Java访问远程接口的几种方式

一、Java访问远程url接口并获取结果

1、原生JavaAPI获取

package com.util;import java.io.DataOutputStream;import java.io.IOException;import java.io.InputStream;import java.io.UnsupportedEncodingException;import java.net.HttpURLConnection;import java.net.MalformedURLException;import java.net.URL;import java.net.URLEncoder;import java.util.Map;/** * <pre> * 功能：httpUrlConnection访问远程接口工具 * 日期：2015年3月17日 上午11:19:21 * </pre> */public class HttpUrlConnectionUtil {    /**     * <pre>     * 方法体说明：向远程接口发起请求，返回字符串类型结果     * @param url 接口地址     * @param requestMethod 请求方式     * @param params 传递参数     重点：参数值需要用Base64进行转码     * @return String 返回结果     * </pre>     */    public static String httpRequestToString(String url, String requestMethod,            Map<String, String> params){        String result = null;        try {            InputStream is = httpRequestToStream(url, requestMethod, params);            byte[] b = new byte[is.available()];            is.read(b);            result = new String(b);        } catch (IOException e) {            e.printStackTrace();        }        return result;    }    /**     * <pre>     * 方法体说明：向远程接口发起请求，返回字节流类型结果     * 作者：高会于     * 日期：2015年3月17日 上午11:20:25     * @param url 接口地址     * @param requestMethod 请求方式     * @param params 传递参数     重点：参数值需要用Base64进行转码     * @return InputStream 返回结果     * </pre>     */    public static InputStream httpRequestToStream(String url, String requestMethod,            Map<String, String> params){        InputStream is = null;        try {            String parameters = "";            boolean hasParams = false;            //将参数集合拼接成特定格式，如name=zhangsan&age=24            for(String key : params.keySet()){                String value = URLEncoder.encode(params.get(key), "UTF-8");                parameters += key +"="+ value +"&";                hasParams = true;            }            if(hasParams){                parameters = parameters.substring(0, parameters.length()-1);            }            //请求方式是否为get            boolean isGet = "get".equalsIgnoreCase(requestMethod);            //请求方式是否为post            boolean isPost = "post".equalsIgnoreCase(requestMethod);            if(isGet){                url += "?"+ parameters;            }            URL u = new URL(url);            HttpURLConnection conn = (HttpURLConnection) u.openConnection();            //请求的参数类型(使用restlet框架时，为了兼容框架，必须设置Content-Type为“”空)            conn.setRequestProperty("Content-Type", "application/octet-stream");            //conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");            //设置连接超时时间            conn.setConnectTimeout(50000);              //设置读取返回内容超时时间            conn.setReadTimeout(50000);            //设置向HttpURLConnection对象中输出，因为post方式将请求参数放在http正文内，因此需要设置为ture，默认false            if(isPost){                conn.setDoOutput(true);            }            //设置从HttpURLConnection对象读入，默认为true            conn.setDoInput(true);            //设置是否使用缓存，post方式不能使用缓存            if(isPost){                conn.setUseCaches(false);            }            //设置请求方式，默认为GET            conn.setRequestMethod(requestMethod);            //post方式需要将传递的参数输出到conn对象中            if(isPost){                DataOutputStream dos = new DataOutputStream(conn.getOutputStream());                dos.writeBytes(parameters);                dos.flush();                dos.close();            }            //从HttpURLConnection对象中读取响应的消息            //执行该语句时才正式发起请求            is = conn.getInputStream();        } catch (UnsupportedEncodingException e) {            e.printStackTrace();        } catch (MalformedURLException e) {            e.printStackTrace();        } catch (IOException e) {            e.printStackTrace();        }        return is;    }}

2、利用httpClient访问获取

package com.util;import java.io.IOException;import java.io.UnsupportedEncodingException;import java.net.URLEncoder;import java.util.Map;import org.apache.http.HttpResponse;import org.apache.http.auth.AuthScope;import org.apache.http.auth.UsernamePasswordCredentials;import org.apache.http.client.CredentialsProvider;import org.apache.http.client.methods.HttpDelete;import org.apache.http.client.methods.HttpGet;import org.apache.http.client.methods.HttpPost;import org.apache.http.client.methods.HttpPut;import org.apache.http.client.methods.HttpRequestBase;import org.apache.http.client.protocol.HttpClientContext;import org.apache.http.entity.StringEntity;import org.apache.http.impl.client.BasicCredentialsProvider;import org.apache.http.impl.client.DefaultHttpClient;import org.apache.http.params.CoreConnectionPNames;import org.apache.http.util.EntityUtils;/** * <pre> * 功能：httpClient访问远程接口工具类 * 日期：2015年3月17日 上午11:19:21 * </pre> */@SuppressWarnings("deprecation")public class HttpClientUtil {    /**     * <pre>     * 方法体说明：向远程接口发起请求，返回字符串类型结果     * @param url 接口地址     * @param requestMethod 请求类型     * @param params 传递参数     * @return String 返回结果     * </pre>     */    public static String httpRequestToString(String url, String requestMethod,            Map<String, String> params, String ...auth){        //接口返回结果        String methodResult = null;        try {            String parameters = "";            boolean hasParams = false;            //将参数集合拼接成特定格式，如name=zhangsan&age=24            for(String key : params.keySet()){                String value = URLEncoder.encode(params.get(key), "UTF-8");                parameters += key +"="+ value +"&";                hasParams = true;            }            if(hasParams){                parameters = parameters.substring(0, parameters.length()-1);            }            //是否为GET方式请求            boolean isGet = "get".equalsIgnoreCase(requestMethod);            boolean isPost = "post".equalsIgnoreCase(requestMethod);            boolean isPut = "put".equalsIgnoreCase(requestMethod);            boolean isDelete = "delete".equalsIgnoreCase(requestMethod);            //创建HttpClient连接对象            DefaultHttpClient client = new DefaultHttpClient();            HttpRequestBase method = null;            if(isGet){                url += "?" + parameters;                method = new HttpGet(url);            }else if(isPost){                method = new HttpPost(url);                HttpPost postMethod = (HttpPost) method;                StringEntity entity = new StringEntity(parameters);                postMethod.setEntity(entity);            }else if(isPut){                method = new HttpPut(url);                HttpPut putMethod = (HttpPut) method;                StringEntity entity = new StringEntity(parameters);                putMethod.setEntity(entity);            }else if(isDelete){                url += "?" + parameters;                method = new HttpDelete(url);            }            method.getParams().setParameter(CoreConnectionPNames.CONNECTION_TIMEOUT, 6000);            //设置参数内容类型            method.addHeader("Content-Type","application/x-www-form-urlencoded");            //httpClient本地上下文            HttpClientContext context = null;            if(!(auth==null || auth.length==0)){                String username = auth[0];                String password = auth[1];                UsernamePasswordCredentials credt = new UsernamePasswordCredentials(username,password);                //凭据提供器                CredentialsProvider provider = new BasicCredentialsProvider();                //凭据的匹配范围                provider.setCredentials(AuthScope.ANY, credt);                context = HttpClientContext.create();                context.setCredentialsProvider(provider);            }            //访问接口，返回状态码            HttpResponse response = client.execute(method, context);            //返回状态码200，则访问接口成功            if(response.getStatusLine().getStatusCode()==200){                methodResult = EntityUtils.toString(response.getEntity());            }            client.close();        }catch (UnsupportedEncodingException e) {            e.printStackTrace();        }catch (IOException e) {            e.printStackTrace();        }        return methodResult;    }}