Mysql实例java实现插入mysql二进制文件，blob类型，遇到问题及解决办法

/**
*
* 把二进制文件(该二进制文件可以是本地硬盘路径,也可以是一个网络路径)存入数据库
* create date:2009-5-13 author:Administrator
*
* @param file
* 可以是本地文件也可以是网络文件
* @param conn
*/
public void saveBinary(String file, Connection conn) {
// 注意二进制文件写入数据库时所用到的类,以及类包装转换过程
File f = null;
if (file.toLowerCase().contains("http:"))
f = DownLoadWithUrl.downLoadFile(file);
else
f = new File(file);
if (f != null) {
try {
InputStream is = new FileInputStream(f);
PreparedStatement ps = conn
.prepareStatement("insert into bankVoice(name,text) values (?,?)");
ps.setString(1, file);
int i = is.available();
ps.setBinaryStream(2, is, is.available());
ps.executeUpdate();
System.out.println("二进制文件插入成功");
ps.clearParameters();
ps.close();
is.close();
} catch (Exception e) {
e.printStackTrace();
System.out.println("二进制文件插入时出现异常");
}
}
}

com.mysql.jdbc.PacketTooBigException: Packet for query is too large (1048587 > 1047552). You can change this value on the server by setting the max_allowed_packet' variable.
at com.mysql.jdbc.MysqlIO.send(MysqlIO.java:2632)
at com.mysql.jdbc.MysqlIO.send(MysqlIO.java:2618)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1551)
at com.mysql.jdbc.ServerPreparedStatement.storeStream(ServerPreparedStatement.java:2180)
at com.mysql.jdbc.ServerPreparedStatement.serverLongData(ServerPreparedStatement.java:1199)
at com.mysql.jdbc.ServerPreparedStatement.serverExecute(ServerPreparedStatement.java:1004)
at com.mysql.jdbc.ServerPreparedStatement.executeInternal(ServerPreparedStatement.java:670)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:1159)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:1076)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:1061)
at SaveBinaryToDB.SaveBinaryToDB.saveBinary(SaveBinaryToDB.java:33)
at SaveBinaryToDB.SaveBinaryToDB.main(SaveBinaryToDB.java:17)
/**
* 从数据库中读取二进制文件 create date:2009-5-13 author:Administrator
*
* @param file
* @param conn
*/
public void getBinary(String file, Connection conn) {
// 注意二进制文件从数据库中读取时所用到的类,以及类的包装转换过程
try {
PreparedStatement ps = conn
.prepareStatement("select text from bankVoice where name=?");
ps.setString(1, file);
Blob blob = null;
ResultSet rs = ps.executeQuery();
if (rs.next()) {
blob = (Blob) rs.getBlob("text");
}
FileOutputStream fos = new FileOutputStream("D:\\test1.mp3");
fos.write(blob.getBytes(1, (int) blob.length()));
System.out.println("二进制文件获得成功");
ps.clearParameters();
ps.close();
fos.close();
} catch (Exception e) {
e.printStackTrace();
System.out.println("二进制文件读取时出现异常");
}
}

/**
* 本程序的功能实现网络下载
* 把指定url的文件下载到本地硬盘
*
*/
import java.io.*;
import java.net.*;
/**
* @todo 将网上获取的图像,mp3等文件存储到本地
*
* @version 1.0
*/
public class DownLoadWithUrl {
public static File downLoadFile(String fromUrl) {
URL url;
File file = null;
try {
// url = new
// URL("http://count.koubei.com/showphone/showphone.php?f=jpg&w=96&h=10&bc=255,255,255&fc=0,0,0&fs=10&fn=arial&phone=NzMwNzIyNTE1%236aWCXtTNZYkxASrj");
url = new URL(fromUrl);
URLConnection uc = url.openConnection();
InputStream is = uc.getInputStream();
// 根据下载文件类型的不同,进行相应的文件命名
file = new File("D:\\forever.mp3");
FileOutputStream out = new FileOutputStream(file);
/*
* 该注释内的也是一种写入文件的方法,不过通常下载mp3或者比mp3更小图片
* 等这些文件用这种带缓冲的方法写文件比较慢,所以说小文件下载通常用下面 的写文件方法就可以了 // byte[] b = new
* byte[102400*3]; // int size = 0; // // while ((size = is.read(b)) !=
* -1) { // out.write(b, 1, size); // // }
*/
int i = 0;
while ((i = is.read()) != -1) {
out.write(i);
}
out.flush();
is.close();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return file;
}
/**
* 删除本地磁盘指定路径的文件 create date:2009-5-13 author:Administrator
*
* @param file
*/
public static void delFile(String file) {
File f = new File(file);
if (f.exists())
f.delete();
System.out.println(file + "已经被删除");
}
public static void main(String[] args) {
// delFile("D:\\forever.mp3");
downLoadFile("");
}
}