[Java]Http请求的工具类

说明

该工具类从网络获取参考，在本人进行工作中，进行了部分修改；

Http请求工具包，包含：
1、常用的GET/POST请求远程接口方法（可带参数、带头部信息）；
2、可自定义请求方式的请求远程接口方法（可带参数、带头部信息）；
3、可进行文件上传的请求远程接口方法；
具体内容，请大家参阅代码，希望分享出来，为朋友们提供便利；
谢谢。

HttpClientUtils .java

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.crm.restapi.result.ApiResult;
import org.apache.http.HttpEntity;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.EntityBuilder;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.*;
import org.apache.http.client.utils.URIBuilder;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.StringEntity;
import org.apache.http.entity.mime.HttpMultipartMode;
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.impl.conn.PoolingHttpClientConnectionManager;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.URISyntaxException;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.Map;

public class HttpClientUtils {
    private static PoolingHttpClientConnectionManager cm;
    private static String EMPTY_STR = "";
    private static String UTF_8 = "UTF-8";

    private static void init() {
        if (cm == null) {
            cm = new PoolingHttpClientConnectionManager();
            cm.setMaxTotal(50);// 整个连接池最大连接数
            cm.setDefaultMaxPerRoute(5);// 每路由最大连接数，默认值是2
        }
    }

    /**
     * 通过连接池获取HttpClient
     *
     * @return
     */
    private static CloseableHttpClient getHttpClient() {
        init();
        return HttpClients.custom().setConnectionManager(cm).build();
    }
    /**
     * @param url
     * @return
     */
    public static String get(String url) {
        HttpGet httpGet = new HttpGet(url);
        return getResult(httpGet);
    }
    /**
     * @param url、params
     * @return
     */
    public static String get(String url, Map<String, String > params) throws URISyntaxException {
        URIBuilder ub = new URIBuilder();
        ub.setPath(url);

        ArrayList<NameValuePair> pairs = covertParams2NVPS(params);
        ub.setParameters(pairs);

        HttpGet httpGet = new HttpGet(ub.build());
        return getResult(httpGet);
    }
    /**
     * @param url、headers、params
     * @return
     */
    public static String get(String url, Map<String, Object> headers, Map<String, String> params)
            throws URISyntaxException {
        URIBuilder ub = new URIBuilder();
        ub.setPath(url);

        if (params != null) {
            ArrayList<NameValuePair> pairs = covertParams2NVPS(params);
            ub.setParameters(pairs);
        }

        HttpGet httpGet = new HttpGet(ub.build());
        for (Map.Entry<String, Object> param : headers.entrySet()) {
            httpGet.addHeader(param.getKey(), String.valueOf(param.getValue()));
        }
        return getResult(httpGet);
    }
    /**
     * @param url
     * @return
     */
    public static String post(String url) {
        HttpPost httpPost = new HttpPost(url);
        return getResult(httpPost);
    }
    /**
     * @param url、params
     * @return
     */
    public static String post(String url, Map<String, String> params) throws UnsupportedEncodingException {
        HttpPost httpPost = new HttpPost(url);
        httpPost.setEntity(new UrlEncodedFormEntity(covertParams2NVPS(params), "utf-8"));//设置表单提交编码

//        httpPost.setEntity(new StringEntity(JSON.toJSONString(params), ContentType.APPLICATION_FORM_URLENCODED));
        return getResult(httpPost);
    }
    /**
     * @param url、headers、params
     * @return
     */
    public static String post(String url, Map<String, Object> headers, Map<String, String> params)
            throws UnsupportedEncodingException {
        HttpPost httpPost = new HttpPost(url);

        if (params != null) {
            for (Map.Entry<String, Object> param : headers.entrySet()) {
                httpPost.addHeader(param.getKey(), String.valueOf(param.getValue()));
            }
        }

        httpPost.setEntity(new StringEntity(JSON.toJSONString(params), ContentType.APPLICATION_JSON));

        return getResult(httpPost);
    }
    /**
     * @param method、url
     * @return
     */
    public static String request(String method, String url)
            throws UnsupportedEncodingException {

        RequestBuilder requestBuilder = RequestBuilder.create(method);
        requestBuilder.setUri(url);
        return getResult(requestBuilder);
    }
    /**
     * @param method、url、params
     * @return
     */
    public static String request(String method, String url, Map<String, Object> params)
            throws UnsupportedEncodingException {

        RequestBuilder requestBuilder = RequestBuilder.create(method);
        requestBuilder.setUri(url);

        EntityBuilder entityBuilder = EntityBuilder.create();
        entityBuilder.setContentEncoding(UTF_8);
        entityBuilder.setText(JSON.toJSONString(params));
        entityBuilder.setContentType(ContentType.APPLICATION_FORM_URLENCODED);

        requestBuilder.setEntity(entityBuilder.build());

        return getResult(requestBuilder);
    }
    /**
     * @param method、url、headers、params
     * @return
     */
    public static String request(String method, String url, Map<String, Object> headers, Map<String, String> params)
            throws UnsupportedEncodingException {

        RequestBuilder requestBuilder = RequestBuilder.create(method);
        requestBuilder.setUri(url);

        for (Map.Entry<String, Object> param : headers.entrySet()) {
            requestBuilder.addHeader(param.getKey(), String.valueOf(param.getValue()));
        }

        EntityBuilder entityBuilder = EntityBuilder.create();
        entityBuilder.setContentEncoding(UTF_8);
        entityBuilder.setText(JSON.toJSONString(params));
        entityBuilder.setContentType(ContentType.APPLICATION_JSON);

        requestBuilder.setEntity(entityBuilder.build());

        return getResult(requestBuilder);
    }
    /**
     * @param url、file、fileName
     * @return
     */
    public static String uploadFile(String url, byte[] file, String fileName) {

        HttpPost httpPost = new HttpPost(url);
        httpPost.setHeader("Accept-Encoding", "gzip");
        httpPost.setHeader("charset", "utf-8");

        MultipartEntityBuilder multipartEntityBuilder = MultipartEntityBuilder.create();
        multipartEntityBuilder.setMode(HttpMultipartMode.BROWSER_COMPATIBLE);
        multipartEntityBuilder.setCharset(Charset.forName(UTF_8));
        multipartEntityBuilder.addBinaryBody("file", file, ContentType.MULTIPART_FORM_DATA, fileName);

        httpPost.setEntity(multipartEntityBuilder.build());

        return getResult(httpPost);
    }

    private static ArrayList<NameValuePair> covertParams2NVPS(Map<String, String> params) {
        ArrayList<NameValuePair> pairs = new ArrayList<NameValuePair>();
        for (Map.Entry<String, String> param : params.entrySet()) {
            if (param.getValue() != null) {
                pairs.add(new BasicNameValuePair(param.getKey(), param.getValue()));
            }
        }

        return pairs;
    }

    /**
     * 处理Http请求
     *
     * @param request
     * @return
     */
    private static String getResult(HttpRequestBase request) {
        // CloseableHttpClient httpClient = HttpClients.createDefault();
        CloseableHttpClient httpClient = getHttpClient();
        try {
            CloseableHttpResponse response = httpClient.execute(request);
            // response.getStatusLine().getStatusCode();
            HttpEntity entity = response.getEntity();
            if (entity != null) {
                // long len = entity.getContentLength();// -1 表示长度未知
                String result = EntityUtils.toString(entity, UTF_8);
                response.close();
                // httpClient.close();
                return result;
            }
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {

        }

        return EMPTY_STR;
    }

    /**
     * 处理Http请求
     *
     * @param requestBuilder
     * @return
     */
    private static String getResult(RequestBuilder requestBuilder) {
        // CloseableHttpClient httpClient = HttpClients.createDefault();
        CloseableHttpClient httpClient = getHttpClient();
        try {
            CloseableHttpResponse response = httpClient.execute(requestBuilder.build());
            // response.getStatusLine().getStatusCode();
            HttpEntity entity = response.getEntity();
            if (entity != null) {
                // long len = entity.getContentLength();// -1 表示长度未知
                String result = EntityUtils.toString(entity, UTF_8);
                response.close();
                // httpClient.close();
                return result;
            }
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {

        }

        return EMPTY_STR;
    }

    public static ApiResult toApiRequest(String resultStr) {
        return JSONObject.parseObject(resultStr, ApiResult.class);
    }
}

HttpClientUtils .java中涉及的自己封装的结果返回类，ApiResult.java

public class ApiResult<T> {
    public Integer code;
    public String msg;
    public T data;

    public ApiResult success(){
        this.code = ResultCode.SUCCESS.getCode();
        this.msg = ResultCode.SUCCESS.getDesc();
        return this;
    }

    public ApiResult success(T data){
        this.code = ResultCode.SUCCESS.getCode();
        this.msg = ResultCode.SUCCESS.getDesc();
        this.data = data;
        return this;
    }

    public ApiResult failure(){
        this.code = ResultCode.ERROR.getCode();
        this.msg = ResultCode.ERROR.getDesc();
        return this;
    }

    public ApiResult failure(T data){
        this.code = ResultCode.ERROR.getCode();
        this.msg = ResultCode.ERROR.getDesc();
        this.data = data;
        return this;
    }

    public Integer getCode() {
        return code;
    }

    public void setCode(Integer code) {
        this.code = code;
    }

    public String getMsg() {
        return msg;
    }

    public void setMsg(String msg) {
        this.msg = msg;
    }

    public T getData() {
        return data;
    }

    public void setData(T data) {
        this.data = data;
    }
}

ApiResult.java中涉及的ResultCode.java

public enum ResultCode {
    SUCCESS(200, "success"), // 正确请求
    ERROR(500, "failure"); // 请求错误

    /** 主键 */
    private final Integer code;

    /** 描述 */
    private final String desc;

    ResultCode(final Integer code, final String desc) {
        this.code = code;
        this.desc = desc;
    }

    public Integer getCode() {
        return this.code;
    }

    public String getDesc() {
        return this.desc;
    }
}

在该工具类中涉及的依赖：
Gradle

compile "org.apache.httpcomponents:httpcore"
compile "org.apache.httpcomponents:httpclient"
compile "org.apache.httpcomponents:httpmime"
compile "com.alibaba:fastjson:1.2.34"

Maven

<dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.33</version>
        </dependency>
        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpcore</artifactId>
            <version>4.4.5</version>
        </dependency>
        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpclient</artifactId>
            <version>4.5.2</version>
        </dependency>
        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpmime</artifactId>
            <version>4.4</version>
</dependency>

不完善的地方希望大家提建议，谢谢；