小编luc*_*umi的帖子

我正在使用hibernate 3.6.7从我的类到oracle表进行映射.我通常不会得到这个例外:

org.hibernate.HibernateException: Unable to access lob stream
    at java.util.concurrent.FutureTask$Sync.innerGet(FutureTask.java:222)
    at java.util.concurrent.FutureTask.get(FutureTask.java:83)
    at com.mycompany.TransferFiles.TransferFilesToHadoop(TransferFiles.java:85)
    at com.mycompany.TransferJob.execute(TransferJob.java:25)
    at org.quartz.core.JobRunShell.run(JobRunShell.java:202)
    at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:525)
 Caused by: org.hibernate.HibernateException: Unable to access lob stream
       at org.hibernate.type.descriptor.java.ClobTypeDescriptor.unwrap(ClobTypeDescriptor.java:117)
    at org.hibernate.type.descriptor.java.ClobTypeDescriptor.unwrap(ClobTypeDescriptor.java:46)
    at org.hibernate.type.descriptor.sql.ClobTypeDescriptor$3$1.doBind(ClobTypeDescriptor.java:83)
    at org.hibernate.type.descriptor.sql.BasicBinder.bind(BasicBinder.java:91)
    at org.hibernate.type.AbstractStandardBasicType.nullSafeSet(AbstractStandardBasicType.java:283)
    at org.hibernate.type.AbstractStandardBasicType.nullSafeSet(AbstractStandardBasicType.java:278)
    at org.hibernate.type.AbstractSingleColumnStandardBasicType.nullSafeSet(AbstractSingleColumnStandardBasicType.java:89)
    at org.hibernate.persister.entity.AbstractEntityPersister.dehydrate(AbstractEntityPersister.java:2184)
    at org.hibernate.persister.entity.AbstractEntityPersister.update(AbstractEntityPersister.java:2558)
    at org.hibernate.persister.entity.AbstractEntityPersister.updateOrInsert(AbstractEntityPersister.java:2494)
    at org.hibernate.persister.entity.AbstractEntityPersister.update(AbstractEntityPersister.java:2821)
    at org.hibernate.action.EntityUpdateAction.execute(EntityUpdateAction.java:113)
    at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:273)
    at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:265)
    at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:185)
    at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321)
    at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:51)
    at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1216)
    at com.mycompany.HibernateUtil.getSession(HibernateUtil.java:36)
    at com.mycompany.BasicDaoImpl.saveOrUpdate(BasicDaoImpl.java:34)
    at com.mycompany.FileCopyRoutine.call(TransferFiles.java:297)
    at com.mycompany..FileCopyRoutine.call(TransferFiles.java:225)
    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
    at java.util.concurrent.FutureTask.run(FutureTask.java:138)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) …

我正在从数据库中读取属性文件.我检查过java.util.Properties,没有方法可以从String实例中解析.有什么办法吗？

我正在尝试使用Google Drive API(Python)下载电子表格文件的某些标签.gid是文件元数据中的信息吗？我想做的是(这可能不正确,请建议:)):

file_metadata = self.service.files().get(file_id=file_id).execute()
# in the following line, how can I get a download url with a gid (a tab in a spreadsheet file)
download_url = file_metadata.get('exportLinks')['text/csv']
# download the file.

谢谢:)

我有以下例外:

线程"main"中的异常java.lang.SecurityException:在sun.security的sun.security.util.SignatureFileVerifier.verifySection(SignatureFileVerifier.java:380)中没有签名文件条目javax/security/cert/CertificateException.class的最明显部分. util.SignatureFileVerifier.processImpl(SignatureFileVerifier.java:231)位于java.util的java.util.jar.JarVerifier.processEntry(JarVerifier.java:288)的sun.security.util.SignatureFileVerifier.process(SignatureFileVerifier.java:176) .jar.JarVerifier.update(JarVerifier.java:199)位于sun的java.util.jar.JarFile.getInputStream(JarFile.java:388)的java.util.jar.JarFile.initializeVerifier(JarFile.java:323). misc.URLClassPath $ JarLoader $ 2.getInputStream(URLClassPath.java:692)位于sun.net的sun.misc.Resource.getByteBuffer(Resource.java:144)的sun.misc.Resource.cachedInputStream(Resource.java:61). URLClassLoader.defineClass(URLClassLoader.java:256)at java.net.URLClassLoader.access $ 000(URLClassLoader.java:58)at java.net.URLClassLoader $ 1.run(URLCl)assLoader.java:197)java.security.AccessController.doPrivileged(Native Method)at java.net.URLClassLoader.findClass(URLClassLoader.java:190)at java.lang.ClassLoader.loadClass(ClassLoader.java:306)at sun .misc.Launcher $ AppClassLoader.loadClass(Launcher.java:301)at java.lang.ClassLoader.loadClass(ClassLoader.java:247)找不到主类:com.mainClass.程序将会退出.

我的pom:

<plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-shade-plugin</artifactId>
                <version>1.5</version>
            <executions>
                <execution>
                    <phase>package</phase>
                    <goals>
                        <goal>shade</goal>
                    </goals>
                    <configuration>
                        <filter>
                            <excludes>
                                <exclude>META-INF/*.SF</exclude>
                                <exclude>META-INF/*.DSA</exclude>
                                <exclude>META-INF/*.RSA</exclude>
                            </excludes>
                        </filter>
                        <transformers>
                            <transformer
                                implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                                <mainClass>com.mainClass</mainClass>
                            </transformer>
                        </transformers>
                    </configuration>
                </execution>
            </executions>
        </plugin>
    </plugins>

我很反应,试图使一些组件工作.我有

    ObjectA:React.createClass({
        propTypes: {
           ...

        },

        getInitialState: function() {
            return {
                myState: null
            }
        },

        updateMyState: function(value) {
           this.setState({
               myState: value
           })
        }

        render: function() {
            return (<div className="my-class">'hello' +{this.state.myState}</div>);
          }
    });

    ObjectB:React.createClass({
            propTypes: {
               ...

            },

            render: function() {
                return (<div className="my-class"><ObjectA / >

            </div>);
            }
        });

我想从ObjectB更新ObjectA的状态.我怎么能在ObjectB中调用ObjectA的updateMyState方法？谢谢!

我正在使用Java为某些文件生成MD5哈希.我需要为几个文件生成一个MD5,总大小约为1千兆字节.这是我的代码:

private String generateMD5(SequenceInputStream inputStream){
    if(inputStream==null){
        return null;
    }
    MessageDigest md;
    try {
        int read =0;
        byte[] buf = new byte[2048];
        md = MessageDigest.getInstance("MD5");
        while((read = inputStream.read(buf))>0){
            md.update(buf,0,read);
        }
        byte[] hashValue = md.digest();
        return new String(hashValue);
    } catch (NoSuchAlgorithmException e) {
        return null;
    } catch (IOException e) {
        return null;
    }finally{
        try {
            if(inputStream!=null)inputStream.close();
        } catch (IOException e) {
            // ...
        }
    } 

}

这似乎永远存在.我怎样才能提高效率？

我正在使用MiniDFSCluster进行junit测试.现在我只是启动并关闭群集,junit运行为绿色.但是我得到了这个例外:

javax.management.InstanceAlreadyExistsException: MXBean already registered with name Hadoop:service=NameNode,name=MetricsSystem,sub=Control
at com.sun.jmx.mbeanserver.MXBeanLookup.addReference(MXBeanLookup.java:120)
at com.sun.jmx.mbeanserver.MXBeanSupport.register(MXBeanSupport.java:143)
at com.sun.jmx.mbeanserver.MBeanSupport.preRegister2(MBeanSupport.java:183)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerDynamicMBean(DefaultMBeanServerInterceptor.java:941)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerObject(DefaultMBeanServerInterceptor.java:917)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerMBean(DefaultMBeanServerInterceptor.java:312)
at com.sun.jmx.mbeanserver.JmxMBeanServer.registerMBean(JmxMBeanServer.java:482)
at org.apache.hadoop.metrics2.util.MBeans.register(MBeans.java:56)
at org.apache.hadoop.metrics2.impl.MetricsSystemImpl.initSystemMBean(MetricsSystemImpl.java:500)
at org.apache.hadoop.metrics2.impl.MetricsSystemImpl.init(MetricsSystemImpl.java:140)
at org.apache.hadoop.metrics2.lib.DefaultMetricsSystem.init(DefaultMetricsSystem.java:40)
at org.apache.hadoop.metrics2.lib.DefaultMetricsSystem.initialize(DefaultMetricsSystem.java:50)
at org.apache.hadoop.hdfs.server.datanode.DataNode.instantiateDataNode(DataNode.java:1483)
at org.apache.hadoop.hdfs.server.datanode.DataNode.instantiateDataNode(DataNode.java:1459)
at org.apache.hadoop.hdfs.MiniDFSCluster.startDataNodes(MiniDFSCluster.java:417)
at org.apache.hadoop.hdfs.MiniDFSCluster.<init>(MiniDFSCluster.java:280)
at org.apache.hadoop.hdfs.MiniDFSCluster.<init>(MiniDFSCluster.java:124)
at com.myCompany.TestAll.testInit(TestAll.java:30)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at junit.framework.TestCase.runTest(TestCase.java:168)
at junit.framework.TestCase.runBare(TestCase.java:134)
at junit.framework.TestResult$1.protect(TestResult.java:110)
at junit.framework.TestResult.runProtected(TestResult.java:128)
at junit.framework.TestResult.run(TestResult.java:113)
at junit.framework.TestCase.run(TestCase.java:124)
at junit.framework.TestSuite.runTest(TestSuite.java:232)
at junit.framework.TestSuite.run(TestSuite.java:227)
at org.junit.internal.runners.JUnit38ClassRunner.run(JUnit38ClassRunner.java:83)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:49)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
at …

我试图从我的python代码连接到redshift.我的点子安装:

psycopg2==2.6.1
redshift-sqlalchemy==0.4.1
SQLAlchemy==1.0.9

我的虚拟机有:

libpq-dev
python-psycopg2

但我还是得到了

 engine = create_engine('redshift+psycopg2://{}:{}@{}'.format(username, password, url))
  File "/opt/project/env/local/lib/python2.7/site-packages/sqlalchemy/engine/__init__.py", line 386, in create_engine
    return strategy.create(*args, **kwargs)
  File "/opt/project/env/local/lib/python2.7/site-packages/sqlalchemy/engine/strategies.py", line 51, in create
    entrypoint = u._get_entrypoint()
  File "/opt/project/env/local/lib/python2.7/site-packages/sqlalchemy/engine/url.py", line 131, in _get_entrypoint
    cls = registry.load(name)
  File "/opt/project/env/local/lib/python2.7/site-packages/sqlalchemy/util/langhelpers.py", line 205, in load
    (self.group, name))
NoSuchModuleError: Can't load plugin: sqlalchemy.dialects:redshift.psycopg2

使用相同的配置,我可以从我的笔记本电脑(mac)运行,但在Linux上,我想有些软件包仍然缺失？任何建议将不胜感激,谢谢!

我在tomcat的server.xml中配置了oracle数据库

<Resource name="jdbc/sgfdb" auth="Container"
          driverClassName="oracle.jdbc.OracleDriver"
          url="jdbc:oracle:thin:@databaseurl:1521:schema"
          username="username" password="password" maxActive="20" maxIdle="10"
          maxWait="-1"
          factory="oracle.jdbc.pool.OracleDataSourceFactory"
          type="oracle.jdbc.pool.OracleDataSource"/>

然后在我的网络应用程序(spring mvc项目)中,我在context.xml中解析它

<Context>
 <ResourceLink name="jdbc/sgfdb"
        global="jdbc/sgfdb"
        type="javax.sql.DataSource"/>
</Context>

之前我能够连接到这个数据库.我没有工作一个星期.然后,当我尝试启动它时,总是得到:

SEVERE: Servlet.service() for servlet [action] in context with path [/WebUI] threw exception [Request processing failed; nested exception is javax.persistence.QueryTimeoutException: Could not open connection] with root cause
**java.sql.SQLException: ORA-01017: invalid username/password; logon denied**

at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:440)
at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:389)
at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:382)
at oracle.jdbc.driver.T4CTTIfun.processError(T4CTTIfun.java:573)
at    oracle.jdbc.driver.T4CTTIoauthenticate.processError(T4CTTIoauthenticate.java:431)
at oracle.jdbc.driver.T4CTTIfun.receive(T4CTTIfun.java:445)
at oracle.jdbc.driver.T4CTTIfun.doRPC(T4CTTIfun.java:191)
at oracle.jdbc.driver.T4CTTIoauthenticate.doOAUTH(T4CTTIoauthenticate.java:366)
at oracle.jdbc.driver.T4CTTIoauthenticate.doOAUTH(T4CTTIoauthenticate.java:752)
at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:366)
at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:536)
at oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:228)
at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:32) …

我正在将大量数据存储到 hdfs 中。我需要将文件从一个文件夹移动到另一个文件夹。

请问文件系统的rename方法的成本一般是多少？假设我必须移动 TB 级的数据。

非常感谢。