目前JAVA实现HTTP请求的方法用的最多的有两种：
1、通过HttpURLConnection去实现，HttpURLConnection是JAVA的标准类，是JAVA比较原生的一种实现方式。
2、通过HTTPClient这种第三方的开源框架去实现。应用最广泛的就是apache的HTTPClient，有两大版本，HttpClient3.1 是 org.apache.commons.httpclient下操作远程 url的工具包，虽然已不再更新，但实现工作中使用httpClient3.1的代码还是很多，HttpClient4.5.x是org.apache.http.client下操作远程 url的工具包；
HttpURLConnection
package com.demo;
import java.io.ByteArrayOutputStream;
import java.io.Closeable;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Map;
public class HttpURLConDemo {
public static final String charsetName = "UTF-8";
public static String doGet(String strUrl) {
return doGet(strUrl, null);
}
public static String doGet(String strUrl, Map<String, String> headers) {
HttpURLConnection connection = null;
String out = null;
InputStream inputStream = null;
try {
URL _url = new URL(strUrl);
// 打开连接
connection = (HttpURLConnection) _url.openConnection();
// 设置请求方式：get请求
connection.setRequestMethod("GET");
// 设置超时时间，单位毫秒：5秒
connection.setConnectTimeout(5000);
// 设置读取远程服务器时间，单位毫秒：10秒
connection.setReadTimeout(10000);
// 设置请求头
if (headers != null) {
for (String headName : headers.keySet()) {
String headValue = headers.get(headName);
connection.setRequestProperty(headName, headValue);
}
}
// 发送请求
connection.connect();
// 通过connection获取输入流数据
if (connection.getResponseCode() == 200) {
inputStream = connection.getInputStream();
out = inToString(inputStream);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
// 关闭资源
close(inputStream);
// 关闭连接
connection.disconnect();
}
return out;
}
public static String doPost(String strUrl, String params, Map<String, String> headers) {
HttpURLConnection connection = null;
String out = null;
InputStream inputStream = null;
OutputStream outputStream = null;
try {
URL _url = new URL(strUrl);
// 打开连接
connection = (HttpURLConnection) _url.openConnection();
// 设置请求方式：get请求
connection.setRequestMethod("POST");
// 设置超时时间，单位毫秒：5秒
connection.setConnectTimeout(5000);
// 设置读取远程服务器时间，单位毫秒：10秒
connection.setReadTimeout(10000);
// 设置请求头
if (headers != null) {
for (String headName : headers.keySet()) {
String headValue = headers.get(headName);
connection.setRequestProperty(headName, headValue);
}
}
// 默认值为：true，当前向远程服务读取数据时，设置为true，该参数可有可无
connection.setDoInput(true);
if (params != null) {
// 默认值为：false，当向远程服务器传送数据/写数据时，需要设置为true
connection.setDoOutput(true);
outputStream = connection.getOutputStream();
outputStream.write(params.getBytes(charsetName));
}
// 发送请求
connection.connect();
// 通过connection获取输入流数据
if (connection.getResponseCode() == 200) {
inputStream = connection.getInputStream();
out = inToString(inputStream);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
// 关闭资源
close(outputStream);
close(inputStream);
// 关闭连接
connection.disconnect();
}
return out;
}
public static String doPost(String strUrl) {
return doPost(strUrl, null, null);
}
//ByteArrayOutputStream无需关闭
private static String inToString(InputStream inputStream) throws IOException {
ByteArrayOutputStream result = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];
int length;
while ((length = inputStream.read(buffer)) != -1) {
result.write(buffer, 0, length);
}
String str = result.toString(charsetName);
return str;
}
private static void close(Closeable closeable) {
try {
if (closeable != null) {
closeable.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
String result = doGet("https://blog.youkuaiyun.com/zhangsweet1991");
System.out.println(result);
}
}
HttpClient3.1
package com.demo;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Map;
import org.apache.commons.httpclient.DefaultHttpMethodRetryHandler;
import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpException;
import org.apache.commons.httpclient.HttpMethod;
import org.apache.commons.httpclient.HttpStatus;
import org.apache.commons.httpclient.methods.GetMethod;
import org.apache.commons.httpclient.methods.PostMethod;
import org.apache.commons.httpclient.params.HttpMethodParams;
public class HttpClientUtils {
public static final String charsetName = "UTF-8";
public static String doGet(String url) {
/*
* 使用 GetMethod 来访问一个 URL 对应的网页,实现步骤: 1:生成一个 HttpClinet 对象并设置相应的参数。
* 2:生成一个 GetMethod 对象并设置响应的参数。 3:用 HttpClinet 生成的对象来执行 GetMethod 生成的Get
* 方法。 4:处理响应状态码。 5:若响应正常，处理 HTTP 响应内容。 6:释放连接。
*/
/* 1 生成 HttpClinet 对象并设置参数 */
HttpClient httpClient = new HttpClient();
// 设置 Http 连接超时为5秒
httpClient.getHttpConnectionManager().getParams().setConnectionTimeout(5000);
/* 2 生成 GetMethod 对象并设置参数 */
GetMethod getMethod = new GetMethod(url);
// 设置 get 请求超时为 5 秒
getMethod.getParams().setParameter(HttpMethodParams.SO_TIMEOUT, 5000);
// 设置请求重试处理，用的是默认的重试处理：请求三次
getMethod.getParams().setParameter(HttpMethodParams.RETRY_HANDLER, new DefaultHttpMethodRetryHandler());
String out = null;
/* 3 执行 HTTP GET 请求 */
try {
int statusCode = httpClient.executeMethod(getMethod);
/* 4 判断访问的状态码 */
if (statusCode == HttpStatus.SC_OK) {
// 读取为 InputStream，在网页内容数据量大时候推荐使用
out = inToString(getMethod.getResponseBodyAsStream());
}
} catch (HttpException e) {
// 发生致命的异常，可能是协议不对或者返回的内容有问题
e.printStackTrace();
} catch (IOException e) {
// 发生网络异常
e.printStackTrace();
} finally {
/* 6 .释放连接 */
getMethod.releaseConnection();
}
return out;
}
public static String doPost(String url, Map<String, String> params) {
String out = null;
HttpClient client = new HttpClient();
HttpMethod method = new PostMethod(url);
// 设置Http Post数据
if (params != null) {
HttpMethodParams p = new HttpMethodParams();
for (Map.Entry<String, String> entry : params.entrySet()) {
p.setParameter(entry.getKey(), entry.getValue());
}
method.setParams(p);
}
try {
client.executeMethod(method);
if (method.getStatusCode() == HttpStatus.SC_OK) {
// 读取为 InputStream，在网页内容数据量大时候推荐使用
out = inToString(method.getResponseBodyAsStream());
}
} catch (IOException e) {
e.printStackTrace();
} finally {
method.releaseConnection();
}
return out;
}
private static String inToString(InputStream inputStream) throws IOException {
ByteArrayOutputStream result = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];
int length;
while ((length = inputStream.read(buffer)) != -1) {
result.write(buffer, 0, length);
}
String str = result.toString(charsetName);
return str;
}
public static void main(String[] args) {
String result = doGet("https://blog.youkuaiyun.com/zhangsweet1991");
System.out.println(result);
}
}
HttpClient4.5.5
package com.youyu.util.http;
import java.io.IOException;
import java.io.InputStream;
import java.nio.charset.Charset;
import java.security.GeneralSecurityException;
import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLException;
import javax.net.ssl.SSLSession;
import javax.net.ssl.SSLSocket;
import org.apache.commons.io.IOUtils;
import org.apache.http.HttpEntity;
import org.apache.http.HttpStatus;
import org.apache.http.NameValuePair;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.conn.ConnectTimeoutException;
import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
import org.apache.http.conn.ssl.SSLContextBuilder;
import org.apache.http.conn.ssl.TrustStrategy;
import org.apache.http.conn.ssl.X509HostnameVerifier;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;
public class HttpUtils {
private static PoolingHttpClientConnectionManager connMgr;
private static RequestConfig requestConfig;
private static final int MAX_TIMEOUT = 7000;// 7秒
private static final String UTF_8 = "UTF-8";
public static final String JSON = "json";
public static final String XML = "xml";
static {
// 设置连接池
connMgr = new PoolingHttpClientConnectionManager();
// 设置连接池大小
connMgr.setMaxTotal(100);
connMgr.setDefaultMaxPerRoute(connMgr.getMaxTotal());
RequestConfig.Builder configBuilder = RequestConfig.custom();
// 设置连接超时
configBuilder.setConnectTimeout(MAX_TIMEOUT);
// 设置读取超时
configBuilder.setSocketTimeout(MAX_TIMEOUT);
// 设置从连接池获取连接实例的超时
configBuilder.setConnectionRequestTimeout(MAX_TIMEOUT);
// 在提交请求之前 测试连接是否可用
configBuilder.setStaleConnectionCheckEnabled(true);
requestConfig = configBuilder.build();
}
/**
* 发送 GET 请求（HTTP），不带输入数据
*
* @param url
* @return
* @throws IOException
*/
public static String doGet(String url) throws IOException {
return doGet(url, null);
}
/**
* 发送 GET 请求（HTTP），K-V形式
*
* @param url
* @param params
* @return
* @throws IOException
*/
public static String doGet(String url, Map<String, String> params) throws IOException {
int i = 0;
if (params != null) {
StringBuffer param = new StringBuffer();
for (String key : params.keySet()) {
if (i == 0)
param.append("?");
else
param.append("&");
param.append(key).append("=").append(params.get(key));
i++;
}
url += param;
}
String result = null;
CloseableHttpClient httpclient = HttpClients.createDefault();
CloseableHttpResponse response = null;
HttpEntity entity = null;
try {
HttpGet httpGet = new HttpGet(url);
response = httpclient.execute(httpGet);
// int statusCode = response.getStatusLine().getStatusCode();
entity = response.getEntity();
if (entity != null) {
InputStream instream = entity.getContent();
result = IOUtils.toString(instream, UTF_8);
}
} finally {
// 最后别忘了关闭应该关闭的资源，适当的释放资源
try {
// 这个方法也可以把底层的流给关闭了
EntityUtils.consume(entity);
// if (null != response) {
// response.close();
// }
} catch (IOException e) {
e.printStackTrace();
}
}
return result;
}
/**
* 发送 POST 请求（HTTP），不带输入数据
*
* @param apiUrl
* @return
* @throws ConnectTimeoutException
*/
public static String doPost(String apiUrl) throws IOException {
return doPost(apiUrl, new HashMap<String, String>());
}
/**
* 发送 POST 请求（HTTP），K-V形式
*
* @param apiUrl API接口URL
* @param params 参数map
* @return
* @throws ConnectTimeoutException
*/
public static String doPost(String apiUrl, Map<String, String> params) throws IOException {
CloseableHttpClient httpClient = HttpClients.createDefault();
String httpStr = null;
HttpPost httpPost = new HttpPost(apiUrl);
CloseableHttpResponse response = null;
try {
httpPost.setConfig(requestConfig);
List<NameValuePair> pairList = new ArrayList<>(params.size());
for (Map.Entry<String, String> entry : params.entrySet()) {
NameValuePair pair = new BasicNameValuePair(entry.getKey(), entry.getValue());
pairList.add(pair);
}
httpPost.setEntity(new UrlEncodedFormEntity(pairList, Charset.forName("UTF-8")));
response = httpClient.execute(httpPost);
HttpEntity entity = response.getEntity();
httpStr = EntityUtils.toString(entity, "UTF-8");
} finally {
if (response != null) {
try {
EntityUtils.consume(response.getEntity());
} catch (IOException e) {
e.printStackTrace();
}
}
}
return httpStr;
}
/**
* 发送 POST 请求（HTTP），JSON形式
*
* @param apiUrl
* @param content 内容
* @return
* @throws IOException
*/
public static String doPost(String apiUrl, String content, String type) throws IOException {
CloseableHttpClient httpClient = HttpClients.createDefault();
String httpStr = null;
HttpPost httpPost = new HttpPost(apiUrl);
CloseableHttpResponse response = null;
try {
httpPost.setConfig(requestConfig);
StringEntity stringEntity = new StringEntity(content, "UTF-8");// 解决中文乱码问题
stringEntity.setContentEncoding("UTF-8");
if (JSON.equals(type)) {
stringEntity.setContentType("application/json");
} else if (XML.equals(type)) {
stringEntity.setContentType("application/xml");
} else {
stringEntity.setContentType("text/plain");
}
httpPost.setEntity(stringEntity);
response = httpClient.execute(httpPost);
HttpEntity entity = response.getEntity();
// System.out.println(response.getStatusLine().getStatusCode());
httpStr = EntityUtils.toString(entity, "UTF-8");
} finally {
if (response != null) {
try {
EntityUtils.consume(response.getEntity());
} catch (IOException e) {
e.printStackTrace();
}
}
}
return httpStr;
}
public static String doPost(String apiUrl, String content, String type,Map<String, String> headers) throws IOException {
CloseableHttpClient httpClient = HttpClients.createDefault();
String httpStr = null;
HttpPost httpPost = new HttpPost(apiUrl);
CloseableHttpResponse response = null;
try {
httpPost.setConfig(requestConfig);
if (headers != null) {
for (String headerName : headers.keySet()) {
httpPost.setHeader(headerName, headers.get(headerName));
}
}
StringEntity stringEntity = new StringEntity(content, "UTF-8");// 解决中文乱码问题
stringEntity.setContentEncoding("UTF-8");
if (JSON.equals(type)) {
stringEntity.setContentType("application/json");
} else if (XML.equals(type)) {
stringEntity.setContentType("application/xml");
} else {
stringEntity.setContentType("text/plain");
}
httpPost.setEntity(stringEntity);
response = httpClient.execute(httpPost);
HttpEntity entity = response.getEntity();
// System.out.println(response.getStatusLine().getStatusCode());
httpStr = EntityUtils.toString(entity, "UTF-8");
} finally {
if (response != null) {
try {
EntityUtils.consume(response.getEntity());
} catch (IOException e) {
e.printStackTrace();
}
}
}
return httpStr;
}
/**
* 发送 SSL POST 请求（HTTPS），K-V形式
*
* @param apiUrl API接口URL
* @param params 参数map
* @return
*/
public static String doPostSSL(String apiUrl, Map<String, Object> params) {
CloseableHttpClient httpClient = HttpClients.custom().setSSLSocketFactory(createSSLConnSocketFactory()).setConnectionManager(connMgr)
.setDefaultRequestConfig(requestConfig).build();
HttpPost httpPost = new HttpPost(apiUrl);
CloseableHttpResponse response = null;
String httpStr = null;
try {
httpPost.setConfig(requestConfig);
List<NameValuePair> pairList = new ArrayList<NameValuePair>(params.size());
for (Map.Entry<String, Object> entry : params.entrySet()) {
NameValuePair pair = new BasicNameValuePair(entry.getKey(), entry.getValue().toString());
pairList.add(pair);
}
httpPost.setEntity(new UrlEncodedFormEntity(pairList, Charset.forName("utf-8")));
response = httpClient.execute(httpPost);
int statusCode = response.getStatusLine().getStatusCode();
if (statusCode != HttpStatus.SC_OK) {
return null;
}
HttpEntity entity = response.getEntity();
if (entity == null) {
return null;
}
httpStr = EntityUtils.toString(entity, "utf-8");
} catch (Exception e) {
e.printStackTrace();
} finally {
if (response != null) {
try {
EntityUtils.consume(response.getEntity());
} catch (IOException e) {
e.printStackTrace();
}
}
}
return httpStr;
}
/**
* 发送 SSL POST 请求（HTTPS），JSON形式
*
* @param apiUrl API接口URL
* @param json JSON对象
* @return
*/
public static String doPostSSL(String apiUrl, Object json) {
CloseableHttpClient httpClient = HttpClients.custom().setSSLSocketFactory(createSSLConnSocketFactory()).setConnectionManager(connMgr)
.setDefaultRequestConfig(requestConfig).build();
HttpPost httpPost = new HttpPost(apiUrl);
CloseableHttpResponse response = null;
String httpStr = null;
try {
httpPost.setConfig(requestConfig);
StringEntity stringEntity = new StringEntity(json.toString(), "UTF-8");// 解决中文乱码问题
stringEntity.setContentEncoding("UTF-8");
stringEntity.setContentType("application/json");
httpPost.setEntity(stringEntity);
response = httpClient.execute(httpPost);
int statusCode = response.getStatusLine().getStatusCode();
if (statusCode != HttpStatus.SC_OK) {
return null;
}
HttpEntity entity = response.getEntity();
if (entity == null) {
return null;
}
httpStr = EntityUtils.toString(entity, "utf-8");
} catch (Exception e) {
e.printStackTrace();
} finally {
if (response != null) {
try {
EntityUtils.consume(response.getEntity());
response.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return httpStr;
}
/**
* 创建SSL安全连接
*
* @return
*/
private static SSLConnectionSocketFactory createSSLConnSocketFactory() {
SSLConnectionSocketFactory sslsf = null;
try {
SSLContext sslContext = new SSLContextBuilder().loadTrustMaterial(null, new TrustStrategy() {
public boolean isTrusted(X509Certificate[] chain, String authType) throws CertificateException {
return true;
}
}).build();
sslsf = new SSLConnectionSocketFactory(sslContext, new X509HostnameVerifier() {
@Override
public boolean verify(String arg0, SSLSession arg1) {
return true;
}
@Override
public void verify(String host, SSLSocket ssl) throws IOException {
}
@Override
public void verify(String host, X509Certificate cert) throws SSLException {
}
@Override
public void verify(String host, String[] cns, String[] subjectAlts) throws SSLException {
}
});
} catch (GeneralSecurityException e) {
e.printStackTrace();
}
return sslsf;
}
/**
* 发送 SSL POST 请求（HTTPS），加载证书
*
* @param apiUrl API接口URL
* @param json JSON对象
* @return
*/
public static String doPostSSL(String url, String content, String type, Map<String, String> headers, SSLConnectionSocketFactory sslsf) {
CloseableHttpClient httpClient = HttpClients.custom().setSSLSocketFactory(createSSLConnSocketFactory()).setConnectionManager(connMgr)
.setDefaultRequestConfig(requestConfig).build();
HttpPost httpPost = new HttpPost(url);
CloseableHttpResponse response = null;
String httpStr = null;
try {
httpPost.setConfig(requestConfig);
if (headers != null) {
for (String headerName : headers.keySet()) {
httpPost.setHeader(headerName, headers.get(headerName));
}
}
StringEntity stringEntity = new StringEntity(content, "UTF-8");// 解决中文乱码问题
stringEntity.setContentEncoding("UTF-8");
if (JSON.equals(type)) {
stringEntity.setContentType("application/json");
} else if (XML.equals(type)) {
stringEntity.setContentType("application/xml");
} else {
stringEntity.setContentType("text/plain");
}
httpPost.setEntity(stringEntity);
response = httpClient.execute(httpPost);
int statusCode = response.getStatusLine().getStatusCode();
if (statusCode != HttpStatus.SC_OK) {
return null;
}
HttpEntity entity = response.getEntity();
if (entity == null) {
return null;
}
httpStr = EntityUtils.toString(entity, "utf-8");
} catch (Exception e) {
e.printStackTrace();
} finally {
if (response != null) {
try {
EntityUtils.consume(response.getEntity());
response.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return httpStr;
}
}
扫一扫
419
被折叠的 条评论
为什么被折叠?
到【灌水乐园】发言
