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DerbyControl.javaAPI DocGlassfish v2 API8683Fri May 04 22:25:08 BST 2007com.sun.enterprise.cli.commands

DerbyControl

public final class DerbyControl extends Object
This class uses Java reflection to invoke Derby NetworkServerControl class. This class is used to start/stop/ping derby database. The reason for creating this class instead of directly invoking NetworkServerControl from the StartDatabaseCommand class is so that a separate JVM is launched when starting the database and the control is return to CLI.
author
Jane Young
version
$Revision: 1.13 $

Fields Summary
public static final String
DB_LOG_FILENAME
private final String
derbyCommand
private final String
derbyHost
private final String
derbyPort
private final String
derbyHome
private final boolean
redirect
Constructors Summary
public DerbyControl(String dc, String dht, String dp, String redirect, String dhe)


        //constructor 
             
                             
    
        this.derbyCommand = dc;
        this.derbyHost = dht;
        this.derbyPort = dp;
        this.derbyHome = dhe;
	    this.redirect = Boolean.valueOf(redirect).booleanValue();
	    if (this.redirect) {

	        try {
                String dbLog = "";
                if (this.derbyHome == null) {
                    // if derbyHome is null then redirect the output to a temporary file
                    // which gets deleted after the jvm exists.
		            dbLog = createTempLogFile();
                }
		    else {
		        dbLog = createDBLog(this.derbyHome);
		    }
            
                //redirect stdout and stderr to a file
                PrintStream printStream = new PrintStream(new FileOutputStream(dbLog, true), true);
                System.setOut(printStream);
                System.setErr(printStream);
            }
            catch (Throwable t) {
	            t.printStackTrace();
	            //exit with an error code of 2
	            System.exit(2);
            }
        }
        //do not set derby.system.home if derbyHome is empty
        if (this.derbyHome!=null && this.derbyHome.length()>0) {
            System.setProperty("derby.system.home", this.derbyHome);
        }
	    //set the property to not overwrite log file
	    System.setProperty("derby.infolog.append", "true");
public DerbyControl(String dc, String dht, String dp)

        this(dc,dht,dp,"true", null);
public DerbyControl(String dc, String dht, String dp, String redirect)

        this(dc,dht,dp,redirect,null);
Methods Summary
private java.lang.StringcreateDBLog(java.lang.String dbHome)
create a db.log file that stdout/stderr will redirect to. dbhome is the derby.system.home directory where derb.log gets created. if user specified --dbhome options, derby.log will be created there.

        //dbHome must exist and  have write permission
        final File fDBHome = new File(dbHome);
	    String dbLogFileName = "";

        final StringManager lsm = StringManager.getManager(DerbyControl.class);
        if (fDBHome.isDirectory() && fDBHome.canWrite()) {
            final File fDBLog = new File(dbHome, DB_LOG_FILENAME);
	        dbLogFileName = fDBLog.toString();

            //if the file exists, check if it is writeable
            if (fDBLog.exists() && !fDBLog.canWrite()) {
	        System.out.println(lsm.getString("UnableToAccessDatabaseLog", dbLogFileName));
	        System.out.println(lsm.getString("ContinueStartingDatabase"));
	        //if exist but not able to write then create a temporary 
	        //log file and persist on starting the database
	        dbLogFileName = createTempLogFile();
            }
            else if (!fDBLog.exists()) {
                //create log file
                fDBLog.createNewFile();
            }
        }
        else {
            System.out.println(lsm.getString("InvalidDirectory", dbHome));
	        System.out.println(lsm.getString("ContinueStartingDatabase"));
	        //if directory does not exist then create a temporary log file
	        //and persist on starting the database
	        dbLogFileName = createTempLogFile();
        }
        return dbLogFileName;
private java.lang.StringcreateTempLogFile()
creates a temporary log file.

        String tempFileName = "";
        try {
            final File fTemp = File.createTempFile("foo", null);
            fTemp.deleteOnExit();
	        tempFileName = fTemp.toString();
	    }
	    catch (IOException ioe) {
            final StringManager lsm = StringManager.getManager(DerbyControl.class);
	        throw new CommandException(lsm.getString("UnableToAccessDatabaseLog", tempFileName));
	    }
        return tempFileName;
private voidinvokeNetworkServerControl()
This methos invokes the Derby's NetworkServerControl to start/stop/ping the database.

        try {
            Class networkServer = Class.forName("org.apache.derby.drda.NetworkServerControl");
            Method networkServerMethod = networkServer.getDeclaredMethod("main",
                                                       new Class[]{String[].class});
            Object [] paramObj = new Object[]{new String[]{derbyCommand, "-h", derbyHost, "-p", derbyPort}};
           
            networkServerMethod.invoke(networkServer, paramObj);
        }
        catch (Throwable t) {
	        t.printStackTrace();
	        System.exit(2);
        }
public static voidmain(java.lang.String[] args)

        
        if (args.length<3){
            System.out.println("paramters not specified.");
            System.out.println("DerbyControl <derby command> <derby host> <derby port> <derby home> <redirect output>");
            System.exit(1);
        }
        
        DerbyControl derbyControl = null;
        if (args.length == 3)
            derbyControl = new DerbyControl(args[0], args[1], args[2]);
        else if (args.length == 4 )
            derbyControl = new DerbyControl(args[0], args[1], args[2], args[3]);
        else if (args.length > 4)
            derbyControl = new DerbyControl(args[0], args[1], args[2], args[3], args[4]);
        if (derbyControl != null)
            derbyControl.invokeNetworkServerControl();