java-programmer >>Mutliple thread access to object method

Mutliple thread access to object method

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- 1
  - Please Help - Java, Database oracle or sybaseHi All,
    
    I am a java programmer used to using oracle database.
    
    In my new job, we have oracle plus sybase database. Some applications
    use oracle and some use Sybase. I am writing framework, so it can be
    used by all applications.
    
    Is it possible to write connection code, independent of database
    driver, by just using java.sql package.
    One problem I am seeing in sql package is java.sql.types does not have
    cursor. I don't know how sybase returns a resultset but java.sql.other
    does not look very promising.
    
    Could any body suggest a general solution using two different database.
    
    Thanks a lot,
    Jill.
- 2
  - FirewireHello everyone,
    
    Does Java's API include Firewire support? I have been doing some googling
    and all I can find are projects that have been started but not completed.
    I'm looking for Firewire support for both Linux and Windows.
    
    Anything information or tips would be great, thank you.
    
    ---
    Alvn Beach
    Email: email***@***.com
    Website: http://users.eastlink.ca/~alvinbeach
- 4
  - Reading data from Text fileimran wrote:
    > Hello,
    >
    > I have a problem on reading data from Text file(notepad) and save as
    a
    
    It looks like a Properties object is what you need. You could do
    something like:
    
    FileInputStream fis = new FileInputStream("injector.txt");
    Properties props = new Properties();
    props.load(fis);
    
    String classString = props.getProperty("classString");
    ...
- 4
  - Where can i download the local oracle client?Hi
    I want to install oracle client in order to connect Oracle(9i)
    database from local web server.I used to go to this
    <a href="http://otn.oracle.com/software/index.html">oracle download
    link </a>.But i dont know which is the suitable one.Could anyone tell
    me?
    
    Thanks
    
    Ricky
- 7
  - Tomcat5.5 queryHi,
    I have installed tomcat5.5.
    In the tomcat docs it is recommended that i install Ant build tool as
    well as Concurrent Version System (CVS) too.
    Can someone tell me, how much neccesary are these to install and use?
    How it can help me for developing my application?
- 7
  - Java Programming: Advanced topics - Sample codeHi,
    
    I am trying to get a Java Bean sample code from Java Programming:
    Advanced topics book working.
    I have modified the code for SQL Server, it does not work??
    
    The Java Virtual Machine throws a "could not find the main class"????
    Could anyone point out what I am doing wrong.
    
    I can get a db connection in a JSP page, am trying to create a
    container that I can call the
    variable from the JSP page.
    
    Thanks for your help.
    
    Clive
    
    java.lang.NoClassDefFoundError: project1/DBdemo
    Exception in thread main
    
    package project1;
    
    import java.sql.*;
    /**
    * Class to create connection to a database and
    * and demonstrate basic SQL queries
    */
    public class DBdemo {
    /**
    * the connection object
    */
    static Connection connection = null;
    // select DB2 type 2 driver
    static final String dbDriver = "net.sourceforge.jtds.jdbc";
    static final String dbUrl = "jdbc:jtds:sqlserver://localhost:
    1032/";
    // use the SKICLUB database
    static final String dbName = "Calibration";
    // set dbUser to any user on your Windows OS
    static final String dbUser = "userid";
    // set dbPassword to Windows password for dbUser
    static final String dbPassword = "password";
    /**
    * method to open the connection
    */
    public Connection getConnection() {
    if ( connection != null )
    return connection;
    try {
    connection = DriverManager.getConnection(
    dbUrl, dbUser, dbPassword );
    } catch( SQLException e ) {
    System.err.println("Cannot connect to database: for SQl
    server, " + "check that SQl is running and " + "the SKICLUB database
    exists." );
    }
    return connection;
    }
    
    public ResultSet getAllMemberInfo() {
    ResultSet rs = null;
    try {
    Statement statement =
    getConnection().createStatement();
    String sql = "Select * from Prop1_Wallfinish,
    Users where Prop1_Wallfinish.SurveyID= Users.SurveyIDS";
    System.out.println( sql );
    statement.executeQuery( sql );
    rs = statement.getResultSet();
    } catch( SQLException e ) {
    System.out.println(
    "SQLException " + e.getMessage() );
    } finally {
    return rs;
    }
    }
    
    public static void main(String[] args) {
    DBdemo dbdemo = new DBdemo();
    System.out.println("Getting Database driver" );
    try {
    Class.forName( dbDriver );
    } catch( ClassNotFoundException e ) {
    System.err.println("Cannot load database
    driver: for SQL, " + "your classpath must include " + "SQLLIB\\JAVA12\
    \DB2JAVA.ZIP." );
    }
    System.out.println(
    "Getting Database connection" );
    Connection connection = dbdemo.getConnection();
    if ( connection == null )
    System.exit(0);
    System.out.println( "Database ready" );
    try {
    // demonstrate a SELECT Statement
    dbdemo.getAllMemberInfo();
    
    connection.close();
    } catch (Exception e) {
    System.err.println(
    e.getClass().getName() + ": " +
    e.getMessage() );
    }
    }// end public main
    
    } // end DB
- 7
  - classpath problems with jar filesokay, i have an odd problem... and maybe it's platform-specific... but i
    figure give it a shot and ask about it in case someone has seen this.
    
    i have an application that is made up of numerous class files. this
    application at one point loads a class from another company using the
    command Class.forName(...).
    
    when i compile the .java files to bytecode and execute from the main()
    entry point, it works fine.
    
    than i create a jar file, and include a manifest line to point to the
    class containing the main() entry point. then i execute the jar file
    (java -jar jarfile).
    
    the program starts running fine, but throws a class not found exception
    when it hits the Class.forName() line.
    
    everything else is the same... same classpath setting, and the other class
    files haven't moved (the other classes are in fact in a jar file which is
    included in the classpath).
    
    so to sum it up... app works fine when not in jar file. jar it up, and
    run with everything else the same... cannot load some external classes.
    
    now, i am running jdk1.4.1 on mac os x.
    
    any thoughts?
    
    murat
    
    --
    Murat Tasan
    email***@***.com
    email***@***.com
    email***@***.com
    http://genomics.cwru.edu
- 7
  - Simple ClassLoaderHi!
    
    Say that I have a string of bytes (byte[]) defining a class, how do I
    create a simple ClassLoader to define the class?
    
    Regards,
    Jesper
- 10
  - javax.comm: Writing to a parallel port?I have the same problem.
    No exception raises.
    Have no idea what to do.
    waiting for anyone's ideas
- 10
  - Hi ALl - Plz HELpHi Friends,
    
    I would be highly grateful if anyone can provide a solution for the
    following :
    
    There is a MS-SQL server hosted on a machine which is our data server.
    We need to access this data server through many client machines. To
    secure the data exchange between client(s) & Data server we use
    JSECURE Client for SSL communication. But this secures the channel
    between client machine and the machine on which my MS -SQL server
    is hosted. Once the data is received on server machine, JSECURE
    decrypts the data and sends to the data server. Now if I enable the
    SSL
    on MS-SQL server , I guess my communication would fail because I
    don't
    know which algorithms are being used by MS-SQL server & JSECURE
    to encrypt their respective data's. So , in this case I need a bridge
    between
    these two ( Precisely a TRANSLATOR which understands both - JSECURE
    & MS-SQL SERVERS).
    
    Please let me know if any such solution exists. Thanks a lot to you
    all friends!!
- 10
  - Compile in memory java source?Hello,
    
    Does anyone know of a java compiler which can be launched in process to
    compile an in memory representation of a java source file? Essentially,
    I generate some source on the fly and I'd like to avoid having to write
    it to disk and all the messiness (permissions, cleanup, etc) that come
    with that. I was surprised to find that javac didn't (as far as I could
    tell) support this interaction. Can anyone point me towards a tool
    which does what I need? Thanks in advance.
    
    -exits
- 12
  - Query in Prepared statements cachingHii ,
    I am using Db2 V 7.1 on ZOS
    I have the following Java Code
    query.append("insert into ");
    query.append(schemaName+".EMAIL_DATA ");
    query.append("(EMAIL_NBR, DT_FIRST_SENT,SUBJECT
    ,EMAIL_ADDR,EMAIL_DTL,ER_NBR, DT_CREATED,DT_LAST_SENT)
    values(?,?,?,?,?,?,?,?) ");
    prepStmt=connect.prepareStatement(query.toString());
    
    I want to know whether the above query would be cached in the data
    base server since apart from the using the standard ? to give various
    parameters at runtime , I am also picking up the schema at runtime and
    not hardcoding.
    But obviously the schema name will remain the same for all the calls
    to the DB.
    I donno whether due to the usage of a Java Variable in the query at
    runtime whether this will be cached or not ?
    Can some one please throw some light on it ?
    Regarda,
    -Neeraj
- 16
  - JRE 5 on Freebsd 6fbsd6-Mimi# rpm --install jre-1_5_0_05-linux-i586.rp
    error: failed dependencies
    glibc >= 2.1.2-11 is needed by jre-1.5.0_05-fc
    sh-utils >= 2.0-1 is needed by jre-1.5.0_05-fc
    fileutils >= 4.0-8 is needed by jre-1.5.0_05-fc
    gawk >= 3.0.4-1 is needed by jre-1.5.0_05-fc
    textutils >= 2.0-2 is needed by jre-1.5.0_05-fc
    /bin/sh is needed by jre-1.5.0_05-fc
    /bin/sh is needed by jre-1.5.0_05-fc
    /bin/sh is needed by jre-1.5.0_05-fc
    
    this is what I get when try to install the rp
    jre-1_5_0_05-linux-i586.rp
    
    I have mounted linprocfs my linux-base is up to date 8.8.0.
    I have Javavmwrapper that says that i have no conf file i
    /usr/local/et
    
    I do not need JDK I have a jar file i want to start thats al
    
    please help[i:cb2c6e6b3c][/i:cb2c6e6b3c
    
    Sent via Archivaty.com
- 16
  - Java One?Did anyone get to go to Java One? What impressed you?
    
    --
    Canadian Mind Products, Roedy Green.
    Coaching, problem solving, economical contract programming.
    See http://mindprod.com/jgloss/jgloss.html for The Java Glossary.
- 16
  - please inform a newbclass A{
    class B{
    boolean flag;
    int value;
    }
    B b[] = new B[10];
    public A(){
    for (int i = 0; i < 10; i++)
    b[i] = new B();
    }
    }
    
    I'm wondering if there is a more elegant way to instantiate the elements of
    b[] than the 'for' loop.

Author

Message

Crouchez

Posted: 2007-8-31 1:59:00

Top

java-programmer, Mutliple thread access to object method Can multiple threads access the same object public void method
simultaneously? Or does the method need to return for each thread? I guess
not because that's what public synchronized void is for?

Manish Pandit

Posted: 2007-8-31 2:03:00

Top

java-programmer >> Mutliple thread access to object method On Aug 30, 10:59 am, "Crouchez"
<email***@***.com> wrote:
> Can multiple threads access the same object public void method
> simultaneously? Or does the method need to return for each thread? I guess
> not because that's what public synchronized void is for?

Your guess is right - they can access the method concurrently, unless
it is synchronized.

-cheers,
Manish

Lew

Posted: 2007-8-31 4:35:00

Top

java-programmer >> Mutliple thread access to object method "Crouchez" wrote:
>> Can multiple threads access the same object public void method
>> simultaneously? Or does the method need to return for each thread? I guess
>> not because that's what public synchronized void is for?

Manish Pandit wrote:
> Your guess is right - they can access the method concurrently, unless
> it is synchronized ...

... on the same monitor.

--
Lew

Index ‹ java-programmer

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- 1
  - JAXB unmarshalling - missing referenced objectsHi
    
    I've come upon a problem which I just can't figure out.
    
    So, here's a little about the context. An enterprise-application is
    running on a Java EE-server. Some POJOs are annotated as Java
    Persistence entities aswell as JAXB-annotations to create wanted XML-
    representation for them. All annotations are added manually (meaning
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    against an Ajax-enabled webpage. The script in the web-page retrieves
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    </ns2:element>
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- 2
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    midp 2.0
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    Long id;
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    id = Long.parseLong(arg1);
    
    This converting isn't working with "0b" or "0a"... but I've read in the
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    public static long parseLong(String s, int radix), and I guess this is the
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- 3
  - Read-only methods for webservices with JavaBeansHello,
    
    unfortunately i wrote this thread before in german, so i will do this
    in english again.
    
    Here we've got a standalone application which stores several data on
    an SQL Server. In the last time we added a webservice to display and
    sometimes modify several information from this data via webpages
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    have webservicemethods returning objects stored in javabeans. To get
    the data out of the beans, we have to use some get methods. Some data
    is "READ-ONLY", so we don't want any set method there. The problem is:
    
    If we don't write some "dummy" Set-Methods, wscompile will not
    generate the needed get-Methods. We find that writing dummy-methods is
    not a very fine way.
    
    Is there another easy posibility to make the getMethods available for
    the client without writing dummy set methods like this?
    
    // That's what we don't need but have to write in order to make
    wscompile ready to produce the getMethod
    public void setName(String value) {}
    
    // That's what we need only
    public String getName()
    {
    return name;
    }
    
    Greetings and thnx a lot!
    
    Andreas
- 4
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    setnearest(keylist,keylist,...) then I want read the second table with
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- 7
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