Java org.h2.jdbc.JdbcSQLException:对象已关闭
就我的一生而言,我看不出它是如何“已经关闭”的 以下是输出:Java org.h2.jdbc.JdbcSQLException:对象已关闭,java,h2,resultset,Java,H2,Resultset,就我的一生而言,我看不出它是如何“已经关闭”的 以下是输出: success. querying database for latest values... 103 Exception in thread "main" org.h2.jdbc.JdbcSQLException: The object is already closed [90007-196] at org.h2.message.DbException.getJdbcSQLException(DbException.ja
success. querying database for latest values...
103
Exception in thread "main" org.h2.jdbc.JdbcSQLException: The object is already closed [90007-196]
at org.h2.message.DbException.getJdbcSQLException(DbException.java:345)
at org.h2.message.DbException.get(DbException.java:179)
at org.h2.message.DbException.get(DbException.java:155)
at org.h2.message.DbException.get(DbException.java:144)
at org.h2.jdbc.JdbcResultSet.checkClosed(JdbcResultSet.java:3208)
at org.h2.jdbc.JdbcResultSet.next(JdbcResultSet.java:130)
at RsetTest2.main(RsetTest2.java:22)
其中22对应于“while(rset.next()){”行
DB正在返回值,请参阅println语句,它给出了103
更奇怪的是,如果我//注释掉executeUpdate行,它会正常完成
线程“main”org.h2.jdbc.JdbcSQLException中出现异常:对象已关闭[90007-196]
您的问题是在while
循环中重用SQL语句。只要在循环中调用qry.executeUpdate(…)
方法,与上一条语句关联的ResultSet rset
就会关闭,因此会出现错误。这是while(rset.next())
语句,在失败的循环中的第一个executeUpdate(…)
之后调用
如果在循环中使用新语句,那么它应该可以工作
Statement qry = conn.createStatement();
String sql = "select id from CONSTITUENTS where manager = 'abc' limit 1";
ResultSet rset = qry.executeQuery(sql);
while (rset.next()) {
int id = rset.getInt("id");
System.out.println(id);
// we can't reuse the same Statement here so we need to create a new one
conn.createStatement().executeUpdate("insert into PAYREQUESTS ...");
}
您可以考虑保留必要的更新集合,然后在循环的末尾发布更新。< /P>
更奇怪的是,如果我//注释掉executeUpdate行,它会正常完成
是的,听起来不错。一点也不奇怪。:-为了简化代码,您可以使用尝试使用
java.lang.AutoCloseable
接口,因此您可以去掉以下行:
rset.close();
qry.close();
整个街区可能看起来像这样:
try (ResultSet rset = conn.createStatement().executeQuery("select id from CONSTITUENTS where manager = 'abc' limit 1")) {
String insertSQL = "insert into PAYREQUESTS (constituent, inblock) values ('%d', 238)";
while (rset.next()) {
int id = rset.getInt("id");
Savepoint savePoint = conn.setSavepoint("beforeInsert");
try {
conn.createStatement().executeUpdate(String.format(insertSQL, id));
conn.commit();
} catch (SQLException ex) {
conn.rollback(savePoint);
//log exception
}
}
} catch (SQLException e) {
//log exception
}
由于您的连接的自动提交模式等于false
,可能对可能的有害操作有意义。,在关闭方法中,如果它已经关闭,则它应该是不可操作的。因此,可能是驱动器实现问题。这不是关闭@Yogesh\D,而是关闭后他仍在使用rset
d、 明白了。while(rset.next())是导致问题的原因,而不是结束。谢谢!
try (ResultSet rset = conn.createStatement().executeQuery("select id from CONSTITUENTS where manager = 'abc' limit 1")) {
String insertSQL = "insert into PAYREQUESTS (constituent, inblock) values ('%d', 238)";
while (rset.next()) {
int id = rset.getInt("id");
Savepoint savePoint = conn.setSavepoint("beforeInsert");
try {
conn.createStatement().executeUpdate(String.format(insertSQL, id));
conn.commit();
} catch (SQLException ex) {
conn.rollback(savePoint);
//log exception
}
}
} catch (SQLException e) {
//log exception
}