[英]Variable declaration from one class to another
下面的代碼工作正常(單獨),我只想將FindDrive類中的letter [i]值傳遞給Ziputils輸入文件位置,以便我可以自動壓縮pendrive數據。
FindDrive類
package com.prosper;
import java.io.File;
public class FindDrive
{
/**
* Application Entry Point
*/
public static void main(String[] args)
{
String[] letters = new String[]{ "A", "B", "C", "D", "E", "F", "G", "H", "I"};
File[] drives = new File[letters.length];
boolean[] isDrive = new boolean[letters.length];
// init the file objects and the initial drive state
for ( int i = 0; i < letters.length; ++i )
{
drives[i] = new File(letters[i]+":/");
isDrive[i] = drives[i].canRead();
}
System.out.println("FindDrive: waiting for devices...");
// loop indefinitely
while(true)
{
// check each drive
for ( int i = 0; i < letters.length; ++i )
{
boolean pluggedIn = drives[i].canRead();
// if the state has changed output a message
if ( pluggedIn != isDrive[i] )
{
if ( pluggedIn ){
System.out.println("Drive "+letters[i]+" has been plugged in");
}
else
System.out.println("Drive "+letters[i]+" has been unplugged");
isDrive[i] = pluggedIn;
}
}
// wait before looping
try { Thread.sleep(100); }
catch (InterruptedException e) { /* do nothing */ }
}
}
}
ZipUtils類
package com.prosper;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;
public class ZipUtils {
private List <String> fileList;
private static final String OUTPUT_ZIP_FILE = "E:\\appu\\Folder.zip";
private static final String SOURCE_FOLDER = "E:\\appu\\"; //SourceFolder
public ZipUtils() {
fileList = new ArrayList < String > ();
}
public static void main(String[] args) {
ZipUtils appZip = new ZipUtils();
appZip.generateFileList(new File(SOURCE_FOLDER));
appZip.zipIt(OUTPUT_ZIP_FILE);
}
public void zipIt(String zipFile) {
byte[] buffer = new byte[1024];
String source = new File(SOURCE_FOLDER).getName();
FileOutputStream fos = null;
ZipOutputStream zos = null;
try {
fos = new FileOutputStream(zipFile);
zos = new ZipOutputStream(fos);
System.out.println("Output to Zip : " + zipFile);
FileInputStream in = null;
for (String file: this.fileList) {
System.out.println("File Added : " + file);
ZipEntry ze = new ZipEntry(source + File.separator + file);
zos.putNextEntry(ze);
try {
in = new FileInputStream(SOURCE_FOLDER + File.separator + file);
int len;
while ((len = in .read(buffer)) > 0) {
zos.write(buffer, 0, len);
}
} finally {
in.close();
}
}
zos.closeEntry();
System.out.println("Folder successfully compressed");
} catch (IOException ex) {
ex.printStackTrace();
} finally {
try {
zos.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
public void generateFileList(File node) {
// add file only
if (node.isFile()) {
fileList.add(generateZipEntry(node.toString()));
}
if (node.isDirectory()) {
String[] subNote = node.list();
for (String filename: subNote) {
generateFileList(new File(node, filename));
}
}
}
private String generateZipEntry(String file) {
return file.substring(SOURCE_FOLDER.length() + 1, file.length());
}
}
要將數據從一個類傳遞到另一類,您可以執行以下操作:
1)在FindDrive類中創建該類的對象:
ZipUtils utils = new ZipUtils();
2)將值傳遞給該類的方法:
utils.zipIt(letter[i])
我插入了一些語句,這些語句創建ZipUtils類的新對象並調用該方法,但是,如果您想在此處提高代碼質量,我建議您也查看Dependency Injection。
package com.prosper;
import java.io.File;
public class FindDrive {
/**
* Application Entry Point
*/
public static void main(String[] args) {
String[] letters = new String[] {"A", "B", "C", "D", "E", "F", "G",
"H", "I"};
ZipUtils utils;
File[] drives = new File[letters.length];
boolean[] isDrive = new boolean[letters.length];
// init the file objects and the initial drive state
for (int i = 0; i < letters.length; ++i) {
drives[i] = new File(letters[i] + ":/");
isDrive[i] = drives[i].canRead();
}
System.out.println("FindDrive: waiting for devices...");
// loop indefinitely
while (true) {
// check each drive
for (int i = 0; i < letters.length; ++i) {
boolean pluggedIn = drives[i].canRead();
utils = new ZipUtils();
utils.changeDirectory(letters[i]);
// if the state has changed output a message
if (pluggedIn != isDrive[i]) {
if (pluggedIn) {
System.out.println("Drive " + letters[i] + " has been plugged in");
} else {
System.out.println("Drive " + letters[i] + " has been unplugged");
}
isDrive[i] = pluggedIn;
}
}
// wait before looping
try {
Thread.sleep(100);
} catch (InterruptedException e) { /* do nothing */ }
}
}
}
要在聲明后對SOURCE_FOLDER進行更改,您需要確保其不是常數,即它不是最終的。 在ZipUtils中添加方法:
private static String source_folder = "E:\\appu\\"; //SourceFolder
public void changeDirectory(String zip) {
source_folder = zip + ":\\";
}
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