《Java就业培训教程》_张孝祥_书内源码_07

《Java就业培训教程》 作者：张孝祥 书中源码
《Java就业培训教程》P239源码
程序清单：FileTest.java
import java.io.*;
public class FileTest
{
 public static void main(String[] args)
 {
  File f=new File("c://1.txt");
  if(f.exists())
   f.delete();
  else
   try
   {
    f.createNewFile();
   }
   catch(Exception e)
   {
    System.out.println(e.getMessage());
   }
  System.out.println("File name:"+f.getName());
  System.out.println("File path:"+f.getPath());
  System.out.println("Abs path:"+f.getAbsolutePath());
  System.out.println("Parent:"+f.getParent());
  System.out.println(f.exists()?"exists":"does not exist");
  System.out.println(f.canWrite()?"is writeable":"is not writeable");
  System.out.println(f.canRead()?"is readable":"is not readable");
  System.out.println(f.isDirectory()?"is ":"is not"+" a directory");
  System.out.println(f.isFile()?"is normal file":"might be a named pipe");
  System.out.println(f.isAbsolute()?"is absolute":"is not absolute");
  System.out.println("File last modified:"+f.lastModified());
  System.out.println("File size:"+f.length()+" Bytes");
 }
}
《Java就业培训教程》P242源码
程序清单：RandomFileTest.java
import java.io.*;
public class RandomFileTest
{
 public static void main(String [] args) throws Exception
 {
  Employee e1 = new Employee("zhangsan",23);
  Employee e2 = new Employee("Lisi",24);
  Employee e3 = new Employee("Wangwu",25);
  RandomAccessFile ra=new RandomAccessFile("c://1.txt","rw");
  ra.write(e1.name.getBytes());
  ra.writeInt(e1.age);
  ra.write(e2.name.getBytes());
  ra.writeInt(e2.age);
  ra.write(e3.name.getBytes());
  ra.writeInt(e3.age);
  ra.close();
  RandomAccessFile raf=new RandomAccessFile("c://1.txt","r");
  int len=8;
  raf.skipBytes(12); //跳过第一个员工的信息，其中姓名8字节，年龄4字节
  System.out.println("第二个员工信息：");
  String str="";
  for(int i=0;i<len;i++)
   str=str+(char)raf.readByte();
  System.out.println("name:"+str);
  System.out.println("age:"+raf.readInt());
  
  System.out.println("第一个员工的信息：");
  raf.seek(0); //将文件指针移动到文件开始位置
  str="";
  for(int i=0;i<len;i++)
   str=str+(char)raf.readByte();
  System.out.println("name:"+str);
  System.out.println("age:"+raf.readInt());
  
  System.out.println("第三个员工的信息：");
  raf.skipBytes(12);  //跳过第二个员工信息
  str="";
  for(int i=0;i<len;i++)
   str=str+(char)raf.readByte();
  System.out.println("name:"+str.trim());
  System.out.println("age:"+raf.readInt());
  
  raf.close();
 }
}
class Employee
{  
  String name;
  int age;
  final static int LEN=8;
  public Employee(String name,int age)
  {
   if(name.length()>LEN)
   {
    name = name.substring(0,8);
   }
   else
   {
    while(name.length()<LEN)
     name=name+"/u0000";
   }
   this.name=name;
   this.age=age;   
  }
}
《Java就业培训教程》P247源码
程序清单：FileStream.java
import java.io.*;
public class FileStream
{
 public static void main(String[] args)
 {
  File f = new File("hello.txt");
  try
  {
   FileOutputStream out = new FileOutputStream(f);
   byte buf[]="www.it315.org".getBytes();
   out.write(buf);
   out.close();
  }
  catch(Exception e)
  {
   System.out.println(e.getMessage());
  }
  
  try
  {
   FileInputStream in = new FileInputStream(f);
   byte [] buf = new byte[1024];
   int len = in.read(buf);
   System.out.println(new String(buf,0,len));
  }
  catch(Exception e)
  {
   System.out.println(e.getMessage());
  }
 }
}
《Java就业培训教程》P250源码
程序清单：PipeStreamTest.java
import java.io.*;
public class PipeStreamTest
{
    public static void main(String args[])
    {
        try
        {
            Sender t1=new Sender();
            Receiver t2=new Receiver();
            PipedOutputStream out = t1.getOutputStream();
            PipedInputStream in = t2.getInputStream();
            out.connect(in);
            t1.start();
            t2.start();
        }
        catch(IOException e)
        {
         System.out.println(e.getMessage());
        }
    }
}
class Sender extends Thread
{
    private PipedOutputStream out=new PipedOutputStream();
    public PipedOutputStream getOutputStream()
    {
        return out;
    }
    public void run()
    {
        String s=new String("hello,receiver,how are you!");
        try
        {
            out.write(s.getBytes());
            out.close();
        }
        catch(IOException e)
        {
         System.out.println(e.getMessage());
        }
    }
}
class Receiver extends Thread
{
    private PipedInputStream in=new PipedInputStream();
    public PipedInputStream getInputStream()
    {
        return in;
    }
    public void run()
    {
        String s=null;
    byte [] buf = new byte[1024];
        try
        {
            int len =in.read(buf);
     s = new String(buf,0,len);
            System.out.println(
"the following message comes from sender:/n"+s);
            in.close();
        }
        catch(IOException e)
        {
         System.out.println(e.getMessage());
        }
    }
}
《Java就业培训教程》P253源码
程序清单：ByteArrayTest.java
import java.io.*;
public class ByteArrayTest
{
 public static void main(String[] args) throws Exception
 {
  String tmp="abcdefghijklmnopqrstuvwxyz";
  byte [] src =tmp.getBytes();//src为转换前的内存块
  ByteArrayInputStream input = new ByteArrayInputStream(src);
  ByteArrayOutputStream output = new ByteArrayOutputStream();
  new ByteArrayTest().transform(input,output);
  byte [] result = output.toByteArray();//result为转换后的内存块
  System.out.println(new String(result));
 }
 public void transform(InputStream in,OutputStream out)
 {
  int c=0;
  try
  {
   while((c=in.read())!=-1)//read在读到流的结尾处返回-1
   {
    int C = (int)Character.toUpperCase((char)c);
    out.write(C);
   
   }
  }
  catch(Exception e)
  {
   e.printStackTrace();
  }
 }
}
《Java就业培训教程》P263源码
程序清单：Serializatioan.java
import java.io.*;
public class serialization
{
    public static void main(String args[])
throws IOException,ClassNotFoundException
    {
        Student stu=new Student(19,"dintdding",50,"huaxue");
        FileOutputStream fos=new FileOutputStream("mytext.txt");
        ObjectOutputStream os=new ObjectOutputStream(fos);
       
        try
        {
            os.writeObject(stu);
            os.close();
        }catch(IOException e)
{
 System.out.println(e.getMessage());
}
        stu=null;
        FileInputStream fi=new FileInputStream("mytext.txt");
        ObjectInputStream si=new ObjectInputStream(fi);
        try
        {
            stu=(Student)si.readObject();
            si.close();
        }catch(IOException e)
{
 System.out.println(e.getMessage());
}
        System.out.println("ID is:"+stu.id);
       System.out.println("name is:"+stu.name);
       System.out.println("age is:"+stu.age);
       System.out.println("department is:"+stu.department);
    }
   
}
class Student implements Serializable
{
    int id;
    String name;
    int age;
    String department;
    public Student(int id,String name,int age,String department)
    {
        this.id=id;
        this.name=name;
        this.age=age;
        this.department=department;
    }
}
《Java就业培训教程》P275源码
import java.io.*;
public class CharDecoder
{
 public static void main(String [] args) throws Exception
 {
  System.getProperties().put("file.encoding","iso8859-1");
  System.out.println("please enter a Chinese String");
  byte [] buf=new byte[1024];
  int ch=0;
  int pos=0;
  String strInfo=null;
  while(true)
  {           
  ch =System.in.read();
  System.out.println(Integer.toHexString(ch));
  switch(ch)
  {
   case '/r':
    break;
   case '/n':
    strInfo= new String(buf,0,pos);
    for(int i=0;i<strInfo.length();i++)
    {
     System.out.println(Integer.toHexString
      ((int)strInfo.charAt(i)));
    }
    System.out.println(strInfo);
    for(int i=0;i<pos;i++)
    System.out.write(buf[i]);
    System.out.println();//想想为什么要这一句
    return;
   default:
    buf[pos++]=(byte)ch;
  }
  }   
 }
}
《Java就业培训教程》P282源码
程序清单: TestInOut.java
import java.io.*;
public class TestInOut implements Runnable
{
 Process p=null;
 public TestInOut()
 {
         try
  {
   p=Runtime.getRuntime().exec("java MyTest");
   new Thread(this).start();
  }
      catch(Exception e)
      {
        System.out.println(e.getMessage());
      }  
 }

 public void send()
 {
         try
  {

           OutputStream ops=p.getOutputStream();
           while(true)
           {
           ops.write("help/r/n".getBytes());
        }
     }
      catch(Exception e)
      {
        System.out.println(e.getMessage());
      }
 }
 public static void main(String [] args)
 {
  TestInOut tio=new TestInOut ();
  tio.send();

 }
 public void run()
 {
  try
  {
   InputStream in = p.getInputStream();
          BufferedReader bfr=new BufferedReader(
           new InputStreamReader(in));
   while(true)
   {
    String strLine=bfr.readLine();
           System.out.println(strLine);
       }
     }
      catch(Exception e)
      {
       System.out.println(e.getMessage());
      }
 }
}

class MyTest
{
 public static void main(String [] args) throws IOException
 {
  while(true)
  {
   System.out.println("hi:"+
   new BufferedReader(new InputStreamReader(System.in)).readLine());
  }
 }
}