JAVA调用http接口、方法 ,发送http get/post请求(转)
原文：https://blog.csdn.net/capmiachael/article/details/51833531
三个例子 —JAVA发送http get/post请求，调用http接口、方法
例1：使用 HttpClient （commons-httpclient-3.0.jar
jar下载地址：http://download.csdn.net/download/capmiachael/9760550）
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.methods.InputStreamRequestEntity;
import org.apache.commons.httpclient.methods.PostMethod;
import org.apache.commons.httpclient.methods.RequestEntity;
public class HttpTool {
/**
* 发送post请求
*
* @author Michael -----CSDN: http://blog.csdn.net/capmiachael
* @param params
* 参数
* @param requestUrl
* 请求地址
* @param authorization
* 授权书
* @return 返回结果
* @throws IOException
*/
public static String sendPost(String params, String requestUrl,
String authorization) throws IOException {
byte[] requestBytes = params.getBytes("utf-8"); // 将参数转为二进制流
HttpClient httpClient = new HttpClient();// 客户端实例化
PostMethod postMethod = new PostMethod(requestUrl);
//设置请求头Authorization
postMethod.setRequestHeader("Authorization", "Basic " + authorization);
// 设置请求头 Content-Type
postMethod.setRequestHeader("Content-Type", "application/json");
InputStream inputStream = new ByteArrayInputStream(requestBytes, 0,
requestBytes.length);
RequestEntity requestEntity = new InputStreamRequestEntity(inputStream,
requestBytes.length, "application/json; charset=utf-8"); // 请求体
postMethod.setRequestEntity(requestEntity);
httpClient.executeMethod(postMethod);// 执行请求
InputStream soapResponseStream = postMethod.getResponseBodyAsStream();// 获取返回的流
byte[] datas = null;
try {
datas = readInputStream(soapResponseStream);// 从输入流中读取数据
} catch (Exception e) {
e.printStackTrace();
}
String result = new String(datas, "UTF-8");// 将二进制流转为String
// 打印返回结果
// System.out.println(result);
return result;
}
/**
* 从输入流中读取数据
*
* @param inStream
* @return
* @throws Exception
*/
public static byte[] readInputStream(InputStream inStream) throws Exception {
ByteArrayOutputStream outStream = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];
int len = 0;
while ((len = inStream.read(buffer)) != -1) {
outStream.write(buffer, 0, len);
}
byte[] data = outStream.toByteArray();
outStream.close();
inStream.close();
return data;
}
例2： 来源：开源中国 teardream http://www.oschina.net/code/snippet_2266157_45252
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.InetSocketAddress;
import java.net.Proxy;
import java.net.URL;
import java.net.URLConnection;
import java.util.List;
import java.util.Map;
/**
* Http请求工具类
* @author snowfigure
* @since 2014-8-24 13:30:56
* @version v1.0.1
*/
public class HttpRequestUtil {
static boolean proxySet = false;
static String proxyHost = "127.0.0.1";
static int proxyPort = 8087;
/**
* 编码
* @param source
* @return
*/
public static String urlEncode(String source,String encode) {
String result = source;
try {
result = java.net.URLEncoder.encode(source,encode);
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
return "0";
}
return result;
}
public static String urlEncodeGBK(String source) {
String result = source;
try {
result = java.net.URLEncoder.encode(source,"GBK");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
return "0";
}
return result;
}
/**
* 发起http请求获取返回结果
* @param req_url 请求地址
* @return
*/
public static String httpRequest(String req_url) {
StringBuffer buffer = new StringBuffer();
try {
URL url = new URL(req_url);
HttpURLConnection httpUrlConn = (HttpURLConnection) url.openConnection();
httpUrlConn.setDoOutput(false);
httpUrlConn.setDoInput(true);
httpUrlConn.setUseCaches(false);
httpUrlConn.setRequestMethod("GET");
httpUrlConn.connect();
// 将返回的输入流转换成字符串
InputStream inputStream = httpUrlConn.getInputStream();
InputStreamReader inputStreamReader = new InputStreamReader(inputStream, "utf-8");
BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
String str = null;
while ((str = bufferedReader.readLine()) != null) {
buffer.append(str);
}
bufferedReader.close();
inputStreamReader.close();
// 释放资源
inputStream.close();
inputStream = null;
httpUrlConn.disconnect();
} catch (Exception e) {
System.out.println(e.getStackTrace());
}
return buffer.toString();
}
/**
* 发送http请求取得返回的输入流
* @param requestUrl 请求地址
* @return InputStream
*/
public static InputStream httpRequestIO(String requestUrl) {
InputStream inputStream = null;
try {
URL url = new URL(requestUrl);
HttpURLConnection httpUrlConn = (HttpURLConnection) url.openConnection();
httpUrlConn.setDoInput(true);
httpUrlConn.setRequestMethod("GET");
httpUrlConn.connect();
// 获得返回的输入流
inputStream = httpUrlConn.getInputStream();
} catch (Exception e) {
e.printStackTrace();
}
return inputStream;
}
/**
* 向指定URL发送GET方法的请求
*
* @param url
* 发送请求的URL
* @param param
* 请求参数，请求参数应该是 name1=value1&name2=value2 的形式。
* @return URL 所代表远程资源的响应结果
*/
public static String sendGet(String url, String param) {
String result = "";
BufferedReader in = null;
try {
String urlNameString = url + "?" + param;
URL realUrl = new URL(urlNameString);
// 打开和URL之间的连接
URLConnection connection = realUrl.openConnection();
// 设置通用的请求属性
connection.setRequestProperty("accept", "*/*");
connection.setRequestProperty("connection", "Keep-Alive");
connection.setRequestProperty("user-agent",
"Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
// 建立实际的连接
connection.connect();
// 获取所有响应头字段
Map> map = connection.getHeaderFields();
// 遍历所有的响应头字段
for (String key : map.keySet()) {
System.out.println(key + "--->" + map.get(key));
}
// 定义 BufferedReader输入流来读取URL的响应
in = new BufferedReader(new InputStreamReader(
connection.getInputStream()));
String line;
while ((line = in.readLine()) != null) {
result += line;
}
} catch (Exception e) {
System.out.println("发送GET请求出现异常！" + e);
e.printStackTrace();
}
// 使用finally块来关闭输入流
finally {
try {
if (in != null) {
in.close();
}
} catch (Exception e2) {
e2.printStackTrace();
}
}
return result;
}
/**
* 向指定 URL 发送POST方法的请求
*
* @param url
* 发送请求的 URL
* @param param
* 请求参数，请求参数应该是 name1=value1&name2=value2 的形式。
* @param isproxy
* 是否使用代理模式
* @return 所代表远程资源的响应结果
*/
public static String sendPost(String url, String param,boolean isproxy) {
OutputStreamWriter out = null;
BufferedReader in = null;
String result = "";
try {
URL realUrl = new URL(url);
HttpURLConnection conn = null;
if(isproxy){//使用代理模式
@SuppressWarnings("static-access")
Proxy proxy = new Proxy(Proxy.Type.DIRECT.HTTP, new InetSocketAddress(proxyHost, proxyPort));
conn = (HttpURLConnection) realUrl.openConnection(proxy);
}else{
conn = (HttpURLConnection) realUrl.openConnection();
}
// 打开和URL之间的连接
// 发送POST请求必须设置如下两行
conn.setDoOutput(true);
conn.setDoInput(true);
conn.setRequestMethod("POST"); // POST方法
// 设置通用的请求属性
conn.setRequestProperty("accept", "*/*");
conn.setRequestProperty("connection", "Keep-Alive");
conn.setRequestProperty("user-agent",
"Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
conn.connect();
// 获取URLConnection对象对应的输出流
out = new OutputStreamWriter(conn.getOutputStream(), "UTF-8");
// 发送请求参数
out.write(param);
// flush输出流的缓冲
out.flush();
// 定义BufferedReader输入流来读取URL的响应
in = new BufferedReader(
new InputStreamReader(conn.getInputStream()));
String line;
while ((line = in.readLine()) != null) {
result += line;
}
} catch (Exception e) {
System.out.println("发送 POST 请求出现异常！"+e);
e.printStackTrace();
}
//使用finally块来关闭输出流、输入流
finally{
try{
if(out!=null){
out.close();
}
if(in!=null){
in.close();
}
}
catch(IOException ex){
ex.printStackTrace();
}
}
return result;
}
public static void main(String[] args) {
//demo:代理访问
String url = "http://api.adf.ly/api.php";
String para = "key=youkeyid&youuid=uid&advert_type=int&domain=adf.ly&url=http://somewebsite.com";
String sr=HttpRequestUtil.sendPost(url,para,true);
System.out.println(sr);
}
}
例3
/**
* 发送Http post请求
*
* @param xmlInfo
* json转化成的字符串
* @param URL
* 请求url
* @return 返回信息
*/
public static String doHttpPost(String xmlInfo, String URL) {
System.out.println("发起的数据:" + xmlInfo);
byte[] xmlData = xmlInfo.getBytes();
InputStream instr = null;
java.io.ByteArrayOutputStream out = null;
try {
URL url = new URL(URL);
URLConnection urlCon = url.openConnection();
urlCon.setDoOutput(true);
urlCon.setDoInput(true);
urlCon.setUseCaches(false);
urlCon.setRequestProperty("content-Type", "application/json");
urlCon.setRequestProperty("charset", "utf-8");
urlCon.setRequestProperty("Content-length",
String.valueOf(xmlData.length));
System.out.println(String.valueOf(xmlData.length));
DataOutputStream printout = new DataOutputStream(
urlCon.getOutputStream());
printout.write(xmlData);
printout.flush();
printout.close();
instr = urlCon.getInputStream();
byte[] bis = IOUtils.toByteArray(instr);
String ResponseString = new String(bis, "UTF-8");
if ((ResponseString == null) || ("".equals(ResponseString.trim()))) {
System.out.println("返回空");
}
System.out.println("返回数据为:" + ResponseString);
return ResponseString;
} catch (Exception e) {
e.printStackTrace();
return "0";
} finally {
try {
out.close();
instr.close();
} catch (Exception ex) {
return "0";
}
}
}