使用 Types.NVARCHAR 和 oracle JDBC 驱动程序来处理西里尔字符
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Using Types.NVARCHAR with oracle JDBC driver to work with Cyrillic chars
提问by L. Holanda
I am trying to use the "New Methods for National Character Set Type Data in JDK 1.6", to get a standard JDBCsolution to handle cyrillic chars, but when the execution reaches any line with NVARCHAR type, for instance:
我正在尝试使用“JDK 1.6 中的国家字符集类型数据的新方法”来获得标准的 JDBC解决方案来处理西里尔字符，但是当执行到达 NVARCHAR 类型的任何行时，例如：
preparedSelect.setObject(3, "суббота", Types.NVARCHAR);
Then I get this exception:
然后我得到这个异常：
java.sql.SQLException: Invalid column type
at oracle.jdbc.driver.SQLStateMapping.newSQLException(SQLStateMapping.java:70)
at oracle.jdbc.driver.DatabaseError.newSQLException(DatabaseError.java:131)
at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:197)
at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:261)
at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:269)
at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:490)
at oracle.jdbc.driver.OraclePreparedStatement.setObjectCritical(OraclePreparedStatement.java:7922)
at oracle.jdbc.driver.OraclePreparedStatement.setObjectInternal(OraclePreparedStatement.java:7502)
at oracle.jdbc.driver.OraclePreparedStatement.setObject(OraclePreparedStatement.java:7975)
at oracle.jdbc.driver.OraclePreparedStatementWrapper.setObject(OraclePreparedStatementWrapper.java:222)
I also tried to use setNString() but I get an even more strange exception:
我也尝试使用 setNString() 但我得到了一个更奇怪的异常：
java.lang.AbstractMethodError: oracle.jdbc.driver.OraclePreparedStatementWrapper.setNString(ILjava/lang/String;)V
If I use java -Doracle.jdbc.defaultNChar=true myApplication with regular Types.VARCHAR, the Russian words are stored correctly. But using -Doracle.jdbc.defaultNChar=true is not an option since I'm working on a legacy application, I do not have control of running production environment, I'm just writing a component to it. Furthermore, this "Readme for NChar How-to"states that "This conversion has a substantial performance impact". So setting everything to NChar by default when only less than 1% of my tables needs this conversion in not a smart choice.
如果我将 java -Doracle.jdbc.defaultNChar=true myApplication 与常规 Types.VARCHAR 一起使用，则会正确存储俄语单词。但是使用 -Doracle.jdbc.defaultNChar=true 不是一个选项，因为我正在处理遗留应用程序，我无法控制运行生产环境，我只是向它编写一个组件。此外，此“NChar How-to 自述文件”指出“此转换对性能有重大影响”。因此，当我只有不到 1% 的表需要这种转换时，默认情况下将所有内容设置为 NChar，这不是一个明智的选择。
I'm using oracle thin driver and I have ojdbc6.jar and orai18n.jar in my classpath.
我正在使用 oracle 瘦驱动程序，并且我的类路径中有 ojdbc6.jar 和 orai18n.jar。
I'm looking for a standard JDBC solution. I can not use any methods or constants with "oracle" on them. OraclePreparedStatement is not an option for me.
我正在寻找标准的 JDBC 解决方案。我不能使用任何带有“oracle”的方法或常量。OraclePreparedStatement 不是我的选择。
I tried using Types.NVARCHAR with MSSQL Server and it runs fine.
我尝试将 Types.NVARCHAR 与 MSSQL Server 一起使用，并且运行良好。
采纳答案by L. Holanda
I found the solution!
我找到了解决方案！
I was using ojdbc 11.2.0.1. When I switched to 11.2.0.2, I could get setNString()working properly.
But I'm still getting the same java.sql.SQLException: Invalid column typeif I use setObject()with Type.NVARCHAR. Shame on you Oracle...
我使用的是 ojdbc 11.2.0.1。当我切换到 11.2.0.2 时，我可以setNString()正常工作。但是java.sql.SQLException: Invalid column type如果我使用setObject()with ，我仍然得到相同的结果Type.NVARCHAR。为你的 Oracle 感到羞耻...
Anyway, the solution: switch to ojdbc 11.2.0.2
反正解决办法：切换到ojdbc 11.2.0.2
回答by Flavio
I managed to make it work some time ago with the following incantations. These methods are an excerpt from a bigger class.
前段时间我设法使用以下咒语使其工作。这些方法摘自一个更大的类。
import com.mchange.v2.c3p0.C3P0ProxyStatement;
import oracle.jdbc.OraclePreparedStatement;
static {
try {
SET_FORM_OF_USE_METHOD = OraclePreparedStatement.class.getDeclaredMethod("setFormOfUse", new Class[] { Integer.TYPE, Short.TYPE });
} catch (NoSuchMethodException ex) {
LOG.fatal("Can't find the setFormOfUse method", ex);
throw new ExceptionInInitializerError(ex);
}
}
public void nullSafeSet(PreparedStatement st, Object value, int index, SessionImplementor session) throws SQLException {
if (st instanceof OraclePreparedStatement) {
((OraclePreparedStatement)st).setFormOfUse(index, OraclePreparedStatement.FORM_NCHAR);
} else if (st instanceof C3P0ProxyStatement) {
try {
C3P0ProxyStatement c3p0St = (C3P0ProxyStatement) st;
c3p0St.rawStatementOperation(SET_FORM_OF_USE_METHOD, C3P0ProxyStatement.RAW_STATEMENT, new Object[]{index, OraclePreparedStatement.FORM_NCHAR});
} catch (IllegalAccessException ex) {
throw new UnexpectedException("Error calling setFormOfUse through C3P0", ex);
} catch (IllegalArgumentException ex) {
throw new UnexpectedException("Error calling setFormOfUse through C3P0", ex);
} catch (InvocationTargetException ex) {
throw new UnexpectedException("Error calling setFormOfUse through C3P0", ex);
}
} else {
throw new IllegalArgumentException("Unkown PreparedStatement implementation: " + st.getClass() + ". Maybe an unknown connection pool is hiding the OraclePreparedStatement?");
}
st.setString(index, (String) value);
}
The nullSafeSet method is structured to work directly on OraclePreparedStatement instances, or on C3P0ProxyStatement in case you have the C3P0 connection pool; other options will have to be used in case of different pools.
nullSafeSet 方法的结构是直接在 OraclePreparedStatement 实例上工作，或者在 C3P0ProxyStatement 上工作（如果您有 C3P0 连接池）；如果池不同，则必须使用其他选项。
This method worked with the ojdbc14.jar from Oracle 10.2.0.4.
此方法适用于 Oracle 10.2.0.4 中的 ojdbc14.jar。
