FileConnection访问本土文件系统

FileConnection访问本地文件系统

FC api是JSR 75, PDA Optional Packages for the J2ME Platform的一部分，用于访问本地文件系统。FC api通过Generic Connection Framework(GCF)访问文件系统，允许访问包括存储卡在内的文件系统。包括如下两个接口和三个类：FileConnection 访问文件和文件夹的接口。FileSystemListener 添加删除根目录文件系统的状态监听的接口。FileSystemRegistry 添加删除根目录文件系统的接口注册类。 ConnectionClosedException 当一个文件句柄的操作被调用，而文件已经被关闭时抛出的异常。 IllegalModeException 当操作所对应的模式不被文件打开模式支持时抛出的异常。判断是否支持FC： 引用文字if(System.getProperty("microedition.io.file.FileConnection.version") != null){ // file.separator    // FCOP available} else {    // FCOP not available}

打开文件：// CFCard/:FileConnection fc = (FileConnection) Connector.open("file:///CFCard/"); // SDCard/:FileConnection fc = (FileConnection) Connector.open("file:///SDCard/"); // MemoryStick/:FileConnection fc = (FileConnection) Connector.open("file:///MemoryStick/"); // C:/:FileConnection fc = (FileConnection) Connector.open("file:///C:/"); // / File:Connection fc = (FileConnection) Connector.open(file:////); 

只读方式打开一个文件： String url = "file:///data.txt";InputConnection conn = null;int mode = Connector.READ_ONLY;   try {    conn =(InputConnection) Connector.open( url, mode );    // Always check whether the file or directory exists.    // Create the file if it doesn't exist.    if(!conn.exists()) {    }} catch( IOException ioe ){    // no file}

创建一个文件：String url = "file:///SDCard/data.txt";FileConnection conn = null;int mode = Connector.WRITE_ONLY;try {    conn = (FileConnection)Connector.open(url, mode);    if(filecon.create()){ // create the file       OutputStream out = conn.openOutputStream();       // now write data to the file    }    conn.close();} catch(IOException e){    // error} catch(SecurityException e){    // no permission to create/write}

列举一个目录下的文件：// FileConnection.list(String filter, boolean includeHidden)String url = "file:///C:/";FileConnection conn = null;try {    conn = (FileConnection) Connector.open(url);    if( conn.isDirectory() ) {        Enumeration names = conn.list();        while( names.hasMoreElements() ){            String name = (String) e.nextElement();            // do something        }    } else {        // not a directory!    }} catch(IOException e) {    // could not access the URL} catch(SecurityException e) {    // no permission to read the directory}

读取文件内容：
String url = "file:///CFCard/data.txt";InputConnection conn = null;int mode = Connector.READ_ONLY; try {????FileConnection fc = (FileConnection)Connector.open(url, mode);????if(!fc.exists()) {????????throw new IOException("File does not exist");????}????InputStream is = fc.openInputStream();????byte b[] = new byte[1024];????int length = is.read(b, 0, 1024);????System.out.println("Content of "+fileName + ": "+ new String(b, 0, length));} catch (Exception e) {}
 

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