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java信息解壓縮編程題

發布時間: 2023-04-25 15:05:41

㈠ 問一道java程序題,如圖所示。

new Son();這擾虛個會調用沒猜Son類的無參構造方法
public Son(){
this("dd");//這緩察燃個會調用自己的方法 Son(String name);//這個方法會調用super("dd")//父類的有參構造方法
}
列印順序等一個方法執行完之後一步一步的執行,也就是你那個列印的東西

㈡ 請教兩道java編程題,關於IO包的。

nio不能實現一行一行讀,只能一塊一塊姿或讀或者一個字元一個字元讀。
代碼如下:

import java.io.*;
import java.nio.*;
import java.nio.channels.FileChannel;
public class Main
{
public static void main(String[] args)
{
Main t = new Main();
t.ReadFlieByLine_IO("E:\\123.txt");
t.ReadFileByLine_NIO("E:\\123.txt");
}

public void ReadFlieByLine_IO(String Filename)
{
File file = new File(Filename);
BufferedReader reader = null;
try
{
System.out.println("以行為局冊咐單位讀取文件內容,一次讀一整行:");
reader = new BufferedReader(new FileReader(file));
String tempString = null;
int line = 1;
//一次讀入一行,直到讀入null為文件結束
while ((tempString = reader.readLine()) != null)
{ //顯示行桐純號
System.out.println("line " + line + ": " + tempString);
line++;
}
reader.close();
}
catch (IOException e) {
e.printStackTrace();
}
/** finally {
if (reader != null){
try {
reader.close();
}
catch (IOException e1) {
}
}
}
*/
}

private void ReadFileByLine_NIO(String Filename)
{
FileInputStream file = null;
FileChannel reader = null;
try
{
file = new FileInputStream(Filename);
reader = file.getChannel();
String tempString = null;
ByteBuffer bb = ByteBuffer.allocate((int)reader.size());
reader.read(bb);
bb.flip();
String fileContent= new String(bb.array());
System.out.println(fileContent);
reader.close();
}
catch (IOException e) {
e.printStackTrace();
}
/** finally {
if (reader != null){
try {
reader.close();
}
catch (IOException e1) {
}
}
}
*/
}
}

㈢ 簡單java解壓縮問題

既然目錄的塵滲悄問題那你可喊改以在輸出流輸出之前創建目錄派渣撒,
你先創建一個File對象
然後測試他是否為一個目錄,不是就創建目錄
如你hello.zip
File f=new File("E:\\hello");
if(!f.isDirectory()){
f.mkdirs();
}

㈣ 5道簡單的JAVA編程題(高分懸賞)

很詳細的幫你寫下,呵呵,所以要給分哦!
1、
(1)源程序如下:
public class One {

public static void main(String[] args) {
String name = "張三";
int age = 23;
char sex = '男';
String myclass = "某某專業2班";
System.out.println("姓名:" + name);
System.out.println("姓名:" + age);
System.out.println("姓名:" + sex);
System.out.println("姓名:" + myclass);

}

}

(2)

編寫完程序的後綴名是.java,如本題,文件名就是One.java。
開始\運行\cmd,進入「命令提示符窗口」,然後用javac編譯器編譯.java文件,語句:javac One.java。

(3)
編譯成功後,生成的文件名後綴是.class,叫做位元組碼文件。再用java解釋器來運行改程序,語句:java One

2、編寫程序,輸出1到100間的所有偶數
(1)for語句
public class Two1 {

public static void main(String[] args) {
for(int i=2;i<=100;i+=2)
System.out.println(i);

}
}

(2)while語句
public class Two2 {

public static void main(String[] args) {
int i = 2;
while (i <= 100) {
System.out.println(i);
i += 2;
}
}
}

(3)do…while語句
public class Two3 {

public static void main(String[] args) {
int i = 2;
do {
System.out.println(i);
i += 2;
}while(i<=100);
}
}

3、編寫程序,從10個數當中找出最大值。
(1)for循環
import java.util.*;

public class Three1 {

public static void main(String[] args) {
Scanner input = new Scanner(System.in);
int number;
int max = 0;
for (int i = 0; i < 10; i++) {
System.out.print("輸入第" + (i + 1) + "個數:");
number = input.nextInt();
if (max < number)
max = number;
}
System.out.println("最大值:" + max);
}
}

(2)while語句
import java.util.*;

public class Three2 {

public static void main(String[] args) {
Scanner input = new Scanner(System.in);
int number;
int max = 0;
int i = 0;
while (i < 10) {
System.out.print("輸入第" + (i + 1) + "個數:");
number = input.nextInt();
if (max < number)
max = number;
i++;
}
System.out.println("最大值:" + max);
}
}

(3)do…while語句
import java.util.*;

public class Three3 {

public static void main(String[] args) {
Scanner input = new Scanner(System.in);
int number;
int max = 0;
int i = 0;
do {
System.out.print("輸入第" + (i + 1) + "個數:");
number = input.nextInt();
if (max < number)
max = number;
i++;
}while(i<10);
System.out.println("最大值:" + max);
}
}

4、編寫程序,計算從1到100之間的奇數之和。
(1)for循環

public class Four1 {

public static void main(String[] args) {
int sum=0;
for(int i = 1;i<=100;i+=2){
sum+=i;
}
System.out.println("1~100間奇數和:" + sum);
}
}

(2)while語句
public class Four2 {

public static void main(String[] args) {
int sum = 0;
int i = 1;
while (i <= 100) {
sum += i;
i += 2;
}
System.out.println("1~100間奇數和:" + sum);
}
}

(3)do…while語句
public class Four3 {

public static void main(String[] args) {
int sum = 0;
int i = 1;
do {
sum += i;
i += 2;
} while (i <= 100);
System.out.println("1~100間奇數和:" + sum);
}
}

5、
(1)什麼是類的繼承?什麼是父類?什麼是子類?舉例說明。
繼承:是面向對象軟體技術當中的一個概念。如果一個類A繼承自另一個類B,就把這個A稱為"B的子類",而把B稱為"A的父類"。繼承可以使得子類具有父類的各種屬性和方法,而不需要再次編寫相同的代碼。在令子類繼承父類的同時,可以重新定義某些屬性,並重寫某些方法,即覆蓋父類的原有屬性和方法,使其獲得與父類不同的功能。另外,為子類追加新的屬性和方法也是常見的做法。繼承需要關鍵字extends。舉例:
class A{}
class B extends A{}
//成員我就不寫了,本例中,A是父類,B是子類。

(2)編寫一個繼承的程序。
class Person {
public String name;
public int age;
public char sex;

public Person(String n, int a, char s) {
name = n;
age = a;
sex = s;
}

public void output1() {
System.out.println("姓名:" + name + "\n年齡:" + age + "\n性別:" + sex);
}
}

class StudentPerson extends Person {
String school, department, subject, myclass;

public StudentPerson(String sc, String d, String su, String m, String n,
int a, char s) {
super(n, a, s);
school = sc;
department = d;
subject = su;
myclass = m;
}

public void output2() {
super.output1();
System.out.println("學校:" + school + "\n系別:" + department + "\n專業:"
+ subject + "\n班級:" + myclass);
}
}

public class Five2 {

public static void main(String[] args) {
StudentPerson StudentPersonDemo = new StudentPerson("某某大學", "某某系別",
" 某專業", "某某班級", " 張三", 23, '男');
StudentPersonDemo.output2();
}
}

㈤ java壓縮文件的問題

有三種方式實現java壓縮:

1、jdk自帶的包java.util.zip.ZipOutputStream,不足之處,文件(夾)名稱帶中文時,出現亂碼問題,實現代碼如下:
/**
* 功能:把 sourceDir 目錄下的所有文件進行 zip 格式的壓縮,保存為指定 zip 文件
* @param sourceDir 如果是目錄,eg:D:\\MyEclipse\\first\\testFile,則壓縮目錄下所有文件;
* 如果是文件,eg:D:\\MyEclipse\\first\\testFile\\aa.zip,則只壓縮本文件
* @param zipFile 最後壓縮的文件路徑和名稱,eg:D:\\MyEclipse\\first\\testFile\\aa.zip
*/
public File doZip(String sourceDir, String zipFilePath) throws IOException {
File file = new File(sourceDir);
File zipFile = new File(zipFilePath);
ZipOutputStream zos = null;
try {
// 創建寫出流操作
OutputStream os = new FileOutputStream(zipFile);
BufferedOutputStream bos = new BufferedOutputStream(os);
zos = new ZipOutputStream(bos);

String basePath = null;

// 獲取目錄
if(file.isDirectory()) {
basePath = file.getPath();
}else {
basePath = file.getParent();
}

zipFile(file, basePath, zos);
}finally {
if(zos != null) {
zos.closeEntry();
zos.close();
}
}

return zipFile;
}
/**
* @param source 源文件
* @param basePath
* @param zos
*/
private void zipFile(File source, String basePath, ZipOutputStream zos)
throws IOException {
File[] files = null;
if (source.isDirectory()) {
files = source.listFiles();
} else {
files = new File[1];
files[0] = source;
}

InputStream is = null;
String pathName;
byte[] buf = new byte[1024];
int length = 0;
try{
for(File file : files) {
if(file.isDirectory()) {
pathName = file.getPath().substring(basePath.length() + 1) + "/";
zos.putNextEntry(new ZipEntry(pathName));
zipFile(file, basePath, zos);
}else {
pathName = file.getPath().substring(basePath.length() + 1);
is = new FileInputStream(file);
BufferedInputStream bis = new BufferedInputStream(is);
zos.putNextEntry(new ZipEntry(pathName));
while ((length = bis.read(buf)) > 0) {
zos.write(buf, 0, length);
}
}
}
}finally {
if(is != null) {
is.close();
}
}
}

2、使用org.apache.tools.zip.ZipOutputStream,代碼如下,
package net.szh.zip;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.util.zip.CRC32;
import java.util.zip.CheckedOutputStream;

import org.apache.tools.zip.ZipEntry;
import org.apache.tools.zip.ZipOutputStream;

public class ZipCompressor {
static final int BUFFER = 8192;

private File zipFile;

public ZipCompressor(String pathName) {
zipFile = new File(pathName);
}

public void compress(String srcPathName) {
File file = new File(srcPathName);
if (!file.exists())
throw new RuntimeException(srcPathName + "不存在!");
try {
FileOutputStream fileOutputStream = new FileOutputStream(zipFile);
CheckedOutputStream cos = new CheckedOutputStream(fileOutputStream,
new CRC32());
ZipOutputStream out = new ZipOutputStream(cos);
String basedir = "";
compress(file, out, basedir);
out.close();
} catch (Exception e) {
throw new RuntimeException(e);
}
}

private void compress(File file, ZipOutputStream out, String basedir) {
/* 判斷是目錄還是文件 */
if (file.isDirectory()) {
System.out.println("壓縮:" + basedir + file.getName());
this.compressDirectory(file, out, basedir);
} else {
System.out.println("壓縮:" + basedir + file.getName());
this.compressFile(file, out, basedir);
}
}

/** 壓縮一個目錄 */
private void compressDirectory(File dir, ZipOutputStream out, String basedir) {
if (!dir.exists())
return;

File[] files = dir.listFiles();
for (int i = 0; i < files.length; i++) {
/* 遞歸 */
compress(files[i], out, basedir + dir.getName() + "/");
}
}

/** 壓縮一個文件 */
private void compressFile(File file, ZipOutputStream out, String basedir) {
if (!file.exists()) {
return;
}
try {
BufferedInputStream bis = new BufferedInputStream(
new FileInputStream(file));
ZipEntry entry = new ZipEntry(basedir + file.getName());
out.putNextEntry(entry);
int count;
byte data[] = new byte[BUFFER];
while ((count = bis.read(data, 0, BUFFER)) != -1) {
out.write(data, 0, count);
}
bis.close();
} catch (Exception e) {
throw new RuntimeException(e);
}
}
}

3、可以用ant中的org.apache.tools.ant.taskdefs.Zip來實現,更加簡單。
package net.szh.zip;

import java.io.File;

import org.apache.tools.ant.Project;
import org.apache.tools.ant.taskdefs.Zip;
import org.apache.tools.ant.types.FileSet;

public class ZipCompressorByAnt {

private File zipFile;

public ZipCompressorByAnt(String pathName) {
zipFile = new File(pathName);
}

public void compress(String srcPathName) {
File srcdir = new File(srcPathName);
if (!srcdir.exists())
throw new RuntimeException(srcPathName + "不存在!");

Project prj = new Project();
Zip zip = new Zip();
zip.setProject(prj);
zip.setDestFile(zipFile);
FileSet fileSet = new FileSet();
fileSet.setProject(prj);
fileSet.setDir(srcdir);
//fileSet.setIncludes("**/*.java"); 包括哪些文件或文件夾 eg:zip.setIncludes("*.java");
//fileSet.setExcludes(...); 排除哪些文件或文件夾
zip.addFileset(fileSet);

zip.execute();
}
}
測試一下
package net.szh.zip;

public class TestZip {
public static void main(String[] args) {
ZipCompressor zc = new ZipCompressor("E:\\szhzip.zip");
zc.compress("E:\\test");

ZipCompressorByAnt zca = new ZipCompressorByAnt("E:\\szhzipant.zip");
zca.compress("E:\\test");
}
}

㈥ 有關java編程題目

按照題目要求源晌編寫的圓,圓錐和測試類的Java程序如下

Test.java文件內容如下

class Circle{

private double r;

private String color;

public Circle(double r){

this.r=r;

}

public double area(){

return Math.PI*r*r;

}

public double perimeter(){

return Math.PI*2*r;

}

public double getR(){

return this.r;

}

public void setR(double r){

this.r=r;

}

public String getColor(){

return this.color;

}

public void setColor(String color){

this.color=color;

}

public String toString(){

return "圓的半徑為"+r+",顏色為"+color;

}

}

class Cone{

private Circle c;

private double h;

private String color;

public Cone(Circle c,double h){

this.c=c;

this.h=h;

}

public double volume(){

return 1.0/3*c.area()*h;

}

public Circle getCircle(){

return this.c;

}

public void setCircle(Circle c){

this.c=c;

}

public double getH(){

return this.h;

}

public void setH(double h){

this.h=h;

}

public String getColor(){

return this.color;

}

public void setColor(String color){

this.color=color;

}

public String toString(){

return "圓錐的底面積為"燃悔+c.area()+",高為"+h+",顏色為"+color;

}

}

public class Test{

public static void main(String[] args){

Circle circle1=new Circle(2.5);

circle1.setColor("紅色");

System.out.println(circle1.toString());

System.out.println("圓的面積為"+circle1.area());

System.out.println("圓的周雹段鋒長為"+circle1.perimeter());

Cone circlar1=new Cone(circle1,2.7);

circlar1.setColor("藍色");

System.out.println(circlar1.toString());

System.out.println("圓錐的體積為"+circlar1.volume());

}

}

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