读取手机本地图片和文本文件（Lwuit版）
读取手机存储文件的核心代码：
程序代码所使用到的图片可在附件中下载，在真机上测试程序，可能部分手机不支持jpg和gif格式的图片，程序可能会报IOException。
package com.mopietek;
import javax.microedition.midlet.MIDlet;
import javax.microedition.midlet.MIDletStateChangeException;
import com.sun.lwuit.Display;
public class MainMIDlet extends MIDlet{
//主显示面板
private MainPanel panel = null;
protected void destroyApp(boolean arg0) throws MIDletStateChangeException {
}
protected void pauseApp() {
}
protected void startApp() throws MIDletStateChangeException {
Display.init(this);
panel = new MainPanel(this);
}
public void exit(){
try {
destroyApp(false);
} catch (MIDletStateChangeException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
this.notifyDestroyed();
}
}
package com.mopietek;
import java.io.DataInputStream;
import java.io.InputStream;
import java.util.Enumeration;
import javax.microedition.io.Connector;
import javax.microedition.io.file.FileConnection;
import javax.microedition.io.file.FileSystemRegistry;
import com.sun.lwuit.Button;
import com.sun.lwuit.Command;
import com.sun.lwuit.Component;
import com.sun.lwuit.Container;
import com.sun.lwuit.Dialog;
import com.sun.lwuit.Form;
import com.sun.lwuit.Image;
import com.sun.lwuit.Label;
import com.sun.lwuit.List;
import com.sun.lwuit.TextArea;
import com.sun.lwuit.events.ActionEvent;
import com.sun.lwuit.events.ActionListener;
import com.sun.lwuit.layouts.BorderLayout;
import com.sun.lwuit.list.ListCellRenderer;
import com.sun.lwuit.plaf.Border;
public class MainPanel implements ActionListener{
//常理定义
private final String UP_DIR = "..";
private final String SEPS_STR = "/";
private final int SEPS_CHAR = '/';
private final String ROOT = "/";
private final String RES_PREFIX = "file://";
private final int BLOCK_SIZE = 256;
//扩展名
private final String TEXT_EXT[] = {".TXT",".H",".HPP",".C",".CPP",".INC"};
private final String IMAGE_EXT[] = {".JPG",".JPEG",".PNG",".GIF",};
private final String WEB_EXT[] = {".HTM",".HTML",".XML",".CSS"};
//字符编码
private final String CHARACTER_CODE = "UTF-8";
//主MIDlet
private MainMIDlet let = null;
//主界面
private Form listForm = null;
//内容列表
private List contentList = null;
//显示文件用窗体
private Form textForm = null;
//装载文本项目用
private TextArea text = null;
//显示图片用的窗体
private Form imageForm = null;
//命令
private Command cmdExit = null;
private Command cmdView = null; //浏览目录/文件
private Command cmdDone = null;//退出浏览文件内容
//图标帮助类
private IconHelper helper = null;
//当前目录路径
private String currentDir = null;
public MainPanel(MainMIDlet mainMIDlet) {
let = mainMIDlet;
//初始化当前目录为根目录
currentDir = ROOT;
//初始化图标帮助实例
helper = new IconHelper();
listForm = new Form("");
listForm.setLayout(new BorderLayout());
//文本显示窗体
textForm = new Form("");
//文本装载项目
text = new TextArea();
text.setWidestChar('-');
//图像显示窗体
imageForm = new Form("");
//创建命令
cmdExit = new Command("退出");
cmdView = new Command("浏览");
cmdDone = new Command("返回");
//添加命令绑定
listForm.addCommand(cmdExit);
listForm.addCommand(cmdView);
listForm.addCommandListener(this);
//添加文字处理框
textForm.setLayout(new BorderLayout());
textForm.addComponent(BorderLayout.CENTER, text);
//设置文本浏览器窗体的绑定命令
textForm.addCommand(cmdDone);
textForm.addCommandListener(this);
//设置图像浏览窗体的命令绑定
imageForm.addCommand(cmdDone);
imageForm.addCommandListener(this);
//初始化显示
new BrowseThread(currentDir,true).start();
}
public void actionPerformed(ActionEvent evt) {
Command c = evt.getCommand();
if(c == cmdExit){
let.exit();
}else if(c == cmdView){//查看命令
//当前列表中没有目录项
if(contentList.size() == 0){
//启动线程来浏览指定目录
new BrowseThread(ROOT,true).start();
}else{
final String url = ((MyContainer) contentList.getSelectedItem()).name.getText();
if(url.endsWith(SEPS_STR) == true){//当前项目为目录,则显示其子项目
//启动浏览线程来浏览指定目录
new BrowseThread(currentDir + url,true).start();
}else if(url.endsWith(UP_DIR) == true){ //当前项目为父目录，则需要回退
backward();
}else{ //当前目录为文件
//启动浏览线程来浏览指定文件
new BrowseThread(currentDir + url,false).start();
}
}
}else if(c == cmdDone){//关闭文本阅读，返回目录浏览
//启动浏览线程来浏览指定文件
new BrowseThread(currentDir,true).start();
}
}
//---------------------------------------------------------------
//回退浏览当前目录的父目录内容
private void backward(){
//获取当前目录的父目录名称
int pos = currentDir.lastIndexOf(SEPS_CHAR,currentDir.length() - 2);
if(pos != -1){//存在上层目录
currentDir = currentDir.substring(0,pos + 1);
}else{//不存在上层目录即根目录
currentDir = ROOT;
}
//启动浏览线程来浏览指定目录
new BrowseThread(currentDir,true).start();
}
class MyContainer extends Container{
private Label name;
public MyContainer(String source){
name = new Label(source);
name.getStyle().setBgTransparency(0);
addComponent(name);
}
}
class MyRenderer implements ListCellRenderer{
private Label focus;
public MyRenderer(){
focus = new Label();
Border b = Border.createLineBorder(1,0xff0000);
focus.getStyle().setBorder(b);
}
public Component getListCellRendererComponent(List list, Object value,
int index, boolean selected) {
return (MyContainer) value;
}
public Component getListFocusComponent(List list) {
return focus;
}
}
class BrowseThread extends Thread{
private String url = null;
private boolean isDirectory = false;
public BrowseThread(final String _url,final boolean _isDirectory){
url = _url;
isDirectory = _isDirectory;
}
public void run(){
//浏览目录或文件
if(isDirectory){
text.setText("");
imageForm.removeAll();
showDir(url);
}else{
showFile(url);
}
}
//显示指定目录
public void showDir(final String dir){
//设置列表title
Enumeration em = null;
FileConnection fc = null;
//设置当前目录
currentDir = dir;
//初始化列表
listForm.removeAll();
contentList = new List();
contentList.setListCellRenderer(new MyRenderer());
listForm.addComponent(BorderLayout.CENTER,contentList);
try{
if(dir.equals(ROOT) == true){
//枚举根目录列表
em = FileSystemRegistry.listRoots();
}else{
//非根目录
fc = (FileConnection) Connector.open(RES_PREFIX + dir);
em = fc.list();
//添加上层根目录
MyContainer up = new MyContainer(UP_DIR);
up.name.setIcon(helper.getIconByExt("/"));
contentList.addItem(up);
}
while(em.hasMoreElements()){
String fileName = (String)em.nextElement();
if(fileName.endsWith(SEPS_STR)){ //如果为目录
MyContainer c = new MyContainer(fileName);
c.name.setIcon(helper.getIconByExt("/"));
contentList.addItem(c);
System.out.println(fileName);
System.out.println("It's OK!");
}else{ //非目录(文件)
MyContainer c = new MyContainer(fileName);
c.name.setIcon(helper.getIconByExt(extractExt(fileName)));
contentList.addItem(c);
}
}
listForm.revalidate();
//初始化选择
contentList.setSelectedIndex(0,true);
//关闭文件连接
if(fc != null){
fc.close();
}
}catch(Exception ex){
ex.printStackTrace();
}
listForm.show();
}
//---------------------------------------------------------
//显示指定文件内容
private void showFile(final String fileName){
String tempFileName = fileName.toUpperCase();
try{
FileConnection fc = (FileConnection) Connector.open(RES_PREFIX + fileName,Connector.READ);
if(!fc.exists()){
Dialog.show("Exception", "未找到文件", "ok","cancel");
}
if(isEndWithIn(tempFileName, IMAGE_EXT) == true){ //图片文件
//创建流
InputStream is = fc.openInputStream();
Image img = Image.createImage(is);
//设置图片窗体Title
imageForm.setTitle(getRelativeName(fileName));
imageForm.setLayout(new BorderLayout());
imageForm.removeAll();
Button b = new Button(img);
imageForm.addComponent(BorderLayout.CENTER,b);
//关闭流
is.close();
//关闭文件连接
fc.close();
imageForm.show();
}else if(isEndWithIn(tempFileName,TEXT_EXT)){//文本文件
int rawFileSize = (int) (fc.fileSize());
int fileSize = ((rawFileSize / BLOCK_SIZE) + 1) * BLOCK_SIZE;
//依据文件内容设置title
textForm.setTitle(getRelativeName(fileName) + "," + rawFileSize + "/" + fileSize);
DataInputStream dis = fc.openDataInputStream();
byte [] buffer = new byte[rawFileSize];
//读取文件内容
dis.readFully(buffer);
textForm.setLayout(new BorderLayout());
textForm.removeAll();
text.setText(new String(buffer,"UTF-8"));
textForm.addComponent(BorderLayout.CENTER,text);
//关闭流
dis.close();
//关闭文件连接
fc.close();
textForm.show();
}else{
Form f = new Form("不认识图片");
f.show();
}
}catch(Exception ex){
ex.printStackTrace();
Dialog.show("Exception:", ex.toString(), "OK",null);
}
}
private boolean isEndWithIn(final String fileName,final String[] extArray){
for(int i=0; i<extArray.length;i++){
if(fileName.endsWith(extArray[i]) == true){
return true;
}
}
return false;
}
//----------------------------------------------------------------
//从完整文件名种提取相对文件名
private String getRelativeName(final String fileName){
int pos = fileName.lastIndexOf(SEPS_CHAR);
if(pos == -1){
return ("");
}
return (fileName.substring(pos + 1, fileName.length()));
}
//----------------------------------------------------------------
//获取扩展名(不包含'.'符号)
private String extractExt(final String fileName){
int pos = fileName.lastIndexOf('.');
return (fileName.substring(pos + 1, fileName.length()).toLowerCase());
}
//-------------------------------------------------
}
}
package com.mopietek;
import java.io.IOException;
import java.util.Hashtable;
import com.sun.lwuit.Image;
public class IconHelper {
//图标资源
private Image imgFolder;
private Image unknownImage;
private Image textImage;
//Audio
private Image audioImage;
//Picture
private Image picImage;
private Image jpgImage;
//Video
private Image sgpImage;
private Image aviImage;
private Image wmvImage;
private Image mpgImage;
//Web
private Image zipImage;
private Image htmlImage;
private Image xmlImage;
//Source
private Image cImage;
private Image cppImage;
private Image headerImage;
//图标管理容器
private Hashtable iconTable;
public IconHelper(){
iconTable = new Hashtable();
try{
//载入图标资源
imgFolder = Image.createImage("/filetype/folder.png");
unknownImage = Image.createImage("/filetype/unknown.png");
textImage = Image.createImage("/filetype/text.png");
//Audio
audioImage = Image.createImage("/filetype/audio.png");
//Picture
picImage = Image.createImage("/filetype/pic.png");
jpgImage = Image.createImage("/filetype/jpg.png");
//Video
sgpImage = Image.createImage("/filetype/3gp.png");
aviImage = Image.createImage("/filetype/avi.png");
wmvImage = Image.createImage("/filetype/wmv.png");
mpgImage = Image.createImage("/filetype/mpg.png");
//Web
zipImage = Image.createImage("/filetype/zip.png");
htmlImage = Image.createImage("/filetype/html.png");
xmlImage = Image.createImage("/filetype/xml.png");
//Source
cImage = Image.createImage("/filetype/c.png");
cppImage = Image.createImage("/filetype/cpp.png");
headerImage = Image.createImage("/filetype/header.png");
}catch(IOException e){
//图标资源
imgFolder = null;
unknownImage = null;
textImage = null;
//Audio
audioImage = null;
//Picture
picImage = null;
jpgImage = null;
//Video
sgpImage = null;
aviImage = null;
wmvImage = null;
mpgImage = null;
//Web
zipImage = null;
htmlImage = null;
xmlImage = null;
//Source
cImage = null;
cppImage = null;
headerImage = null;
e.printStackTrace();
}
initTable();
}
private void initTable() {
//Key为扩展名(不包括'.'符号),值为content type
iconTable.put("/", imgFolder);
iconTable.put("", unknownImage);
iconTable.put("txt", textImage);
//Source
iconTable.put("c", cImage);
iconTable.put("cpp", cppImage);
iconTable.put("h", headerImage);
//Web
iconTable.put("html", htmlImage);
iconTable.put("htm", htmlImage);
iconTable.put("xml", xmlImage);
iconTable.put("zip", zipImage);
iconTable.put("jar", zipImage);
//audio
iconTable.put("mp3", audioImage);
iconTable.put("wma", audioImage);
iconTable.put("mid", audioImage);
iconTable.put("wav", audioImage);
//Picture
iconTable.put("gif", picImage);
iconTable.put("png", picImage);
iconTable.put("jpg", jpgImage);
iconTable.put("jepg", jpgImage);
//Video
iconTable.put("3gp", sgpImage);
iconTable.put("avi", aviImage);
iconTable.put("wmv", wmvImage);
iconTable.put("mpeg", mpgImage);
iconTable.put("mpg", mpgImage);
iconTable.put("mp4", mpgImage);
}
//按照扩展名(不包括'.'符号) 获取文件的图标对象
public Image getIconByExt(final String extension) {
Image temp = (Image) iconTable.get(extension);
//是否为空,则使用默认图标替代
return ((temp == null) ? unknownImage : temp);
}
}
程序代码所使用到的图片可在附件中下载，在真机上测试程序，可能部分手机不支持jpg和gif格式的图片，程序可能会报IOException。