java url 获取文件_[转]从URL获取文件保存到本地的J

url下载文件的地方.参数需要 urlencode..否则会下载不到.

java url获取文件_[转]从URL获取文件保存到本地的JAVA代码,url请求设置http请求头

    public boolean saveUrlAs(String photoUrl, String fileName) {

//此方法只能用户HTTP协议

        try {

URL url =new URL(photoUrl);

HttpURLConnection connection = (HttpURLConnection) url.openConnection();

DataInputStream in =new DataInputStream(connection.getInputStream());

DataOutputStream out =new DataOutputStream(new FileOutputStream(fileName));

byte[] buffer =new byte[4096];

int count =0;

while ((count = in.read(buffer)) >0) {

out.write(buffer,0, count);

}

out.close();

in.close();

return true;

}catch (Exception e) {

return false;

}

}

public String getDocumentAt(String urlString) {

//此方法兼容HTTP和FTP协议

        StringBuffer document =new StringBuffer();

try {

URL url =new URL(urlString);

URLConnection conn = url.openConnection();

BufferedReader reader =new BufferedReader(new InputStreamReader(conn.getInputStream()));

String line =null;

while ((line = reader.readLine()) !=null) {

document.append(line +"\n");

}

reader.close();

}catch (MalformedURLException e) {

System.out.println("Unable to connect to URL: " + urlString);

}catch (IOException e) {

System.out.println("IOException when connecting to URL: " + urlString);

}

return document.toString();

}

<%//测试

        String photoUrl="http://ad4.sina.com.cn/200601/12/43932_750450.jpg";

String fileName=photoUrl.substring(photoUrl.lastIndexOf("/"));

String filePath="d:/ghost/";

boolean flag=saveUrlAs(photoUrl,filePath+fileName);

out.println("Run ok!\n                Get URL file"+flag);

%>

设置http请求头

        HttpURLConnection.setRequestProperty（String key，String value）;

//设置请求头

        conn.setRequestProperty("Charsert","UTF-8");

conn.setRequestProperty("Content-Type","application/json; charset=UTF-8");//设置参数类型是json格式

        conn.setRequestProperty("Connection","Keep-Alive");

conn.setRequestProperty("logType","base");