Java语言实验报告四

《Java语言与面向对象程序设计基础》课程

实验报告四

姓名：

学号：111**********

实验题1

[实验要求]

?掌握Java IO流处理

?掌握文件操作

?掌握多线程程序设计

[实验程序]

import java.io.*;

public class Test4_1 {

public static void main(String[] args) {

try {

File myDir=new File("C:/T est");

if ( !myDir.exists()) myDir.mkdir();

else if ( !myDir.isDirectory()) {

System.err.println(" 'C:/Test' is not a directory");

return;

}

File f=new File(myDir,"a.txt");

f.createNewFile();

FileWriter out = new FileWriter(f);

for (int i=0;i<26;i++){

out.write((char)('A'+i));

}

out.close();

} catch (IOException e) {

System.out.println(e);

}

}

}

[运行结果]

[实验结论与收获]

掌握文件及文件夹的创建及文件的写入。

实验题2

[实验要求]

将实验1题中新建的"a.txt"文件内容复制到"C:\Test\Ex"目录中"b.txt"文件中。[实验程序]

import java.io.*;

public class Test4_2 {

public static void main(String[] args) {

try {

File myDir=new File("C:/Test/Ex");

if ( !myDir.exists()) myDir.mkdir();

else if ( !myDir.isDirectory()) {

System.err.println(myDir+ " is not a directory");

return;

}

File myFile =new File(myDir,"b.txt");

myFile.createNewFile();

FileReader in= new FileReader("C:/Test/a.txt");

BufferedReader bufIn = new BufferedReader(in);

FileWriter out= new FileWriter (myFile);

BufferedWriter bufOut= new BufferedWriter(out);

String line;

line = bufIn.readLine();

//System.out.println(line);

while ( line!= null ) {

System.out.println(line);

bufOut.write(line,0,line.length());

bufOut.newLine();

line = bufIn.readLine();

}

bufIn.close();

bufOut.close();

} catch (IOException e) {

System.out.println(e);

}

}

}

[运行结果]

[实验结论与收获]

掌握文件读取和写入。

实验题3

[实验要求]

?将实验1题中新建的“a.txt”文件中写入字符“*”，替换第6个字符。

[实验程序]

import java.io.*;

public class Test4_3 {

public static void main(String[] args) {

try {

RandomAccessFile r = new RandomAccessFile("C:/Test/a.txt","rw");

r.seek(5);

r.write('*');

r.close();

} catch (IOException e) {

System.out.println(e);

}

}

}

[运行结果]

[实验结论与收获]

掌握随机文件创建与写入。

实验题4

[实验要求]

?调试并记录多线程程序（生产者/消费者实例）结果。

?体会多线程机制。

[实验程序]

Consumer.java

class Consumer implements Runnable{

SStack theStack;

public Consumer(SStack s){

theStack = s;

}

public void run(){

char c;

for (int i=0;i<20;i++) {

c = theStack.pop();

System.out.println("Consumed: "+c);

try{

Thread.sleep((int)(Math.random()*1000));

}catch(InterruptedException e){}

}

}

}

Producer.java

class Producer implements Runnable{

SStack theStack;

public Producer(SStack s){

theStack = s;

}

public void run(){

char c;

for(int i=0; i<20; i++){

c =(char)(Math.random()*26+'A');

theStack.push(c);

System.out.println("Produced: "+c);

try{

Thread.sleep((int)(Math.random()*100));

}catch(InterruptedException e){}

}

}

}

SStack.java

class SStack{

private int index = 0;

private char []data = new char[10];

public synchronized void push(char c){

while(index == data.length){

try{ this.wait();

}catch(InterruptedException e){ }

}

this.notify();

data[index] = c;

index++;

}

public synchronized char pop(){

while(index ==0){

try{ this.wait();

}catch(InterruptedException e){ } }

this.notify();

index--;

return data[index];

}

}

STest.java

public class ST est{

public static void main(String args[]){

SStack stack = new SStack();

Runnable p=new Producer(stack);

Runnable c = new Consumer(stack);

Thread t1 = new Thread(p);

Thread t2 = new Thread(c);

t1.start();

t2.start();

}

}

[运行结果]

[实验结论与收获]

掌握多线程应用