java 四种遍历List的方法及比较
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
public class ListTest {
public static void main(String args[]){
List<Long> lists = new ArrayList<Long>();
for(Long i=0l;i<1000000l;i++){
lists.add(i);
}
Long oneOk = oneMethod(lists);
Long twoOk = twoMethod(lists);
Long threeOk = threeMethod(lists);
Long fourOk = fourMethod(lists);
System.out.println("One:" + oneOk);
System.out.println("Two:" + twoOk);
System.out.println("Three:" + threeOk);
System.out.println("four:" + fourOk);
}
public static Long oneMethod(List<Long> lists){
Long timeStart = System.currentTimeMillis();
for(int i=0;i<lists.size();i++) {
System.out.println(lists.get(i));
}
......
import java.util.Random;
public class MathOperators {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
//随机数的产生
int[] arr = new int[10];
Random r = new Random();
for (int m = 0; m < arr.length; m++)
{
arr[m] = r.nextInt(100);
}
for (int n = 0; n < arr.length; n++)
{
System.out.println(arr[n]);
}
}
}
......
http://ilovelate.itpub.net/post/7368/40836
JAVA相关基础知识
1、面向对象的特征有哪些方面
1.抽象：
抽象就是忽略一个主题中与当前目标无关的那些方面，以便更充分地注意与当前目标有关的方面。抽象并不打算了解全部问题，而只是选择其中的一部分，暂时不用部分细节。抽象包括两个方面，一是过程抽象，二是数据抽象。
2.继承：
继承是一种联结类的层次模型，并且允许和鼓励类的重用，它提供了一种明确表述共性的方法。对象的一个新类可以从现有的类中派生，这个过程称为类继承。新类继承了原始类的特性，新类称为原始类的派生类（子类），而原始类称为新类的基类（父类）。派生类可以从它的基类那里继承方法和实例变量，并且类可以修改或增加新的方法使之更适合特殊的需要。
3.封装：
封装是把过程和数据包围起来，对数据的访问只能通过已定义的界面。面向对象计算始于这个基本概念，即现实世界可以被描绘成一系列完全自治、封装的对象，这些对象通过一个受保护的接口访问其他对象。
4. 多态性：
多态性是指允许不同类的对象对同一消息作出响应。多态性包括参数化多态性和包含多态性。多态性语言具有灵活、抽象、行为共享、代码共享的优势，很好的解决了� ......
Job Title: Java Consultant- Staff Software Engineering
Location: Shanghai
Company: HP China (www.hp.com)
This is a position reporting to Product Development Manager. The Staff Software Engineering will be responsible for leading development of robust high-volume kernel framework. The successful candidate will be a top performer and versatile professional leading the design, development and implementation of system infrastructure at eBay. This position will be based in Shanghai.
Responsibilities:
ž Define, design, implement, unit test and debug complex, multi-tier distributed software applications on eBay platform.
ž Work with other engineers, product management, QA and Operation team to design and implement application features
ž Estimate engineering effort, plan implementation, and rollout system changes.
ž Develop industry and product technical expertise.
......
依旧没有文字说明，只有少量的注释，二叉查找树有很多参考资料，这里就不多说了。下面奉上JAVA代码
package utility.structure;
import java.io.Serializable;
import java.security.InvalidParameterException;
import java.util.Comparator;
import java.util.ConcurrentModificationException;
/**
*
* @author odie.tang
* @version 1.0 11/09/09
*/
public class BinarySearchTree<E> implements Comparable<E>,Serializable{
private static final long serialVersionUID = -8154673525487170187L;
/**
* The comparator, or null if priority queue uses elements'
* natural ordering.
*/
private Comparator<? super E> comparator = null;
private E data;
private BinarySearchTree<E> parent = null;
private BinarySearchTree<E> leftChild = null;
private BinarySearchTree<E> rightChild = null;
/**
* level indicates node's level in the whole tree, eg: root's level is 1, and its children's level is 2...
*/
private int level;
/**
......
---------MySql-----
Class.forName("com.mysql.jdbc.Driver").newInstance();
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/test","username", "password");
--------Access ---------
建立ODBC数据源
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
Connection con=DriverManager.getConnection("jdbc:odbc:accessdb");
--------oracle---------
Class.forName("
oracle.jdbc.driver.OracleDriver"
).newInstance();
Connection con=DriverManager.getConnection("
jdbc:oracle:thin:@localhost:1521:dbname
","username","password");
---------db2---------
Class.forName("com.ibm.db2.jdbc.net.DB2Driver");
String url="jdbc:db2://192.9.200.108:6789/SAMPLE";
cn = DriverManager.getConnection( url, sUsr, sPwd );
---------Microsoft SQL Server---------
Class.forName( "com.microsoft.jdbc.sqlserver.SQLServerDriver" );
cn = DriverManager.getConnection( &qu ......
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