访问网络最主要的也就是 http协议了。
http协议很简单，但是很重要。
直接上代码了，里面都是1个代码块 代码块的，用哪一部分直接拷出去用就好了。
1.访问网络用 get 和 post 自己组拼提交参数 ，httpclient 方式提交
2.上传 和 下载
3.比如访问服务器后 返回来的 xml 和 json 的简单解析方法
String path = "http://192.168.13.1";
String username ="ll";
String pwd="123"; /** get 组拼 */
public void httpGet()
throws Exception { String param1 = URLEncoder.encode(username);
String param2 = URLEncoder.encode(pwd);
URL url = new URL(path + "?name=" + param1 + "&password=" + param2);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("GET");
conn.setReadTimeout(5000);
// 数据并没有发送给服务器
// 获取服务器返回的流信息
InputStream in = conn.getInputStream();
byte[] result = StreamTool.getBytes(in); //return new String(result);
} /** post 组拼 */
public void httpPost() throws Exception { URL url = new URL(path);
String param1 = URLEncoder.encode(username);
String param2 = URLEncoder.encode(pwd);
//开始连接
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
String data = "username=" + param1 + "&password=" + param2;
//设置方式 post
conn.setRequestMethod("POST");
//timeout 5000
conn.setConnectTimeout(5000);
// 设置 http协议可以向服务器写数据
conn.setDoOutput(true);
// 设置http协议的消息头
conn.setRequestProperty("Content-Type","application/x-www-form-urlencoded");
conn.setRequestProperty("Content-Length", String.valueOf(data.length()));
// 把我们准备好的data数据写给服务器
OutputStream os = conn.getOutputStream();
os.write(data.getBytes());
// httpurlconnection 底层实现 outputstream 是一个缓冲输出流
// 只要我们获取任何一个服务器返回的信息 , 数据就会被提交给服务器 , 得到服务器返回的流信息
int code = conn.getResponseCode();
if (code == 200) {
InputStream is = conn.getInputStream();
byte[] result = StreamTool.getBytes(is);
String ss= new String(result);
} } /** httpclient get */
public void httpClentGet () throws Exception{
//获取到一个浏览器的实例
HttpClient client = new DefaultHttpClient();
//准备请求的地址
String param1 = URLEncoder.encode(username);
String param2 = URLEncoder.encode(pwd);
HttpGet httpGet = new HttpGet(path + "?name=" + param1 + "&password=" + param2);
//敲回车 发请求
HttpResponse ressponse = client.execute(httpGet);
int code = ressponse.getStatusLine().getStatusCode();
if( code == 200){
InputStream is =ressponse.getEntity().getContent();
//byte[] result = StreamTool.getBytes(is); } } // 不需要的时候关闭 httpclient client.getConnectionManager().shutdown();
/** httpclient post **/
public void httpClentPost() throws Exception{
//1. 获取到一个浏览器的实例
HttpClient client = new DefaultHttpClient();
HttpPost httppost = new HttpPost(path);
// 键值对 BasicNameValuePair
List<NameValuePair> parameters = new ArrayList<NameValuePair>();
parameters.add(new BasicNameValuePair("username", username));
parameters.add(new BasicNameValuePair("pwd", pwd));
UrlEncodedFormEntity entity = new UrlEncodedFormEntity(parameters, "utf-8");
//3.设置post请求的数据实体
httppost.setEntity(entity);
//4. 发送数据给服务器
HttpResponse ressponse = client.execute(httppost);
int code = ressponse.getStatusLine().getStatusCode();
if(code == 200){
InputStream is =ressponse.getEntity().getContent();
byte[] result = StreamTool.getBytes(is); //return new String(result);
} } /*** 下载一个东西 ***/
public void getFileData(Context context){ try {
HttpClient client = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(path);
//执行
HttpResponse ressponse = client.execute(httpGet);
int code = ressponse.getStatusLine().getStatusCode(); if(code == HttpStatus.SC_OK){
InputStream in =ressponse.getEntity().getContent();
//图片
// Bitmap bitmap = BitmapFactory.decodeStream(in);
// in.close(); //文件什么的比如读取了是要写在本地的
//小文件直接读取 大文件读取一点写一点
//byte[] result = StreamTool.getBytes(in);
// //这里可以得到文件的类型 如image/jpg /zip /tiff 等等 但是发现并不是十分有效，有时明明后缀是.rar但是取到的是null，这点特别说明
System.out.println(ressponse.getEntity().getContentType());
//可以判断是否是文件数据流
System.out.println(ressponse.getEntity().isStreaming());
//设置本地保存的文件
//File storeFile = new File("c:/0431la.zip");
String path="sdcard/aa.txt";
FileOutputStream output = context.openFileOutput(path, context.MODE_PRIVATE);
//得到网络资源并写入文件
InputStream input = ressponse.getEntity().getContent();
byte b[] = new byte[1024];
int j = 0;
while( (j = input.read(b))!=-1){
output.write(b,0,j);
}
output.flush();
output.close();
}
} catch (Exception e) {
// TODO: handle exception
}
} /**
* 提交数据给服务器 带一个文件
* @param filepath 文件在手机上的路径
*/
public void PostData(String filepath) throws Exception{ // 实例化上传数据的 数组 part [] username pwd
Part[] parts = {
new StringPart("username", username),
new StringPart("pwd", pwd),
new FilePart("file", new File(filepath))
}; PostMethod file_Post = new PostMethod(path);
// 多种类型的数据实体
file_Post.setRequestEntity(new MultipartRequestEntity(parts, file_Post.getParams()));
//创建 client
org.apache.commons.httpclient.HttpClient client = new org.apache.commons.httpclient.HttpClient();
//timeout
client.getHttpConnectionManager().getParams().setConnectionTimeout(5000);
//执行
int status = client.executeMethod(file_Post); if(status==200){ } } //传送文件
public void setFile() throws Exception{ HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://192.168.1.1");
File file = new File(path);
InputStreamEntity reqEntity = new InputStreamEntity(
new FileInputStream(file), -1);
reqEntity.setContentType("binary/octet-stream");
reqEntity.setChunked(true); // FileEntity entity = new FileEntity(file, "binary/octet-stream");
httppost.setEntity(reqEntity);
System.out.println("executing request " + httppost.getRequestLine());
HttpResponse response = httpclient.execute(httppost); if(response.getStatusLine().getStatusCode() == 200){ } } /** 1.
* 一般访问了就会返回来1个 webservice
* pull解析访问webservice 返回来的xml
* **/ public void pullJX(byte[] bb) throws Exception{
// byte[] bb = EntityUtils.toByteArray(response.getEntity());
XmlPullParser pullParser = Xml.newPullParser();
pullParser.setInput(new ByteArrayInputStream(bb), "UTF-8");
int event = pullParser.getEventType();
List<Object> info;
while(event != XmlPullParser.END_DOCUMENT){
switch (event) {
case XmlPullParser.START_DOCUMENT:
info = new ArrayList<Object>();
break; case XmlPullParser.START_TAG:
if("aa".equals(pullParser.getName())){
String id = pullParser.nextText().toString(); }
break; case XmlPullParser.END_TAG:
if("aa".equals(pullParser.getName())){
}
break;
}
event = pullParser.next();
}
} /**2.
* 解析 json 数据 [{id:"001",name:"lilei",age:"20"},{id:"002",name:"zhangjia",age:"30"}]
*/
private static List parseJSON(InputStream in) throws Exception{
byte[] data = StreamTool.getBytes(in);
String s =new String(data);
// 转换成 json 数组对象 [{"001","ll","20"},{"002","zj","30"},]
JSONArray json = new JSONArray(s);
for (int i = 0; i < json.length() ; i++) {
JSONObject j = json.getJSONObject(i);
String aa1 = j.getString("id");
String aa2 = j.getString("name");
String aa3 = j.getString("age");
}
return null;
}
HttpClient其实是一个interface类型，HttpClient封装了对象需要执行的Http请求、身份验证、连接管理和其它特性
HttpClient有三个已知的实现类分别是：
AbstractHttpClient, AndroidHttpClient, DefaultHttpClient
AndroidHttpClient是对HttpClient的包装，内部带访问连接器，并设置为可以多线程使用，
public class MyApplication extends Application{
private AndroidHttpClient httpClient;
// application oncreate的时候创建
public void onCreate(){
super.onCreate();
httpClient = AndroidHttpClient.newInstance("Android");
}
//供外部调用
public AndroidHttpClient getHttpClient() {
if (httpClient == null){
httpClient = AndroidHttpClient.newInstance("Android");
}
return httpClient;
}
@Override
public void onLowMemory() {
super.onLowMemory();
shutdownHttpClient();
}
@Override
public void onTerminate() {
super.onTerminate();
shutdownHttpClient();
}
//关闭
private void shutdownHttpClient() {
if (httpClient != null) {
if (httpClient.getConnectionManager() != null) {
httpClient.getConnectionManager().shutdown();
}
httpClient.close();
httpClient = null;
}
}
}
外部调用的话
AndroidHttpClient httpClient = ((MyApplication)getApplication()).getHttpClient();