java使用apache http client发送get和post请求；支持文件上传和ssl

HttpClient.java

package com;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
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.ssl.SSLConnectionSocketFactory;
import org.apache.http.conn.ssl.SSLContextBuilder;
import org.apache.http.conn.ssl.TrustStrategy;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.StringEntity;
import org.apache.http.entity.mime.MultipartEntityBuilder;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;
import org.codehaus.jackson.map.ObjectMapper;

import javax.net.ssl.SSLContext;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.security.KeyManagementException;
import java.security.KeyStoreException;
import java.security.NoSuchAlgorithmException;
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;

/**
 * Created by george on 2017/1/3.
 */

/**
 * 使用apache http client发送get和post请求；支持文件上传
 */
public class RestClient {

    private static SSLConnectionSocketFactory sslConnectionSocketFactory;

    {
        try {
            SSLContext sslContext = new SSLContextBuilder().loadTrustMaterial(null, new TrustStrategy() {
                //信任所有
                public boolean isTrusted(X509Certificate[] chain, String authType) throws CertificateException {
                    return true;
                }
            }).build();
            sslConnectionSocketFactory = new SSLConnectionSocketFactory(sslContext);
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (KeyManagementException e) {
            e.printStackTrace();
        } catch (KeyStoreException e) {
            e.printStackTrace();
        }
    }

    public static CloseableHttpClient createHttpClient() {
        return HttpClients.custom().setSSLSocketFactory(sslConnectionSocketFactory).build();
    }

    public static String SendGet(String url) throws Exception {
        return sendGet(url, null);
    }

    public static String sendGet(String url, Map<String, Object> params) throws Exception {
        String result = "";
        BufferedReader reader = null;
        CloseableHttpClient httpClient = createHttpClient();
        String fullUrl = url + generateParam(params);
        HttpGet httpGet = new HttpGet(fullUrl);
        CloseableHttpResponse response = httpClient.execute(httpGet);
        HttpEntity entity = response.getEntity();
        if (entity != null) {
            result = EntityUtils.toString(entity);
        }
        return result;
    }

    /**
     * 发送post请求；上传文件时，map的value为File对象
     *
     * @param url
     * @param contentType
     * @param params
     * @return
     * @throws Exception
     */
    public static String sendPost(String url, ContentType contentType, Map<String, Object> params) throws Exception {
        String result = "";
        CloseableHttpClient closeableHttpClient = createHttpClient();
        HttpPost httpPost = new HttpPost(url);
        HttpEntity httpEntity = null;

        MultipartEntityBuilder builder = null;
        if (contentType.equals(ContentType.APPLICATION_JSON)) {
            ObjectMapper mapper = new ObjectMapper();
            httpEntity = new StringEntity(mapper.writeValueAsString(params));
        } else if (contentType.equals(ContentType.APPLICATION_FORM_URLENCODED)) {
            if (params != null && !params.isEmpty()) {
                List<NameValuePair> pairs = new ArrayList<NameValuePair>(params.size());
                for (Map.Entry<String, Object> entry : params.entrySet()) {
                    Object value = entry.getValue();
                    if (value != null) {
                        pairs.add(new BasicNameValuePair(entry.getKey(), value.toString()));
                    }
                }
                httpEntity = new UrlEncodedFormEntity(pairs);
            }
        } else if (contentType.equals(ContentType.MULTIPART_FORM_DATA)) {
            if (params != null && !params.isEmpty()) {
                builder = MultipartEntityBuilder.create();
                for (Map.Entry<String, Object> entry : params.entrySet()) {
                    Object value = entry.getValue();
                    if (value != null) {
                        if (value instanceof File) {
                            File file = (File) value;
                            builder.addBinaryBody(entry.getKey(), new FileInputStream(file), org.apache.http.entity.ContentType.APPLICATION_OCTET_STREAM, file.getName());
                        } else {
                            builder.addTextBody(entry.getKey(), value.toString(), org.apache.http.entity.ContentType.MULTIPART_FORM_DATA);
                        }
                    }
                }
                httpEntity = builder.build();
            }
        }
        httpPost.setEntity(httpEntity);

        HttpResponse res = closeableHttpClient.execute(httpPost);
        HttpEntity entity = res.getEntity();
        result = EntityUtils.toString(entity);

        return result;
    }

    /**
     * 生成请求的参数；name=value&name2=value2
     *
     * @param params
     * @return
     */
    private static String generateParam(Map<String, Object> params) {
        if (params == null || params.size() == 0) {
            return "";
        }
        StringBuilder builder = new StringBuilder();

        for (Map.Entry<String, Object> key : params.entrySet()) {
            builder.append(key.getKey()).append("=").append(key.getValue()).append("&");
        }
        if (builder.length() > 0) {
            builder.setLength(builder.length() - 1);
        }
        return builder.toString();
    }

    public static void main(String[] arg) {
        try {
            String url = "http://localhost:9999/home/upload";
            Map<String, Object> map = new HashMap<String, Object>() {
                {
                    File file = new File("file.txt");
                    put("file", file);
                    put("filename", "abc");
                }
            };
            String result = sendPost(url, ContentType.MULTIPART_FORM_DATA, map);

        } catch (Exception e) {
            System.out.println(e);
        }
    }
}