吴裕雄--天生自然 JAVA开发学习：异常处理

try
{
   // 程序代码
}catch(ExceptionName e1)
{
   //Catch 块
}

import java.io.*;
public class ExcepTest{

   public static void main(String args[]){
      try{
         int a[] = new int[2];
         System.out.println("Access element three :" + a[3]);
      }catch(ArrayIndexOutOfBoundsException e){
         System.out.println("Exception thrown  :" + e);
      }
      System.out.println("Out of the block");
   }
}

try{
   // 程序代码
}catch(异常类型1 异常的变量名1){
  // 程序代码
}catch(异常类型2 异常的变量名2){
  // 程序代码
}catch(异常类型2 异常的变量名2){
  // 程序代码
}

try {
    file = new FileInputStream(fileName);
    x = (byte) file.read();
} catch(FileNotFoundException f) { // Not valid!
    f.printStackTrace();
    return -1;
} catch(IOException i) {
    i.printStackTrace();
    return -1;
}

import java.io.*;
public class className
{
  public void deposit(double amount) throws RemoteException
  {
    // Method implementation
    throw new RemoteException();
  }
  //Remainder of class definition
}

import java.io.*;
public class className
{
   public void withdraw(double amount) throws RemoteException,
                              InsufficientFundsException
   {
       // Method implementation
   }
   //Remainder of class definition
}

try{
  // 程序代码
}catch(异常类型1 异常的变量名1){
  // 程序代码
}catch(异常类型2 异常的变量名2){
  // 程序代码
}finally{
  // 程序代码
}

public class ExcepTest{
  public static void main(String args[]){
    int a[] = new int[2];
    try{
       System.out.println("Access element three :" + a[3]);
    }catch(ArrayIndexOutOfBoundsException e){
       System.out.println("Exception thrown  :" + e);
    }
    finally{
       a[0] = 6;
       System.out.println("First element value: " +a[0]);
       System.out.println("The finally statement is executed");
    }
  }
}

class MyException extends Exception{
}

import java.io.*;

//自定义异常类，继承Exception类
public class InsufficientFundsException extends Exception
{
  //此处的amount用来储存当出现异常（取出钱多于余额时）所缺乏的钱
  private double amount;
  public InsufficientFundsException(double amount)
  {
    this.amount = amount;
  }
  public double getAmount()
  {
    return amount;
  }
}

import java.io.*;

//此类模拟银行账户
public class CheckingAccount
{
  //balance为余额，number为卡号
   private double balance;
   private int number;
   public CheckingAccount(int number)
   {
      this.number = number;
   }
  //方法：存钱
   public void deposit(double amount)
   {
      balance += amount;
   }
  //方法：取钱
   public void withdraw(double amount) throws
                              InsufficientFundsException
   {
      if(amount <= balance)
      {
         balance -= amount;
      }
      else
      {
         double needs = amount - balance;
         throw new InsufficientFundsException(needs);
      }
   }
  //方法：返回余额
   public double getBalance()
   {
      return balance;
   }
  //方法：返回卡号
   public int getNumber()
   {
      return number;
   }
}

public class BankDemo
{
   public static void main(String [] args)
   {
      CheckingAccount c = new CheckingAccount(101);
      System.out.println("Depositing $500...");
      c.deposit(500.00);
      try
      {
         System.out.println("\nWithdrawing $100...");
         c.withdraw(100.00);
         System.out.println("\nWithdrawing $600...");
         c.withdraw(600.00);
      }catch(InsufficientFundsException e)
      {
         System.out.println("Sorry, but you are short $"
                                  + e.getAmount());
         e.printStackTrace();
      }
    }
}