Question

我使用JTDS连接到MS SQL Server。连接到数据库没有问题，但是当我尝试执行一个语句时，我得到了一个数据库＆＃39; java＆＃39;不存在例外。

的ConnectionString：

conn = DriverManager.getConnection("jdbc:jtds:sqlserver://localhost;DatabaseName=MyDatabase;user=testuser;password=testpassword");

尝试执行脚本：

private void runStatement(String scriptLocation) {
    if(scriptLocation == null) {
        return;
    }

    try {
        InputStream is = getClass().getClassLoader().getResourceAsStream(scriptLocation);
        String query = is.toString();
        is.close();

        Statement stmt = conn.createStatement();
        stmt.executeQuery(query);
    } catch(IOException | SQLException ex) {
        log.warning(ex.getMessage());
    }
}

堆栈跟踪：

WARNING: Database 'java' does not exist. Make sure that the name is entered correctly.
java.sql.SQLException: Database 'java' does not exist. Make sure that the name is entered correctly.
    at net.sourceforge.jtds.jdbc.SQLDiagnostic.addDiagnostic(SQLDiagnostic.java:372)
    at net.sourceforge.jtds.jdbc.TdsCore.tdsErrorToken(TdsCore.java:2988)
    at net.sourceforge.jtds.jdbc.TdsCore.nextToken(TdsCore.java:2421)
    at net.sourceforge.jtds.jdbc.TdsCore.getMoreResults(TdsCore.java:671)
    at net.sourceforge.jtds.jdbc.JtdsStatement.executeSQLQuery(JtdsStatement.java:505)
    at net.sourceforge.jtds.jdbc.JtdsStatement.executeQuery(JtdsStatement.java:1427)
    at com.exampe.MyJTDSConnection.runStatement(MyJTDSConnection.java:238)
    at com.exampe.MyJTDSConnection.loadPageTitle(MyJTDSConnection.java:208)
    at com.exampe.MyJTDSConnection.runTesting(MyJTDSConnection.java:69)
    at com.exampe.SeleniumTesting.runTest(SeleniumTesting.java:59)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    ...

Answer 1

如您对问题的评论中所述，将.toString()方法应用于InputStream对象不会读取InputStream。相反，它只返回对象本身的String表示，而不是对象包含的内容。

例如，我的Java项目有一个名为＆＃34; script.sql＆＃34;的资源文件。包含：

SELECT @@VERSION

以下代码比较了简单地在对象上使用.toString()与使用Apache Commons IO实际读取将InputStream转换为字符串的结果：

package resourceTest;

import java.io.InputStream;
import org.apache.commons.io.IOUtils;

public class ResourceTestMain {

    public static void main(String[] args) {
        try (InputStream is = ResourceTestMain.class.getClassLoader().getResourceAsStream("resources/script.sql")) {
            String toStringValue = is.toString();
            String contents = IOUtils.toString(is, "UTF-8");
            is.close();
            System.out.println("is.toString() returned:");
            System.out.println("    " + toStringValue);
            System.out.println();
            System.out.println("IOUtils.toString(is, \"UTF-8\") returned:");
            System.out.println("    " + contents);
        } catch (Exception e) {
            e.printStackTrace(System.out);
        }
    }

}

结果是：

is.toString() returned:
    java.io.BufferedInputStream@804a77

IOUtils.toString(is, "UTF-8") returned:
    SELECT @@VERSION

JTDS没有连接到正确的数据库

1 个答案: