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<%@ page contenttype=”text/html;charset=gb2312″%>
<%@ page import=”java.sql.*,java.io.*,java.awt.image,java.awt.image.*,com.sun.image.codec.jpeg.*”%>
<html>
<body>
<%
/*
drop table imagetable;
create table imagetable
(
nid int not null,
image blob,
primary key (nid)
)
type = innodb;
*/
/*
//＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝ 一 、将文件写入到数据库的大字段中begin＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝
class.forname(“org.gjt.mm.mysql.driver”).newinstance();
string url =”jdbc:mysql://localhost:3306/test?user=root&password=eastsoftweb”;
connection conn= drivermanager.getconnection(url);
java.io.file file = new file(“d:/temp/1.jpg”);
fileinputstream is=new fileinputstream(file);
preparedstatement stmt = conn.preparestatement(
“insert into imagetable (nid,image)” +
“values (?, ?)”); //预编译sql语句
stmt.setint(1, 1);
stmt.setbinarystream(2, is,(int)file.length());
stmt.executeupdate();
stmt.close();
is.close();
out.println(“update end”);
//＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝将文件写入到数据库的大字段中end＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝
*/
/*
//＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝ 二、jsp显示服务器硬盘图片示例 begin＝＝＝＝＝＝＝＝＝＝＝＝＝＝
fileinputstream is=new fileinputstream(“d:/temp/1.jpg”);
response.reset();
response.setcontenttype(“image/jpeg”);
servletoutputstream sos = response.getoutputstream();
byte[] buffer = new byte[1024];
int len=0;
while((len=is.read(buffer))>0){
sos.write(buffer,0,len);
}
sos.flush();
sos.close();
//＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝jsp显示服务器硬盘图片示例 end＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝
*/
//＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝ 三、将数据库的大字段图片还原到本地,并在网页上显示begin＝＝＝＝＝＝＝＝＝＝＝＝＝＝
class.forname(“org.gjt.mm.mysql.driver”).newinstance();
string url =”jdbc:mysql://localhost:3306/test?user=root&password=eastsoftweb”;
connection conn= drivermanager.getconnection(url);
java.io.file file = new file(“d:/temp/db.jpg”);
fileoutputstream os=new fileoutputstream(file);
statement stmt=conn.createstatement(resultset.type_scroll_sensitive,resultset.concur_read_only);
resultset rs=stmt.executequery(“select nid,image from imagetable where nid=1”);
rs.next();
byte[] buffer=rs.getbytes(2);
stmt.close();
os.write(buffer);
os.flush();
os.close();
out.println(“query end”);
//网页上显示
response.reset();
response.setcontenttype(“image/jpeg”);
servletoutputstream sos = response.getoutputstream();
sos.write(buffer);
sos.flush();
sos.close();
//＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝将数据库的大字段图片还原到本地,并在网页上显示end＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝
/*
//＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝四、生成缩略图begin＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝
file file = new file(“d:/temp/1.jpg”);
string newurl=”d:/temp/2.jpg”; //新的缩略图保存地址
image src = javax.imageio.imageio.read(file); //构造image对象
float tagsize=200;
int old_w=src.getwidth(null); //得到源图宽
int old_h=src.getheight(null);
int new_w=0;
int new_h=0; //得到源图长
int tempsize;
float tempdouble;
if(old_w>old_h){
tempdouble=old_w/tagsize;
}else{
tempdouble=old_h/tagsize;
}
new_w=math.round(old_w/tempdouble);
new_h=math.round(old_h/tempdouble);//计算新图长宽
bufferedimage tag = new bufferedimage(new_w,new_h,bufferedimage.type_int_rgb);
tag.getgraphics().drawimage(src,0,0,new_w,new_h,null); //绘制缩小后的图
fileoutputstream newimage=new fileoutputstream(newurl); //输出到文件流
jpegimageencoder encoder = jpegcodec.createjpegencoder(newimage);
encoder.encode(tag); //近jpeg编码
newimage.close();
//＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝生成缩略图end＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝
*/
%>
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