Post with HttpClient

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Apache HttpClient是Java中经常使用的Http Client，总结下HttpClient4中经常使用的post请求用法。

1 Basic Post

使用2个参数进行post请求：

@Test
public void whenPostRequestUsingHttpClient_thenCorrect()
throws ClientProtocolException, IOException {
CloseableHttpClient client = HttpClients.createDefault();
HttpPost httpPost = new HttpPost("http://www.example.com"); List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("username", "John"));
params.add(new BasicNameValuePair("password", "pass"));
httpPost.setEntity(new UrlEncodedFormEntity(params)); CloseableHttpResponse response = client.execute(httpPost);
assertThat(response.getStatusLine().getStatusCode(), equalTo(200));
client.close();
}

2 POST with Authorization

使用Post进行Basic Authentication credentials验证：

@Test
public void whenPostRequestWithAuthorizationUsingHttpClient_thenCorrect()
throws ClientProtocolException, IOException, AuthenticationException {
CloseableHttpClient client = HttpClients.createDefault();
HttpPost httpPost = new HttpPost("http://www.example.com"); httpPost.setEntity(new StringEntity("test post"));
UsernamePasswordCredentials creds =
new UsernamePasswordCredentials("John", "pass");
httpPost.addHeader(new BasicScheme().authenticate(creds, httpPost, null)); CloseableHttpResponse response = client.execute(httpPost);
assertThat(response.getStatusLine().getStatusCode(), equalTo(200));
client.close();
}

3 Post with JSON

使用JSON body进行post请求：

@Test
public void whenPostJsonUsingHttpClient_thenCorrect()
throws ClientProtocolException, IOException {
CloseableHttpClient client = HttpClients.createDefault();
HttpPost httpPost = new HttpPost("http://www.example.com"); String json = "{"id":1,"name":"John"}";
StringEntity entity = new StringEntity(json);
httpPost.setEntity(entity);
httpPost.setHeader("Accept", "application/json");
httpPost.setHeader("Content-type", "application/json"); CloseableHttpResponse response = client.execute(httpPost);
assertThat(response.getStatusLine().getStatusCode(), equalTo(200));
client.close();
}

4 Post with HttpClient Fluent API

使用Request进行post请求：

@Test
public void whenPostFormUsingHttpClientFluentAPI_thenCorrect()
throws ClientProtocolException, IOException {
HttpResponse response =
Request.Post("http://www.example.com").bodyForm(
Form.form().add("username", "John").add("password", "pass").build())
.execute().returnResponse(); assertThat(response.getStatusLine().getStatusCode(), equalTo(200));
}

5 Post Multipart Request

Post一个Multipart Request：

@Test
public void whenSendMultipartRequestUsingHttpClient_thenCorrect()
throws ClientProtocolException, IOException {
CloseableHttpClient client = HttpClients.createDefault();
HttpPost httpPost = new HttpPost("http://www.example.com"); MultipartEntityBuilder builder = MultipartEntityBuilder.create();
builder.addTextBody("username", "John");
builder.addTextBody("password", "pass");
builder.addBinaryBody("file", new File("test.txt"),
ContentType.APPLICATION_OCTET_STREAM, "file.ext"); HttpEntity multipart = builder.build();
httpPost.setEntity(multipart); CloseableHttpResponse response = client.execute(httpPost);
assertThat(response.getStatusLine().getStatusCode(), equalTo(200));
client.close();
}

6 Upload a File using HttpClient

使用一个Post请求上传一个文件：

@Test
public void whenUploadFileUsingHttpClient_thenCorrect()
throws ClientProtocolException, IOException {
CloseableHttpClient client = HttpClients.createDefault();
HttpPost httpPost = new HttpPost("http://www.example.com"); MultipartEntityBuilder builder = MultipartEntityBuilder.create();
builder.addBinaryBody("file", new File("test.txt"),
ContentType.APPLICATION_OCTET_STREAM, "file.ext");
HttpEntity multipart = builder.build(); httpPost.setEntity(multipart); CloseableHttpResponse response = client.execute(httpPost);
assertThat(response.getStatusLine().getStatusCode(), equalTo(200));
client.close();
}

7 Get File Upload Progress

使用HttpClient获取文件上传的进度。扩展HttpEntityWrapper 获取进度。

上传代码：

@Test
public void whenGetUploadFileProgressUsingHttpClient_thenCorrect()
throws ClientProtocolException, IOException {
CloseableHttpClient client = HttpClients.createDefault();
HttpPost httpPost = new HttpPost("http://www.example.com"); MultipartEntityBuilder builder = MultipartEntityBuilder.create();
builder.addBinaryBody("file", new File("test.txt"),
ContentType.APPLICATION_OCTET_STREAM, "file.ext");
HttpEntity multipart = builder.build(); ProgressEntityWrapper.ProgressListener pListener =
new ProgressEntityWrapper.ProgressListener() {
@Override
public void progress(float percentage) {
assertFalse(Float.compare(percentage, 100) > 0);
}
}; httpPost.setEntity(new ProgressEntityWrapper(multipart, pListener)); CloseableHttpResponse response = client.execute(httpPost);
assertThat(response.getStatusLine().getStatusCode(), equalTo(200));
client.close();
}

观察上传进度接口：

public static interface ProgressListener {
void progress(float percentage);
}

扩展了HttpEntityWrapper的ProgressEntityWrapper：

public class ProgressEntityWrapper extends HttpEntityWrapper {
private ProgressListener listener; public ProgressEntityWrapper(HttpEntity entity,
ProgressListener listener) {
super(entity);
this.listener = listener;
} @Override
public void writeTo(OutputStream outstream) throws IOException {
super.writeTo(new CountingOutputStream(outstream,
listener, getContentLength()));
}
}

扩展了FilterOutputStream的CountingOutputStream：

public static class CountingOutputStream extends FilterOutputStream {
private ProgressListener listener;
private long transferred;
private long totalBytes; public CountingOutputStream(
OutputStream out, ProgressListener listener, long totalBytes) {
super(out);
this.listener = listener;
transferred = 0;
this.totalBytes = totalBytes;
} @Override
public void write(byte[] b, int off, int len) throws IOException {
out.write(b, off, len);
transferred += len;
listener.progress(getCurrentProgress());
} @Override
public void write(int b) throws IOException {
out.write(b);
transferred++;
listener.progress(getCurrentProgress());
} private float getCurrentProgress() {
return ((float) transferred / totalBytes) * 100;
}
}