SQL语句中出现中文字符时JDBC报错，解决办法

（1）当SQL中出现汉字时，直接执行SQL命令，可以得到正确结果

（2）当使用JDBC查询时，报错

严重: Servlet.service() for servlet [springMvc] in context with path [/web_store] threw exception [Request processing failed; nested exception is org.springframework.jdbc.BadSqlGrammarException: StatementCallback;
bad SQL grammar [select remainGB 空闲,usedGB 已使用,usedNonDFSGB 非HDFS使用 from hdfsData  limit 1]; nested exception is java.sql.SQLException: You have an error in your SQL syntax;
check the manual that corresponds to your MariaDB server version for the right syntax to use near '??,usedGB ???,usedNonDFSGB ?HDFS?? from hdfsData  limit 1' at line 1] with root cause
java.sql.SQLException: You have an error in your SQL syntax;
check the manual that corresponds to your MariaDB server version for the right syntax to use near '??,usedGB ???,usedNonDFSGB ?HDFS?? from hdfsData  limit 1' at line 1

（3）解决办法

在JDBC连接的url中加入useUnicode=true&characterEncoding=UTF-8，

比如：

jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=UTF-8

这样，SQL语句可以将中文正确编码，查询出结果。

如果JDBC连接的url在XML，需要将&转义

<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close" >
<property name="driverClassName" value="${jdbc.driverClassName}"/>
<property name="url" value="${jdbc.url}${jdbc.dbName}?useUnicode=true&characterEncoding=UTF-8"/>
<property name="username" value="${jdbc.username}"/>
<property name="password" value="${jdbc.password}"/>