Java 课下练习题 T4

1. 对指定的图片(>2M)进行复制，将其复制到另外一个文件夹下，要求使用InputStream,OutputStream或它们的子类来实现。

2. 对指定的文本文件进行从头到尾的遍历，并将遍历的内容写入到另外一个文件里。

3. 把键盘输入的内容写入到文本文件中,按以下格式

4、 设计一个类读取用户输入的文本行并对文本行进行编码，然后输出编码的文本行,编码要求：将字母表中的每个字母用其后第13 个位置的字母代替.

5、 将一个文件的内容装换为大写，显示出来，并把内容复制到文件中去。

6、 书写一个以.properties命名的文件，这个文件的特点是以key=value的形式书写文件内容，例如：

key1=value1

key2=value2

key3=value3

…..

然后当用户输入指定的key值时能够准确的把其对应的value值取出。

7、 使用学习的IO知识构建一个基于控制台的应用程序，要求具有系统欢迎菜单功能，并且可以循环选择菜单，在选中相应的项目的时候进入二级菜单进行执行，执行完毕可以返回上一级菜单，用户可以根据需要退出系统。

package zuoye4;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;public class T1 { public static void main(String[] args) throws IOException {                demo1();            }public static void demo1() throws FileNotFoundException, IOException {FileInputStream fis = new FileInputStream("E:\\x.jpg");FileOutputStream fos = new FileOutputStream("d:\\01.jpg");int len = 0;byte[] buf = new byte[4096];while ((len = fis.read(buf)) != -1) {fos.write(buf, 0, len);}fis.close();fos.close();}}

package zuoye4;import java.io.FileNotFoundException;import java.io.FileReader;import java.io.FileWriter;import java.io.IOException;public class T2 {public static void main(String[] args) {FileReader fr = null;char ch[] = new char[100];try {fr = new FileReader("E:/a.txt");//char ch[] = new char[100];int len = fr.read(ch);for (int i = 0; i < len; i++) {System.out.println(ch[i]);}String ss = new String(ch,0,len);System.out.println(ss);} catch (FileNotFoundException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}finally{try {fr.close();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}fr = null;}FileWriter fw = null;String strStringType="my string";strStringType= String.valueOf(ch);try {fw = new FileWriter("E:/at2.txt");fw.write(strStringType);fw.flush();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}finally{try {fw.close();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}fw = null;}}}

package zuoye4;import java.io.File;import java.io.FileWriter;import java.io.IOException;import java.util.Scanner;public class T3 {private static Scanner sc;  public static void main(String[] args) {sc = new Scanner(System.in);String ch;ch =sc.nextLine();FileWriter fw = null;try {fw = new FileWriter(new File("E:/aa3.txt"),true);fw.write(ch+"\r\n");fw.flush();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}finally{try {fw.close();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}fw = null;}}}

package zuoye4;import java.util.Scanner;public class T4 {public static void main(String[] args) {        String lower="abcdefghijklmnopqrstuvwxyz";        String upper="ABCDEFGHIJKLMNOPQRSTUVWXYZ";        @SuppressWarnings("resource")Scanner sc= new Scanner(System.in );        String text=sc.nextLine();        StringBuilder sb= new StringBuilder();        final int offset=13;        for (char A:text.toCharArray()) {            if (Character.isLowerCase(A)) {                sb.append(lower.charAt((lower.indexOf(A)+offset)%lower.length()));            } else {                sb.append(upper.charAt((upper.indexOf(A)+offset)%upper.length()));            }         }         System.out.println(sb.toString());}      }

package zuoye4;import java.io.File;import java.io.FileNotFoundException;import java.io.FileReader;import java.io.FileWriter;import java.io.IOException;public class T5 {public static void main(String[] args) {FileReader fr = null;String uppercase = new String();char ch[] = new char[100];try {fr = new FileReader("E:/a5.txt");int len = fr.read(ch);for (int i = 0; i < len; i++) {System.out.println(ch[i]);}String ss = new String(ch,0,len);System.out.println(ss);} catch (FileNotFoundException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}finally{try {fr.close();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}fr = null;}FileWriter fw = null;String strStringType="my string";strStringType= String.valueOf(ch);uppercase = strStringType.toUpperCase();try {fw = new FileWriter(new File("E:/a5.txt"),true);//fw = new FileWriter("E:/at2.txt");fw.write(uppercase);fw.flush();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}finally{try {fw.close();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}fw = null;}System.out.println(uppercase); }}

package zuoye4;import java.io .FileInputStream;import java.io .IOException;import java.io .InputStream;import java.util.Properties;import java.util.Scanner;public class T6 {private static Scanner sc;   public static void main(String args[]) throws IOException {  test4f(); } public static void test4f() throws IOException { sc = new Scanner(System.in);String ch;ch =sc.nextLine();         InputStream is = new FileInputStream("E:\\a6.properties");         Properties prop = new Properties();         prop.load(is);         System.out.println(prop.getProperty(ch));  }}

package zuoye4;import java.io.BufferedReader;import java.io.InputStreamReader;import java.util.Scanner;public class T7 {public static void main(String[] args) {int num ;String str ;BufferedReader brd=new BufferedReader(new InputStreamReader(System.in)) ;while(true){System.out.println("欢迎来到欢迎系统") ;System.out.println("----------------------") ;System.out.println("进入登录系统请输入1") ;System.out.println("进入注册系统请输入2") ;System.out.println("退出系统请输入0") ;System.out.println("请输入数字:") ;try{str=brd.readLine() ;num=Integer.parseInt(str) ;if(num==1){fun1();}else if(num==2){fun2();}else if(num==0){System.out.println("正在退出") ;break;}else System.out.println("对不起，只能输入0、1、2，请重新输入。") ;}catch(Exception e){System.out.println("对不起，只能输入整数，请重新输入。") ;}}}public static void fun1(){System.out.println("欢迎来到登录系统") ;System.out.println("返回上一步请输入0") ;System.out.println("请输入数字:") ;BufferedReader brd1=new BufferedReader(new InputStreamReader(System.in)) ;int num1;while(true){try{String str=brd1.readLine() ;num1=Integer.parseInt(str) ;if(num1==0){break;}}catch(Exception e){System.out.println("对不起，只能输入整数，请重新输入。") ;}}};public static void fun2(){System.out.println("欢迎来到注册系统") ;System.out.println("返回上一步请输入0") ;System.out.println("请输入数字:") ;BufferedReader brd1=new BufferedReader(new InputStreamReader(System.in)) ;int num2;while(true){try{String str=brd1.readLine() ;num2=Integer.parseInt(str) ;if(num2==0){break;}}catch(Exception e){System.out.println("对不起，只能输入整数，请重新输入。") ;}}};}