java 无法从底层数据库获取连接！-- HSQL 数据库
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/4117764/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Connections could not be acquired from th e underlying database! -- HSQL DB
提问by javanoob
I am trying to learn Hibernate from Java Persistence with hibernate by Gavin King.
我正在尝试从 Java Persistence 和 Gavin King 的 hibernate 中学习 Hibernate。
I just downloaded the examples given in the book from this location http://downloads.jboss.org/hibernate/caveatemptor/jpwh-gettingstarted-070401.zip
我刚刚从这个位置下载了书中给出的例子http://downloads.jboss.org/hibernate/caveatempor/jpwh-gettingstarted-070401.zip
I started my HSQL db using ant startdb and database started successfully.
我使用 ant startdb 启动了我的 HSQL 数据库，并且数据库成功启动。
When trying to run the target schemaexport I am getting the below error..
尝试运行目标 schemaexport 时，出现以下错误..
schemaexport: [hibernatetool] Executing Hibernate Tool with a Standard Configuration [hibernatetool] 1. task: hbm2ddl (Generates database schema) [hibernatetool] 18:07:56,555 INFO Environment:500 - Hibernate 3.2.0.cr5 [hibernatetool] 18:07:56,555 INFO Environment:533 - hibernate.properties not fo und [hibernatetool] 18:07:56,555 INFO Environment:667 - Bytecode provider name : cg lib [hibernatetool] 18:07:56,571 INFO Environment:584 - using JDK 1.4 java.sql.Time stamp handling [hibernatetool] 18:07:56,617 INFO Configuration:1384 - configuring from file: h ibernate.cfg.xml [hibernatetool] 18:07:56,680 INFO Configuration:507 - Reading mappings from res ource: hello/Message.hbm.xml [hibernatetool] 18:07:56,758 INFO HbmBinder:300 - Mapping class: hello.Message -> MESSAGES [hibernatetool] 18:07:56,851 INFO Configuration:1465 - Configured SessionFactor y: null [hibernatetool] 18:07:56,851 INFO Dialect:141 - Using dialect: org.hibernate.di alect.HSQLDialect [hibernatetool] 18:07:56,914 INFO SchemaExport:154 - Running hbm2ddl schema exp ort [hibernatetool] 18:07:56,914 INFO SchemaExport:174 - writing generated schema t o file: C:\Users\Ramesh\Desktop\Tutorials\hibernate\Hibernate Code samples\jpwh- gettingstarted-070401\helloworld-native\helloworld-ddl.sql [hibernatetool] 18:07:56,914 INFO SchemaExport:179 - exporting generated schema to database [hibernatetool] 18:07:56,914 INFO C3P0ConnectionProvider:50 - C3P0 using driver : org.hsqldb.jdbcDriver at URL: jdbc:hsqldb:hsql://localhost [hibernatetool] 18:07:56,914 INFO C3P0ConnectionProvider:51 - Connection proper ties: {user=sa} [hibernatetool] 18:07:56,914 INFO C3P0ConnectionProvider:54 - autocommit mode: false [hibernatetool] 18:08:26,554 WARN BasicResourcePool:1222 - com.mchange.v2.resou rcepool.BasicResourcePool$AcquireTask@61f1680f -- Acquisition Attempt Failed!!! Clearing pending acquires. While trying to acquire a needed new resource, we fai led to succeed more than the maximum number of allowed acquisition attempts (30) . [hibernatetool] 18:08:26,554 ERROR SchemaExport:202 - schema export unsuccessful
[hibernatetool] java.sql.SQLException: Connections could not be acquired from th e underlying database! [hibernatetool] at com.mchange.v2.sql.SqlUtils.toSQLException(SqlUtils.j ava:104) [hibernatetool] at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.che ckoutPooledConnection(C3P0PooledConnectionPool.java:236) [hibernatetool] at com.mchange.v2.c3p0.PoolBackedDataSource.getConnectio n(PoolBackedDataSource.java:94) [hibernatetool] at org.hibernate.connection.C3P0ConnectionProvider.getCo nnection(C3P0ConnectionProvider.java:35) [hibernatetool] at org.hibernate.tool.hbm2ddl.ManagedProviderConnectionH elper.prepare(ManagedProviderConnectionHelper.java:28) [hibernatetool] at org.hibernate.tool.hbm2ddl.SchemaExport.execute(Schem aExport.java:180) [hibernatetool]
at org.hibernate.tool.hbm2ddl.SchemaExport.create(Schema Export.java:133) [hibernatetool]
at org.hibernate.tool.ant.Hbm2DDLExporterTask.execute(Hb m2DDLExporterTask.java:55) [hibernatetool] at org.hibernate.tool.ant.HibernateToolTask.execute(Hibe rnateToolTask.java:171) [hibernatetool] at org.apache.tools.ant.UnknownElement.execute(UnknownEl ement.java:291) [hibernatetool]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native M ethod) [hibernatetool] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMet hodAccessorImpl.java:39) [hibernatetool] at sun.reflect.DelegatingMethodAccessorImpl.invoke(Deleg atingMethodAccessorImpl.java:25) [hibernatetool] at java.lang.reflect.Method.invoke(Method.java:597) [hibernatetool] at org.apache.tools.ant.dispatch.DispatchUtils.execute(D ispatchUtils.java:106) [hibernatetool] at org.apache.tools.ant.Task.perform(Task.java:348) [hibernatetool] at org.apache.tools.ant.Target.execute(Target.java:390) [hibernatetool] at org.apache.tools.ant.Target.performTasks(Target.java: 411) [hibernatetool] at org.apache.tools.ant.Project.executeSortedTargets(Pro ject.java:1397) [hibernatetool]
at org.apache.tools.ant.Project.executeTarget(Project.ja va:1366) [hibernatetool] at org.apache.tools.ant.helper.DefaultExecutor.executeTa rgets(DefaultExecutor.java:41) [hibernatetool] at org.apache.tools.ant.Project.executeTargets(Project.j ava:1249) [hibernatetool] at org.apache.tools.ant.Main.runBuild(Main.java:801) [hibernatetool] at org.apache.tools.ant.Main.startAnt(Main.java:218) [hibernatetool] at org.apache.tools.ant.launch.Launcher.run(Launcher.jav a:280) [hibernatetool] at org.apache.tools.ant.launch.Launcher.main(Launcher.ja va:109) [hibernatetool] Caused by: com.mchange.v2.resourcepool.CannotAcquireResourceExce ption: A ResourcePool could not acquire a resource from its primary factory or s ource. [hibernatetool]
at com.mchange.v2.resourcepool.BasicResourcePool.awaitAc quire(BasicResourcePool.java:970) [hibernatetool] at com.mchange.v2.resourcepool.BasicResourcePool.checkou tResource(BasicResourcePool.java:208) [hibernatetool] at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.che ckoutPooledConnection(C3P0PooledConnectionPool.java:232) [hibernatetool] ... 24 more [hibernatetool] 1 errors occurred while performing . [hibernatetool] Error #1: java.sql.SQLException: Connections could not be acquir ed from the underlying database! [hibernatetool] 18:08:26,569 WARN BasicResourcePool:1222 - com.mchange.v2.resou rcepool.BasicResourcePool$AcquireTask@72f864fe -- Acquisition Attempt Failed!!! Clearing pending acquires. While trying to acquire a needed new resource, we fai led to succeed more than the maximum number of allowed acquisition attempts (30) .`
{user=sa} [hibernatetool] 18:07:56,914 INFO C3P0ConnectionProvider:54 - 自动提交模式：false [hibernatetool] 18:08:26,554 WARN BasicResourcePool:1222 - com.mchange.v2.resou rcepool.Basic1Task8rePool.Basic1Task800$Ac - 获取尝试失败！！！清除挂起的收购。在尝试获取所需的新资源时，我们导致成功超过允许获取尝试的最大次数 (30)。[hibernatetool] 18:08:26,554 错误 SchemaExport:202 - 模式导出失败 我们 fai 导致成功超过允许的最大获取尝试次数 (30)。[hibernatetool] 18:08:26,554 错误 SchemaExport:202 - 模式导出失败 我们 fai 导致成功超过允许的最大获取尝试次数 (30)。[hibernatetool] 18:08:26,554 错误 SchemaExport:202 - 模式导出失败
[hibernatetool] java.sql.SQLException: 无法从底层数据库获取连接！[hibernatetool] 在 com.mchange.v2.sql.SqlUtils.toSQLException(SqlUtils.j ava:104) [hibernatetool] 在 com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.che ckoutPooledConnection(C3P0PooledConnectionPool.java:236) [hibernatetool] ] 在 com.mchange.v2.c3p0.PoolBackedDataSource.getConnectio n(PoolBackedDataSource.java:94) [hibernatetool] 在 org.hibernate.connection.C3P0ConnectionProvider.getConnection(C3P0ConnectionProvider.java:35) [hibernatetool] 在 org.hibernate. tool.hbm2ddl.ManagedProviderConnectionH elper.prepare(ManagedProviderConnectionHelper.java:28) [hibernatetool] 在 org.hibernate.tool.hbm2ddl.SchemaExport.execute(Schem aExport.java:180) [hibernatetool]
在 org.hibernate.tool.hbm2ddl.SchemaExport.create(Schema Export.java:133) [hibernatetool]
在 org.hibernate.tool.ant.Hbm2DDLExporterTask.execute(Hb m2DDLExporterTask.java:55) [hibernatetool] 在 org.hibernate .tool.ant.HibernateToolTask.execute(Hibe rnateToolTask.java:171) [hibernatetool] 在 org.apache.tools.ant.UnknownElement.execute(UnknownEl ement.java:291) [hibernatetool]
在 sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [hibernatetool] 在 sun.reflect.NativeMethodAccessorImpl.invoke(NativeMet hodAccessorImpl.java:39) [hibernatetool] 在 sun.reflect.DelegatingMethodAccessorImpl.invoke(Deleg atingMethod) ) [hibernatetool] 在 java.lang.reflect.Method.invoke(Method.java:597) [hibernatetool] 在 org.apache.tools.ant.dispatch.DispatchUtils.execute(D ispatchUtils.java:106) [hibernatetool] 在org.apache.tools.ant.Task.perform(Task.java:348) [hibernatetool] 在 org.apache.tools.ant.Target.execute(Target.java:390) [hibernatetool] 在 org.apache.tools。 ant.Target.performTasks(Target.java: 411) [hibernatetool] 在 org.apache.tools.ant.Project.executeSortedTargets(Project.java:1397) [hibernatetool]
在 org.apache.tools.ant.Project.executeTarget(Project.ja va:1366) [hibernatetool] 在 org.apache.tools.ant.helper.DefaultExecutor.executeTa rgets(DefaultExecutor.java:41) [hibernatetool] 在 org .apache.tools.ant.Project.executeTargets(Project.j ava:1249) [hibernatetool] 在 org.apache.tools.ant.Main.runBuild(Main.java:801) [hibernatetool] 在 org.apache.tools。 ant.Main.startAnt(Main.java:218) [hibernatetool] 在 org.apache.tools.ant.launch.Launcher.run(Launcher.java a:280) [hibernatetool] 在 org.apache.tools.ant.launch .Launcher.main(Launcher.ja va:109) [hibernatetool] 原因：com.mchange.v2.resourcepool.CannotAcquireResourceExce ption：ResourcePool 无法从其主要工厂或来源获取资源。[休眠工具]
在 com.mchange.v2.resourcepool.BasicResourcePool.awaitAc quire(BasicResourcePool.java:970) [hibernatetool] 在 com.mchange.v2.resourcepool.BasicResourcePool.checkout tResource(BasicResourcePool.java:208) [hibernatetool] 在 com. .v2.c3p0.impl.C3P0PooledConnectionPool.che ckoutPooledConnection(C3P0PooledConnectionPool.java:232) [hibernatetool] ... 24 more [hibernatetool] 1 执行时发生错误。[hibernatetool] 错误 #1：java.sql.SQLException：无法从底层数据库获取连接！[hibernatetool] 18:08:26,569 WARN BasicResourcePool:1222 - com.mchange.v2.resou rcepool.BasicResourcePool$AcquireTask@72f864fe - 获取尝试失败！！！清除挂起的收购。在尝试获取所需的新资源时，
I don't have too much knowledge about either hiberate or HSQL..
我对 hiberate 或 HSQL 的了解不多。
Some one please explain whats wrong here??
有人请解释一下这里出了什么问题？
Thanks
谢谢
EDIT:I am trying to run the project helloworld-native.
编辑：我正在尝试运行该项目helloworld-native。
The target given in the ant build.xml for startdb is as below:
startdb的ant build.xml中给出的target如下：
<!-- Start the HSQL DB server -->
<target name="startdb" description="Run HSQL database server with clean DB">
<!-- Delete database files -->
<delete dir="${database.dir}"/>
<java classname="org.hsqldb.Server"
fork="yes"
classpathref="project.classpath"
failonerror="true">
<arg value="-database.0"/>
<arg value="file:${database.dir}/db"/>
</java>
</target>
and when i run the command ant startdbi see the below output:
当我运行命令时，ant startdb我看到以下输出：
startdb:
[delete] Deleting directory C:\Users\Ramesh\Desktop\Tutorials\hibernate\Hibernate Code samples\jpwh-gettingstarted-070401\helloworld-native\database
[java] [Server@15ded0fd]: [Thread[main,5,main]]: checkRunning(false) entered
[java] [Server@15ded0fd]: [Thread[main,5,main]]: checkRunning(false) exited
[java] [Server@15ded0fd]: Startup sequence initiated from main() method
[java] [Server@15ded0fd]: Loaded properties from [C:\Users\Ramesh\Desktop\Tutorials hibernate\Hibernate Code samples\jpwh-gettingstarted-070401\helloworld-native\server.properties]
[java] [Server@15ded0fd]: Initiating startup sequence...
[java] [Server@15ded0fd]: Server socket opened successfully in 29 ms.
[java] [Server@15ded0fd]: Database [index=0, id=0, db=file:database/db, alias=] opened sucessfully in 469 ms.
[java] [Server@15ded0fd]: Startup sequence completed in 523 ms.
[java] [Server@15ded0fd]: 2010-11-08 22:11:08.027 HSQLDB server 1.8.0 is online
[java] [Server@15ded0fd]: To close normally, connect and execute SHUTDOWN SQL
[java] [Server@15ded0fd]: From command line, use [Ctrl]+[C] to abort abruptly
Then, i think i am running HSQL DB in server mode only (from the above output)..
然后，我想我只在服务器模式下运行 HSQL DB（来自上面的输出）。
Please tell me what else I am missing..
请告诉我我还缺少什么..
采纳答案by Pascal Thivent
Update:After a second look, it appears that I was wrong, you can start HSQL in server mode using the ant script and you're not forced to use the command line. Actually, I tried to reproduce the problem with the helloworld-nativesample but it worked fine for me.
更新：再次查看后，似乎我错了，您可以使用 ant 脚本在服务器模式下启动 HSQL，而不必强制使用命令行。实际上，我试图用helloworld-native示例重现该问题，但对我来说效果很好。
First, I started HSQLDB in a first shell using ant startdb:
首先，我在第一个 shell 中使用ant startdb以下命令启动了 HSQLDB ：
$ ant startdb
Buildfile: /home/pascal/Projects/jpwh-gettingstarted-070401/helloworld-native/build.xml
startdb:
[java] [Server@a97b0b]: [Thread[main,5,main]]: checkRunning(false) entered
[java] [Server@a97b0b]: [Thread[main,5,main]]: checkRunning(false) exited
[java] [Server@a97b0b]: Startup sequence initiated from main() method
[java] [Server@a97b0b]: Loaded properties from [/home/pascal/Projects/jpwh-gettingstarted-070401/helloworld-native/server.properties]
[java] [Server@a97b0b]: Initiating startup sequence...
[java] [Server@a97b0b]: Server socket opened successfully in 39 ms.
[java] [Server@a97b0b]: Database [index=0, id=0, db=file:database/db, alias=] opened sucessfully in 1148 ms.
[java] [Server@a97b0b]: Startup sequence completed in 1281 ms.
[java] [Server@a97b0b]: 2010-11-08 18:29:20.094 HSQLDB server 1.8.0 is online
[java] [Server@a97b0b]: To close normally, connect and execute SHUTDOWN SQL
[java] [Server@a97b0b]: From command line, use [Ctrl]+[C] to abort abruptly
Then, I ran ant schemaexportfrom another shell:
然后，我ant schemaexport从另一个 shell 运行：
$ ant schemaexport
Buildfile: /home/pascal/Projects/jpwh-gettingstarted-070401/helloworld-native/build.xml
compile:
[mkdir] Created dir: /home/pascal/Projects/jpwh-gettingstarted-070401/helloworld-native/build
[javac] /home/pascal/Projects/jpwh-gettingstarted-070401/helloworld-native/build.xml:39: warning: 'includeantruntime' was not set, defaulting to build.sysclasspath=last; set to false for repeatable builds
[javac] Compiling 3 source files to /home/pascal/Projects/jpwh-gettingstarted-070401/helloworld-native/build
copymetafiles:
[copy] Copying 3 files to /home/pascal/Projects/jpwh-gettingstarted-070401/helloworld-native/build
schemaexport:
[hibernatetool] Executing Hibernate Tool with a Standard Configuration
[hibernatetool] 1. task: hbm2ddl (Generates database schema)
[hibernatetool]
[hibernatetool] alter table MESSAGES
[hibernatetool] drop constraint FK_NEXT_MESSAGE;
[hibernatetool]
[hibernatetool] drop table MESSAGES if exists;
[hibernatetool]
[hibernatetool] create table MESSAGES (
[hibernatetool] MESSAGE_ID bigint generated by default as identity (start with 1),
[hibernatetool] MESSAGE_TEXT varchar(255),
[hibernatetool] NEXT_MESSAGE_ID bigint,
[hibernatetool] primary key (MESSAGE_ID)
[hibernatetool] );
[hibernatetool]
[hibernatetool] alter table MESSAGES
[hibernatetool] add constraint FK_NEXT_MESSAGE
[hibernatetool] foreign key (NEXT_MESSAGE_ID)
[hibernatetool] references MESSAGES;
[hibernatetool] 1 errors occurred while performing <hbm2ddl>.
[hibernatetool] Error #1: java.sql.SQLException: Table not found: MESSAGES in statement [alter table MESSAGES]
BUILD SUCCESSFUL
Total time: 14 seconds
And indeed, when running ant dbmanager, I can see the MESSAGEStable as expected.
事实上，在运行时ant dbmanager，我可以MESSAGES按预期看到表格。
So everything worked just fine, out of the box. If it doesn't for you, maybe start looking at things such as a networking issue, a personal firewall, etc.
所以一切都很好，开箱即用。如果它不适合您，也许可以开始查看诸如网络问题、个人防火墙等问题。
According to the trace, it looks like HSQL is not started (at least not in server mode) and I suspect that you didn't start it like you are supposed to. To start it in server mode, from the helloworld-reversedirectory, run (as explained in the section Starting the HSQL database system, p 98):
根据跟踪，看起来 HSQL 没有启动（至少不是在服务器模式下），我怀疑你没有像你应该的那样启动它。要以服务器模式启动它，请从helloworld-reverse目录中运行（如启动 HSQL 数据库系统部分中所述，第 98 页）：
$ java -cp lib/hsqldb.jar org.hsqldb.Server
Then you'll be able to connect to it using the jdbc:hsqldb:hsql://localhostconnection string.
然后您将能够使用jdbc:hsqldb:hsql://localhost连接字符串连接到它。
