本文将分享在过去2天检索到的Java1.7.0下运行的SQL-Server的详细内容，并且还将对MSSQL-JDBC3.0中的日期列进行详尽解释，此外，我们还将为大家带来关于ApacheKafka中的

本文将分享在过去2天检索到的Java 1.7.0下运行的SQL-Server的详细内容，并且还将对MSSQL-JDBC 3.0中的日期列进行详尽解释，此外，我们还将为大家带来关于Apache Kafka 中的 IDENTITY_INSERT 问题 - JDBC - MSSQL、com.mysql.jdbc.Driver 和 com.mysql.cj.jdbc.Driver的区别、Could not load JDBC driver class [com.mysql.jdbc.Driver]、Could not resolve placeholder ''jdbc.driverClassName'' in string value "${jdbc.driverClassName} 错误的相关知识，希望对你有所帮助。

• 在过去2天检索到的Java 1.7.0下运行的SQL-Server（MSSQL-JDBC 3.0）中的日期列
• Apache Kafka 中的 IDENTITY_INSERT 问题 - JDBC - MSSQL
• com.mysql.jdbc.Driver 和 com.mysql.cj.jdbc.Driver的区别
• Could not load JDBC driver class [com.mysql.jdbc.Driver]
• Could not resolve placeholder ''jdbc.driverClassName'' in string value "${jdbc.driverClassName} 错误

在过去2天检索到的Java 1.7.0下运行的SQL-Server（MSSQL-JDBC 3.0）中的日期列

CREATE TABLE Java7DateTest (
  dateColumn DATE
);
INSERT INTO Java7DateTest VALUES('2011-10-10');

public class Java7SQLDateTest {

    public static void main(final String[] argv) {
        try {
            Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
            Connection connection = DriverManager.getConnection(
                    "jdbc:sqlserver://192.168.0.1:1433;databaseName=dbNameHere","user","password");
            PreparedStatement statement = connection.prepareStatement("SELECT * FROM Java7DateTest");
            ResultSet resultSet = statement.executeQuery();
            while (resultSet.next()) {
                final java.sql.Date date = resultSet.getDate("dateColumn");
                final String str = resultSet.getString("dateColumn");
                System.out.println(date + " (raw: " + str + ")");
            }
            resultSet.close();
            statement.close();
            connection.close();
        } catch (final Throwable t) {
            throw new RuntimeException(t.getMessage(),t);
        }
    }

}

Apache Kafka 中的 IDENTITY_INSERT 问题 - JDBC - MSSQL

如何解决Apache Kafka 中的 IDENTITY_INSERT 问题 - JDBC - MSSQL

使用 Apache Kafka 接收器连接器将数据从 sql Server 插入/更新到 sql Server 得到以下错误

java.sql.BatchUpdateException：无法为表“table_name”中的标识列插入显式值 当 IDENTITY_INSERT 设置为 OFF 时。 在 com.microsoft.sqlserver.jdbc.sqlServerPreparedStatement.executeBatch(sqlServerPreparedStatement.java:2075)

源配置

name=jdbc-mssql-prod-5
connector.class=io.confluent.connect.jdbc.JdbcSourceConnector
connection.url=jdbc:sqlserver:
connection.user=
connection.password=
topic.prefix= source_topic.
mode=timestamp
table.whitelist=A,B,C
timestamp.column.name=ModifiedDateTime

connection.backoff.ms=60000
connection.attempts=300

validate.non.null= false
# enter timestamp in milliseconds 
timestamp.initial= -1

接收器配置

name=MysqL-sink-prod-5
connector.class=io.confluent.connect.jdbc.JdbcSinkConnector
tasks.max=1
topics= sink_topic_a,sink_topic_b
connection.url=jdbc:sqlserver:
connection.user=
connection.password=

insert.mode=upsert
delete.enabled=true
pk.mode=record_key


errors.log.enable= true
errors.log.include.messages=true

在该表中，主键列和标识列相同。

com.mysql.jdbc.Driver 和 com.mysql.cj.jdbc.Driver的区别

com.mysql.jdbc.Driver 是 mysql-connector-java 5中的，
com.mysql.cj.jdbc.Driver 是 mysql-connector-java 6中的

Could not load JDBC driver class [com.mysql.jdbc.Driver]

我使用 Spring JDBC 编程时，遇到一个错误消息：Could not load JDBC driver class [com.mysql.jdbc.Driver]

完整的错误为：

Jul 27, 2020 12:22:26 PM org.springframework.context.support.ClassPathXmlApplicationContext prepareRefresh
INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@5b80350b: startup date [Mon Jul 27 12:22:26 CST 2020]; root of context hierarchy
Jul 27, 2020 12:22:26 PM org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from class path resource [Beans.xml]
Jul 27, 2020 12:22:26 PM org.springframework.context.support.ClassPathXmlApplicationContext refresh
WARNING: Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name ''dataSource'' defined in class path resource [Beans.xml]: Error setting property values; nested exception is org.springframework.beans.PropertyBatchUpdateException; nested PropertyAccessExceptions (1) are:
PropertyAccessException 1: org.springframework.beans.MethodInvocationException: Property ''driverClassName'' threw exception; nested exception is java.lang.IllegalStateException: Could not load JDBC driver class [com.mysql.jdbc.Driver]
Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name ''dataSource'' defined in class path resource [Beans.xml]: Error setting property values; nested exception is org.springframework.beans.PropertyBatchUpdateException; nested PropertyAccessExceptions (1) are:
PropertyAccessException 1: org.springframework.beans.MethodInvocationException: Property ''driverClassName'' threw exception; nested exception is java.lang.IllegalStateException: Could not load JDBC driver class [com.mysql.jdbc.Driver]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1650)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1357)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:582)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:502)
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:312)
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:310)
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:200)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:758)
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:868)
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549)
	at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:144)
	at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:85)
	at com.sap.MainApp.main(MainApp.java:10)
Caused by: org.springframework.beans.PropertyBatchUpdateException; nested PropertyAccessExceptions (1) are:
PropertyAccessException 1: org.springframework.beans.MethodInvocationException: Property ''driverClassName'' threw exception; nested exception is java.lang.IllegalStateException: Could not load JDBC driver class [com.mysql.jdbc.Driver]
	at org.springframework.beans.AbstractPropertyAccessor.setPropertyValues(AbstractPropertyAccessor.java:123)
	at org.springframework.beans.AbstractPropertyAccessor.setPropertyValues(AbstractPropertyAccessor.java:77)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1646)
	... 13 more

解决方法：

下载 MySQL Connector/J (the official JDBC driver for MySQL).
https://dev.mysql.com/downloads/connector/j/

将下载的 mysql-connector-java.jar 添加到 Java build path 后问题解决：

使用 mySQL client 命令行可以看到之前用 Java JDBC 插入的数据库条目：

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Could not resolve placeholder ''jdbc.driverClassName'' in string value "${jdbc.driverClassName} 错误

今天在 MyEclipse 搭建 spring 框架，通过自动生成 spring 框架，布好 DAO 层还有 Service 层后，还导入了单元测试，没想到在测试时出现了

Could not resolve placeholder ''jdbc.driverClassName'' in string value "${jdbc.driverClassName} 错误

具体代码如下：

test 类

import javax.annotation.Resource;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import Service.AccountService;
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class test {
	@Resource(name="accountService")
	private AccountService accountService;
	
	@Test
	public void demo1(){
		accountService.transfer("aaa", "bbb", 200d);
		
	}

}

<tx:annotation-driven transaction-manager="transactionManager" />
	
	
	<bean id="accountService" class="Service.AccountServiceImpl"></bean>

<context:property-placeholder location="classpath:jdbc.properties" ignore-unresolvable="true" />

<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
<property name="driverClass" value="${jdbc.driverClass}"/>
<property name="jdbcUrl" value="${jdbc.url}" />
<property name="user" value="${jdbc.username}" />
<property name="password" value="${jdbc.password}" />
</bean>	


<bean id="accountDao" class="Dao.AccountDaoImpl">
   <property name="dataSource" ref="dataSource"></property>
</bean>

jdbc.properties 文件已导入，设置好数据库的键值对、

然后在测试时出现该错误，思考一下，可能是该数据库文件的键名称与 DAO 层的 dataSource 不对应，或者是名称打错

开始调试 bug-----------------------------------

我先删除了 DAO 层的第一行

<property name="driverClass" value="${jdbc.driverClass}"/>

然后错误信息就变了

Could not resolve placeholder ''jdbc.driverClassName'' in string value "${jdbc.url}  错误

证明不是名称打错，应该是文件 jdbc.properties 导入失败 -------------------------

再次寻找原因

网上说修改一下

<context:property-placeholder location="classpath:jdbc.properties" ignore-unresolvable="true" />

再次寻找原因

在网上找到

可能是 Spring 容器的配置问题

Spring 容器采用反射扫描的发现机制，在探测到 Spring 容器中有一个 org.springframework.beans.factory.config.PropertyPlaceholderConfigurer 的 Bean 就会停止对剩余 PropertyPlaceholderConfigurer 的扫描（Spring 3.1 已经使用 PropertySourcesPlaceholderConfigurer 替代 PropertyPlaceholderConfigurer 了）。 

而这个基于命名空间的配置，其实内部就是创建一个 PropertyPlaceholderConfigurer Bean 而已。换句话说，即 Spring 容器仅允许最多定义一个 PropertyPlaceholderConfigurer (或)，其余的会被 Spring 忽略掉（其实 Spring 如果提供一个警告就好了）。 

PropertyPlaceholderConfigurer 配置，我将其全部删除，然后测试，没有错误，成功了，成功修改数据库数据！

今天关于在过去2天检索到的Java 1.7.0下运行的SQL-Server和MSSQL-JDBC 3.0中的日期列的分享就到这里，希望大家有所收获，若想了解更多关于Apache Kafka 中的 IDENTITY_INSERT 问题 - JDBC - MSSQL、com.mysql.jdbc.Driver 和 com.mysql.cj.jdbc.Driver的区别、Could not load JDBC driver class [com.mysql.jdbc.Driver]、Could not resolve placeholder ''jdbc.driverClassName'' in string value "${jdbc.driverClassName} 错误等相关知识，可以在本站进行查询。