Java从网络读取图片并保存至本地实例

package getUrlPic;import java.io.ByteArrayOutputStream;import java.io.File;import java.io.FileOutputStream;import java.io.InputStream;import java.net.HttpURLConnection;import java.net.URL;public class GetUrlPic {  public static void main(String[] args) throws Exception {   //new一个URL对象   URL url = new URL("http://www.gz135.cn/data/attachment/forum/201702/13/165605xyayykq5vy4h81vy.jpg");   //打开链接   HttpURLConnection conn = (HttpURLConnection)url.openConnection();   //设置请求方式为"GET"   conn.setRequestMethod("GET");   //超时响应时间为5秒   conn.setConnectTimeout(5 * 1000);   //通过输入流获取图片数据   InputStream inStream = conn.getInputStream();   //得到图片的二进制数据，以二进制封装得到数据，具有通用性   byte[] data = readInputStream(inStream);   //new一个文件对象用来保存图片，默认保存当前工程根目录   File imageFile = new File("pic20170419.jpg");   //创建输出流   FileOutputStream outStream = new FileOutputStream(imageFile);   //写入数据   outStream.write(data);   //关闭输出流   outStream.close();  }  public static byte[] readInputStream(InputStream inStream) throws Exception{   ByteArrayOutputStream outStream = new ByteArrayOutputStream();   //创建一个Buffer字符串   byte[] buffer = new byte[1024];   //每次读取的字符串长度，如果为-1，代表全部读取完毕   int len = 0;   //使用一个输入流从buffer里把数据读取出来   while( (len=inStream.read(buffer)) != -1 ){    //用输出流往buffer里写入数据，中间参数代表从哪个位置开始读，len代表读取的长度    outStream.write(buffer, 0, len);   }   //关闭输入流   inStream.close();   //把outStream里的数据写入内存   return outStream.toByteArray();  } }