我有一个这样设置的数据库
CREATE TABLE item (
ItemID int(11) NOT NULL auto_increment,
ItemName char(25),
YearManufactured int(11),
CopiesSold int(11),
AmountInStock int(11),
image blob,
Description char(30),
PRIMARY KEY (`ItemID`)
);
该表工作正常，我已经能够很好地插入和删除它。我想组织我的代码有点不同，并使用 Java 而不是编写脚本来更新表。我想切换到这样做的最初原因是因为我希望能够更轻松地上传图像。这是我的代码：
这是最初打开的脚本。URL、UserID 和 Password 绝对正确。
<%
// Instantiating the connection to the database
String mysJDBCDriver = "com.mysql.jdbc.Driver";
String mysURL = "MY_ADDRESS";
String mysUserID = "USERNAME";
String mysPassword = "PASSWORD";
java.sql.Connection conn=null; // a new connection
try
{
DB db = new DB();
conn=db.dbConnect(mysJDBCDriver, mysURL,mysUserID,mysPassword);
db.insertImage(conn,"c:/Users/DPiganell/image_launch_a5.jpg");
db.getImageData(conn);
System.out.println("Connected successfully to database using JConnect");
session.setAttribute("connection", conn);
}
catch(Exception e)
{
e.printStackTrace();
out.print(e.toString());
}
%>
这是我的数据库对象
package DBPackage;
import java.io.*;
import java.sql.*;
public class DB
{
public DB() {}
public Connection dbConnect(String db_driver, String db_connect_string,
String db_userid, String db_password)
{
try
{
Class.forName(db_driver);
Connection conn = DriverManager.getConnection(
db_connect_string, db_userid, db_password);
System.out.println("connected");
return conn;
}
catch (Exception e)
{
e.printStackTrace();
return null;
}
}
public void insertImage(Connection conn,String img)
{
int len;
String query;
PreparedStatement pstmt;
try
{
File file = new File(img);
FileInputStream fis = new FileInputStream(file);
len = (int)file.length();
// query = ("UPDATE item SET image = ? WHERE ItemID = ?");
query = ("INSERT INTO ITEM (ItemType, ItemName, YearManufactured, CopiesSold, AmountInStock, image, description) "
+ "VALUES(?,?,?,?,?,?,?");
pstmt = conn.prepareStatement(query);
pstmt.setString(1, "DVD");
pstmt.setString(2, "fsd");
pstmt.setInt(3, 1991);
pstmt.setInt(4, 6);
pstmt.setInt(5, 7);
pstmt.setString(7, "works");
// Method used to insert a stream of bytes
pstmt.setBinaryStream(6, (InputStream)fis, len);
pstmt.executeUpdate();
}
catch (SQLException e)
{
e.printStackTrace();
}
catch (Exception e)
{
e.printStackTrace();
}
}
public void getImageData(Connection conn)
{
byte[] fileBytes;
String query;
try
{
query = "select image from item where ItemID=3";
Statement state = conn.createStatement();
ResultSet rs = state.executeQuery(query);
if (rs.next())
{
fileBytes = rs.getBytes(1);
OutputStream targetFile=
new FileOutputStream(
"C:/Users/DPiganell/newImage.jpg");
targetFile.write(fileBytes);
targetFile.close();
}
}
catch (Exception e)
{
e.printStackTrace();
}
}
};
一旦程序到达executeUpdate，就会抛出异常。任何帮助表示赞赏。如果它更容易，我愿意采取不同的方法。
SQLException 堆栈跟踪：
SEVERE: 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 '' at line 1
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:525)
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:1053)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4096)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4028)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2490)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2651)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2734)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2155)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2458)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2375)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2359)
at DBPackage.DB.insertImage(DB.java:55)
at org.apache.jsp.header_jsp._jspService(header_jsp.java:61)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:111)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:847)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:403)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:492)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:378)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:847)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1539)
at org.apache.catalina.core.ApplicationDispatcher.doInvoke(ApplicationDispatcher.java:787)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:649)
at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:604)
at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:534)
at org.apache.jasper.runtime.JspRuntimeLibrary.include(JspRuntimeLibrary.java:1015)
at org.apache.jsp.index_jsp._jspService(index_jsp.java:60)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:111)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:847)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:403)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:492)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:378)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:847)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1539)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:281)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:655)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:595)
at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:98)
at com.sun.enterprise.web.PESessionLockingStandardPipeline.invoke(PESessionLockingStandardPipeline.java:91)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:162)
at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:330)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:231)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:174)
at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:828)
at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:725)
at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:1019)
at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:225)
at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:137)
at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:104)
at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:90)
at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:79)
at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:54)
at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:59)
at com.sun.grizzly.ContextTask.run(ContextTask.java:71)
at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:532)
at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:513)
at java.lang.Thread.run(Thread.java:722)
SEVERE: at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
SEVERE: at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
SEVERE: at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
SEVERE: at java.lang.reflect.Constructor.newInstance(Constructor.java:525)
SEVERE: at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
SEVERE: at com.mysql.jdbc.Util.getInstance(Util.java:386)
SEVERE: at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1053)
SEVERE: at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4096)
SEVERE: at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4028)
SEVERE: at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2490)
SEVERE: at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2651)
SEVERE: at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2734)
SEVERE: at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2155)
SEVERE: at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2458)
SEVERE: at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2375)
SEVERE: at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2359)
SEVERE: at DBPackage.DB.insertImage(DB.java:55)
SEVERE: at org.apache.jsp.header_jsp._jspService(header_jsp.java:61)
SEVERE: at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:111)
SEVERE: at javax.servlet.http.HttpServlet.service(HttpServlet.java:847)
SEVERE: at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:403)
SEVERE: at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:492)
SEVERE: at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:378)
SEVERE: at javax.servlet.http.HttpServlet.service(HttpServlet.java:847)
SEVERE: at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1539)
SEVERE: at org.apache.catalina.core.ApplicationDispatcher.doInvoke(ApplicationDispatcher.java:787)
SEVERE: at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:649)
SEVERE: at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:604)
SEVERE: at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:534)
SEVERE: at org.apache.jasper.runtime.JspRuntimeLibrary.include(JspRuntimeLibrary.java:1015)
SEVERE: at org.apache.jsp.index_jsp._jspService(index_jsp.java:60)
SEVERE: at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:111)
SEVERE: at javax.servlet.http.HttpServlet.service(HttpServlet.java:847)
SEVERE: at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:403)
SEVERE: at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:492)
SEVERE: at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:378)
SEVERE: at javax.servlet.http.HttpServlet.service(HttpServlet.java:847)
SEVERE: at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1539)
SEVERE: at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:281)
SEVERE: at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
SEVERE: at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:655)
SEVERE: at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:595)
SEVERE: at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:98)
SEVERE: at com.sun.enterprise.web.PESessionLockingStandardPipeline.invoke(PESessionLockingStandardPipeline.java:91)
SEVERE: at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:162)
SEVERE: at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:330)
SEVERE: at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:231)
SEVERE: at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:174)
SEVERE: at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:828)
SEVERE: at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:725)
SEVERE: at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:1019)
SEVERE: at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:225)
SEVERE: at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:137)
SEVERE: at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:104)
SEVERE: at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:90)
SEVERE: at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:79)
SEVERE: at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:54)
SEVERE: at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:59)
SEVERE: at com.sun.grizzly.ContextTask.run(ContextTask.java:71)
SEVERE: at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:532)
SEVERE: at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:513)
SEVERE: at java.lang.Thread.run(Thread.java:722)