[转载]Android_HttpClient_get请求post表单提交上传 – 子墨的Android开发之旅 – 博客频道 – CSDN.NET.

关于HttpUrlConnection用法

1.HttpRequestBase(HttpGet..)

HttpClient 支持多种访问网络的方式，包括GET, HEAD, POST, PUT, DELETE, TRACE and OPTIONS. 其对应子类为HttpGet, HttpHead, HttpPost, HttpPut, HttpDelete, HttpTrace, and HttpOptions.但在使用时多为HttpGet, HttpPost两种方式。

/**
* 一个简单的get请求
*/
private static void get() {
// 1.得到HttpClient对象
HttpClient httpClient = new DefaultHttpClient();
// 2.实例化一个HttpGet对象
HttpGet httpGet = new HttpGet("http://www.baidu.com");
try {
// 3.httpClient执行httpGet请求
HttpResponse response = httpClient.execute(httpGet);
HttpEntity entity = response.getEntity();
if (entity != null) { // 如果有数据表示请求成功
System.out.println(EntityUtils.toString(entity, "utf-8"));
} else {
System.out.println("连接失败！");
}
} catch (Exception e) {
e.printStackTrace();
} finally {
// 4.释放资源(Shuts down this connection manager and releases allocated
// resources)
httpClient.getConnectionManager().shutdown();
}
}

2.HttpResponse

通过得到HttpResponse对象，可以得到相关访问网络的信息，比如getEntity() getStatusLine()等等

System.out.println(response.getProtocolVersion());
System.out.println(response.getStatusLine().getStatusCode());
System.out.println(response.getStatusLine().getReasonPhrase());
System.out.println(response.getStatusLine().toString());

输出结果为

/*
HTTP/1.1
200
OK
HTTP/1.1 200 OK
*/

//得到请求的响应数据
//方式一.
HttpEntity entity = response.getEntity();
if (entity != null) { // 如果有数据表示请求成功
System.out.println(EntityUtils.toString(entity, “utf-8”));
} else {
System.out.println(“连接失败！”);
}
//方式二.
if(response.getStatusLine().getStatusCode() == 200){
HttpEntity myEntity = response.getEntity();
BufferedInputStream in = new BufferedInputStream(myEntity.getContent());
byte[] bytes = read(in);//通过自定义的read方法，取得该输入流对应的数据
}
[/java]

3.ResponseHandler

/**
* 通过ResponseHandler处理请求
*/
private static void test() {
HttpClient httpClient = new DefaultHttpClient();
HttpGet httpGet = new HttpGet("http://www.baidu.com");

//自定义ResponseHandler对象
ResponseHandler myHandler = new ResponseHandler() {
@Override
public String handleResponse(HttpResponse response)
throws ClientProtocolException, IOException {
HttpEntity entity = response.getEntity();
String result = "连接失败！";
if (entity != null) { // 如果有数据表示请求成功
result = EntityUtils.toString(entity, "utf-8");
}
return result;
}
};
try {
String result = httpClient.execute(httpGet, myHandler);//接收该myHandler对象
System.out.println(result);
} catch (Exception e) {
e.printStackTrace();
} finally {
// 释放资源(Shuts down this connection manager and releases allocated resources)
httpClient.getConnectionManager().shutdown();
}
}

5.GZIP压缩

对于文本数据，特别是json数据或者html网页数据，最好使用gzip进行压缩，理论上文本数据可以压缩为原来的1/3，效果很明显，压缩之后应该使用gzip流进行解压缩！

get.addHeader("Accept-Encoding", "gzip");//使用addHeader，否则没有效果

HttpResponse response = client.execute(get);
int code = response.getStatusLine().getStatusCode();
Header header = response.getFirstHeader("Content-Encoding");
InputStream is = new BufferedInputStream(response.getEntity().getContent());
if (header != null && header.getValue().contains("gzip")) {//首先判断服务器是否支持gzip压缩
is = new GZIPInputStream(is);
}

6.Post完成Form表单的提交

/**
* 完成form表单的提交
*/
private static void post() {
HttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost("http://127.0.0.1:8080/My/upload");

try {
// 为httpPost设置HttpEntity对象
List parameters = new ArrayList();
parameters.add(new BasicNameValuePair("username", "zhangsan"));
parameters.add(new BasicNameValuePair("password", "123321"));
HttpEntity entity = new UrlEncodedFormEntity(parameters);
httpPost.setEntity(entity);
// httpClient执行httpPost表单提交
HttpResponse response = httpClient.execute(httpPost);
// 得到服务器响应实体对象
HttpEntity responseEntity = response.getEntity();
if (responseEntity != null) {
System.out.println(EntityUtils
.toString(responseEntity, "utf-8"));
System.out.println("表单上传成功！");
} else {
System.out.println("服务器无响应！");
}
} catch (Exception e) {
e.printStackTrace();
} finally {
// 释放资源
httpClient.getConnectionManager().shutdown();
}
}

7.Post完成文件的长传

/**
 * 通过post完成文件的上传
 */
private static void postFile() {
	HttpClient httpClient = new DefaultHttpClient();
	HttpPost httpPost = new HttpPost("http://127.0.0.1:8080/My/upload");
	try {
		// 需要上传的文件
		String root = "D:/api/";
		String fileName = "JDK6.0 中文文档.CHM";
		File uploadFile = new File(root+fileName);
		//定义FileEntity对象
		HttpEntity entity = new FileEntity(uploadFile);
		//为httpPost设置头信息
		httpPost.setHeader("filename", URLEncoder.encode(fileName,"utf-8"));//服务器可以读取到该文件名
		httpPost.setHeader("Content-Length", String.valueOf(entity.getContentLength()));//设置传输长度
		httpPost.setEntity(entity);	//设置实体对象
		
		// httpClient执行httpPost提交
		HttpResponse response = httpClient.execute(httpPost);
		// 得到服务器响应实体对象
		HttpEntity responseEntity = response.getEntity();
		if (responseEntity != null) {
			System.out.println(EntityUtils.toString(responseEntity, "utf-8"));
			System.out.println("文件 "+fileName+"上传成功！");
		} else {
			System.out.println("服务器无响应！");
		}
	} catch (Exception e) {
		e.printStackTrace();
	} finally {
		// 释放资源
		httpClient.getConnectionManager().shutdown();
	}
}