Java中的OkHttp使用教程

2024-04-02 19:04:59 782人浏览泡泡鱼

Python 官方文档：入门教程 => 点击学习

摘要

目录什么是OKHttpOkHttp基本使用添加依赖OkHttp工具类使用案例发送get请求发送Post请求发送异步请求什么是OKHttp 一般在Java平台上，我们会使用Apache

什么是OKHttp

一般在Java平台上，我们会使用Apache HttpClient作为Http客户端，用于发送 HTTP 请求，并对响应进行处理。比如可以使用http客户端与第三方服务(如SSO服务)进行集成，当然还可以爬取网上的数据等。OKHttp与HttpClient类似，也是一个Http客户端，提供了对 HTTP/2 和 SPDY 的支持，并提供了连接池，GZIP 压缩和 HTTP 响应缓存功能；

OkHttp是目前非常火的网络库，它有以下特性：

1.支持HTTP/2，允许所有同一个主机地址的请求共享同一个Socket连接

2.连接池减少请求延时

3.透明的GZIP压缩减少响应数据的大小

4.缓存响应内容，避免一些完全重复的请求

OkHttp基本使用

OkHttpClient：客户端对象
Request：访问请求，Post请求中需要包含RequestBody
RequestBody：请求数据，在Post请求中用到
Response：即网络请求的响应结果
MediaType：数据类型，用来表明数据是JSON，image，pdf等一系列格式
client.newCall(request).execute()：同步的请求方法
client.newCall(request).enqueue(Callback callBack)：异步的请求方法，但Callback是执行在子线程中的，因此不能在此进行UI更新操作

官网：http://square.GitHub.io/okhttp/

添加依赖

 <dependency>
            <groupId>com.squareup.okhttp3</groupId>
            <artifactId>okhttp</artifactId>
            <version>3.10.0</version>
        </dependency>

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.60</version>
        </dependency>

OkHttp工具类

package com.loginsimpl.utils;

import com.alibaba.fastjson.JSON;
import okhttp3.*;

import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLSocketFactory;
import javax.net.ssl.TrustManager;
import javax.net.ssl.X509TrustManager;
import java.io.IOException;
import java.net.URLEncoder;
import java.security.SecureRandom;
import java.security.cert.X509Certificate;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.concurrent.Semaphore;
import java.util.concurrent.TimeUnit;

public class OkHttpUtils {
    private static volatile OkHttpClient okHttpClient = null;
    private static volatile Semaphore semaphore = null;
    private Map<String, String> headerMap;
    private Map<String, String> paramMap;
    private String url;
    private Request.Builder request;

    
    private OkHttpUtils() {
        if (okHttpClient == null) {
            synchronized (OkHttpUtils.class) {
                if (okHttpClient == null) {
                    TrustManager[] trustManagers = buildTrustManagers();
                    okHttpClient = new OkHttpClient.Builder()
                            .connectTimeout(15, TimeUnit.SECONDS)
                            .writeTimeout(20, TimeUnit.SECONDS)
                            .readTimeout(20, TimeUnit.SECONDS)
                            .sslSocketFactory(createSSLSocketFactory(trustManagers), (X509TrustManager) trustManagers[0])
                            .hostnameVerifier((hostName, session) -> true)
                            .retryOnConnectionFailure(true)
                            .build();
                    addHeader("User-Agent", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWEBKit/537.36 (Khtml, like Gecko) Chrome/63.0.3239.132 Safari/537.36");
                }
            }
        }
    }

    
    private static Semaphore getSemaphoreInstance() {
        //只能1个线程同时访问
        synchronized (OkHttpUtils.class) {
            if (semaphore == null) {
                semaphore = new Semaphore(0);
            }
        }
        return semaphore;
    }

    
    public static OkHttpUtils builder() {
        return new OkHttpUtils();
    }

    
    public OkHttpUtils url(String url) {
        this.url = url;
        return this;
    }

    
    public OkHttpUtils addParam(String key, String value) {
        if (paramMap == null) {
            paramMap = new LinkedHashMap<>(16);
        }
        paramMap.put(key, value);
        return this;
    }

    
    public OkHttpUtils addHeader(String key, String value) {
        if (headerMap == null) {
            headerMap = new LinkedHashMap<>(16);
        }
        headerMap.put(key, value);
        return this;
    }

    
    public OkHttpUtils get() {
        request = new Request.Builder().get();
        StringBuilder urlBuilder = new StringBuilder(url);
        if (paramMap != null) {
            urlBuilder.append("?");
            try {
                for (Map.Entry<String, String> entry : paramMap.entrySet()) {
                    urlBuilder.append(URLEncoder.encode(entry.geTKEy(), "utf-8")).
                            append("=").
                            append(URLEncoder.encode(entry.getValue(), "utf-8")).
                            append("&");
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
            urlBuilder.deleteCharAt(urlBuilder.length() - 1);
        }
        request.url(urlBuilder.toString());
        return this;
    }

    
    public OkHttpUtils post(boolean isJsonPost) {
        RequestBody requestBody;
        if (isJsonPost) {
            String json = "";
            if (paramMap != null) {
                json = JSON.toJSONString(paramMap);
            }
            requestBody = RequestBody.create(MediaType.parse("application/json; charset=utf-8"), json);
        } else {
            FORMBody.Builder formBody = new FormBody.Builder();
            if (paramMap != null) {
                paramMap.forEach(formBody::add);
            }
            requestBody = formBody.build();
        }
        request = new Request.Builder().post(requestBody).url(url);
        return this;
    }

    
    public String sync() {
        setHeader(request);
        try {
            Response response = okHttpClient.newCall(request.build()).execute();
            assert response.body() != null;
            return response.body().string();
        } catch (IOException e) {
            e.printStackTrace();
            return "请求失败：" + e.getMessage();
        }
    }

    
    public String async() {
        StringBuilder buffer = new StringBuilder("");
        setHeader(request);
        okHttpClient.newCall(request.build()).enqueue(new Callback() {
            @Override
            public void onFailure(Call call, IOException e) {
                buffer.append("请求出错：").append(e.getMessage());
            }

            @Override
            public void onResponse(Call call, Response response) throws IOException {
                assert response.body() != null;
                buffer.append(response.body().string());
                getSemaphoreInstance().release();
            }
        });
        try {
            getSemaphoreInstance().acquire();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        return buffer.toString();
    }

    
    public void async(ICallBack callBack) {
        setHeader(request);
        okHttpClient.newCall(request.build()).enqueue(new Callback() {
            @Override
            public void onFailure(Call call, IOException e) {
                callBack.onFailure(call, e.getMessage());
            }

            @Override
            public void onResponse(Call call, Response response) throws IOException {
                assert response.body() != null;
                callBack.onSuccessful(call, response.body().string());
            }
        });
    }

    
    private void setHeader(Request.Builder request) {
        if (headerMap != null) {
            try {
                for (Map.Entry<String, String> entry : headerMap.entrySet()) {
                    request.addHeader(entry.getKey(), entry.getValue());
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }


    
    private static SSLSocketFactory createSSLSocketFactory(TrustManager[] trustAllCerts) {
        SSLSocketFactory ssfFactory = null;
        try {
            SSLContext sc = SSLContext.getInstance("SSL");
            sc.init(null, trustAllCerts, new SecureRandom());
            ssfFactory = sc.getSocketFactory();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return ssfFactory;
    }

    private static TrustManager[] buildTrustManagers() {
        return new TrustManager[]{
                new X509TrustManager() {
                    @Override
                    public void checkClientTrusted(X509Certificate[] chain, String authType) {
                    }

                    @Override
                    public void checkServerTrusted(X509Certificate[] chain, String authType) {
                    }

                    @Override
                    public X509Certificate[] getAcceptedIssuers() {
                        return new X509Certificate[]{};
                    }
                }
        };
    }

    
    public interface ICallBack {

        void onSuccessful(Call call, String data);

        void onFailure(Call call, String errorMsg);

    }
}

使用案例

发送get请求

        String sync = OkHttpUtils.builder().url("http://localhost:9100/user/all")
                .addHeader("token", "xxxxxxx")
                .addParam("name", "xxx").addParam("pass", "xxx")
                .get()
                .sync();
        System.out.println(sync);

发送Post请求

        String sync = OkHttpUtils.builder().url("http://localhost:9100/user/all")
                .addHeader("token", "xxxxxxx")
                .addParam("name", "xxx").addParam("pass", "xxx")
                .post(true) // true 为json提交方式
                .sync();
        System.out.println(sync);

发送异步请求

需要实现ICallBack接口

//回调实现类
public class AsynchttpserviceImpl implements OkHttpUtils.ICallBack {
    @Override
    public void onSuccessful(Call call, String data) {
        //接口正常返回的内容
        System.out.println("onSuccessful"+data);

    }

    @Override
    public void onFailure(Call call, String errorMsg) {
        //接口错误返回的内容
        System.out.println("onFailure"+errorMsg);
    }
}

发送异步请求

       OkHttpUtils.builder().url("http://localhost:9100/user/all")
                .addHeader("token", "xxxxxxx")
                .addParam("name", "xxx").addParam("pass", "xxx")
                .post(true)
                .async(new AsyncHttpServiceImpl());

到此这篇关于Java-OkHttp使用教程的文章就介绍到这了,更多相关Java-OkHttp使用内容请搜索编程网以前的文章或继续浏览下面的相关文章希望大家以后多多支持编程网！

您可能感兴趣的文档:

点击免费下载>>软考高级考试备考技巧/历年真题/备考精华资料

--结束END--

本文标题: Java中的OkHttp使用教程

本文链接: https://www.lsjlt.com/news/146197.html(转载时请注明来源链接)

有问题或投稿请发送至: 邮箱/279061341@qq.com QQ/279061341