JSch基本使用
JSch 是SSH2的一個純Java實現。它允許你連接到一個sshd 服務器，使用端口轉發，X11轉發，文件傳輸等等。你可以將它的功能集成到你自己的 程序中。同時該項目也提供一個J2ME版本用來在手機上直連SSHD服務器。
官網:http://www.jcraft.com/jsch/中有很多例子http://www.jcraft.com/jsch/examples/，這里先采用（已做修改）其中2個來進行簡單論述，希望對大家有所幫助。
本文采用的jsch版本是0.1.51. 下載地址：http://sourceforge.net/projects/jsch/files/jsch/0.1.54/jsch-0.1.54.zip/download。
本文采用的Linux操作系統是CentOS6.5.
TIPS: 查看Linux操作系統（內核）版本可以使用：uname -a; uname -r; cat /etc/issue; cat /etc/redhat-release等命令。
第一個例子：采用Java模擬shell操作。
這里涉及到幾個參數，會在下面的代碼中有所體現：
- USER：所連接的Linux主機登錄時的用戶名
- PASSWORD：登錄密碼
- HOST：主機地址
- DEFAULT_SSH_PROT=端口號，默認為22
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package
com.test.jsch;
/**
* This program enables you to connect to sshd server and get the shell prompt.
* You will be asked username, hostname and passwd.
* If everything works fine, you will get the shell prompt. Output may
* be ugly because of lacks of terminal-emulation, but you can issue commands.
*/
import
com.jcraft.jsch.JSch;
import
com.jcraft.jsch.Session;
import
com.jcraft.jsch.UserInfo;
import
com.jcraft.jsch.Channel;
public
class
Shell{
private
static
final
String USER=
"root"
;
private
static
final
String PASSWORD=
"********"
;
private
static
final
String HOST=
"localhost"
;
private
static
final
int
DEFAULT_SSH_PORT=
22
;
public
static
void
main(String[] arg){
try
{
JSch jsch=
new
JSch();
Session session = jsch.getSession(USER,HOST,DEFAULT_SSH_PORT);
session.setPassword(PASSWORD);
UserInfo userInfo =
new
UserInfo() {
@Override
public
String getPassphrase() {
System.out.println(
"getPassphrase"
);
return
null
;
}
@Override
public
String getPassword() {
System.out.println(
"getPassword"
);
return
null
;
}
@Override
public
boolean
promptPassword(String s) {
System.out.println(
"promptPassword:"
+s);
return
false
;
}
@Override
public
boolean
promptPassphrase(String s) {
System.out.println(
"promptPassphrase:"
+s);
return
false
;
}
@Override
public
boolean
promptYesNo(String s) {
System.out.println(
"promptYesNo:"
+s);
return
true
;
//notice here!
}
@Override
public
void
showMessage(String s) {
System.out.println(
"showMessage:"
+s);
}
};
session.setUserInfo(userInfo);
// It must not be recommended, but if you want to skip host-key check,
// invoke following,
// session.setConfig("StrictHostKeyChecking", "no");
//session.connect();
session.connect(
30000
);
// making a connection with timeout.
Channel channel=session.openChannel(
"shell"
);
// Enable agent-forwarding.
//((ChannelShell)channel).setAgentForwarding(true);
channel.setInputStream(System.in);
/*
// a hack for MS-DOS prompt on Windows.
channel.setInputStream(new FilterInputStream(System.in){
public int read(byte[] b, int off, int len)throws IOException{
return in.read(b, off, (len>1024?1024:len));
}
});
*/
channel.setOutputStream(System.out);
/*
// Choose the pty-type "vt102".
((ChannelShell)channel).setPtyType("vt102");
*/
/*
// Set environment variable "LANG" as "ja_JP.eucJP".
((ChannelShell)channel).setEnv("LANG", "ja_JP.eucJP");
*/
//channel.connect();
channel.connect(
3
*
1000
);
}
catch
(Exception e){
System.out.println(e);
}
}
}
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運行結果：
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promptYesNo:
The authenticity of host
'10.101.139.5'
can't be established.
RSA key fingerprint is 59:0f:32:fc:7b:54:3d:90:c0:ef:5a:6b:fb:11:55:e1.
Are you sure you want to
continue
connecting?
trueLast login: Thu Sep 29 18:40:56 2016 from 10.101.48.240
[root@hidden ~]
#
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輸入ls查看：
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(省略一些....)
[root@hidden ~]
# ls
ls
1.txt
install
.log.syslog vmware-tools-distrib 模板 文檔 桌面
anaconda-ks.cfg logs workspace 視頻 下載
install
.log util 公共的 圖片 音樂
[root@hidden ~]
#
|
這樣就和在原linux系統中一樣使用shell功能了。
如果需要跳過如下的檢測：
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The authenticity of host
'10.101.139.5'
can't be established.
RSA key fingerprint is 59:0f:32:fc:7b:54:3d:90:c0:ef:5a:6b:fb:11:55:e1.
Are you sure you want to
continue
connecting?
|
只需要在程序中加入相應的代碼：
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session.setConfig(
"StrictHostKeyChecking"
,
"no"
);
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運行結果：
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2
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Last login: Thu Sep 29 18:39:18 2016 from 10.101.48.240
[root@hidden ~]
#
|
第二個例子：運行一條shell指令，這里就那“ls”做例子好了。
No more talk, show you the code:
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package
com.test.jsch;
import
com.jcraft.jsch.*;
import
java.io.*;
public
class
Exec{
private
static
final
String USER=
"root"
;
private
static
final
String PASSWORD=
"********"
;
private
static
final
String HOST=
"localhost"
;
private
static
final
int
DEFAULT_SSH_PORT=
22
;
public
static
void
main(String[] arg){
try
{
JSch jsch=
new
JSch();
Session session = jsch.getSession(USER,HOST,DEFAULT_SSH_PORT);
session.setPassword(PASSWORD);
// username and password will be given via UserInfo interface.
session.setUserInfo(
new
MyUserInfo());
session.connect();
String command=
"ls"
;
Channel channel=session.openChannel(
"exec"
);
((ChannelExec)channel).setCommand(command);
// X Forwarding
// channel.setXForwarding(true);
//channel.setInputStream(System.in);
channel.setInputStream(
null
);
//channel.setOutputStream(System.out);
//FileOutputStream fos=new FileOutputStream("/tmp/stderr");
//((ChannelExec)channel).setErrStream(fos);
((ChannelExec)channel).setErrStream(System.err);
InputStream in=channel.getInputStream();
channel.connect();
byte
[] tmp=
new
byte
[
1024
];
while
(
true
){
while
(in.available()>
0
){
int
i=in.read(tmp,
0
,
1024
);
if
(i<
0
)
break
;
System.out.print(
new
String(tmp,
0
, i));
}
if
(channel.isClosed()){
if
(in.available()>
0
)
continue
;
System.out.println(
"exit-status: "
+channel.getExitStatus());
break
;
}
try
{Thread.sleep(
1000
);}
catch
(Exception ee){}
}
channel.disconnect();
session.disconnect();
}
catch
(Exception e){
System.out.println(e);
}
}
private
static
class
MyUserInfo
implements
UserInfo{
@Override
public
String getPassphrase() {
System.out.println(
"getPassphrase"
);
return
null
;
}
@Override
public
String getPassword() {
System.out.println(
"getPassword"
);
return
null
;
}
@Override
public
boolean
promptPassword(String s) {
System.out.println(
"promptPassword:"
+s);
return
false
;
}
@Override
public
boolean
promptPassphrase(String s) {
System.out.println(
"promptPassphrase:"
+s);
return
false
;
}
@Override
public
boolean
promptYesNo(String s) {
System.out.println(
"promptYesNo:"
+s);
return
true
;
//notice here!
}
@Override
public
void
showMessage(String s) {
System.out.println(
"showMessage:"
+s);
}
}
}
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運行結果：
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promptYesNo:The authenticity of host
'10.101.139.5'
can't be established.
RSA key fingerprint is 59:0f:32:fc:7b:54:3d:90:c0:ef:5a:6b:fb:11:55:e1.
Are you sure you want to
continue
connecting?
1.txt
anaconda-ks.cfg
install
.log
install
.log.syslog
logs
util
vmware-tools-distrib
workspace
公共的
模板
視頻
圖片
文檔
下載
音樂
桌面
exit
-status: 0
|
第二個例子相比於第一個例子來說將UserInfo采用static class的方式提取出來，這樣更直觀一點。
JSch是以多線程方式一下，所以代碼在connect后如果不disconnect channel和session,以及相關stream, 程序會一直等待，直到關閉。
需要注意的一個問題，相關的Stream和Channel是一定要關閉的，那么應該在什么時候來關？執行connect后，JSch接受客戶端結果需要一定的時間（以秒計），如果馬上關閉session就會發現什么都沒接受到或內容不全。
還有一點注意，使用shell時，看到執行后沒有結果，解決辦法是在命令行后加上”\n”字符，server端就認為是一條完整的命令了。
最后將第一個和第二個例子合並，並提取一些公用模塊，以便更好的理解和使用：
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package
com.test.jsch;
import
com.jcraft.jsch.*;
import
java.io.*;
import
java.util.concurrent.TimeUnit;
import
static
java.lang.String.format;
/**
* Created by hidden on 2016/9/29.
*/
public
class
SSHExecutor {
private
static
long
INTERVAL = 100L;
private
static
int
SESSION_TIMEOUT =
30000
;
private
static
int
CHANNEL_TIMEOUT =
3000
;
private
JSch jsch =
null
;
private
Session session =
null
;
private
SSHExecutor(SSHInfo sshInfo)
throws
JSchException {
jsch =
new
JSch();
session = jsch.getSession(sshInfo.getUser(),sshInfo.getHost(),sshInfo.getPort());
session.setPassword(sshInfo.getPassword());
session.setUserInfo(
new
MyUserInfo());
session.connect(SESSION_TIMEOUT);
}
/*
* 在這里修改訪問入口,當然可以把這個方法弄到SSHExecutor外面，這里是方便操作才這么做的
* */
public static SSHExecutor newInstance() throws JSchException {
SSHInfo sshInfo = new SSHInfo("root","******","locahost",22);
return new SSHExecutor(sshInfo);
}
/*
* 注意編碼轉換
* */
public long shell(String cmd, String outputFileName) throws JSchException, IOException, InterruptedException {
long start = System.currentTimeMillis();
Channel channel = session.openChannel("shell");
PipedInputStream pipeIn = new PipedInputStream();
PipedOutputStream pipeOut = new PipedOutputStream( pipeIn );
FileOutputStream fileOut = new FileOutputStream( outputFileName, true);
channel.setInputStream(pipeIn);
channel.setOutputStream(fileOut);
channel.connect(CHANNEL_TIMEOUT);
pipeOut.write(cmd.getBytes());
Thread.sleep( INTERVAL );
pipeOut.close();
pipeIn.close();
fileOut.close();
channel.disconnect();
return System.currentTimeMillis() - start;
}
public int exec(String cmd) throws IOException, JSchException, InterruptedException {
ChannelExec channelExec = (ChannelExec)session.openChannel( "exec" );
channelExec.setCommand( cmd );
channelExec.setInputStream( null );
channelExec.setErrStream( System.err );
InputStream in = channelExec.getInputStream();
channelExec.connect();
int res = -1;
StringBuffer buf = new StringBuffer( 1024 );
byte[] tmp = new byte[ 1024 ];
while ( true ) {
while ( in.available() > 0 ) {
int i = in.read( tmp, 0, 1024 );
if ( i < 0 ) break;
buf.append( new String( tmp, 0, i ) );
}
if ( channelExec.isClosed() ) {
res = channelExec.getExitStatus();
System.out.println( format( "Exit-status: %d", res ) );
break;
}
TimeUnit.MILLISECONDS.sleep(100);
}
System.out.println( buf.toString() );
channelExec.disconnect();
return res;
}
public Session getSession(){
return session;
}
public void close(){
getSession().disconnect();
}
/*
* SSH連接信息
* */
public static class SSHInfo{
private String user;
private String password;
private String host;
private int port;
public SSHInfo(String user, String password, String host, int port) {
this.user = user;
this.password = password;
this.host = host;
this.port = port;
}
public String getUser() {
return user;
}
public String getPassword() {
return password;
}
public String getHost() {
return host;
}
public int getPort() {
return port;
}
}
/*
* 自定義UserInfo
* */
private
static
class
MyUserInfo
implements
UserInfo{
@Override
public
String getPassphrase() {
return
null
; }
@Override
public
String getPassword() {
return
null
; }
@Override
public
boolean
promptPassword(String s) {
return
false
; }
@Override
public
boolean
promptPassphrase(String s) {
return
false
; }
@Override
public
boolean
promptYesNo(String s) {
System.out.println(s);
System.out.println(
"true"
);
return
true
;
}
@Override
public
void
showMessage(String s) { }
}
}
|
測試代碼：
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SSHExecutor ssh = SSHExecutor.newInstance();
System.out.println(
"================"
);
long
shell1 = ssh.shell(
"ls\n"
,
"C:\\Users\\hidden\\Desktop\\shell.txt"
);
long
shell2 = ssh.shell(
"pwd\n"
,
"C:\\Users\\hidden\\Desktop\\shell.txt"
);
System.out.println(
"shell 1 執行了"
+shell1+
"ms"
);
System.out.println(
"shell 2 執行了"
+shell2+
"ms"
);
System.out.println(
"================"
);
int
cmd1 = ssh.exec(
"ls\n"
);
ssh.close();
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測試結果：
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The authenticity of host
'10.101.139.5'
can't be established.
RSA key fingerprint is 59:0f:32:fc:7b:54:3d:90:c0:ef:5a:6b:fb:11:55:e1.
Are you sure you want to
continue
connecting?
true
================
shell 1 執行了142ms
shell 2 執行了132ms
================
Exit-status: 0
1.txt
anaconda-ks.cfg
install
.log
install
.log.syslog
logs
util
vmware-tools-distrib
workspace
公共的
模板
視頻
圖片
文檔
下載
音樂
桌面
|
還有解釋查看一下左邊是否有個shell.txt以及shell.txt是否有相應的內容。