httpClient----Post 和 GET请求

在http请求失败是要进行下列操作：

[java] view
plaincopy

if (response.getStatusLine ().getStatusCode () != 200) {

get.abort();

return null;

}

HttpGet操作：

[java] view
plaincopy

public final static void main(String[] args) throws Exception {

HttpClient httpclient = new DefaultHttpClient();

try {

HttpGet httpget = new HttpGet("http://www.apache.org/");

System.out.println("executing request " + httpget.getURI());

HttpResponse response = httpclient.execute(httpget);

HttpEntity entity = response.getEntity();

System.out.println("----------------------------------------");

System.out.println(response.getStatusLine());

if (entity != null) {

System.out.println("Response content length: " + entity.getContentLength());

}

System.out.println("----------------------------------------");

InputStream inSm = entity.getContent();

Scanner inScn = new Scanner(inSm);

while (inScn.hasNextLine()) {

System.out.println(inScn.nextLine());

}

// Do not feel like reading the response body

// Call abort on the request object

httpget.abort();

} finally {

// When HttpClient instance is no longer needed,

// shut down the connection manager to ensure

// immediate deallocation of all system resources

httpclient.getConnectionManager().shutdown();

}

}

读取response响应内容部分，也可以借助于 httpcore-4.1.2.jar 里面的：

[java] view
plaincopy

public class Demo1 {

/**

* 用 get 方法访问 www.apache.org 并返回内容

*

* @param args

*/

public static void main(String[] args) {

//创建默认的 HttpClient 实例

HttpClient httpClient = new DefaultHttpClient();

try {

//创建 httpUriRequest 实例

HttpGet httpGet = new HttpGet("http://www.apache.org/");

System.out.println("uri=" + httpGet.getURI());

//执行 get 请求

HttpResponse httpResponse = httpClient.execute(httpGet);

//获取响应实体

HttpEntity httpEntity = httpResponse.getEntity();

//打印响应状态

System.out.println(httpResponse.getStatusLine());

if (httpEntity != null) {

//响应内容的长度

long length = httpEntity.getContentLength();

//响应内容

String content = EntityUtils.toString(httpEntity);

System.out.println("Response content length:" + length);

System.out.println("Response content:" + content);

}

//有些教程里没有下面这行

httpGet.abort();

} catch (Exception e) {

e.printStackTrace();

} finally {

//关闭连接，释放资源

httpClient.getConnectionManager().shutdown();

}

}

}

分析请求包中这六个头信息：httpget.setHeader("Accept-Encoding", "gzip, deflate")可能产生乱码

[java] view
plaincopy

/**

* @param args

* @throws IOException

*/

public static void main(String[] args) {

HttpClient httpClient = new DefaultHttpClient();

try {

HttpGet httpget = new HttpGet("http://www.iteye.com");

httpget.setHeader("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8");

httpget.setHeader("Accept-Language", "zh-cn,zh;q=0.5");

httpget.setHeader("User-Agent", "Mozilla/5.0 (Windows NT 5.1; rv:7.0.1) Gecko/20100101 Firefox/7.0.1)");

httpget.setHeader("Accept-Encoding", "gzip, deflate");

httpget.setHeader("Accept-Charset", "GB2312,utf-8;q=0.7,*;q=0.7");

httpget.setHeader("Host", "www.iteye.com");

httpget.setHeader("Connection", "Keep-Alive");

HttpResponse response = httpClient.execute(httpget);

HttpEntity entity = response.getEntity();

System.out.println("----------------------------------------");

System.out.println(response.getStatusLine());

if (entity != null) {

System.out.println("Response content length: " + entity.getContentLength());

}

System.out.println("----------------------------------------");

InputStream inSm = entity.getContent();

Scanner inScn = new Scanner(inSm);

while (inScn.hasNextLine()) {

System.out.println(inScn.nextLine());

}

// Do not feel like reading the response body

// Call abort on the request object

httpget.abort();

} catch (Exception e) {

e.printStackTrace();

} finally {

// When HttpClient instance is no longer needed,

// shut down the connection manager to ensure

// immediate deallocation of all system resources

httpClient.getConnectionManager().shutdown();

}

}

HttpPost操作：

[java] view
plaincopy

public class Demo2 {

/**

* 用post方法访问本地应用根据传递参数不同，返回不同结果

*

* @param args

*/

public static void main(String[] args) {

//创建默认的 HttpClient 实例

HttpClient httpClient = new DefaultHttpClient();

HttpPost httpPost = new HttpPost("http://localhost:86/test1Servlet");

List<NameValuePair> formParams = new ArrayList<NameValuePair>();

formParams.add(new BasicNameValuePair("param1", "***"));

UrlEncodedFormEntity urlEncodedFormEntity;

try {

urlEncodedFormEntity = new UrlEncodedFormEntity(formParams, "UTF-8");

httpPost.setEntity(urlEncodedFormEntity);

System.out.println("execurting request:" + httpPost.getURI());

HttpResponse httpResponse = null;

httpResponse = httpClient.execute(httpPost);

HttpEntity httpEntity = httpResponse.getEntity();

if (httpEntity != null) {

String content = EntityUtils.toString(httpEntity, "UTF-8");

System.out.println("Response content:" + content);

}

} catch (ClientProtocolException e) {

e.printStackTrace();

} catch (UnsupportedEncodingException e) {

e.printStackTrace();

} catch (IOException e) {

e.printStackTrace();

} finally {

//关闭连接，释放资源

httpClient.getConnectionManager().shutdown();

}

}

}