代码的基本部分:
(以示例为例:Java如何编程第10版,作者:Paul Deitel,Harvey Deitel(p。1063))::
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
public class DisplayAuthors
{
public static void main(String args[])
{
final String DATABASE_URL = "jdbc:derby:books";
try (
Connection connection =
DriverManager.getConnection(DATABASE_URL, "user", "pass");
)
{
// ...
}
catch (SQLException sqlException)
{
sqlException.printStackTrace();
}
}
}
我在Ubuntu 16.04
尽管Java DB的Java网站说DB包含在JDK中,但我有经过几个小时的网络搜索,学会了openjdk java,建议在Ubuntu上安装,不带Java DB。
建议运行的有用信息的网站:
sudo apt-get install sun-javadb-client sun-javadb-core
产生错误并且未安装的
所以我下载了JDK-8U111-Linux-x64.tar.gz,按照指示提取,只是为了安全(我相信,我可以将Java_home,derby_home设置为提取的位置,而这确实是"半工作的"直至IJ零件[请参见下文]),删除了我/usr/lib/jvm/java-8-openjdk-amd64/中的所有内容,并替换为我下载的内容。
并将它们添加到我的.bashrc:
JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64/
DERBY_HOME=/usr/lib/jvm/java-8-openjdk-amd64/db
export DERBY_HOME
在终端中输入以创建数据库并按照书中的指示插入数据:
$JAVA_HOME/db/bin/ij
connect 'jdbc:derby:books;create=true;user=usr;password=pass';
run 'book-basic-table-create-and-insertions.sql';
exit;
它在其中制作了带有DB信息/数据的文件书。
at ./还有一个名为derby.log的文件,其中包含以下信息:
----------------------------------------------------------------
Wed Dec 14 19:01:58 EST 2016:
Booting Derby version The Apache Software Foundation - Apache Derby - 10.11.1.2 - (1629631): instance a816c00e-0158-ffc9-1471-000006d047c8
on database directory /tmp/deleteme-IuI/books with class loader sun.misc.Launcher$AppClassLoader@6f94fa3e
Loaded from file:/usr/lib/jvm/java-8-openjdk-amd64/db/lib/derby.jar
java.vendor=Oracle Corporation
java.runtime.version=1.8.0_111-b14
user.dir=/tmp/deleteme-IuI
os.name=Linux
os.arch=amd64
os.version=4.4.0-53-generic
derby.system.home=null
Database Class Loader started - derby.database.classpath=''
----------------------------------------------------------------
Wed Dec 14 19:04:25 EST 2016: Shutting down Derby engine
----------------------------------------------------------------
Wed Dec 14 19:04:27 EST 2016:
Shutting down instance a816c00e-0158-ffc9-1471-000006d047c8 on database directory /tmp/deleteme-IuI/books with class loader sun.misc.Launcher$AppClassLoader@6f94fa3e
----------------------------------------------------------------
编译并运行:
javac DisplayAuthors.java # compiles without error
java DisplayAuthors
程序输出:
java.sql.SQLException: No suitable driver found for jdbc:derby:books
at java.sql.DriverManager.getConnection(DriverManagerager.java:689)
at java.sql.DriverManager.getConnection(DriverManager.javaava:247)
at DisplayAuthors.main(DisplayAuthors.java:15)
我如何使程序工作?
您缺少代码的加载驱动程序部分
,例如
String driver = "org.apache.derby.jdbc.EmbeddedDriver";
...
try {
Class.forName(driver);
} catch(java.lang.ClassNotFoundException e) {
...
}
请参阅http://docs.oracle.com/javadb/10.8.3.0/getstart/rwwdactivity3.html for示例
编辑
作为证据,我已经完成了以下
- 在Eclipse中创建简单的Java项目
- 添加derby.jar,derbynet.jar&derbyclient.jat to classPath
我的代码
public static void main(String[] args) {
String driver = "org.apache.derby.jdbc.EmbeddedDriver";
try {
Class.forName(driver);
} catch(java.lang.ClassNotFoundException e) {
e.printStackTrace();
}
final String DATABASE_URL = "jdbc:derby:myDB;create=true;user=user;password=pass";
try (
Connection connection = DriverManager.getConnection(DATABASE_URL, "user", "pass");
)
{
// ...
}
catch (SQLException sqlException)
{
sqlException.printStackTrace();
}
}
这毫无例外地运行