Java 在数据库中插入blob数据
我想我对这段代码有点问题: 当我尝试在数据库中插入值时,我收到一个错误 PS:我尝试使用:Java 在数据库中插入blob数据,java,sql,jsp,servlets,web-applications,Java,Sql,Jsp,Servlets,Web Applications,我想我对这段代码有点问题: 当我尝试在数据库中插入值时,我收到一个错误 PS:我尝试使用: setBinaryStream(int parameterIndex,InputStream x)-将根据需要从InputStream读取数据,直到到达文件末尾。这是在JDBC4.0(Java1.6)中添加的 setBinaryStream(int parameterIndex,InputStream x,int length)—数据将根据“长度”字节的需要从InputStream中读取 setBinar
public class DataServlet extends HttpServlet{
public void doPost(HttpServletRequest request,HttpServletResponse response)throws ServletException,IOException {
Connection conn = ConnectionToDB.connettiDB();
InputStream inputstream = null;
Part filepart = request.getPart("image");
inputstream = filepart.getInputStream();
try{
String sql = "insert into blob (data) values (?)";
PreparedStatement statement = conn.prepareStatement(sql);
if (inputstream != null) {
// fetches input stream of the upload file for the blob column
statement.setBlob(1, inputstream);
}
// sends the statement to the database server
int row = statement.executeUpdate();
if (row > 0) {
System.out.println( "File uploaded and saved into database");
}
} catch (SQLException ex) {
System.out.println( "ERROR: " + ex.getMessage());
ex.printStackTrace();}
}
}
这是错误消息:
com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to
your MySQL server version for the right syntax to use near 'blob
(data) values (_binary'‰PNG
\0\0\0
IHDR\0\0\0\0\0\0\0\0\0;0®¢\0\' at line 1
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown
Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
at com.mysql.jdbc.Util.getInstance(Util.java:386)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1052)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3609)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3541)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2002)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2163)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2624)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2127)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2427)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2345)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2330)
at com.CvManagement.src.servlet.DataServlet.doPost(DataServlet.java:69)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:646)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:503)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:421)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1070)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:314)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)
我最初认为这是驱动程序中的一个bug,这可能是错误的。最可能的问题是在查询中使用了不带引号的单词
blob
blob
是一个对象名,因此当用作对象名时需要引用
如果您将查询更改为:
String sql = "insert into `blob` (data) values (?)";
尝试使用
PreparedStatement.setInputStream()
而不是setBlob()
也许这会对@a_horse\u和\u no_name有帮助方法setInputStream()对于类型PreparedStatement没有定义我将关闭它,因为@prsmax提供的链接似乎有帮助。对不起,我的意思是setBinaryStream()