     摘要: 今天项目里遇到的, 在这里做个记录!  阅读全文

     摘要: 通过Spring-mvc的@InitBinder注释的方法可以对WebDataBinder做一些初始化操作。
比如设置Validator。
我一直在想能不能为每个Request或者每个Action方法单独设置Validator。
也就是说Controller里有多个被@InitBinder标注的方法。 在不同的Action时被分别调用。  阅读全文

     摘要: 当客户端和服务器都在自己的机器上时,用wireshark是看不到发送和接受到的数据包的.  阅读全文

     摘要: 调用mongoTemplate的save方法时, spring-data-mongodb的TypeConverter会自动给document添加一个_class属性, 值是你保存的类名. 这种设计并没有什么坏处. spring-data-mongodb是为了在把document转换成Java对象时能够转换到具体的子类. 但有时候我们并不希望出现这个字段, 主要是看上去会比较"烦". 可以通过设置MappingMongoConverter的MongoTypeMapper来解决这个问题.  阅读全文

     摘要: Visual Studio 2010 配置相关  阅读全文

     摘要: 在Tomcat的发行包中有一个bat文件很有意思.
可以把指定的参数添加到classpath里面.
和bat脚本for一起配合,可以实现自动的把某个目录下的jar包都放到classpath里.  阅读全文

     摘要: 显示文件列表的groovy脚本  阅读全文

     摘要: American Standard Code for Information Interchange (ASCII), pronounced /ˈæski/ is a character-encoding scheme based on the ordering of the English alphabet. ASCII codes represent text in computers, communications equipment, and other devices that work with text. ASCII includes definitions for 128 characters: 33 are non-printing control characters (number 0 to 31 and 127), now mostly obsolete that affect how text is processed; 94 are printable characters (numbers 32 to 126), and the space is cons  阅读全文

     摘要: In Groovy we can group the elements of a Collection type in a map. We define the rule for grouping with a closure. The result is a map where the key is the grouping condition and the value contains the elements of the Collection type belonging to the key. Let's see the groupBy method in action:  阅读全文

     摘要:
Constructors in Groovy can be invoked in a classic Java way, but we can also use lists or maps to create objects. Groovy supports an explicit coersion of a list to a constructor with the as keyword. Or we can rely on the implicit coersion when Groovy looks at the type of the variable to automatically convert the list to the right constructor call.  阅读全文

     摘要: Groovy has some features and methods we can categorize as functional programming. The inject() method is a so called higher-order function. Other languages call it a fold, reduce or accumulate. The inject() method processes a data structure with a closure and builds up a return value. The first parameter of the inject() method is the first value of the intermediary results of the second parameter: the closure. When we use the inject() we don't introduce any side effects, because we build up the   阅读全文

     摘要: Groovy has some elegant ways to work with date and time values. One of them is the support of durations. We can define a duration to denote a certain time amount, like 7 days, 2 hours and 50 minutes. We can use these durations to add or subtract them from date and time objects.

The TimeCategory provides an even Groovier way to work with durations. We can use constructs like 7.days + 12.minutes to create a duration. When we read this code it is just like reading English text. Here is som  阅读全文

     摘要: Since Groovy 1.6 we can define and assign values to several variables at once. This is especially useful when a method returns multiple values and we want to assign them to separate variables.  阅读全文

     摘要: Groovy has a with method we can use to group method calls and property access to an object. The with method accepts a closure and every method call or property access in the closure applies to the object if applicable. The method is part of Groovy's extensions to the java.lang.Object class. Let's see this with an example:  阅读全文

     摘要: 制作图片缩略图的Groovy脚本  阅读全文

     摘要: 改文件名的Groovy代码  阅读全文

     摘要: 下划线分割字符串转换成驼峰式字符串的groovy脚本  阅读全文

     摘要: 这是个什么问题呢?

首先你要在这样的环境下:
iBatis-2.3.4.726
oracle jdbc driver 10.2.0.3.0
你的数据库中字段定义为TIMESTAMP
你的sqlMap中的resultClass为hashmap
这是如果你这样调用

Map result = xxxDao.queryForObject(......);
Date someTime = (Date)result.get("someTime");

你会的到如下ClassCaseException: oracle.sql.TIMESTAMP  阅读全文