摘要: Atomic從JDK5開始, java.util.concurrent包里提供了很多面向并發編程的類. 使用這些類在多核CPU的機器上會有比較好的性能.
主要原因是這些類里面大多使用(失敗-重試方式的)樂觀鎖而不是synchronized方式的悲觀鎖.

今天有時間跟蹤了一下AtomicInteger的incrementAndGet的實現.
本人對并發編程也不是特別了解, 在這里就是做個筆記, 方便以后再深入研究.  閱讀全文

     摘要: 概述
Apache MINA 是一個網絡應用框架， 它可以幫助你簡單容易的開發高性能，高可擴展性的網絡應用程序。Apache MINA底層利用Java NIO實現，在TCP/IP和UPD/IP等傳輸層上提供一個抽象的基于事件驅動的異步API。  閱讀全文

     摘要: 今天項目里遇到的, 在這里做個記錄!  閱讀全文

     摘要: 通過Spring-mvc的@InitBinder注釋的方法可以對WebDataBinder做一些初始化操作。
比如設置Validator。
我一直在想能不能為每個Request或者每個Action方法單獨設置Validator。
也就是說Controller里有多個被@InitBinder標注的方法。 在不同的Action時被分別調用。  閱讀全文

     摘要: 當客戶端和服務器都在自己的機器上時,用wireshark是看不到發送和接受到的數據包的.  閱讀全文

     摘要: 調用mongoTemplate的save方法時, spring-data-mongodb的TypeConverter會自動給document添加一個_class屬性, 值是你保存的類名. 這種設計并沒有什么壞處. spring-data-mongodb是為了在把document轉換成Java對象時能夠轉換到具體的子類. 但有時候我們并不希望出現這個字段, 主要是看上去會比較"煩". 可以通過設置MappingMongoConverter的MongoTypeMapper來解決這個問題.  閱讀全文

     摘要: Visual Studio 2010 配置相關  閱讀全文

     摘要: 在Tomcat的發行包中有一個bat文件很有意思.
可以把指定的參數添加到classpath里面.
和bat腳本for一起配合,可以實現自動的把某個目錄下的jar包都放到classpath里.  閱讀全文

     摘要: 顯示文件列表的groovy腳本  閱讀全文

     摘要: American Standard Code for Information Interchange (ASCII), pronounced /??ski/ 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  閱讀全文

     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:  閱讀全文

     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.  閱讀全文

     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   閱讀全文

     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  閱讀全文

     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.  閱讀全文

     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:  閱讀全文

     摘要: 制作圖片縮略圖的Groovy腳本  閱讀全文

     摘要: 改文件名的Groovy代碼  閱讀全文

     摘要: 下劃線分割字符串轉換成駝峰式字符串的groovy腳本  閱讀全文

     摘要: 這是個什么問題呢?

首先你要在這樣的環境下:
iBatis-2.3.4.726
oracle jdbc driver 10.2.0.3.0
你的數據庫中字段定義為TIMESTAMP
你的sqlMap中的resultClass為hashmap
這是如果你這樣調用

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

你會的到如下ClassCaseException: oracle.sql.TIMESTAMP  閱讀全文