g.txt

清华本科全套java课件 经典不用多说

//-------------------1  Math类 ---------------
class a
{ public static void main(String args[])
  { System.out.println(Math.E);  //2.718281828459045
    System.out.println(Math.PI);  // 3.141592653589793
    System.out.println(Math.exp( 5.7));   //298.8674009670603
    System.out.println(Math.random());   //0.1453998409754137
    System.out.println(Math.sqrt(9.08)); //3.0133038346638727
    System.out.println(Math.pow( 2,3));  //8.0
    System.out.println(Math.round(99.6));  //100
    System.out.println(Math.abs(- 8.09));  //8.09
  }
}
//--------2  Class 类 ----------------   
import java.lang.reflect.* ;
class test{

 public static void main(String args[]){
   
   MyClass a1 = new MyClass(2,5);
   System.out.println(a1.toString());
   System.out.println(a1.getClass().getName());
   Field[] f = a1.getClass().getFields()  ;
   Method[] m = a1.getClass().getMethods() ;
   for(int i = 0; i < f.length; i++)
	System.out.println(f[i].getName());
   for(int i = 0; i < m.length; i++)
	System.out.println(m[i].getName());
 }
}
class MyClass{
public int x,y;
public MyClass(int p1,int p2){x=p1;y=p2;}
public int getx(){ return x ;}
public int gety(){ return y ;}
public int getxy(){ return x*y ;}
}
//---------4   Vector 类  --------------------
import java.util.*;
class a
{ public static void main(String args[])
  {
    Vector v1 = new Vector();
    for(int i=0;i<15;i++)
    {v1.add(new String(Integer.toString(i)));
    }
    System.out.println(v1.get(2));
    System.out.println(v1.contains("3"));
    System.out.println(v1.indexOf("4"));
    v1.set(2,new String("wang"));
    System.out.println(v1.get(2));
    System.out.println(v1.size());
    System.out.println(v1.capacity());
    System.out.println(v1.isEmpty());
    v1.clear();
    System.out.println(v1.isEmpty());
  }
} 
//------------- 5  Date类 和  Calendar 类  ----------
import java.util.*;
class a
{ public static void main(String args[])
  {
    Date d = new Date();
    System.out.println(d.getTime());
    System.out.println(d.getTime()/1000/3600/24/365);
    System.out.println("----------------------------");
    Calendar  c = Calendar.getInstance();
    System.out.print(c.get(Calendar.YEAR)+" 年 " +
                     (c.get(Calendar.MONTH)+1)+" 月 " +
                     c.get(Calendar.DATE)+" 日   " );
    System.out.println(c.get(Calendar.HOUR)+ " 时 " +
                       c.get(Calendar.MINUTE)+ " 分 " +
                       c.get(Calendar.SECOND)+ " 秒 ");
    System.out.println(c.getTime().getTime());
    c.set(2001,4,1);           //  2001/5/1
    System.out.println(c.get(Calendar.YEAR)+" 年 " +
                     (c.get(Calendar.MONTH)+1)+" 月 " +
                     c.get(Calendar.DATE)+" 日   " );
    System.out.println(c.getTime().getTime()/1000/3600/24/365);
  }
}
//-------------6  向量类  银行帐户例 ----------------- 
import java.io.*;
import java.util.*;

public class a 
{
  public static void main(String args[])
  {
    BankAccount ba = new BankAccount();
	
    System.out.println(ba.saveMoney(100));
    System.out.println(ba.getMoney(30));
    System.out.println(ba.getMoney(500));
    System.out.println(ba.accountMsg());
    System.out.println("清户，本利共计： "+ba.clearAccount());
    
  }
}

class BankAccount
{
  private static long c_nextAccNum;		//银行帐号序列
  private static double c_interestRate;		//银行存款利率
  static  final  double c_LOWESTBALANCE=10.0;	//帐户最低存款余额
  private long m_accNum;			//帐户号
  private double m_balance;			//帐户余额
  Vector m_transRecord;				//帐户存/取款交易记录

  static{
    c_nextAccNum = 00001;
    c_interestRate = 0.02 ;
  }

  BankAccount()  {
    m_accNum = c_nextAccNum++;
    m_balance = c_LOWESTBALANCE;
    m_transRecord = new Vector();
  }

  BankAccount(double initBalance)  {
    this();
    if (initBalance > c_LOWESTBALANCE)	m_balance = initBalance;
  }
  double getBalance()  {
    return m_balance;
  }

  String saveMoney(double amount)  {	    //存款、记录交易情况
    if(amount > 0.0)  {
      m_balance += amount;
      Transaction tr=new Transaction(amount,'s',m_balance);
      m_transRecord.add(tr);
      return tr.transMeg();
    }
    else
      return ("存款额错");
  }

  String getMoney(double amount)  {       //取款、记录交易情况
    if((amount >= 0.0) && (amount <= m_balance - c_LOWESTBALANCE))  {
      m_balance -= amount;
      Transaction tr=new Transaction(amount,'g',m_balance);
      m_transRecord.add(tr);
      return tr.transMeg();
    }
    else
      return ("取款额错。目前存折上有： "+ m_balance);
  }

  double clearAccount()         //清户，取出本利     
  {
    double total_final=m_balance;
    Transaction tr=new Transaction(0,'s',0);
    m_transRecord.add(tr);
    total_final += accumulateInterest();
    m_transRecord.clear();
    return total_final;
  }
	
  double accumulateInterest()
  {
    double total=0;	
    Transaction temp1,temp2;

    for(int i=0; i<m_transRecord.size()-1; i++)
    {
	temp1 = (Transaction)m_transRecord.get(i);
	temp2 = (Transaction)m_transRecord.get(i+1);
        total += temp1.getRemain() * c_interestRate *
                 (temp2.getDays()-temp1.getDays())/365.0 ;
    }
    return total;
  }

  String accountMsg()
  {
    return  "帐号:\t" + m_accNum + "\n帐面余额:\t"+ m_balance;		
  }
}   // end of class BankAccount

class Transaction	//有关存取款的交易记录类
{
  private Calendar m_date  ;    //交易日期
  private double m_amount;	//存取的钱数
  private char m_type;		//交易类型标志： s 存 g 取
  private double m_remain;	//交易后余额

  Transaction(double a,char t,double r)  {
    m_date = Calendar.getInstance(); 
    m_amount = a;
    m_type = t;
    m_remain = r;
  }

  int getDateY()  {
    return m_date.get(Calendar.YEAR);
  }
  int getDateM()  {
    return m_date.get(Calendar.MONTH);
  }
  int getDateD()  {
    return m_date.get(Calendar.DATE);
  }

  long getDays()  {
    return m_date.getTime().getTime()/1000/3600/24;
  }

  double getAmount()
  {
    return m_amount;
  }

  String getType()
  {
    if(m_type=='s')  return "存款" ;
    else  return "取款";
  }

  double getRemain()
  {
    return m_remain;
  }

  String transMeg()
  {
   return "交易时间:" + getDateY()+"年" + getDateM() +"月" + getDateD() + "日  " 
          + getType()  + getAmount() + "  结存 " + getRemain();
  }
}
//-------------- 7   堆栈类  表达式计算例 -----------------
import java.util.* ;
public class a {
  public static void main(String[] args)  {
  
   Stack  s1 = new Stack();   
   Stack  s2 = new Stack();   
   String exp ;
   Oper op,optemp ;
   Data x,y,z ;
   int i=0 ;
   char c ;
   
   exp = args[0]+"#" ;
   s2.push(new Oper('#'));
   c = exp.charAt(i++) ;
   while(!(c=='#'&& ((Oper)s2.peek()).getop()=='#')) {
     if (c >= '0' && c <= '9')
        {s1.push(new Data(c));
         c = exp.charAt(i++) ;
        }
     else {
        op = new Oper(c);
        if ( ((Oper)s2.peek()).compare(op)<0 ) 
          { s2.push(op);
            c = exp.charAt(i++) ;
          }
        else if (((Oper)s2.peek()).compare(op)==0) 
          { s2.pop();
            c = exp.charAt(i++) ;
          }
        else
          { y = (Data)s1.pop();
            x = (Data)s1.pop();
            optemp = (Oper)s2.pop();
            z = optemp.compute(x,y);
            s1.push(z);
          }
      }  
   }  // end of while 
    System.out.println( ((Data)s1.pop()).getData() );
  }   // end of main()
}     // end of class a

class Oper {
  private char m_op ;

  Oper(char ch) {
    m_op = ch ;
  }

  char getop() {
    return m_op;
  }

  int compare(Oper p) {
    int i,j ;
    String ops = "+-*/()#" ;
    int[][] opa = { { 1, 1,-1,-1,-1, 1, 1},
                    { 1, 1,-1,-1,-1, 1, 1},
                    { 1, 1, 1, 1,-1, 1, 1},
                    { 1, 1, 1, 1,-1, 1, 1},
                    {-1,-1,-1,-1,-1, 0, 9},
                    { 1, 1, 1, 1, 9, 1, 1},
                    {-1,-1,-1,-1,-1, 9, 0}  };
     
    i = ops.indexOf(m_op);
    j = ops.indexOf(p.getop());
    return opa[i][j] ;
  }
    
  Data compute(Data m,Data n) {
     int result ;
    switch(m_op) {
     case '+' : result = m.getData() + n.getData() ; break;
     case '-' : result = m.getData() - n.getData() ; break;
     case '*' : result = m.getData() * n.getData() ; break;
     case '/' : result = m.getData() / n.getData() ; break;
     default  : result=0;
    }
     return new Data(result);
  }
}
    
class Data {
  private int m_dat ;

  Data(char ch) {
   m_dat = Character.digit(ch ,10) ;  
  }

  Data(int i) {
   m_dat = i ;
  }
  int getData() {
    return m_dat ;
  }
}