Commons Net 2.0 API 之ftpClient类
ftpClient类囊括了Java对于ftp服务器上的一系列操作。
ftpClient类继承自ftp类，增加了上传文件流、下载文件流、获得目录名称和文件名称等一系列操作。
创建ftpClient对象
ftpClient = new FTPClient();
连接ftpClient对象，为该对象添加一个connect方法
public boolean connect() {
??????? boolean isConnectionSuccess = false;
??????? if (ftpClient == null) {
??????????? ftpClient = new FTPClient();
??????? }
??????? try {
??????????? ftpClient.connect(host, port);
??????????? int reply = ftpClient.getReplyCode();
??????????? if (!FTPReply.isPositiveCompletion(reply)) {
??????????????? return false;
??????????? }
??????????? isConnectionSuccess = ftpClient.login(userName, password);
??????????? if (!isConnectionSuccess) {
??????????????? return false;
??????????? }
??????????? if (!ftpClient.setFileType(FTP.BINARY_FILE_TYPE)) {
??????????????? return false;
??????????? }
??????????? if (workingDirectory != null) {
??????????????? ftpClient.makeDirectory(workingDirectory);
??????????????? if (!ftpClient.changeWorkingDirectory(workingDirectory)) {
??????????????????? return false;
??????????????? }
??????????? }
??????????? ftpClient.enterLocalPassiveMode();
??????? } catch (IOException e) {
??????????? if (ftpClient != null && ftpClient.isConnected())
??????????????? try {
??????????????????? ftpClient.disconnect();
??????????????? } catch (IOException e1) {
??????????????????? return false;
??????????????? }
??????? }
??????? return isConnectionSuccess;
??? }
关闭连接
public void disConnect() {
??????? if (ftpClient != null && ftpClient.isConnected())
??????????? try {
??????????????? ftpClient.disconnect();
??????????? } catch (IOException e1) {
??????????????? logger
??????????????????????? .error("[error]--disConnect exception:"
??????????????????????????????? + e1.getMessage());
??????????? }
??? }
上传至ftp方法 ftpclient.appendFile(string filename,fileinputstream fileinputstream)
public boolean uploadFile(File file) {
??????? boolean isUpload = false;
??????? InputStream in = null;
??????? if (file != null) {
??????????? try {
??????????????? in = new FileInputStream(file);
??????????????? isUpload = ftpClient.appendFile(file.getName(), in);
??????????? } catch (IOException e) {
??????????????? return false;
??????????? } finally {
??????????????? if (in != null) {
??????????????????? try {
??????????????????????? in.close();
??????????????????? } catch (IOException e) {
??????????????????????? return false;
??????????????????? }
??????????????? }
??????????? }
??????? } else {
??????????? return false;
??????? }
??????? return isUpload;
??? }
从ftp下载文件
public boolean downloadFile(String remoteFile,String localFile) throws IOException
??? {
??????? boolean flag=false;
??????? File outfile=new File(localFile);
??????? FileOutputStream out=null;
??????? if(!outfile.exists())
??????? {
??????????? String[] names = ftpClient.listNames(remoteFile);
??????????? if(names.length!=0)
??????????? {
??????????????? try
??????????????? {????????????
??????????????????? out=new FileOutputStream(outfile);?????????????
??????????????????? flag=ftpClient.retrieveFile(remoteFile, out);
??????????????? }
??????????????? catch (IOException e) {
??????????????????? flag = false;
??????????????????? return flag;
??????????????????? } finally {
??????????????????????? try {
??????????????????????????? if (out != null)
??????????????????????????? {
??????????????????????????????? out.close();
??????????????????????????????? flag=true;
??????????????????????????????? logger.info("Download successfully...");
??????????????????????????? }
??????????????????????? } catch (Exception e) {
??????????????????????????? e.printStackTrace();
??????????????????????? }
??????????????????????? finally
??????????????????????? {
??????????????????????????? return flag;
??????????????????????? }
??????????????????? }
??????????? }
??????????? else
??????????? {
??????????????? logger.error("File not found from the FTP...");
??????????????? flag=false;
??????????????? return flag;
??????????? }
??????? }
??????? else
??????? {
??????????? logger.error("The localFile exists,please renamed the localFile!");
??????????? flag=false;
??????????? return flag;
??????? }
??? }
请注意ftpclient 的listFiles()和listNames()的区别：
1.listFiles()可以列出目录下所有的文件 返回对象为ftpFile类的数组ftpFile[]。
2.重载：同时在listFiles(string filename)增加参数可以用于查询 当前目录下所有名称包含"filename"的文件，返回同样是ftpFile[]。
3.技巧：可以根据ftpFile[]数组的length来确认文件是否存在。
4.区别：listFiles()和listNames()的区别在于listFiles()返回文件数组ftpFile[]，而listNames()返回文件名称数组string[]。
