Java利用ssh协议实现从远程Linux服务器下载文件和文件夹
近来应需求需要，做了服务器之间的文件传输，利用的ssh协议。查阅各种资料博客，基本都是下载文件的方法，找不到下载文件夹得方法。思索多日写了一个下载文件夹的简单方法，可能步骤繁琐，优化不大好。由于jsch不能得到服务器端文件的绝对路径，目前还没能想出怎么遍历下载文件夹和文件。只好利用ssh2 jar包的session方法操作Linux命令实现下载。话不多说，直接上代码。
一：导入的jar包，jar包在Apache可以自己下载
import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.util.ResourceBundle;
import java.util.zip.GZIPInputStream;
import org.apache.tools.tar.TarEntry;
import org.apache.tools.tar.TarInputStream;
import ch.ethz.ssh2.Connection;
import ch.ethz.ssh2.SCPClient;
import ch.ethz.ssh2.Session;
import ch.ethz.ssh2.StreamGobbler;
二：类和方法
/**
*
* @param dataServerIp 服务器IP
* @param dataServerUsername 服务器用户名
* @param dataServerPassword 服务器登录密码
* @param srcFile 要下载的文件路径
* @param saveFile 保存路径
* @param port 端口号，null时为默认端口
*/
public static void downLoadFile(String dataServerIp,String dataServerUsername,String dataServerPassword,String srcFile,String saveFile,int port){
Connection conn = new Connection(dataServerIp);
Session session = null;
SCPClient client =null;
//session=(Session) getObject(dataServerIp, dataServerUsername, dataServerPassword, 0, "session");
//client=(SCPClient) getObject(dataServerIp, dataServerUsername, dataServerPassword, 0, "client");
conn=getConn(dataServerIp, dataServerUsername, dataServerPassword, 22);
try {
session=conn.openSession();
client=conn.createSCPClient();
} catch (IOException e1) {
e1.printStackTrace();
}
try {
boolean flag=download(srcFile, saveFile, session, client);
//如果是打包文件，删除包裹
if (flag) {
System.out.println("文件打包下载完成！");
//解压tar.gz包
String fileName=srcFile.substring(srcFile.lastIndexOf("/")+1);
File file=new File(saveFile+"/"+fileName+".tar.gz");
unTarGz(file, saveFile);
System.out.println("文件解压完成！");
//解压完后删除本地压缩包
file.delete();
String cmdDel="rm -rf "+srcFile+".tar.gz";
session=(Session) getObject(dataServerIp, dataServerUsername, dataServerPassword, 0, "session");
//删除服务器生成的压缩包
session.execCommand(cmdDel);
}else {
System.out.println("文件下载完成！");
}
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally {
session.close();
conn.close();
}
}
/**
* 根据不同的需求得到相应的连接
* @param ip
* @param userName
* @param pwd
* @param port
* @param whatWant 必须是client或者session
* @return
*/
public static Object getObject(String ip,String userName,String pwd,int port,String whatWant){
Connection conn = new Connection(ip);
Session session = null;
SCPClient client =null;
try {
conn.connect();
boolean isAuthenticated = conn.authenticateWithPassword(userName, pwd);
session=conn.openSession();
client = new SCPClient(conn);
if (isAuthenticated == false) {
throw new IOException("Authentication failed.文件scp到数据服务器时发生异常");
}
} catch (IOException e) {
e.printStackTrace();
}
if (whatWant!=null&&whatWant.equals("session")) {
return session;
}if (whatWant!=null&&whatWant.equals("client")) {
return client;
}
return null;
}
/**
* 获得连接
* @param ip
* @param userName
* @param pwd
* @param port
* @return
*/
public static Connection getConn(String ip,String userName,String pwd,int port){
Connection conn = new Connection(ip);
boolean blag=false;
try {
conn.connect();
boolean isAuthenticated = conn.authenticateWithPassword(userName, pwd);
//session=conn.openSession();
// client = new SCPClient(conn);
if (isAuthenticated) {
blag=true;
}
if (isAuthenticated == false) {
throw new IOException("Authentication failed.文件scp到数据服务器时发生异常");
}
} catch (IOException e) {
e.printStackTrace();
}
if (blag) {
return conn;
}else {
return null;
}
}
/**
*
* @param srcFile 要下载的文件
* @param saveFile 保存目录，必须是目录
* @param sessionSsh
* @param client
* @return
* @throws UnsupportedEncodingException
*/
public static boolean download(String srcFile, String saveFile, Session sessionSsh, SCPClient client
) throws UnsupportedEncodingException {
//String cdmTar="tar czf /var/ftp/upload/ruku/ruku.tar.gz –directory=/var/ftp/upload/ruku ruku";
boolean flag=false;
// 是文件,直接下载
try {
String filename=srcFile.substring(srcFile.lastIndexOf("/")+1);
if (filename.contains(".")) {
try {
client.get(srcFile, saveFile);
} catch (Exception e) {
//是文件夹，打包下载
String src=srcFile.substring(0, srcFile.lastIndexOf("/"));
String cmdGet = "tar -zcvf " + srcFile + ".tar.gz " + filename;
//String cmdGet="tar czf /home/"+filename+".tar.gz –directory="+src+"/"+filename+".";
// 执行压缩命令
sessionSsh.execCommand("cd "+src+";"+cmdGet);
InputStream stdout = new StreamGobbler(sessionSsh.getStdout());
BufferedReader br = new BufferedReader(new InputStreamReader(stdout));
// cmriots!@#
while (true) {
String line = br.readLine();
if (line == null)
break;
System.out.println(line);
}
System.out.println("ExitCode: " + sessionSsh.getExitStatus());
// 下载文件
client.get(src+"/"+filename+".tar.gz", saveFile);
flag=true;
e.printStackTrace();
}
}else {
//是文件夹，打包下载
String src=srcFile.substring(0, srcFile.lastIndexOf("/"));
String cmdGet = "tar -zcvf " + srcFile + ".tar.gz " + filename;
//String cmdGet="tar czf /home/"+filename+".tar.gz –directory="+src+"/"+filename+".";
// 执行压缩命令
sessionSsh.execCommand("cd "+src+";"+cmdGet);
InputStream stdout = new StreamGobbler(sessionSsh.getStdout());
BufferedReader br = new BufferedReader(new InputStreamReader(stdout));
// cmriots!@#
while (true) {
String line = br.readLine();
if (line == null)
break;
System.out.println(line);
}
System.out.println("ExitCode: " + sessionSsh.getExitStatus());
// 下载文件
client.get(src+"/"+filename+".tar.gz", saveFile);
//unGzipFile(saveFile+"/"+filename+".tar.gz");
flag=true;
}
} catch (IOException e) {
e.printStackTrace();
}
return flag;
}
//------------------------------------------------------------------------------------------------------
/**
* 解压tar.gz 文件
* @param file 要解压的tar.gz文件对象
* @param outputDir 要解压到某个指定的目录下
* @throws IOException
*/
public static void unTarGz(File file,String outputDir) throws IOException{
TarInputStream tarIn = null;
try{
tarIn = new TarInputStream(new GZIPInputStream(
new BufferedInputStream(new FileInputStream(file))),
1024 * 2);
createDirectory(outputDir,null);//创建输出目录
TarEntry entry = null;
while( (entry = tarIn.getNextEntry()) != null ){
if(entry.isDirectory()){//是目录
entry.getName();
createDirectory(outputDir,entry.getName());//创建空目录
}else{//是文件
File tmpFile = new File(outputDir + "/" + entry.getName());
createDirectory(tmpFile.getParent() + "/",null);//创建输出目录
OutputStream out = null;
try{
out = new FileOutputStream(tmpFile);
int length = 0;
byte[] b = new byte[2048];
while((length = tarIn.read(b)) != -1){
out.write(b, 0, length);
}
}catch(IOException ex){
throw ex;
}finally{
if(out!=null)
out.close();
}
}
}
}catch(IOException ex){
throw new IOException("解压归档文件出现异常",ex);
} finally{
try{
if(tarIn != null){
tarIn.close();
}
}catch(IOException ex){
throw new IOException("关闭tarFile出现异常",ex);
}
}
}
/**
* 构建目录
* @param outputDir
* @param subDir
*/
public static void createDirectory(String outputDir,String subDir){
File file = new File(outputDir);
if(!(subDir == null || subDir.trim().equals(""))){//子目录不为空
file = new File(outputDir + "/" + subDir);
}
if(!file.exists()){
if(!file.getParentFile().exists())
file.getParentFile().mkdirs();
file.mkdirs();
}
}