java中的java.lang.IndexOutOfBoundsException

Question

我在Java类下面，尝试从CSV文件导入数据并插入到oracle数据库表中。

[当我尝试运行此Java类时，出现错误，如'java.lang.IndexOutOfBoundsException'。我只是尝试使用log.info("Insert values to table" +sql);查看插入语句，我可以看到生成了一些插入语句，然后引发了错误。

我是Java的新手，所以不确定如何处理此异常。

下面是我的代码：

@Service
public class OBSCSVImporter {
    private final static Logger log = LoggerFactory.getLogger(tur.class);

    //Tabellenname auf Spalten in der Tabelle
    Map<String, List<ColumnData>> columnDataCache = new HashMap<>();

    private final JdbcTemplate jdbcTemplate;

    public OBSCSVImporter(JdbcTemplate jdbcTemplate) {
        this.jdbcTemplate = jdbcTemplate;
    }
    /**
     * Be careful: Deletes all the data from the given table.
     * @param tableName the name of the table the data of which should be deleted.
     */
    public void deleteTableData(String tableName){
        jdbcTemplate.update("delete from " + tableName);
    }

    public void importFile(BufferedReader bufferedReader, String tableName, String fileName,
                           Map<Integer, Function<String, String>> COLUMN_TYPE_MAPPINGS,
                           Map<String, Function<String, String>> COLUMN_NAME_MAPPINGS) throws IOException {
        importFile(bufferedReader, tableName, fileName, COLUMN_TYPE_MAPPINGS, COLUMN_NAME_MAPPINGS, new ArrayList<>());
    }

    public void importFile(BufferedReader bufferedReader, String tableName, String fileName,
                           Map<Integer, Function<String, String>> COLUMN_TYPE_MAPPINGS,
                           Map<String, Function<String, String>> COLUMN_NAME_MAPPINGS,
                           List<FixedValue> fixedValues) throws IOException {
        String firstLine = bufferedReader.readLine();
        List<String> headings = Splitter
                .on(";")
                .trimResults()
                .splitToList(firstLine)
                .stream()
                .map(str -> str.replace("XXX-", ""))
                .map(str -> str.replace("-", ""))
                .map(str -> str.replaceAll("\\.", ""))
                .map(str -> str.equals("ORDER") ? "ORDERID": str) // to work for ORDER columns in CSV files
                .map(String::toUpperCase)
                .filter(str -> str.length() > 0) // to suppress empty columns at the end of the line
                .collect(toList());

        List<ColumnData> columnData = getColumns(tableName)
                .stream()
                .filter(cd -> !cd.getName().equals("SYSTEM_INSERTED_AT") && !cd.getName().equals("DATEINAME"))
                .collect(toList());

        List<String> columnNames = columnData.stream().map(ColumnData::getName).collect(toList());

        //Nur Spalten, die sowohl in der Datenbank als auch in der CSV-Datei enthalten sind, werden verarbeitet
        List<String> matchingColumns = intersection(headings, columnNames);

        List<String> columnsInDbButNotInCsv = subtract(columnNames, headings);
        columnsInDbButNotInCsv = subtract(columnsInDbButNotInCsv, fixedValues.stream().map(f -> f.getColumnName()).collect(toList()));
        columnsInDbButNotInCsv.forEach(s -> log.warn("Spalte '" + s + "' in Datenbank vorhanden, wird jedoch nicht in der CSV bereitgestellt"));

        //Index to columnData
        Map<Integer, ColumnData> columnsToInsert = new HashMap<>();

        for (String column : matchingColumns) {
            columnsToInsert.put(headings.indexOf(column), columnData.stream().filter(cd -> cd.getName().equals(column)).findAny().get());
        }

        int counter = 0;
        while (true) {
            String line = bufferedReader.readLine();
            if (line == null) {
                break;
            }

            counter++;

            List<String> columns = Splitter
                    .on(";")
                    .splitToList(line);

            StringBuilder columnSqlFragment = new StringBuilder();
            StringBuilder valuesSqlFragment = new StringBuilder();

            for (int i = 0; i < headings.size(); i++) {
                String columnName = headings.get(i);
                String value = columns.get(i);

                if (!columnsToInsert.containsKey(i)) {
                    continue;
                }

                if (i != 0) {
                    columnSqlFragment.append(", ");
                    valuesSqlFragment.append(", ");
                }

                int columnType = columnsToInsert.get(i).getType();
                java.util.function.Function<String, String> mapping = COLUMN_NAME_MAPPINGS.containsKey(columnName) ? COLUMN_NAME_MAPPINGS.get(columnName) : COLUMN_TYPE_MAPPINGS.get(columnType);
                if(mapping == null) {
                    throw new IllegalStateException("Kein Mapping für Spalte mit dem Namen " + columnName +  " aus der Tabelle " + tableName + " mit Typ " + columnType + " gefunden");
                }

                columnSqlFragment.append("\"" + columnName + "\"");
                valuesSqlFragment.append(mapping.apply(value));
            }

            for(FixedValue fv : fixedValues) {
                columnSqlFragment.append(", ");
                columnSqlFragment.append(fv.getColumnName());

                valuesSqlFragment.append(", ");
                valuesSqlFragment.append(fv.getValueSQLFragment());
            }

            String sql = "insert into " + tableName + " (SYSTEM_INSERTED_AT, DATEINAME, " + columnSqlFragment + ") VALUES (sysdate, '" + fileName + "', " + valuesSqlFragment + ")";
            log.info("Insert values to table" +sql);
            jdbcTemplate.update(sql);
        }

        log.info(counter + " Zeilen erfolgreich eingelesen.");
    }

    private List<ColumnData> getColumns(String tableName) {
        if(columnDataCache.containsKey(tableName)) {
            return columnDataCache.get(tableName);
        }

        List<ColumnData> result = new ArrayList<>();
        try (Connection connection = jdbcTemplate.getDataSource().getConnection()) {
            ResultSet rs = connection.getMetaData().getColumns(null, null, tableName, null);

            boolean anyResults = false;
            while (rs.next()) {
                anyResults = true;
                String columnName = rs.getString(4).toUpperCase();
                int type = rs.getInt(5);
                result.add(new ColumnData(columnName, type));
            }
            columnDataCache.putIfAbsent(tableName, result);

            if(!anyResults) {
                throw new RuntimeException("Could not retrieve columns for table " + tableName);
            }

            return result;
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
    }
}

CSV文件仅包含1000行。以下是CSV文件中的示例数据：

1;KK;130560;Morgan Stanley & Co. International,;RW 2018/0465;20190805;-1179,92;CHF;20191128;20191110;J;20191110;C;
1;KK;130561;Arkem Ltd, London;RSUK 2019/0145;20191127;-4500,00;EUR;20191128;20200326;N;0;6;
1;KK;130562;Morgan Stanley & Co. International,;ABW 2019-01292;20190807;-102,40;USD;20191128;20191112;J;20191112;C;
1;KK;130562;Morgan Stanley & Co. International,;ABW 2019-01547;20191008;-4,80;USD;20191128;20200113;N;0;6;
1;KK;130563;Vogt Consulting & Management AG, Va;RSCH 2019/0126;20191127;-833,33;EUR;20191128;20200326;N;0;6;
1;KK;130563;Vogt Consulting & Management AG, Va;RSCH 2019/0127;20191127;-2500,00;EUR;20191128;20200326;N;0;6;
1;KK;130565;Garraway Capital Management LLP, Lo;RSUK 2019/0095;20190822;-4000,00;GBP;20191128;20191220;N;0;6;
1;KK;130566;Acoro Asset Management AG, Küsnacht;RSCH 2019/0107;20191118;-1077,00;CHF;20191128;20200223;N;0;6;
1;KK;130569;Marathon Asset Management LLP, Lond;RSUK 2019/0138;20191111;-6000,00;USD;20191128;20200216;N;0;6;
1;KK;130572;LeanVal Invest GmbH, Leverkusen;122019;20191125;-240,00;EUR;20191128;20200226;N;0;6;
1;KK;130576;Mako Global Derivatives Partnership;RSUK 2019/0149;20191127;-2625,00;GBP;20191128;20200326;N;0;6;
1;KK;130578;Gladstone Capital Management LLP, L;RSUK 2019/0129;20190930;-2040,00;EUR;20191128;20200128;N;0;6;
1;KK;130579;WA Capital GmbH, Siegsdorf;RSDE 2019/0169;20190923;-892,50;EUR;20191128;20200121;N;0;6;
1;KK;130584;Mandamus Capital Limited, Dublin 2
;RSUK 2019/0156;20191127;-1200,00;EUR;20191128;20200326;N;0;6;
1;KK;130588;Morgan Stanley Europe SE, Frankfurt;ABW 2019-01796;20191106;-97,50;USD;20191128;20200211;N;0;6;

Answer 1

我不确定是哪一行导致了错误-您可以输入行号或堆栈跟踪信息吗？但是，这让我担心：

for (int i = 0; i < headings.size(); i++) {
                String columnName = headings.get(i);
                String value = columns.get(i); // <- this

您正在从i到headings.size()进行迭代，但是如果headings.size()大于columns.size()怎么办？然后，您的程序将尝试访问不存在的索引columns，这将为您提供IndexOutOfBounds异常。