最近剛剛學習J2ME??真可惜 J2ME的類太少 功能太弱了！哎~..... 而且什么東西都受安全限制,不過也有很多因素是硬件方面的！而且當 CLASS訪問本地文件的時候,需要在文件訪問權限那里開啟

package cn.isto;

import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
import javax.microedition.io.*;
import java.io.*;
/**
?*
?* @author Administrator
?*/
public class EncryptTool extends MIDlet implements CommandListener {
???
??? /** Creates a new instance of HelloMidlet */
??? public EncryptTool() {
??? }
???
??? private Form Encrypt;????????????????????
??? private Command exitCommand;
??? private TextField filepath;
??? private TextField enterpass;
??? private TextField againpass;
??? private ChoiceGroup choiceTypeGroup;
??? private Command okCommand;
??? private TextField outputPath;
??? private Spacer spacer1;
??? private Gauge gauge1;
??? private Ticker tickerMsg;??????????????????

????????????????????

??? /** This method initializes UI of the application.???????????????????????
???? */
??? private void initialize() {?????????????????????
?// Insert pre-init code here
??????? getDisplay().setCurrent(get_Encrypt());?????????????????????
?// Insert post-init code here
??? }????????????????????
???
??? /** Called by the system to indicate that a command has been invoked on a particular displayable.?????????????????????
???? * @param command the Command that ws invoked
???? * @param displayable the Displayable on which the command was invoked
???? */
??? public void commandAction(Command command, Displayable displayable) {???????????????????
??????? // Insert global pre-action code here
??????? if (displayable == Encrypt) {????????????????????
??????????? if (command == exitCommand) {??????????????????
??????????????? // Insert pre-action code here
??????????????? exitMIDlet();??????????????????????
??????????????? // Insert post-action code here
??????????? } else if (command == okCommand) {????????????????????
??????????????? tickerMsg.setString("kj021320簡單加密程序");
??????????????? String operateFile=filepath.getString();
??????????????? String outputFile=outputPath.getString();
??????????????? InputStream fileR=null;
??????????????? OutputStream fileW=null;
??????????????? if((operateFile!=null&&!"".equals(operateFile))&&(outputPath!=null&&!"".equals(outputPath))){
??????????????????? if(enterpass.getString().equals(againpass.getString())){
??????????????????????? int pas=getPass(enterpass.getString());
??????????????????????? try {
??????????????????????????? fileR=Connector.openInputStream(operateFile);
??????????????????????????? fileW=Connector.openOutputStream(outputFile);
??????????????????????????? int b=fileR.read();
??????????????????????????? int xorB=0;
??????????????????????????? while(b!=-1){
??????????????????????????????? xorB= b ^ pas;
??????????????????????????????? fileW.write(xorB);
??????????????????????????????? b=fileR.read();
??????????????????????????? }
??????????????????????????? tickerMsg.setString("加密成功 你的密碼為 "+enterpass.getString()+" 請記住");
??????????????????????? } catch (Exception ex) {
??????????????????????????? tickerMsg.setString("加密失敗~ 有錯誤"+ex.toString());
??????????????????????????? ex.printStackTrace();
??????????????????????? } finally{
??????????????????????????? try{fileR.close();}catch(Exception e){}
??????????????????????????? try{fileW.close();}catch(Exception e){}
??????????????????????? }
??????????????????? }else{
??????????????????????? tickerMsg.setString("兩次輸入的密碼不一樣");
??????????????????? }
??????????????? }else{
??????????????????? tickerMsg.setString("文件路徑不能為空");
??????????????? }
???????????????
??????????????? // Do nothing???????????????????????
??????????????? // Insert post-action code here
??????????? }??????????????????????
??????? }????????????????????
??????? // Insert global post-action code here
}??????????????????
??? public int getPass(String pass){
??????? byte[] passes=pass.getBytes();
??????? int result=0;
??????? for(int len=0;len<passes.length;len++){
??????????? result+=passes[len];
??????? }
??????? return result;
??? }
??? /**
???? * This method should return an instance of the display.
???? */
??? public Display getDisplay () {????????????????????????
??????? return Display.getDisplay(this);
??? }???????????????????????
???
??? /**
???? * This method should exit the midlet.
???? */
??? public void exitMIDlet () {????????????????????????
??????? getDisplay().setCurrent(null);
??????? destroyApp(true);
??????? notifyDestroyed();
??? }???????????????????????
???
??? /** This method returns instance for Encrypt component and should be called instead of accessing Encrypt field directly.???????????????????????
???? * @return Instance for Encrypt component
???? */
??? public Form get_Encrypt() {
??????? if (Encrypt == null) {?????????????????????
??????????? // Insert pre-init code here
??????????? Encrypt = new Form(null, new Item[] {??????????????????????
??????????????? get_filepath(),
??????????????? get_outputPath(),
??????????????? get_enterpass(),
??????????????? get_againpass(),
??????????????? get_choiceTypeGroup()
??????????? });
??????????? Encrypt.addCommand(get_exitCommand());
??????????? Encrypt.addCommand(get_okCommand());
??????????? Encrypt.setCommandListener(this);
??????????? Encrypt.setTicker(get_tickerMsg());????????????????????
??????????? // Insert post-init code here
??????? }?????????????????????
??????? return Encrypt;
??? }???????????????????
???
???
??? /** This method returns instance for exitCommand component and should be called instead of accessing exitCommand field directly.???????????????????????
???? * @return Instance for exitCommand component
???? */
??? public Command get_exitCommand() {
??????? if (exitCommand == null) {?????????????????????
??????????? // Insert pre-init code here
??????????? exitCommand = new Command("Exit", Command.EXIT, 1);?????????????????????
??????????? // Insert post-init code here
??????? }?????????????????????
??????? return exitCommand;
??? }???????????????????
?
??? /** This method returns instance for filepath component and should be called instead of accessing filepath field directly.????????????????????????
???? * @return Instance for filepath component
???? */
??? public TextField get_filepath() {
??????? if (filepath == null) {??????????????????????
??????????? // Insert pre-init code here
??????????? filepath = new TextField("filePath:", null, 120, TextField.ANY);??????????????????????
??????????? // Insert post-init code here
??????? }??????????????????????
??????? return filepath;
??? }????????????????????

??? /** This method returns instance for enterpass component and should be called instead of accessing enterpass field directly.????????????????????????
???? * @return Instance for enterpass component
???? */
??? public TextField get_enterpass() {
??????? if (enterpass == null) {??????????????????????
??????????? // Insert pre-init code here
??????????? enterpass = new TextField("enterpass", null, 120, TextField.ANY | TextField.PASSWORD);??????????????????????
??????????? // Insert post-init code here
??????? }??????????????????????
??????? return enterpass;
??? }????????????????????

??? /** This method returns instance for againpass component and should be called instead of accessing againpass field directly.????????????????????????
???? * @return Instance for againpass component
???? */
??? public TextField get_againpass() {
??????? if (againpass == null) {??????????????????????
??????????? // Insert pre-init code here
??????????? againpass = new TextField("againpass", null, 120, TextField.ANY | TextField.PASSWORD);??????????????????????
??????????? // Insert post-init code here
??????? }??????????????????????
??????? return againpass;
??? }????????????????????
?

??? /** This method returns instance for choiceTypeGroup component and should be called instead of accessing choiceTypeGroup field directly.????????????????????????
???? * @return Instance for choiceTypeGroup component
???? */
??? public ChoiceGroup get_choiceTypeGroup() {
??????? if (choiceTypeGroup == null) {??????????????????????
??????????? // Insert pre-init code here
??????????? choiceTypeGroup = new ChoiceGroup("chooseType", Choice.POPUP, new String[0], new Image[0]);???????????????????????
??????????? choiceTypeGroup.setSelectedFlags(new boolean[0]);?????????????????????
??????????? // Insert post-init code here
??????????? choiceTypeGroup.insert(0,"encrypt",null);
??????????? choiceTypeGroup.insert(0,"decrypt",null);
??????? }??????????????????????
??????? return choiceTypeGroup;
??? }????????????????????

??? /** This method returns instance for okCommand component and should be called instead of accessing okCommand field directly.????????????????????????
???? * @return Instance for okCommand component
???? */
??? public Command get_okCommand() {
??????? if (okCommand == null) {??????????????????????
??????????? // Insert pre-init code here
??????????? okCommand = new Command("OK", Command.OK, 1);??????????????????????
??????????? // Insert post-init code here
??????? }??????????????????????
??????? return okCommand;
??? }????????????????????

??? /** This method returns instance for outputPath component and should be called instead of accessing outputPath field directly.????????????????????????
???? * @return Instance for outputPath component
???? */
??? public TextField get_outputPath() {
??????? if (outputPath == null) {??????????????????????
??????????? // Insert pre-init code here
??????????? outputPath = new TextField("outputPath:", null, 120, TextField.ANY);??????????????????????
??????????? // Insert post-init code here
??????? }??????????????????????
??????? return outputPath;
??? }????????????????????

??? /** This method returns instance for spacer1 component and should be called instead of accessing spacer1 field directly.????????????????????????
???? * @return Instance for spacer1 component
???? */
??? public Spacer get_spacer1() {
??????? if (spacer1 == null) {??????????????????????
??????????? // Insert pre-init code here
??????????? spacer1 = new Spacer(1000, 1);??????????????????????
??????????? // Insert post-init code here
??????? }??????????????????????
??????? return spacer1;
??? }????????????????????

??? /** This method returns instance for gauge1 component and should be called instead of accessing gauge1 field directly.????????????????????????
???? * @return Instance for gauge1 component
???? */
??? public Gauge get_gauge1() {
??????? if (gauge1 == null) {??????????????????????
??????????? // Insert pre-init code here
??????????? gauge1 = new Gauge("gauge1", false, 100, 50);??????????????????????
??????????? // Insert post-init code here
??????? }??????????????????????
??????? return gauge1;
??? }????????????????????

??? /** This method returns instance for tickerMsg component and should be called instead of accessing tickerMsg field directly.????????????????????????
???? * @return Instance for tickerMsg component
???? */
??? public Ticker get_tickerMsg() {
??????? if (tickerMsg == null) {??????????????????????
??????????? // Insert pre-init code here
??????????? tickerMsg = new Ticker("kj021320/u7B80/u5355/u52A0/u5BC6/u7A0B/u5E8F");??????????????????????
??????????? // Insert post-init code here
??????? }??????????????????????
??????? return tickerMsg;
??? }????????????????????
????
??? public void startApp() {
??????? initialize();
??? }
???
??? public void pauseApp() {
??? }
???
??? public void destroyApp(boolean unconditional) {
??? }
}

程序采用 異或形式加密~ 所以加密就是解密...choosetype那個按扭是多余的！呵呵.忘記說一點~ Connector不支持創建文件！ 所以輸入和輸出文件必須要存在,-_-郁悶了吧！ 本地文件協議如下例如

file:///c:/13.jpg?這樣才能訪問本地文件

總結

以上是生活随笔為你收集整理的J2ME手机文件加密的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。