java 使用IO从网络下载图片-

/***
* 下载图片到本地
* @param imgUri
* @param fileName
* @return
*/
public static String downloadImg(String imgUri,String directory, String fileName) {
HttpClient client = HttpClients.createDefault();
HttpGet get = new HttpGet(imgUri);
FileImageOutputStream fios=null;
InputStream in=null;
ByteArrayOutputStream baos =null;
try {
baos= new ByteArrayOutputStream();
HttpResponse hr = client.execute(get);
HttpEntity entity = hr.getEntity();
in= entity.getContent();
byte[] buffer = new byte[1024];
int len = -1;
while ((len = in.read(buffer))>0) {
baos.write(buffer,0,len);
}
byte[] b = baos.toByteArray();
//创建目录
File dir = new File(directory);
if(!dir.exists()){
dir.mkdirs();
File file=new File(dir,fileName);
if(!file.exists()){
file.createNewFile();
fios = new FileImageOutputStream(file);
fios.write(b);
}
}else{
File file=new File(dir,fileName);
file.createNewFile();
fios = new FileImageOutputStream(file);
fios.write(b);
}
return dir+"/"+fileName;
} catch (IOException e) {
//异常处理
if(null!=fios){
try {
fios.close();
} catch (IOException e1) {

}
}

}
return null;
}

String newImgUrl=downloadImg(imgUrl,"/home/test/workspace/images","test"+System.currentTimeMillis()+".png");