用JAVA实现数据库图片的存取 打错了..如何用java语言实现对SQL数据库的图片存取啊??可以给我例子吗?有相关书籍吗??求教啊~~ 解决方案 » 免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货 本身这种做法就是不对的,这样效率很差,数据库的压力也太大!你如果要存取,可以用jdbc!有一个PreparedStatement可以用下面方法进行存取setBinaryStream(int parameterIndex, InputStream x, int length) 保存ResultSet里面可以用InputStream getBinaryStream(String columnName) 读取InputStream getBinaryStream(int columnIndex) 读取 就这么简单和普通的一样,但是你要会jdbc哦 可以问一下..InputStream getBinaryStream(String columnName) 读取InputStream getBinaryStream(int columnIndex) 读取这两个函数是怎样用吗?/ 楼主没说清楚不知道是怎么搞。一般做法是不把图片以二进制的方式存进数据库的,这样很明显,压力大,一般做法是把图片的路径存进数据库,然后用JDBC读出来做为图片地址显示。 基本工能我都可以实现了!但我下载的文件变得好大!30K的文件上传到数据库,再从数据库读取生成一个JPG的文件足足有9M.为什么??这是上传代码:import java.io.*;import java.awt.event.*;import java.sql.*;import java.lang.*;public class odbc { public static void main(String args[]) { try { String url="jdbc:odbc:zhouonline"; FileInputStream file=new FileInputStream("1.jpg"); Class.forName("sun.jdbc.odbc.JdbcOdbcDriver"); Connection cn=DriverManager.getConnection(url); PreparedStatement st=cn.prepareStatement("insert into img(abc) values(?)"); st.setBinaryStream(1,file,file.available());//得到文件大小 st.execute(); System.out.println("成功"); } catch(Exception e) { e.printStackTrace(); } }}这是从数据库读取代码:import java.io.*;import java.awt.event.*;import java.sql.*;import java.lang.*;public class imag { public static void main(String args[]) { try { String url="jdbc:odbc:zhouonline"; Class.forName("sun.jdbc.odbc.JdbcOdbcDriver"); Connection cn=DriverManager.getConnection(url); PreparedStatement st=cn.prepareStatement("select abc from img"); // st.setBinaryStream(1,file,file.available()); ResultSet rs=st.executeQuery(); byte b[]=new byte[10240000]; while(rs.next()) { InputStream in=rs.getBinaryStream(1); in.read(b); File file=new File("test.jpg"); FileOutputStream write=new FileOutputStream(file); write.write(b); write.close(); } } catch(Exception e) { e.printStackTrace(); } }} 读取应该按大小读:int readSize;byte b[]=new byte[1024];FileOutputStream write=new FileOutputStream(file);InputStream in=rs.getBinaryStream(1);try{ while ((readSize = in.read(b)) != -1) { write.write(b,0,readSize); }}finally{ write.close(); in.close();} package classes;import java.sql.*;import java.io.*;class SaveImage { static { try { Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver"); } catch (Exception e) { e.printStackTrace(); } } SaveImage() { try { Connection conn = DriverManager.getConnection("jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=imageDB","sa",""); File []files=new File("image").listFiles(new FilenameFilter() { public boolean accept(File dir,String name) { if(name.endsWith(".jpg")) { return true; } return false; } }); for(int i=0;i<files.length;i++) { // System.out.println(files[i]); try{ FileInputStream fileImage=new FileInputStream(files[i]); ByteArrayOutputStream byteArray=new ByteArrayOutputStream(); byte buffer[]=new byte[1024]; int length=-1; while((length=fileImage.read(buffer))!=-1) { // byteArray.write(buffer,0,length); byteArray.write(buffer); } String insertString="insert into imageTable(imageName,imageData,length) values(?,?,?)"; PreparedStatement insertStm=conn.prepareStatement(insertString); insertStm.setString(1,files[i].getName()); insertStm.setBytes(2,byteArray.toByteArray()); insertStm.setInt(3,(int)files[i].length()); insertStm.execute(); fileImage.close(); byteArray.close(); conn.close(); } catch(Exception ee) { ee.printStackTrace(); } } conn.close(); } catch (SQLException e) { e.printStackTrace(); } } public static void main(String[] args) { new SaveImage(); }}-------------以上是存图片----------- package classes;import java.sql.*;import java.io.*;import javax.swing.*;import java.awt.event.*;import java.awt.*;class SaveImage extends JFrame implements ActionListener{ JButton buttonNext=new JButton("Next"); JButton buttonPrevious=new JButton("Previous"); JLabel labelImage=new JLabel(); JLabel labelFileName=new JLabel(); Connection conn=null; ResultSet rst=null; byte []buffer=null; static { try { Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver"); } catch (Exception e) { e.printStackTrace(); } } SaveImage() { Container con=this.getContentPane(); JPanel panelSouth=new JPanel(); panelSouth.setLayout(new GridLayout(1,2)); panelSouth.add(buttonNext); panelSouth.add(buttonPrevious); buttonNext.addActionListener(this); buttonPrevious.addActionListener(this); con.add(panelSouth,BorderLayout.SOUTH); con.add(labelImage,BorderLayout.CENTER); con.add(labelFileName,BorderLayout.NORTH); String stringSQL="select * from imageTable"; try { conn = DriverManager.getConnection("jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=imageDB","sa",""); Statement stm=conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE); rst=stm.executeQuery(stringSQL); rst.next(); labelFileName.setText(rst.getString(2)); buffer=rst.getBytes(3); labelImage.setIcon(new ImageIcon(buffer)); } catch (SQLException e) { e.printStackTrace(); } this.setSize(600,400); this.show(); } public static void main(String[] args) { new SaveImage(); } public void actionPerformed(ActionEvent ae) { try{ if(ae.getSource()==buttonNext) { if(!rst.isLast()) rst.next(); } if(ae.getSource()==buttonPrevious) { if(!rst.isFirst()) rst.previous(); } buffer=rst.getBytes(2); labelImage.setIcon(new ImageIcon(buffer)); labelFileName.setText(rst.getString(1)); } catch(Exception e) { e.printStackTrace(); } }}----------------以上是取图片-------- Oracle的Blob字段比较特殊,他比long字段的性能要好很多,可以用来保存例如图片之类的二进制数据。 写入Blob字段和写入其它类型字段的方式非常不同,因为Blob自身有一个cursor,你必须使用cursor对blob进行操作,因而你在写入Blob之前,必须获得cursor才能进行写入,那么如何获得Blob的cursor呢? 这需要你先插入一个empty的blob,这将创建一个blob的cursor,然后你再把这个empty的blob的cursor用select查询出来,这样通过两步操作,你就获得了blob的cursor,可以真正的写入blob数据了。 看下面的JDBC的demo,把oraclejdbc.jar这个二进制文件写入数据库表javatest的content字段(这是一个blob型字段)import java.sql.*;import java.io.*;import oracle.sql.*;public class WriteBlob {public static void main(String[] args) { try { DriverManager.registerDriver(new oracle.jdbc.driver.OracleDriver()); Connection conn = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:orcl","fankai","fankai"); conn.setAutoCommit(false); BLOB blob = null; PreparedStatement pstmt = conn.prepareStatement("insert into javatest(name,content) values(?,empty_blob())"); pstmt.setString(1,"fankai"); pstmt.executeUpdate(); pstmt.close(); pstmt = conn.prepareStatement("select content from javatest where name= ? for update"); pstmt.setString(1,"fankai"); ResultSet rset = pstmt.executeQuery(); if (rset.next()) blob = (BLOB) rset.getBlob(1); String fileName = "oraclejdbc.jar"; File f = new File(fileName); FileInputStream fin = new FileInputStream(f); System.out.println("file size = " + fin.available()); pstmt = conn.prepareStatement("update javatest set content=? where name=?"); OutputStream out = blob.getBinaryOutputStream(); int count = -1, total = 0; byte[] data = new byte[(int)fin.available()]; fin.read(data); out.write(data); /* byte[] data = new byte[blob.getBufferSize()]; 另一种实现方法,节省内存 while ((count = fin.read(data)) != -1) { total += count; out.write(data, 0, count); } */ fin.close(); out.close(); pstmt.setBlob(1,blob); pstmt.setString(2,"fankai"); pstmt.executeUpdate(); pstmt.close(); conn.commit(); conn.close(); } catch (SQLException e) { System.err.println(e.getMessage()); e.printStackTrace(); } catch (IOException e) { System.err.println(e.getMessage()); }}} 仔细看上例,分三步: 1、插入空blobinto javatest(name,content) values(?,empty_blob()); 2、获得blob的cursorselect content from javatest where name= ? for update; 注意!!!必须加for update,这将锁定该行,直至该行被修改完毕,保证不产生并发冲突。 3、update javatest set content=? where name= 用cursor往数据库写数据 这里面还有一点要提醒大家: JDK1.3带的JDBC2.0规范是不完善的,只有读Blob的接口,而没有写Blob的接口,JDK1.4带的JDBC3.0加入了写Blob的接口。你可以使用JDBC3.0的接口,也可以直接使用Oracle的JDBC的API,我在上例中使用了Oracle的JDBC的API。 另外要注意的是:java.sql.Bloboracle.sql.BLOB 注意看blob的大小写,是不一样的。写程序的时候不要搞混了。 下面看看用Hibernate怎么写,原理是一样的,也要分三步,但是代码简单很多 这是Cat对象定义package com.fankai;import java.sql.Blob;public class Cat { private String id; private String name; private char sex; private float weight; private Blob image; public Cat() { } public String getId() { return id; } public void setId(String id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public char getSex() { return sex; } public void setSex(char sex) { this.sex = sex; } public float getWeight() { return weight; } public void setWeight(float weight) { this.weight = weight; } public Blob getImage() { return image; } public void setImage(Blob image) { this.image = image;}}这是Cat.hbm.xml<?xml version="1.0"?><!DOCTYPE hibernate-mapping SYSTEM "http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd"><hibernate-mapping><class name="com.fankai.Cat" table="cat"><!--jcs-cache usage="read-only"/--><id name="id" unsaved-value="null"><generator class="uuid.hex"/></id><property name="name" length="16" not-null="true"/><property name="sex" length="1" not-null="true"/><property name="weight" /><property name="image" /></class></hibernate-mapping> 下面是完整的用Hibernate写入Blob的例子,相比JDBC,已经简单轻松多了,也不用写那些Oracle特殊的sql了:package com.fankai;import java.sql.Blob;import net.sf.hibernate.*;import oracle.sql.*;import java.io.*;public class TestCatHibernate { public static void testBlob() { Session s = null; byte[] buffer = new byte[1]; buffer[0] = 1; try { SessionFactory sf = HibernateSessionFactory.getSessionFactory(); s = sf.openSession(); Transaction tx = s.beginTransaction(); Cat c = new Cat(); c.setName("Robbin"); c.setImage(Hibernate.createBlob(buffer)); s.save(c); s.flush(); s.refresh(c, LockMode.UPGRADE); BLOB blob = (BLOB) c.getImage(); OutputStream out = blob.getBinaryOutputStream(); String fileName = "oraclejdbc.jar"; File f = new File(fileName); FileInputStream fin = new FileInputStream(f); int count = -1, total = 0; byte[] data = new byte[(int)fin.available()]; fin.read(data); out.write(data); fin.close(); out.close(); s.flush(); tx.commit(); } catch (Exception e) { System.out.println(e.getMessage()); } finally { if (s != null) try { s.close(); } catch (Exception e) {} } }} 求前辈给小妹看一段代码 如何实现https Action接收 xml数据&&Struts2 的ServletActionContext.getRequest与HttpServlet中的request的区别 SSH2标签问题 struts2 . js给当前页面传值 hibernate + mysql 连接问题! 高分送上! 一个关于如何在jsp页面间传值的问题 求java 电商平台 源码 java问题 Weblogic8.1在部署ejb时发生问题? 怎样设置tomcat和weblogic:如果用户输入的路径不存在,就自动转向指定的页面。 (转帖)学习日记Struts开源项目的更新通告
你如果要存取,可以用jdbc!
有一个PreparedStatement可以用下面方法进行存取
setBinaryStream(int parameterIndex, InputStream x, int length) 保存
ResultSet里面可以用
InputStream getBinaryStream(String columnName) 读取
InputStream getBinaryStream(int columnIndex) 读取
就这么简单和普通的一样,但是你要会jdbc哦
InputStream getBinaryStream(int columnIndex) 读取这两个函数是怎样用吗?/
这是上传代码:
import java.io.*;
import java.awt.event.*;
import java.sql.*;
import java.lang.*;
public class odbc
{
public static void main(String args[])
{
try
{
String url="jdbc:odbc:zhouonline";
FileInputStream file=new FileInputStream("1.jpg");
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
Connection cn=DriverManager.getConnection(url);
PreparedStatement st=cn.prepareStatement("insert into img(abc) values(?)");
st.setBinaryStream(1,file,file.available());//得到文件大小
st.execute();
System.out.println("成功");
}
catch(Exception e)
{
e.printStackTrace();
} }
}这是从数据库读取代码:
import java.io.*;
import java.awt.event.*;
import java.sql.*;
import java.lang.*;
public class imag
{
public static void main(String args[])
{
try
{
String url="jdbc:odbc:zhouonline";
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
Connection cn=DriverManager.getConnection(url);
PreparedStatement st=cn.prepareStatement("select abc from img");
// st.setBinaryStream(1,file,file.available());
ResultSet rs=st.executeQuery();
byte b[]=new byte[10240000];
while(rs.next())
{
InputStream in=rs.getBinaryStream(1);
in.read(b);
File file=new File("test.jpg");
FileOutputStream write=new FileOutputStream(file);
write.write(b);
write.close();
}
}
catch(Exception e)
{
e.printStackTrace();
} }
}
int readSize;
byte b[]=new byte[1024];
FileOutputStream write=new FileOutputStream(file);
InputStream in=rs.getBinaryStream(1);
try{
while ((readSize = in.read(b)) != -1) {
write.write(b,0,readSize);
}
}finally{
write.close();
in.close();
}
import java.sql.*;
import java.io.*;
class SaveImage {
static {
try {
Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");
}
catch (Exception e) {
e.printStackTrace();
}
}
SaveImage()
{
try {
Connection conn = DriverManager.getConnection("jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=imageDB","sa","");
File []files=new File("image").listFiles(new FilenameFilter()
{
public boolean accept(File dir,String name)
{
if(name.endsWith(".jpg"))
{
return true;
}
return false;
}
});
for(int i=0;i<files.length;i++)
{
// System.out.println(files[i]);
try{
FileInputStream fileImage=new FileInputStream(files[i]);
ByteArrayOutputStream byteArray=new ByteArrayOutputStream();
byte buffer[]=new byte[1024];
int length=-1;
while((length=fileImage.read(buffer))!=-1)
{
// byteArray.write(buffer,0,length);
byteArray.write(buffer);
}
String insertString="insert into imageTable(imageName,imageData,length) values(?,?,?)";
PreparedStatement insertStm=conn.prepareStatement(insertString);
insertStm.setString(1,files[i].getName());
insertStm.setBytes(2,byteArray.toByteArray());
insertStm.setInt(3,(int)files[i].length());
insertStm.execute();
fileImage.close();
byteArray.close();
conn.close();
}
catch(Exception ee)
{
ee.printStackTrace();
}
} conn.close();
}
catch (SQLException e) {
e.printStackTrace();
}
}
public static void main(String[] args)
{
new SaveImage();
}
}
-------------以上是存图片-----------
import java.sql.*;
import java.io.*;
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
class SaveImage extends JFrame implements ActionListener{
JButton buttonNext=new JButton("Next");
JButton buttonPrevious=new JButton("Previous");
JLabel labelImage=new JLabel();
JLabel labelFileName=new JLabel();
Connection conn=null;
ResultSet rst=null;
byte []buffer=null;
static {
try {
Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");
}
catch (Exception e) {
e.printStackTrace();
}
}
SaveImage()
{
Container con=this.getContentPane();
JPanel panelSouth=new JPanel();
panelSouth.setLayout(new GridLayout(1,2));
panelSouth.add(buttonNext);
panelSouth.add(buttonPrevious);
buttonNext.addActionListener(this);
buttonPrevious.addActionListener(this);
con.add(panelSouth,BorderLayout.SOUTH);
con.add(labelImage,BorderLayout.CENTER);
con.add(labelFileName,BorderLayout.NORTH);
String stringSQL="select * from imageTable";
try {
conn = DriverManager.getConnection("jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=imageDB","sa","");
Statement stm=conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE);
rst=stm.executeQuery(stringSQL);
rst.next();
labelFileName.setText(rst.getString(2));
buffer=rst.getBytes(3);
labelImage.setIcon(new ImageIcon(buffer));
}
catch (SQLException e) {
e.printStackTrace();
}
this.setSize(600,400);
this.show();
}
public static void main(String[] args)
{
new SaveImage();
}
public void actionPerformed(ActionEvent ae)
{
try{
if(ae.getSource()==buttonNext)
{
if(!rst.isLast())
rst.next();
}
if(ae.getSource()==buttonPrevious)
{
if(!rst.isFirst())
rst.previous();
}
buffer=rst.getBytes(2);
labelImage.setIcon(new ImageIcon(buffer));
labelFileName.setText(rst.getString(1));
}
catch(Exception e)
{
e.printStackTrace();
}
}
}
----------------以上是取图片--------
import java.sql.*;
import java.io.*;
import oracle.sql.*;
public class WriteBlob {public static void main(String[] args) { try {
DriverManager.registerDriver(new oracle.jdbc.driver.OracleDriver());
Connection conn = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:orcl","fankai","fankai");
conn.setAutoCommit(false); BLOB blob = null; PreparedStatement pstmt = conn.prepareStatement("insert into javatest(name,content) values(?,empty_blob())");
pstmt.setString(1,"fankai");
pstmt.executeUpdate();
pstmt.close(); pstmt = conn.prepareStatement("select content from javatest where name= ? for update");
pstmt.setString(1,"fankai");
ResultSet rset = pstmt.executeQuery();
if (rset.next()) blob = (BLOB) rset.getBlob(1); String fileName = "oraclejdbc.jar";
File f = new File(fileName);
FileInputStream fin = new FileInputStream(f);
System.out.println("file size = " + fin.available()); pstmt = conn.prepareStatement("update javatest set content=? where name=?"); OutputStream out = blob.getBinaryOutputStream(); int count = -1, total = 0;
byte[] data = new byte[(int)fin.available()];
fin.read(data);
out.write(data);
/*
byte[] data = new byte[blob.getBufferSize()]; 另一种实现方法,节省内存
while ((count = fin.read(data)) != -1) {
total += count;
out.write(data, 0, count);
}
*/ fin.close();
out.close(); pstmt.setBlob(1,blob);
pstmt.setString(2,"fankai"); pstmt.executeUpdate();
pstmt.close(); conn.commit();
conn.close();
} catch (SQLException e) {
System.err.println(e.getMessage());
e.printStackTrace();
} catch (IOException e) {
System.err.println(e.getMessage());
}
}}
仔细看上例,分三步: 1、插入空blobinto javatest(name,content) values(?,empty_blob()); 2、获得blob的cursorselect content from javatest where name= ? for update; 注意!!!必须加for update,这将锁定该行,直至该行被修改完毕,保证不产生并发冲突。 3、update javatest set content=? where name= 用cursor往数据库写数据 这里面还有一点要提醒大家: JDK1.3带的JDBC2.0规范是不完善的,只有读Blob的接口,而没有写Blob的接口,JDK1.4带的JDBC3.0加入了写Blob的接口。你可以使用JDBC3.0的接口,也可以直接使用Oracle的JDBC的API,我在上例中使用了Oracle的JDBC的API。 另外要注意的是:java.sql.Bloboracle.sql.BLOB 注意看blob的大小写,是不一样的。写程序的时候不要搞混了。 下面看看用Hibernate怎么写,原理是一样的,也要分三步,但是代码简单很多 这是Cat对象定义package com.fankai;import java.sql.Blob;public class Cat {
private String id;
private String name;
private char sex;
private float weight;
private Blob image;
public Cat() { } public String getId() { return id; }
public void setId(String id) { this.id = id; } public String getName() { return name; }
public void setName(String name) { this.name = name; } public char getSex() { return sex; }
public void setSex(char sex) { this.sex = sex; } public float getWeight() { return weight; }
public void setWeight(float weight) { this.weight = weight; } public Blob getImage() { return image; }
public void setImage(Blob image) { this.image = image;}
}
这是Cat.hbm.xml<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping SYSTEM "http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd"><hibernate-mapping>
<class name="com.fankai.Cat" table="cat">
<!--jcs-cache usage="read-only"/-->
<id name="id" unsaved-value="null">
<generator class="uuid.hex"/>
</id>
<property name="name" length="16" not-null="true"/>
<property name="sex" length="1" not-null="true"/>
<property name="weight" />
<property name="image" />
</class>
</hibernate-mapping> 下面是完整的用Hibernate写入Blob的例子,相比JDBC,已经简单轻松多了,也不用写那些Oracle特殊的sql了:package com.fankai;import java.sql.Blob;
import net.sf.hibernate.*;
import oracle.sql.*;
import java.io.*;public class TestCatHibernate {
public static void testBlob() {
Session s = null;
byte[] buffer = new byte[1];
buffer[0] = 1;
try {
SessionFactory sf = HibernateSessionFactory.getSessionFactory();
s = sf.openSession();
Transaction tx = s.beginTransaction();
Cat c = new Cat();
c.setName("Robbin");
c.setImage(Hibernate.createBlob(buffer));
s.save(c);
s.flush();
s.refresh(c, LockMode.UPGRADE);
BLOB blob = (BLOB) c.getImage();
OutputStream out = blob.getBinaryOutputStream();
String fileName = "oraclejdbc.jar";
File f = new File(fileName);
FileInputStream fin = new FileInputStream(f);
int count = -1, total = 0;
byte[] data = new byte[(int)fin.available()];
fin.read(data);
out.write(data);
fin.close();
out.close();
s.flush();
tx.commit(); } catch (Exception e) {
System.out.println(e.getMessage());
} finally {
if (s != null)
try {
s.close();
} catch (Exception e) {}
}
}
}