大致的需求就是, 浏览文件夹,以及文件,然后选取文件后,返回给调用窗口,进行进一步处理。
使用方式:
fileSelector= new FileSelector(this); //this 为MIDlet
fileSelector.sender = invoker; //invoker 为自定义的Canvas
Display.getDisplay(this).setCurrent(fileSelector);
附带完整代码：
package BaseEngine;
/**
* <p>Title: FileSelector</p>
* <p>Description: </p>
* <p>Copyright: cnsoft Copyright (c) 2009</p>
* <p>Company: </p>
* @author cnsoft#gmail.com
* @version 1.0
*/
/*
* File Connection Using JSR 75
*/
import javax.microedition.lcdui.*;
import java.io.*;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.*;
import javax.microedition.io.*;
import javax.microedition.io.file.*;
import javax.microedition.io.file.FileConnection;
import BaseEngine.xApplication;
import BaseEngine.UI.xForm;
public class FileSelector extends List implements CommandListener,FileSystemListener
{
private static String FILE_SEPARATOR ;
private Command open = new Command("Open", Command.OK, 1);
private Command back = new Command("Back", Command.BACK, 1);
private String errorMsg = null;
private Alert alert;
private Vector rootsList = new Vector();
private final static String upper_dir = "...";
private FileConnection currentRoot = null;
private static FileConnection fileConn2 = null;
private static final int CHUNK_SIZE = 1024;
public static ByteArrayInputStream bis = null;
public static xForm sender = null;
FileSelector(xApplication xApplication) {
super("File Browser", List.IMPLICIT);
FILE_SEPARATOR = "/";
//(System.getProperty("file.separator") != null) ? System.getProperty("file.separator") : "/";
deleteAll();
addCommand(open);
addCommand(back);
setSelectCommand(open);
setCommandListener(this);
FileSystemRegistry.addFileSystemListener(FileSelector.this);
new Thread(new Runnable()
{
public void run() {
execute();
try {
Thread.sleep(10);
}
catch (InterruptedException ex) {
}
}
}).start();
}
public void execute() {
//存储位置? Nokia机器上是啥呢?
String initDir = "file:///root1/";//System.getProperty("fileconn.dir");
//NokiaDevice = "file:///C:/Data/Images/"
String platform = System.getProperty("microedition.platform");
if (platform.startsWith("Nokia"))
initDir = "file:///C:/Data/Images/";
loadRoots();
if (initDir != null) {
try {
currentRoot = (FileConnection) Connector.open(initDir, Connector.READ);
displayCurrentRoot();
}
catch (Exception e) {
displayAllRoots();
}
}
else {
displayAllRoots();
}
}
private void loadRoots() {
if (!rootsList.isEmpty()) {
rootsList.removeAllElements();
}
try {
Enumeration roots = FileSystemRegistry.listRoots();
while (roots.hasMoreElements()) {
rootsList.addElement(FILE_SEPARATOR + (String) roots.nextElement());
}
}
catch (Throwable e) {
}
}
private void displayCurrentRoot() {
try {
setTitle(currentRoot.getURL());
deleteAll();
append(upper_dir, null);
Enumeration listOfDirs = currentRoot.list();//"*", false);
while (listOfDirs.hasMoreElements()) {
String currentDir = (String) listOfDirs.nextElement();
if (currentDir.endsWith(FILE_SEPARATOR)) {
append(currentDir, null);
}
else {
append(currentDir, null);
}
}
/* Enumeration listOfFiles = currentRoot.list("*.txt",false);
while(listOfFiles.hasMoreElements())
{
String currentFile=(String) listOfFiles.nextElement();
if(currentFile.endsWith(FILE_SEPARATOR))
{
//append(currentFile,null);
}
else
{
append(currentFile,null);
}
} */
}
catch (IOException e) {
e.printStackTrace();
}
catch (SecurityException e) {
e.printStackTrace();
}
System.out.println("Display Root ok!");
}
private void displayAllRoots() {
setTitle("[Roots]");
deleteAll();
Enumeration roots = rootsList.elements();
while (roots.hasMoreElements()) {
String root = (String) roots.nextElement();
append(root.substring(1), null);
}
currentRoot = null;
}
private void openSelected() {
int selectedIndex = getSelectedIndex();
if (selectedIndex >= 0) {
String selectedFile = getString(selectedIndex);
if (selectedFile.endsWith(FILE_SEPARATOR)) {
try {
if (currentRoot == null) {
currentRoot = (FileConnection) Connector.open("file:///" +
selectedFile, Connector.READ);
}
else {
currentRoot.setFileConnection(selectedFile);
}
displayCurrentRoot();
}
catch (IOException e) {
System.out.println(e.getMessage());
}
catch (SecurityException e) {
System.out.println(e.getMessage());
}
}
else if (selectedFile.equals(upper_dir)) {
if (rootsList.contains(currentRoot.getPath() + currentRoot.getName())) {
displayAllRoots();
}
else {
try {
currentRoot = (FileConnection) Connector.open("file://" +
currentRoot.getPath(), Connector.READ);
displayCurrentRoot();
}
catch (IOException e) {
System.out.println(e.getMessage());
}
}
}
else {
//选择的是文件.检查是否是.txt 后缀的文件,
//并尝试加载以后,如果失败,提示错误
String url = currentRoot.getURL() + selectedFile;
//设置回Canvas界面. 并传递数据 用于初始化.
loadfiledata(url);
//xForm. Invoker, 初始化新的卡片数据
FlashGame flash = (FlashGame)sender;
flash.LoadCard(flash.cards,(InputStream)bis);
flash.resetGame();
xApplication.instance.ReturnToCanvas();
}
}
}
public void loadfiledata(String url) {
//FileConnection fileConn = null;
try {
fileConn2 = (FileConnection) Connector.open(url,
Connector.READ);
fis = fileConn2.openInputStream();
int overallSize = (int)fileConn2.fileSize();
byte[] b = new byte[overallSize];
int length = fis.read(b, 0, overallSize);
// ByteArrayInputStream
bis= new ByteArrayInputStream(b);
fis.close();
fileConn2.close();
}
catch (IOException ex) {
}
}
public void stop() {
if (currentRoot != null) {
try {
currentRoot.close();
}
catch (IOException e) {
}
}
}
public void byteConvert(String url, String filename) {
try {
FileConnection fileConn = (FileConnection) Connector.open(url,
Connector.READ);
InputStream fis = fileConn.openInputStream();
long overallSize = fileConn.fileSize();
int length = 0;
byte[] filedata = new byte[0];
while (length < overallSize) { //converting the selected file to bytes
byte[] data = new byte[CHUNK_SIZE];
int readAmount = fis.read(data, 0, CHUNK_SIZE);
byte[] newFileData = new byte[filedata.length + CHUNK_SIZE];
System.arraycopy(filedata, 0, newFileData, 0, length);
System.arraycopy(data, 0, newFileData, length, readAmount);
filedata = newFileData;
length += readAmount;
}
fis.close();
fileConn.close();
//here u can write a code to connect with the server for sending the selected file
}
catch (Exception e) {
//showAlert(e.getMessage());
}
finally {
}
}
public void commandAction(Command c, Displayable d) {
if (c == open) {
new Thread(new Runnable()
{
public void run()
{
openSelected();
}}).start();
}else
if(c == back) {
xApplication.instance.ReturnToCanvas();
}
;// commandListener.commandAction(c, d);
}
public void rootChanged(int state, String rootNmae) {
}
}