将Java Double Infinity和NaN值存储到MS SQL 2008数据库

Question

在我们的业务逻辑中,我们必须处理正值和负值Double.Infinity以及Double.NaN值.

我们必须将这些值存储到Microsot SQL Server 2008数据库中.问题是Microsot SQL Server不支持infinity或nan值.(SQL Server 2005的问题描述,也适用于MS SQL Server 2008).

我们使用Hibernate 3.6.7作为我们的JPA实现和Microsoft的sqljdbc4驱动程序版本4.0.2206.100.

我们试图通过将JPA实体的列定义设置为VARCHAR来解决此问题

@Column(columnDefinition = "VARCHAR(40)")
private Double foo;

即使列定义在数据库中正确更改为VARCHAR,这似乎也没有任何影响.似乎无限值是在JDBC驱动程序的验证中捕获的,因为我们在尝试INSERT Double.Infinity值时得到以下stacktrace :

Caused by: com.microsoft.sqlserver.jdbc.SQLServerException: The incoming tabular data  stream (TDS) remote procedure call (RPC) protocol stream is incorrect. Parameter 6 (""): The supplied value is not a valid instance of data type float. Check the source data for invalid values. An example of an invalid value is data of numeric type with scale greater than precision.
    at com.microsoft.sqlserver.jdbc.SQLServerException.makeFromDatabaseError(SQLServerException.java:216)
    at com.microsoft.sqlserver.jdbc.SQLServerStatement.getNextResult(SQLServerStatement.java:1515)
    at com.microsoft.sqlserver.jdbc.SQLServerPreparedStatement.doExecutePreparedStatement(SQLServerPreparedStatement.java:404)
    at com.microsoft.sqlserver.jdbc.SQLServerPreparedStatement$PrepStmtExecCmd.doExecute(SQLServerPreparedStatement.java:350)
    at com.microsoft.sqlserver.jdbc.TDSCommand.execute(IOBuffer.java:5696)
    at com.microsoft.sqlserver.jdbc.SQLServerConnection.executeCommand(SQLServerConnection.java:1715)
    at com.microsoft.sqlserver.jdbc.SQLServerStatement.executeCommand(SQLServerStatement.java:180)
    at com.microsoft.sqlserver.jdbc.SQLServerStatement.executeStatement(SQLServerStatement.java:155)
    at com.microsoft.sqlserver.jdbc.SQLServerPreparedStatement.executeUpdate(SQLServerPreparedStatement.java:314)
    at org.apache.commons.dbcp.DelegatingPreparedStatement.executeUpdate(DelegatingPreparedStatement.java:105)
    at org.apache.commons.dbcp.DelegatingPreparedStatement.executeUpdate(DelegatingPreparedStatement.java:105)
    at org.hibernate.id.IdentityGenerator$GetGeneratedKeysDelegate.executeAndExtract(IdentityGenerator.java:94)
    at org.hibernate.id.insert.AbstractReturningDelegate.performInsert(AbstractReturningDelegate.java:57)
    ... 79 more

如何解决这个问题的任何想法都是受欢迎的.

Answer 1

以下是解决此问题的简单方法：使用String字段类型并在 getter 和 setter 中进行转换。这样您就不必更改业务逻辑，并且实际的转换逻辑得到了很好的封装。

// Column definition is not a necessity here
@Column(columnDefinition = "VARCHAR(40)")
private String foo;

public Double getFoo() {
    return this.foo != null ? Double.valueOf(this.foo) : null;
}

public void setFoo(Double d) {
    this.foo = d != null ? d.toString() : null;
}