Java类库和常用类库介绍——序

java中map集合的用法

1.声明一个map: Map map = new HashMap();
2.向map中放值,注意：map是key-value的形式存放的.如:
map.put("sa","dd");
3.从map中取值:String str = map.get("sa").toString();结果是:str = "dd";
4.遍历一个map，从中取得key 和value
JDK1.5
Map m = new HashMap();
for ( ......

JPetStore 5.0(iBATIS for java)中Item.xml的bug

Caused by: java.sql.SQLException: ORA-00918: column ambiguously defined
Caused by: com.ibatis.common.jdbc.exception.NestedSQLException:
--- The error occurred in com/ibatis/jpetstore/persistence/sqlmapdao/sql/Item.xml.
--- The error occurred while applying a parameter map.&nbs ......

使用Java编写Telnet客户端

使用Java编写Telnet客户端
2009-12-24
Kagula
环境
   [1]Eclipse3.4.2
   [2]JDK 1.6.x
   [3] jta26.jar
可从下面网址下载这个Jar包
http://javassh.org/space/start
概要
    通过两个例子，介绍Telnet客户端的编写

正文
例子一：向OPhone虚拟机发送� ......

java面试中一些String常见问题

String s = new String("abc");
String s1 = "abc";
String s2 = new String("abc");

System.out.println(s == s1);
System.out.println(s == s2);
S ......