jdbc ant run build.xml classpath

Question

I'm having trouble running from ant. When I run straight from the class 
    file as follows it compiles and runs 

    Jasons-MacBook-Pro:src js$ java Hw5 
    Student ID: 1 
    First Name: Jason 
    Last Name: S 
    Phone: 555-220-5169 
    Email: js@ucsd.edu 
    Personal Tagline: Never say never 

    The following line of code is used when it runs correctly as above 
    Connection connection = DriverManager.getConnection("jdbc:derby:/Users/js/Desktop/JavaDevelopmentAnt/HW5_JDBC/lib/Hw5Db"); 

    my code 

    import java.sql.*; 
    import java.util.Enumeration; 

    public class Hw5{ 
     public static void main (String [] args){ 
      try{ 
      Connection connection = DriverManager.getConnection("jdbc:derby:/Users/js/Desktop/JavaDevelopmentAnt/HW5_JDBC/lib/Hw5Db"); 
      //Connection connection = DriverManager.getConnection("jdbc:derby:Hw5Db");//ant file code 
      Statement statement = connection.createStatement(); 
      ResultSet resultSet = statement.executeQuery("SELECT * FROM STUDENT"); 

      while(resultSet.next()){ 
       int studentID = resultSet.getInt("STUDENT_ID"); 
       String firstName = resultSet.getString("FIRSTNAME"); 
       String lastName = resultSet.getString("LASTNAME"); 
       String phone = resultSet.getString("PHONE"); 
       String email = resultSet.getString("EMAIL"); 
       String mantra = resultSet.getString("PERSONAL_TAGLINE"); 
       System.out.println("Student ID: " + studentID + "\n" + 
           "First Name: " + firstName + "\n" + 
           "Last Name: " + lastName + "\n" + 
           "Phone: " + phone + "\n" + 
           "Email: " + email + "\n" + 
           "Personal Tagline: " + mantra + "\n"); 
      } 
      resultSet.close(); 
      statement.close(); 
      connection.close();   
      } 
      catch(SQLException sqle){ 
      System.err.println("SQL Exception: " + sqle); 
      } 
     } 
    } 



    but when I try from my build.xml i change the following line of code to 
    Connection connection = DriverManager.getConnection("jdbc:derby:Hw5Db"); 

    because i think database jar file (Hw5Db) is in the classpath of my build.xml 

    my build.xml 


<?xml version="1.0"?> 
    <project name="Hw5" default="compile" basedir="."> 
    <property environment="env"/> 
    <property name="src" value="${basedir}/src"/> 
    <property name="bin" value="${basedir}/bin"/> 
    <property name="lib" value="${basedir}/lib"/> 
    <property name="doc" value="${basedir}/doc"/> 
    <property name="build" value="${basedir}/build"/> 

    <target name="prepare" description="Setting up temporary directory to support build"> 
     <mkdir dir="${build}"/> 
     <mkdir dir="${bin}"/> 
    </target> 

    <target name="compile" depends="prepare" description="compile java sources"> 
     <javac srcdir="${src}" destdir="${build}" includes="**/*.java" listfiles="yes" includeantruntime="false"> 
     </javac> 
    </target> 

    <target name="deploy" depends="compile"> 
     <jar destfile="${bin}/Hw5.jar" basedir="${build}"/> 
     <jar destfile="${bin}/Hw5Db.jar" basedir="${lib}"/> 
    </target> 

    <target name="run" depends="deploy" description="run the project"> 
     <java fork="true" classname="Hw5"> 
      <classpath path="${bin}/Hw5.jar"/> 
      <classpath path="${bin}/Hw5Db.jar"/> 
     </java> 
    </target> 

    <target name="clean"> 
     <delete dir="${build}"/> 
     <delete dir="${bin}"/> 
    </target> 
</project> 

Jasons-MacBook-Pro:HW5_JDBC jsteindorf$ ant run 
    Buildfile: /Users/js/Desktop/JavaDevelopmentAnt/HW5_JDBC/build.xml 

    prepare: 
     [mkdir] Created dir: /Users/js/Desktop/JavaDevelopmentAnt/HW5_JDBC/build 
     [mkdir] Created dir: /Users/js/Desktop/JavaDevelopmentAnt/HW5_JDBC/bin 

    compile: 
     [javac] Compiling 1 source file to /Users/js/Desktop/JavaDevelopmentAnt/HW5_JDBC/build 
     [javac] /Users/js/Desktop/JavaDevelopmentAnt/HW5_JDBC/src/Hw5.java 

    deploy: 
      [jar] Building jar: /Users/jsteindorf/Desktop/JavaDevelopmentAnt/HW5_JDBC/bin/Hw5.jar 
      [jar] Building jar: /Users/jsteindorf/Desktop/JavaDevelopmentAnt/HW5_JDBC/bin/Hw5Db.jar 

    run: 
     [java] SQL Exception: java.sql.SQLException: No suitable driver found for jdbc:derby:Hw5Db 

    BUILD SUCCESSFUL 
    Total time: 2 seconds  

    I'm trying, I just can't get it to work 

Answer 1

i résolu le problème, le build.xml n'a pas été de trouver les pilotes de base de données

chemin classpath = "$ {} env.DERBY_HOME /lib/derby.jar

chemin classpath = "$ {} env.DERBY_HOME /lib/derbytools.jar

et le chemin de connexion à la base de données aurait été

jdbc: derby: ./ lib/Hw5Db

Answer 2

Vous ne savez pas, mais vous devez peut-être enregistrer le pilote avant de l'utiliser.

Class.forName("class_of_driver").getInstance(); 

Et après:

Connection connection = DriverManager.getConnection("jdbc:derby:./Hw5Db"); 

Answer 3

Le classpath en double sur la tâche java ressemble un peu étrange pour moi. Effectuez les opérations suivantes à la place:

<java fork="true" classname="Hw5"> 
    <classpath path="${bin}/Hw5.jar:${bin}/Hw5Db.jar"/> 
</java>