为什么在读取数据库hsqldb中的blob时抛出java.lang.IndexOutOfBoundsException

Question

你好。 我正在使用以下代码在服务器端将blob写入数据库。

    @Override
    public void write(TypeHandlerContext context, ResultSet resultSet, Object value) {
        int column = context.getColumn();
        LargeObject lo = (LargeObject)value;
        if(lo == null) {
            try {
                resultSet.updateNull(column);
            } catch(SQLException e) {
                throw new RuntimeException(e);
            }
        } else {
            InputStream is = lo.getInputStream();
            try {
                if(is == null) {
                    Reader r = lo.getReader();
                    if(r == null) {
                        resultSet.updateNull(column);
                        return;//empty Large object
                    }
                    is = new ReaderInputStream(r, "UTF-8");
                } 
                resultSet.updateBlob(column, is, lo.getLength());
            } catch(Exception e) {
                Throwables.throwAsUndeclarable(e);
            } finally {
                Tools.closeSilent(is);
            }
        }
    }

为了读取blob，使用了以下代码：

    @Override
    public LargeObject read(TypeHandlerContext context, ResultSet resultSet) {
        try {
            Blob blob = resultSet.getBlob(context.getColumn());
            if(blob == null) {
                return null;
            }
            final long len = blob.length();
            final byte[] bytes = readBytes((int)len, blob);
            return new ByteArrayLargeObject(bytes, true, false);
        } catch(Exception e) {
            Throwables.throwAsUndeclarable(e);
            return null;
        }
    }

    private byte[] readBytes(int len, Blob blob) throws Exception {
        try {
            return blob.getBytes(1l, len);
        } catch(SQLFeatureNotSupportedException e) {
            InputStream is = blob.getBinaryStream();
            try {
                return IOUtils.toByteArray(is, len);
            } finally {
                Tools.closeSilent(is);
            }
        }
    }

Blob包含下一个要测试的文本：

and(
     gt(
      field("sinSystems.childsCount"),
      param(0, "integer")
     ),
     security.checkAccessForTarget("sinSystems.target", "sinSystems.targetType")
    )

我已经在oracle和postresql上成功测试过，但是在hsqldb上测试失败，但出现以下异常：

    Caused by: java.lang.IndexOutOfBoundsException: Index out of bounds: 0 >= 0
        at org.hsqldb.lib.HsqlArrayList.get(Unknown Source)
        at org.hsqldb.persist.LobStoreMem.getBlockBytes(Unknown Source)
        at org.hsqldb.persist.LobManager.getBytesNormal(Unknown Source)
        at org.hsqldb.persist.LobManager.getBytes(Unknown Source)
        at org.hsqldb.Session.performLOBOperation(Unknown Source)
        at org.hsqldb.Session.execute(Unknown Source)
        at org.hsqldb.types.BlobDataID.getBytes(Unknown Source)
        at org.hsqldb.jdbc.JDBCBlobClient.getBytes(Unknown Source)
        at ru.kih.sin.db.types.LargeObjectHandler.readBytes(LargeObjectHandler.java:100)
        at ru.kih.sin.db.types.LargeObjectHandler.read(LargeObjectHandler.java:44)
        at ru.kih.sin.db.types.LargeObjectHandler.read(LargeObjectHandler.java:27)
        at ru.kih.sql.types.NullValueWrapper.read(NullValueWrapper.java:24)
        at ru.kih.sql.types.TypeHandlerWrapper.read(TypeHandlerWrapper.java:74)
        at ru.kih.sql.types.TypeConverter.read(TypeConverter.java:48)
        at ru.kih.sin.model.impl.ObjectReadFunction.apply(ObjectReadFunction.java:119)
        at ru.kih.sin.model.impl.ObjectHandler.handle(ObjectHandler.java:41)
        at ru.kih.sin.model.impl.ObjectHandler.handle(ObjectHandler.java:16)
        at ru.kih.sql.query.handlers.SimpleSelect.handle(SimpleSelect.java:63)
        at ru.kih.sql.query.QueryHelper$UnsafeFunctionImpl.apply(QueryHelper.java:39)
        at ru.kih.sql.query.QueryHelper$UnsafeFunctionImpl.apply(QueryHelper.java:25)
        at ru.kih.sql.query.QueryContext.runIn(QueryContext.java:479)
        at ru.kih.sql.query.QueryContext.run(QueryContext.java:228)
        at ru.kih.sql.query.QueryContext.run(QueryContext.java:212)
        at ru.kih.sql.query.QueryContext.call(QueryContext.java:242)
        at ru.kih.sql.query.QueryHelper.query(QueryHelper.java:57)
        at ru.kih.sin.model.impl.SelectLobFunction.apply(SelectLobFunction.java:62)
        at ru.kih.sin.model.impl.SelectLobFunction.apply(SelectLobFunction.java:24)
        at ru.kih.sql.query.QueryContext.runIn(QueryContext.java:479)
        at ru.kih.sql.query.QueryContext.run(QueryContext.java:228)
        at ru.kih.sql.query.QueryContext.run(QueryContext.java:212)
        at ru.kih.sql.query.QueryContext.call(QueryContext.java:242)
        at ru.kih.sin.model.impl.ModelImpl.lambda$loadLob$8(ModelImpl.java:280)
        at ru.kih.sin.model.impl.ModelImpl$$Lambda$16/26663026.call(Unknown Source)
        at java.util.concurrent.FutureTask.run(FutureTask.java:266)
        at ru.kih.sin.model.impl.ModelImpl.loadLob(ModelImpl.java:285)
        ... 48 more

调试器可以看到blob.getLength（）大于0。

使用驱动程序hsqldb-2.3.1连接到数据库

告诉我是什么问题？

PS对不起我的英语））

Answer 1

编写Blob的代码不完整。 您必须在resultSet.updateBlob(...)之后调用resultSet.updateRow() resultSet.updateBlob(...) 。

最好使用最新版本的HSQLDB，当前版本为2.3.2和2.3.3（候选发布）。

Answer 2

答案已关闭。 行Tools.closeSilent(is); 方法public void write(TypeHandlerContext context, ResultSet resultSet, Object value) 。 在调用resultSet.updateRow()之前，它将关闭InputStream 。