1.JSch介绍
JSch是SSH2的纯Java实现。JSch允许您连接到sshd服务器并使用端口转发，X11转发，文件传输等，并且可以将其功能集成到您自己的Java程序中。
2.实现原理
根据远程主机的IP地址，用户名和端口，建立会话（Session）
设置用户信息（包括密码和Userinfo），然后连接session，getSession()只是创建一个session，需要设置必要的认证信息之后，调用connect()才能建立连接。
设置channel上需要远程执行的Shell脚本，连接channel，就可以远程执行该Shell脚本，调用openChannel(String type) 可以在session上打开指定类型的channel。该channel只是被初始化，使用前需要先调用connect()进行连接。
可以读取远程执行Shell脚本的输出，然后依次断开channel和session的连接
3.代码工程
实验目标：实现文件上传到服务，服务器下载文件以及执行服务器命令
pom.xml
<project xmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><parent><artifactId>springboot-demo</artifactId><groupId>com.et</groupId><version>1.0-SNAPSHOT</version></parent><modelVersion>4.0.0</modelVersion><artifactId>JSch</artifactId><properties><maven.compiler.source>8</maven.compiler.source><maven.compiler.target>8</maven.compiler.target></properties><dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-autoconfigure</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency><!-- https://mvnrepository.com/artifact/com.jcraft/jsch --><dependency><groupId>com.jcraft</groupId><artifactId>jsch</artifactId><version>0.1.55</version></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId></dependency><dependency><groupId>com.alibaba</groupId><artifactId>fastjson</artifactId><version>1.2.78</version></dependency></dependencies></project>
remote.java
package com.et.jsch.model;import lombok.Data;public class Remote {private String host;private final int port = 22;private String user;private String password;private final String identity = "~/.ssh/id_rsa";private String passphrase;}
JSchUtil.java
package com.et.jsch.util;import com.et.jsch.model.Remote;import com.jcraft.jsch.*;import lombok.extern.slf4j.Slf4j;import java.io.*;import java.nio.file.Files;import java.nio.file.Paths;import java.util.ArrayList;import java.util.List;import java.util.function.Function;/*** ssh tools*/@Slf4jpublic class JSchUtil {public static final int SESSION_TIMEOUT = 30000;public static final int CONNECT_TIMEOUT = 3000;/*** get session** @param remote ssh server info* @return session* @throws JSchException /*/public static Session getSession(Remote remote) throws JSchException {JSch jSch = new JSch();if (Files.exists(Paths.get(remote.getIdentity()))) {jSch.addIdentity(remote.getIdentity(), remote.getPassphrase());}Session session = jSch.getSession(remote.getUser(), remote.getHost(), remote.getPort());session.setPassword(remote.getPassword());session.setConfig("StrictHostKeyChecking", "no");return session;}/*** excute remote command** @param session session* @param command command* @return /* @throws JSchException /*/public static List<String> remoteExecute(Session session, String command) throws JSchException {log.debug(">> {}", command);List<String> resultLines = new ArrayList<>();ChannelExec channel = null;try {channel = openExecChannel(session);channel.setCommand(command);InputStream input = channel.getInputStream();channel.connect(CONNECT_TIMEOUT);try {BufferedReader inputReader = new BufferedReader(new InputStreamReader(input));String inputLine;while ((inputLine = inputReader.readLine()) != null) {log.debug(" {}", inputLine);resultLines.add(inputLine);}} finally {if (input != null) {try {input.close();} catch (Exception e) {log.error("JSch inputStream close error:", e);}}}} catch (IOException e) {log.error("IOException:", e);} finally {disconnect(channel);}return resultLines;}/*** scp file to remote server** @param session session* @param source local file* @param destination remote target file* @return file size*/public static long scpTo(Session session, String source, String destination) {FileInputStream fileInputStream = null;ChannelExec channel = null;try {channel = openExecChannel(session);OutputStream out = channel.getOutputStream();InputStream in = channel.getInputStream();boolean ptimestamp = false;String command = "scp";if (ptimestamp) {command += " -p";}command += " -t " + destination;channel.setCommand(command);channel.connect(CONNECT_TIMEOUT);if (checkAck(in) != 0) {return -1;}File _lfile = new File(source);if (ptimestamp) {command = "T " + (_lfile.lastModified() / 1000) + " 0";// The access time should be sent here,// but it is not accessible with JavaAPI ;-<command += (" " + (_lfile.lastModified() / 1000) + " 0\n");out.write(command.getBytes());out.flush();if (checkAck(in) != 0) {return -1;}}//send "C0644 filesize filename", where filename should not include '/'long fileSize = _lfile.length();command = "C0644 " + fileSize + " ";if (source.lastIndexOf('/') > 0) {command += source.substring(source.lastIndexOf('/') + 1);} else {command += source;}command += "\n";out.write(command.getBytes());out.flush();if (checkAck(in) != 0) {return -1;}//send content of filefileInputStream = new FileInputStream(source);byte[] buf = new byte[1024];long sum = 0;while (true) {int len = fileInputStream.read(buf, 0, buf.length);if (len <= 0) {break;}out.write(buf, 0, len);sum += len;}//send '\0'buf[0] = 0;out.write(buf, 0, 1);out.flush();if (checkAck(in) != 0) {return -1;}return sum;} catch (JSchException e) {log.error("scp to caught jsch exception, ", e);} catch (IOException e) {log.error("scp to caught io exception, ", e);} catch (Exception e) {log.error("scp to error, ", e);} finally {closeInputStream(fileInputStream);disconnect(channel);}return -1;}/*** scp remote file to local** @param session session* @param source remote file* @param destination local file* @return file size*/public static long scpFrom(Session session, String source, String destination) {FileOutputStream fileOutputStream = null;ChannelExec channel = null;try {channel = openExecChannel(session);channel.setCommand("scp -f " + source);OutputStream out = channel.getOutputStream();InputStream in = channel.getInputStream();channel.connect();byte[] buf = new byte[1024];//send '\0'buf[0] = 0;out.write(buf, 0, 1);out.flush();while (true) {if (checkAck(in) != 'C') {break;}}//read '644 'in.read(buf, 0, 4);long fileSize = 0;while (true) {if (in.read(buf, 0, 1) < 0) {break;}if (buf[0] == ' ') {break;}fileSize = fileSize * 10L + (long) (buf[0] - '0');}String file = null;for (int i = 0; ; i++) {in.read(buf, i, 1);if (buf[i] == (byte) 0x0a) {file = new String(buf, 0, i);break;}}// send '\0'buf[0] = 0;out.write(buf, 0, 1);out.flush();// read a content of lfileif (Files.isDirectory(Paths.get(destination))) {fileOutputStream = new FileOutputStream(destination + File.separator + file);} else {fileOutputStream = new FileOutputStream(destination);}long sum = 0;while (true) {int len = in.read(buf, 0, buf.length);if (len <= 0) {break;}sum += len;if (len >= fileSize) {fileOutputStream.write(buf, 0, (int) fileSize);break;}fileOutputStream.write(buf, 0, len);fileSize -= len;}return sum;} catch (JSchException e) {log.error("scp to caught jsch exception, ", e);} catch (IOException e) {log.error("scp to caught io exception, ", e);} catch (Exception e) {log.error("scp to error, ", e);} finally {closeOutputStream(fileOutputStream);disconnect(channel);}return -1;}/*** remote edit** @param session session* @param source target file* @param process edit command collect* @return isSuccess*/private static boolean remoteEdit(Session session, String source, Function<List<String>, List<String>> process) {InputStream in = null;OutputStream out = null;try {String fileName = source;int index = source.lastIndexOf('/');if (index >= 0) {fileName = source.substring(index + 1);}//backup sourceremoteExecute(session, String.format("cp %s %s", source, source + ".bak." + System.currentTimeMillis()));//scp from remoteString tmpSource = System.getProperty("java.io.tmpdir") + session.getHost() + "-" + fileName;scpFrom(session, source, tmpSource);in = new FileInputStream(tmpSource);//edit file according function processString tmpDestination = tmpSource + ".des";out = new FileOutputStream(tmpDestination);List<String> inputLines = new ArrayList<>();BufferedReader reader = new BufferedReader(new InputStreamReader(in));String inputLine = null;while ((inputLine = reader.readLine()) != null) {inputLines.add(inputLine);}List<String> outputLines = process.apply(inputLines);for (String outputLine : outputLines) {out.write((outputLine + "\n").getBytes());out.flush();}//scp to remotescpTo(session, tmpDestination, source);return true;} catch (Exception e) {log.error("remote edit error, ", e);return false;} finally {closeInputStream(in);closeOutputStream(out);}}/*** update file** @param session session* @param in file stream* @param directory local dir* @param fileName FTP server file name：xxx.txt ||xxx.txt.zip*/public static boolean uploadFile(Session session, InputStream in, String directory, String fileName) {log.info(">>>>>>>>uploadFile--ftp start>>>>>>>>>>>>>");ChannelSftp channel = null;try {channel = openSftpChannel(session);channel.connect(CONNECT_TIMEOUT);String[] folders = directory.split("/");try {for (int i = 0; i < folders.length; i++) {if (i == 0 && folders[i].length() == 0) {channel.cd("/");} else if (folders[i].length() > 0) {try {channel.cd(folders[i]);} catch (SftpException e) {channel.mkdir(folders[i]);channel.cd(folders[i]);}}}} catch (SftpException e) {log.error("ftp create file fail" + directory, e);return false;}try {channel.put(in, fileName);} catch (SftpException e) {log.error("sftp error-->" + e.getMessage(), e);return false;}log.info(">>>>>>>>uploadFile--ftp upload end>>>>>>>>>>>>>");log.info(">>>>>>>>ftp upload dir：{}，filename：{}>>>>>>>>>>>>>", directory, fileName);return true;} catch (JSchException e) {log.error("JSch error-->" + e.getMessage(), e);return false;} finally {closeInputStream(in);disconnect(channel);}}/***** @param channel sftp connect* @param directory* @param fileName* @return*/public static InputStream stream(ChannelSftp channel, String directory, String fileName) {try {channel.connect(CONNECT_TIMEOUT);InputStream inputStream = channel.get(directory + "/" + fileName);log.info(">>>>>>>>ftp file directory：{}，filename：{}>>>>>>>>>>>>>", directory, fileName);return inputStream;} catch (SftpException e) {log.error("sftp error-->" + e.getMessage());return null;} catch (JSchException e) {log.error("JSch error-->" + e.getMessage());return null;}}/*** ftp delete remote file** @param session session* @param directory directory* @param fileName filename* @return is Success*/public static boolean deleteFile(Session session, String directory, String fileName) {log.info(">>>>>>>>deleteFile--ftp delete file end>>>>>>>>>>>>>");ChannelSftp channel = null;try {channel = openSftpChannel(session);channel.connect(CONNECT_TIMEOUT);channel.rm(directory + "/" + fileName);log.info(">>>>>>>>deleteFile--deletefile end>>>>>>>>>>>>>");log.info(">>>>>>>>ftp delete file directory：{}，filename：{}>>>>>>>>>>>>>", directory, fileName);} catch (SftpException e) {log.error("ftp create directory fail" + directory);return false;} catch (JSchException e) {log.error("JSch error-->" + e.getMessage());return false;} finally {disconnect(channel);}return true;}public static Channel openChannel(Session session, String type) throws JSchException {if (!session.isConnected()) {session.connect(SESSION_TIMEOUT);}return session.openChannel(type);}public static ChannelSftp openSftpChannel(Session session) throws JSchException {return (ChannelSftp) openChannel(session, "sftp");}public static ChannelExec openExecChannel(Session session) throws JSchException {return (ChannelExec) openChannel(session, "exec");}/*** disconnect** @param session*/public static void disconnect(Session session) {if (session != null) {if (session.isConnected()) {try {session.disconnect();log.info("session disconnect successfully");} catch (Exception e) {log.error("JSch session disconnect error:", e);}}}}/*** close connection** @param channel channel connection*/public static void disconnect(Channel channel) {if (channel != null) {if (channel.isConnected()) {try {channel.disconnect();log.info("channel is closed already");} catch (Exception e) {log.error("JSch channel disconnect error:", e);}}}}public static int checkAck(InputStream in) throws IOException {int b = in.read();// b may be 0 for success,// 1 for error,// 2 for fatal error,// -1if (b == 0) {return b;}if (b == -1) {return b;}if (b == 1 || b == 2) {StringBuilder sb = new StringBuilder();int c;do {c = in.read();sb.append((char) c);}while (c != '\n');if (b == 1) { // errorlog.debug(sb.toString());}if (b == 2) { // fatal errorlog.debug(sb.toString());}}return b;}public static void closeInputStream(InputStream in) {if (in != null) {try {in.close();} catch (IOException e) {log.error("Close input stream error." + e.getMessage());}}}public static void closeOutputStream(OutputStream out) {if (out != null) {try {out.close();} catch (IOException e) {log.error("Close output stream error." + e.getMessage());}}}}
DemoApplication.java
package com.et.jsch;import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;public class DemoApplication {public static void main(String[] args) {SpringApplication.run(DemoApplication.class, args);}}
代码仓库
https://github.com/Harries/springboot-demo
4.测试
import com.alibaba.fastjson.JSONObject;import com.et.jsch.DemoApplication;import com.et.jsch.model.Remote;import com.et.jsch.util.JSchUtil;import com.jcraft.jsch.JSchException;import com.jcraft.jsch.Session;import org.junit.After;import org.junit.Before;import org.junit.Test;import org.junit.runner.RunWith;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.springframework.boot.test.context.SpringBootTest;import org.springframework.test.context.junit4.SpringRunner;import java.io.File;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.InputStream;import java.util.List;(SpringRunner.class)(classes = DemoApplication.class)public class JSchUtilTests {private Logger log = LoggerFactory.getLogger(getClass());Session session;public void before() throws JSchException {Remote remote= new Remote();remote.setHost("xxx.xxx.xxx.xxx");remote.setUser("root");remote.setPassword("xxxx");session= JSchUtil.getSession(remote);}public void after(){JSchUtil.disconnect(session);}public void remoteExecute() throws JSchException {List<String> list= JSchUtil.remoteExecute(session,"ls");System.out.println(JSONObject.toJSON(list));}public void uploadFile() throws JSchException, FileNotFoundException {String filestr ="D:\\tmp\\test\\file_utils\\file1.txt";File file = new File(filestr);InputStream in = new FileInputStream(file);String directory="/root/test";String fileName="test.txt";boolean flag= JSchUtil.uploadFile(session,in,directory,fileName);System.out.println(flag);}public void deleteFile() throws JSchException, FileNotFoundException {String directory="/root/test";String fileName="test.txt";boolean flag= JSchUtil.deleteFile(session,directory,fileName);System.out.println(flag);}public void scpFrom() throws JSchException, FileNotFoundException {String source="/root/test/file1.txt";String destination ="D:\\tmp\\scfFrom.txt";long filesize= JSchUtil.scpFrom(session,source,destination);System.out.println(filesize);}public void scpTo() throws JSchException, FileNotFoundException {String filestr ="D:\\tmp\\test\\file_utils\\file1.txt";String destination="/root/test/file1.txt";long filesize= JSchUtil.scpTo(session,filestr,destination);System.out.println(filesize);}}
自己尝试一下吧，非常好的一个工具，更多功能可以去官网看例子
5.引用
http://www.jcraft.com/jsch/examples/
http://www.liuhaihua.cn/archives/710346.html
原文作者：HBLOG；如有侵权，请联系管理员删除。
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