URL 和 HttpClient 從服務器下載數據(GET) 或 上傳數據方式(POST)java
package com.homwork12_29;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;apache
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
public class DownLoadMethod {
public static byte[] urlmethod(String path){
try {
//建立一個URL對象
URL url = new URL(path);
//打開鏈接
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
//設置請求 爲 get(從服務器拿數據)
connection.setRequestMethod("GET");
//開始鏈接
connection.connect();
//取得服務器 的響應
int code = connection.getResponseCode();
//判斷服務器響應是否成功
if(code == 200){
InputStream is = connection.getInputStream();
//內存流 把要從服務器下載的數據寫到內存中
ByteArrayOutputStream bos = new ByteArrayOutputStream();
byte[] b = new byte[1024];
int length = 0;
while((length = is.read(b)) != -1){
bos.write(b,0,length);
}
//從內存中去出數據(字節型)返回給用戶
return bos.toByteArray();
}
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
public static byte[] clientmethod(String path){
//建立一個httpclient對象
HttpClient client = new DefaultHttpClient();
//建立一個請求
HttpGet get = new HttpGet(path);
//執行請求 並返回一個HttpResponse 對象
HttpResponse response;
try {
response = client.execute(get);
int code = response.getStatusLine().getStatusCode();
//判斷服務器是否 響應
if(code == 200){
//從服務器 拿下載的數據
HttpEntity entity = response.getEntity();
//把從服務器拿到的數據轉換成字節 返回
byte[] b = EntityUtils.toByteArray(entity);
return b;
}
} catch (ClientProtocolException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
return null;
}
//保存 數據到 指定的文件夾 的方法
public static void savapath(String path ,String decpath){
byte[] b = urlmethod(path);
if(b != null){
try {
//文件名字
String file_name = path.substring(path.lastIndexOf('/')+1);
File file = new File(decpath);
file.mkdirs();
//寫入數據到指定的文件夾
OutputStream os = new FileOutputStream(decpath + "\\"+ file_name);
os.write(b);
os.close();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
-----------
Test服務器
import java.util.Scanner;
public class Test1 {
public static void main(String[] args) {
DownLoadMethod download = new DownLoadMethod();
System.out.println("[1] url方法下載\r\n[2] client方法下載\r\n[0] 退出");
System.out.println("請選擇下載方式:");
Scanner sc = new Scanner(System.in);
while(true){
int choose = sc.nextInt();
if(choose == 1 || choose == 2 || choose == 0){
switch(choose){
case 1: System.out.println("請輸入下載地址:");
String url_name = sc.next();
System.out.println("請輸入保存路徑:");
String sava_path1 = sc.next();
download.urlmethod(url_name);
download.savapath(url_name, sava_path1);
break;
case 2: System.out.println("請輸入下載地址:");
String client_name = sc.next();
System.out.println("請輸入保存路徑:");
String sava_path2 = sc.next();
download.clientmethod(client_name);
download.savapath(client_name, sava_path2);
break;
default: System.exit(0);
}
}else{
System.out.println("輸入錯誤,請從新輸入0-2的選項!");
}
}
}
}
-------------------------------------------------------------------------
URL postpost
public class WriterServlet {
public static void main(String[] args) throws Exception {
String path = "http://127.0.0.1:8080/Login/login";
URL url = new URL(path);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("POST");
connection.setDoOutput(true);
OutputStream os = connection.getOutputStream();
// connection.connect();
os.write("name=admin&pwd=110".getBytes());
int code = connection.getResponseCode();
byte[] b = new byte[1024];
int length = 0;
if(code == 200){
InputStream is = connection.getInputStream();
length = is.read(b);
System.out.println(new String(b,0,length));
}
}
}
---------------------------------------------------------------------
HttpClient postui
public class HttpClientPost {
public static void main(String[] args) {
//須要導入阿帕奇第三方 包 而後右鍵 在build path 配置路徑
//建立一個HttpClient 對象
HttpClient client = new DefaultHttpClient();
String path = "";
//建立一個請求
HttpPost post = new HttpPost(path);
NameValuePair parameters1 = new BasicNameValuePair("username", "admin");
NameValuePair parameters2 = new BasicNameValuePair("userpwd","123");
List<NameValuePair> list = new ArrayList<NameValuePair>();
list.add(parameters1);
list.add(parameters2);
HttpEntity entity;
try {
entity = new UrlEncodedFormEntity(list);
post.setEntity(entity);
HttpResponse response = client.execute(post);
int code = response.getStatusLine().getStatusCode();
if(code == 200){
HttpEntity entity2 = response.getEntity();
String str = EntityUtils.toString(entity2);
System.out.println(str);
}
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}url