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。
[java]
/**
* 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
[java]
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
[java]
/*
HTTP/1.1
200
OK
HTTP/1.1 200 OK
*/
[java]
//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
}
3.ResponseHandler
[java]
/**
* 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<String> myHandler = new ResponseHandler<String>() {
@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();
}
}
4.Post完成Form表单的提交
[java]
/**
* 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<NameValuePair> parameters = new ArrayList<NameValuePair>();
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();
}
}
5.Post完成文件的长传
[java]
/**
* 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();
}
}
转载地址:http://www.2cto.com/kf/201310/248095.html