Java 使用SSH连接Linux 使用passwd命令修改密码
使用InputStream和OutputStream来获得命令行运行结果和输入内容是首先需要具备的.然后要解决SSH连接问题.在OpenSource项目里找到了Ganymed SSH-2 for Java .下载后有例子,但是没有找到有关交互命令的例子.所以自己探索了一下在网上看有老外讨论用这个如何改密码,基本上的问题都是因为找不到返回的提示Linux修改密码输入passwd后,首先是输入当前密码,然后是输入两个新密码如果当前密码输入错误,或者新密码输入不符合系统密码规则要求,会要求重新输入.如果碰到这种情况,程序很容易进入一个不太好控制的循环.可能一般人都认为输入命令后所有的返回都应该是用session.getStdout();而不是session.getStderr();从方法名称上看确实如此,一个是取得标准输出,一个是取得错误信息.其实在输入passwd后.Changing password for user [username].
Changing password for [username]这两行是需要通过session.getStdout();来获得的.但是后面的(current) UNIX password:New UNIX password:Retype new UNIX password:这三行是需要使用sessssion.getStderr();来获取的如果用户输入没有通过系统检测,会返回具体原因,但是都是BAD PASSWORD开始的.如果最后修改成功了.你也会看到有successfully来表示.这些信息是通过session.getStdout();来获取的.现在问题很好解决了吧.写了一个类来完成修改密码的操作
import ch.ethz.ssh2.Connection;import ch.ethz.ssh2.Session;import ch.ethz.ssh2.StreamGobbler;import com.io.Debug;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStream;import java.io.InputStreamReader;import java.io.OutputStream;public class ChangeEmailPassword { private String username = ""; private String oldpassword = ""; private Connection conn = null; private boolean hasError = false; private String ErrorMessage = ""; private boolean isSuccessfully = false; private String SystemMessage = ""; public static final String HOST = "127.0.0.1"; //server ip public boolean isSuccessfully(){ return isSuccessfully; } public boolean isHasError(){ return hasError; } public String getErrorMessage(){ return ErrorMessage; } public void setErrorMessage(String msg){ hasError = true; this.ErrorMessage = msg; } public ChangeEmailPassword(String username,String oldpassword) { this.username = username; this.oldpassword = oldpassword; try{ conn = new Connection(HOST); conn.connect(); boolean isAuthenticated = conn.authenticateWithPassword(username, oldpassword); if (isAuthenticated == false) { setErrorMessage("Authentication failed."); conn=null; } }catch(Exception e){ conn.close(); conn = null; System.out.println(e); } } public void setNewPassword(String newpassword) { if(hasError){ return; } if (conn==null){ return; } try{ Session sess = conn.openSession(); sess.execCommand("passwd"); InputStream so = sess.getStdout(); InputStream err = sess.getStderr(); OutputStream out = sess.getStdin(); byte[] buffer = new byte[500];//其实没有必要这么大.130就差不多了.怕万一有什么提示. int length = 0; length = err.read(buffer);// if (length > 0) {// System.out.println("#1:"+ new String(buffer, 0, length));// //(current) UNIX password:// } String coldpassword = oldpassword+"\n"; out.write(coldpassword.getBytes()); length = err.read(buffer);// if (length > 0) {// System.out.println("#2:"+ new String(buffer, 0, length));// //(current) UNIX password:// } String cnewpass = newpassword +"\n"; out.write(cnewpass.getBytes()); length = err.read(buffer); if (length > 0) { String rs = new String(buffer, 0, length); //System.out.println("#3:"+rs); if(rs.indexOf("BAD")>-1){ sess.close(); conn.close(); setErrorMessage(rs); return; } } out.write(cnewpass.getBytes()); length = so.read(buffer); if (length > 0) { String rs = new String(buffer, 0, length); if(rs.indexOf("successfully")>-1){ this.isSuccessfully = true; this.SystemMessage = rs; } } sess.close(); conn.close(); } catch (IOException e) { e.printStackTrace(System.err); } } public static void main(String[] args) { ChangeEmailPassword cep = new ChangeEmailPassword("username", "oldpassword"); if(cep.isHasError()){ System.out.println(cep.getErrorMessage()); cep = null; return; } cep.setNewPassword("newpassword"); if(cep.isHasError()){ System.out.println(cep.getErrorMessage()); cep = null; return; } if(cep.isSuccessfully){ System.out.println(cep.getSystemMessage()); } } public String getSystemMessage() { return SystemMessage; }} //把里面注解掉的System.out.println打开可以看到系统提示的信息.我只保留了最关键的信息提示?