当有更多行时执行ArrayIndexOutOfBoundsException时执行resultSet.next()

Question

我正在试图查询一个表，该表中有一个包含文本的长raw()类型的数据。我需要将这些数据导出到一个平面文件。对于给定的id，我看到表中有14行。我使用JDBC连接获取数据，当使用ResultSet获取数据时，我将在第13行获取ArrayIndexOutOfBoundsException。不知道为什么会发生这个问题。

长原始列中的数据可能很大。我怀疑它无法获取所有现有的数据。我可能也错了。在这种情况下，当ArrayIndexOutOfBoundsException发生时，我找不到很多信息。完整的代码如下-

import java.io.*;
import java.sql.*;
import java.util.ArrayList;


public class TestMain {

    private static String URL = "jdbc:oracle:thin:@localhost:8080:xe";
    private static String USER_NAME = "scott";
    private static String PASSWORD = "tiger";

    public static void main(String[] args) throws SQLException, IOException {

        Connection newConnection = getNewConnection();
        BufferedWriter bw = new BufferedWriter(new FileWriter("./extractedFile/RawDataFile.txt"));
        PreparedStatement extractableRowCount = getExtractableRowCount(newConnection, (long)34212);
        ResultSet foundCountRs = extractableRowCount.executeQuery();
        foundCountRs.next();
        int foundCount = foundCountRs.getInt(1);
        //`here I get 14 as the count`
        System.out.println("Available rows for id:: 34212 are "+foundCount);
        foundCountRs.close();
        extractableRowCount.close();
        PreparedStatement fetchBinaryQueryStatement = getExtractableRow(newConnection, (long)34212);
        ResultSet fetchedRowsRs = fetchBinaryQueryStatement.executeQuery();

        int i=0;
        while (fetchedRowsRs.next()) {
            i++;
            //`I see outputs upto i=13, and then I get ArrayIndexOutOfBoundsException 
            System.out.println("i = " + i);
            String userName = fetchedRowsRs.getString("user_name");
            InputStream savedTextData = fetchedRowsRs.getBinaryStream("saved_text");

            bw.write(userName + ":: ");
            int len = 0;
            if (savedTextData != null) {
                while ((len = savedTextData.read()) != -1) {
                    bw.write((char) len);
                    bw.flush();
                }
            }
            fetchedRowsRs.close();
            fetchBinaryQueryStatement.close();

        }
        bw.close();

    }

    public static Connection getNewConnection() throws SQLException {

        DriverManager.registerDriver(new oracle.jdbc.OracleDriver());
        return DriverManager.getConnection(URL, USER_NAME, PASSWORD);

    }

    public static PreparedStatement getExtractableRow(Connection connection, Long id) throws SQLException {
        PreparedStatement statement = connection.prepareStatement("SELECT user_name, saved_text FROM user_email_text_data where id = ?");
        statement.setLong(1, id);
        return statement;
    }

    public static PreparedStatement getExtractableRowCount(Connection connection, Long id) throws SQLException {
        PreparedStatement statement = connection.prepareStatement("SELECT count(1) FROM user_email_text_data where id = ?");
        statement.setLong(1, id);
        return statement;
    }

}

错误的完整堆栈跟踪：

Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 8
    at oracle.jdbc.driver.T4CMAREngineNIO.buffer2Value(T4CMAREngineNIO.java:814)
    at oracle.jdbc.driver.T4CMAREngineNIO.unmarshalUB2(T4CMAREngineNIO.java:577)
    at oracle.jdbc.driver.T4CMAREngineNIO.unmarshalSB2(T4CMAREngineNIO.java:557)
    at oracle.jdbc.driver.T4CMAREngine.processIndicator(T4CMAREngine.java:1573)
    at oracle.jdbc.driver.T4CMarshaller$StreamMarshaller.unmarshalOneRow(T4CMarshaller.java:179)
    at oracle.jdbc.driver.T4CLongRawAccessor.unmarshalOneRow(T4CLongRawAccessor.java:159)
    at oracle.jdbc.driver.T4CTTIrxd.unmarshal(T4CTTIrxd.java:1526)
    at oracle.jdbc.driver.T4CTTIrxd.unmarshal(T4CTTIrxd.java:1289)
    at oracle.jdbc.driver.T4C8Oall.readRXD(T4C8Oall.java:850)
    at oracle.jdbc.driver.T4CTTIfun.receive(T4CTTIfun.java:543)
    at oracle.jdbc.driver.T4CTTIfun.doRPC(T4CTTIfun.java:252)
    at oracle.jdbc.driver.T4C8Oall.doOALL(T4C8Oall.java:612)
    at oracle.jdbc.driver.T4CPreparedStatement.doOall8(T4CPreparedStatement.java:226)
    at oracle.jdbc.driver.T4CPreparedStatement.fetch(T4CPreparedStatement.java:1023)
    at oracle.jdbc.driver.OracleStatement.fetchMoreRows(OracleStatement.java:3353)
    at oracle.jdbc.driver.InsensitiveScrollableResultSet.fetchMoreRows(InsensitiveScrollableResultSet.java:736)
    at oracle.jdbc.driver.InsensitiveScrollableResultSet.absoluteInternal(InsensitiveScrollableResultSet.java:692)
    at oracle.jdbc.driver.InsensitiveScrollableResultSet.next(InsensitiveScrollableResultSet.java:406)

Answer 1

在使用ojdbc8-12.2.0.1调用ResultSet.next()时，我得到了完全相同的异常。

java.lang.ArrayIndexOutOfBoundsException: 8
at oracle.jdbc.driver.T4CMAREngineNIO.buffer2Value(T4CMAREngineNIO.java:814)
at oracle.jdbc.driver.T4CMAREngineNIO.unmarshalUB2(T4CMAREngineNIO.java:577)
at oracle.jdbc.driver.T4CMAREngineNIO.unmarshalSB2(T4CMAREngineNIO.java:557)
at oracle.jdbc.driver.T4CMAREngine.processIndicator(T4CMAREngine.java:1573)
at oracle.jdbc.driver.T4CMarshaller$StreamMarshaller.unmarshalOneRow(T4CMarshaller.java:179)
at oracle.jdbc.driver.T4CLongRawAccessor.unmarshalOneRow(T4CLongRawAccessor.java:159)
at oracle.jdbc.driver.T4CTTIrxd.unmarshal(T4CTTIrxd.java:1526)
at oracle.jdbc.driver.T4CTTIrxd.unmarshal(T4CTTIrxd.java:1289)
at oracle.jdbc.driver.T4C8Oall.readRXD(T4C8Oall.java:850)
at oracle.jdbc.driver.T4CTTIfun.receive(T4CTTIfun.java:543)
at oracle.jdbc.driver.T4CTTIfun.doRPC(T4CTTIfun.java:252)
at oracle.jdbc.driver.T4C8Oall.doOALL(T4C8Oall.java:612)
at oracle.jdbc.driver.T4CPreparedStatement.doOall8(T4CPreparedStatement.java:226)
at oracle.jdbc.driver.T4CPreparedStatement.fetch(T4CPreparedStatement.java:1023)
at oracle.jdbc.driver.OracleStatement.fetchMoreRows(OracleStatement.java:3353)

当我将驱动程序版本升级到ojdbc8-18.3.0.0.时，异常消失了。

更新JDBC驱动程序可能值得一试，如果任何人都发现自己处于相同的情况下。

Answer 2

下面的行位于外部while循环的末尾，但是它们需要在循环之后执行，因为您不能关闭结果集对象，然后调用next()

fetchedRowsRs.close();
fetchBinaryQueryStatement.close();

Answer 3

因为数组的大小是14，所以最后一个索引是13，因为它是从0开始的，所以您访问的索引值大于数组的大小，这会给ArrayOutOfBound异常。