本文目录一览：
- 1、Java编写一下图片下载程序？
- 2、能不能用JAVA编写一个程序从网上下载一张图片呢？求完整程序！
- 3、java如何从数据库中下载以二进制存储的图片
- 4、java从服务器下载图片怎么讲图片保存到本地的sdcard上
- 5、java关于下载图片。
- 6、java中怎么把当前项目中images文件夹中的图片下载到本地磁盘中？？
Java编写一下图片下载程序？
楼上的写的没错，不过感觉太麻烦了，用hutool工具包来写个方法
HttpUtil.downloadFile(“”, new File(“F://demo4/baidu_logo.png”));
第一个参数为百度logo图片，第二个为我本地下载位置，下载结果如图
能不能用JAVA编写一个程序从网上下载一张图片呢？求完整程序！
package com.capinfotech.net;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
public class ImageRequest {
public static void main(String[] args) throws IOException {
URL url = new URL(“”);
HttpURLConnection conn = (HttpURLConnection)url.openConnection();
InputStream inputStream = conn.getInputStream(); //通过输入流获得图片数据
byte[] getData = readInputStream(inputStream); //获得图片的二进制数据
File imageFile = new File(“tupian.jpg”);
FileOutputStream fos = new FileOutputStream(imageFile);
fos.write(getData);
fos.close();
System.out.println(” read picture success”);
}
public static byte[] readInputStream(InputStream inputStream) throws IOException {
byte[] buffer = new byte[1024];
int len = 0;
ByteArrayOutputStream bos = new ByteArrayOutputStream();
while((len = inputStream.read(buffer)) != -1) {
bos.write(buffer, 0, len);
}
bos.close();
return bos.toByteArray();
}
}
java如何从数据库中下载以二进制存储的图片
/**
* Created by IntelliJ IDEA.
* User: ljt
* Date: 2003-3-31
* Time: 18:51:38
* To change this template use Options | File Templates.
*/
import oracle.jdbc.driver.OraclePreparedStatement;
import oracle.jdbc.driver.OracleResultSet;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.Statement;
import java.sql.Clob;
public class TestOpenDoc {
public OracleResultSet ors = null; //**这里rs一定要用Oracle提供的
public OraclePreparedStatement opst = null; //**PreparedStatement用
public Connection conn = null;
public Statement stmt = null;
public TestOpenDoc() {
}
public boolean getConnect() {
//这是我的数据库所在
String serverName = “prosrv”;
try {
Class.forName(“oracle.jdbc.driver.OracleDriver”);
String url = “jdbc:oracle:thin:@” + serverName + “:1521:BOHDATA”;
conn = DriverManager.getConnection(url, “appuser”, “appuser”);
}
catch (Exception e) {
System.out.println(e);
return false;
}
return true;
}
public static void main(String[] args) {
TestOpenDoc test = new TestOpenDoc();
if (!test.getConnect()) {
System.out.println(“数据库连结错误”);
return ;
}
try{
test.conn.setAutoCommit(false);
byte a[] = null; //**将测试文件test.doc读入此字节数组
java.io.FileInputStream fin = null;
java.io.FileOutputStream fout = null;
//Oracle提供的
try {
java.io.File f1 = new java.io.File(“c:/test.doc”);
java.io.File f2 = new java.io.File(“d:/testout.doc”); //**从BLOB读出的信息写
//入该文 件，和源文件对比测试用
fin = new java.io.FileInputStream(f1);
fout = new java.io.FileOutputStream(f2);
int flength = (int) f1.length(); //**读入文件的字节长度
System.out.println(“file length::” + flength);
a = new byte[flength];
int i = 0;
int itotal = 0;
//* 将文件读入字节数组
for (; itotal flength; itotal = i + itotal) {
i = fin.read(a, itotal, flength – itotal);
}
fin.close();
System.out.println(“read itotal::” + itotal);
//**注意Oracle的 BLOB一定要用EMPTY_BLOB()初始化
String mysql =
“insert into filelist (FileName,FileSize,FileBody) values (?,?,EMPTY_BLOB())”;
OraclePreparedStatement opst = (OraclePreparedStatement) test.conn.
prepareStatement(mysql);
opst.setString(1, “wordtemplate2”);
opst.setInt(2, flength);
opst.executeUpdate();
opst.clearParameters();
// /**插入其它数据后，定位BLOB字段
mysql = “select filebody from filelist where filename=?”;
opst = (OraclePreparedStatement) test.conn.prepareStatement(mysql);
opst.setString(1, “wordtemplate2”);
OracleResultSet ors = (OracleResultSet) opst.executeQuery();
if (ors.next()) {
oracle.sql.BLOB blob = ors.getBLOB(1); //**得到BLOB字段
int j = blob.putBytes(1, a); //**将字节数组写入BLOB字段
System.out.println(“j:” + j);
test.conn.commit();
ors.close();
Clob clob;
clob = ors.getClob(“”);
String str;
str = clob.toString();
str = clob.getSubString(0L,(int)clob.length());
System.out.println(str);
}
System.out.println(“insert into ok”);
byte b[] = null; //**保存从BLOB读出的字节
opst.clearParameters();
mysql = “select filebody from filelist where filename=?”;
opst = (OraclePreparedStatement) test.conn.
prepareStatement(mysql);
opst.setString(1, “wordtemplate2”);
ors = (OracleResultSet) opst.executeQuery();
if (ors.next()) {
oracle.sql.BLOB blob2 = ors.getBLOB(1);
System.out.println(“blob2 length:” + blob2.length());
b = blob2.getBytes(1, flength); //**从BLOB取出字节流数据
System.out.println(“b length::” + b.length);
test.conn.commit();
}
ors.close();
// 将从BLOB读出的字节写入文件
fout.write(b, 0, b.length);
fout.close();
System.out.println(“write itotal::” + b.length);
}
catch (Exception e) {
System.out.println(“errror :” + e.toString());
e.printStackTrace();
}
finally { //**关闭所有数据联接
test.conn.commit();
}
}
catch(Exception e){
System.out.println(e);
}
}
}
java从服务器下载图片怎么讲图片保存到本地的sdcard上
ublic HttpServletResponse download(String path, HttpServletResponse response) {
try {
// path是指欲下载的文件的路径。
File file = new File(path);
// 取得文件名。
String filename = file.getName();
// 取得文件的后缀名。
String ext = filename.substring(filename.lastIndexOf(“.”) + 1).toUpperCase();
// 以流的形式下载文件。
InputStream fis = new BufferedInputStream(new FileInputStream(path));
byte[] buffer = new byte[fis.available()];
fis.read(buffer);
fis.close();
// 清空response
response.reset();
// 设置response的Header
response.addHeader(“Content-Disposition”, “attachment;filename=” + new String(filename.getBytes()));
response.addHeader(“Content-Length”, “” + file.length());
OutputStream toClient = new BufferedOutputStream(response.getOutputStream());
response.setContentType(“application/octet-stream”);
toClient.write(buffer);
toClient.flush();
toClient.close();
} catch (IOException ex) {
ex.printStackTrace();
}
return response;
}
java关于下载图片。
URL url = new URL(“图片地址”);
File outFile = new File(“图片保存到本地路径”);
OutputStream os = new FileOutputStream(outFile);
InputStream is = url.openStream();
byte[] buff = new byte[1024];
while(true) {
int readed = is.read(buff);
if(readed == -1) {
break;
}
byte[] temp = new byte[readed];
System.arraycopy(buff, 0, temp, 0, readed);
os.write(temp);
}
is.close();
os.close();
java中怎么把当前项目中images文件夹中的图片下载到本地磁盘中？？
将项目中images文件夹中文件的绝对路径作为超链接，点击链接就可以下载了。至于下载到本地那个磁盘就是用户自己选择了。
原创文章，作者：小蓝，如若转载，请注明出处：https://www.506064.com/n/188524.html
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