unixuser.java

java高级使用教程 全书一共分六章

// UnixUser - a Unix user
//
// Copyright (C)1996,1998 by Jef Poskanzer <[e-mail]>. All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// 1. Redistributions of source code must retain the above copyright
//    notice, this list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright
//    notice, this list of conditions and the following disclaimer in the
//    documentation and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
// OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
// HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
// OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
// SUCH DAMAGE.
//
// Visit the ACME Labs Java page for up-to-date versions of this and other
// fine Java utilities: http://www.acme.com/java/

package Acme;

import java.io.*;

/// A Unix user.
// This just encapsulates access to /etc/passwd, equivalent to
// the Unix getpwnam() and getpwuid() routines.
// <P>
// <A HREF="/resources/classes/Acme/UnixUser.java">Fetch the software.</A><BR>
// <A HREF="/resources/classes/Acme.tar.gz">Fetch the entire Acme package.</A>

public class UnixUser
    {

    private String userName;
    private String encPasswd;
    private int userId;
    private int groupId;
    private String realName;
    private String homeDir;
    private String loginShell;

    private static final String etcPasswd = "/etc/passwd";

    /// Constructor by username.
    // @exception IOException if something goes wrong
    public UnixUser( String name ) throws IOException
	{
	BufferedReader br = openFile();
	while ( true )
	    {
	    readFields( br );
	    if ( userName.equals( name ) )
		break;
	    }
	}

    /// Constructor by userid.
    // @exception IOException if something goes wrong
    public UnixUser( int id ) throws IOException
	{
	BufferedReader br = openFile();
	while ( true )
	    {
	    readFields( br );
	    if ( userId == id )
		break;
	    }
	}

    private BufferedReader openFile() throws IOException
	{
	return new BufferedReader( new FileReader( "/etc/passwd" ) );
	}

    private void readFields( BufferedReader br ) throws IOException
	{
	while ( true )
	    {
	    String line = br.readLine();
	    if ( line == null )
		throw new IOException( "unknown user: " + userName );
	    String[] fields = Utils.splitStr( line, ':' );
	    if ( fields.length != 7 )
		continue;	// ignore malformed lines
	    userName = fields[0];
	    encPasswd = fields[1];
	    userId = Integer.parseInt( fields[2] );
	    groupId = Integer.parseInt( fields[3] );
	    realName = fields[4];
	    homeDir = fields[5];
	    loginShell = fields[6];
	    return;
	    }
	}


    public String getUserName()
	{
	return userName;
	}

    public String getEncPasswd()
	{
	return encPasswd;
	}

    public int getUserId()
	{
	return userId;
	}

    public int getGroupid()
	{
	return groupId;
	}

    public String getRealName()
	{
	return realName;
	}

    public String getHomeDir()
	{
	return homeDir;
	}

    public String getLoginShell()
	{
	return loginShell;
	}

    }