Java 中使用 OkHttpClent 请求接口 get方式 post方式-摩杜云开发者社区

学习记录，不喜勿喷

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优点

（1）支持HTTP2/SPDY（SPDY是Google开发的基于TCP的传输层协议，用以最小化网络延迟，提升网络速度，优化用户的网络使用体验）
（2）socket自动选择最好路线，并支持自动重连，拥有自动维护的socket连接池，减少握手次数，减少了请求延迟，共享Socket,减少对服务器的请求次数
（3）基于Headers的缓存策略减少重复的网络请求
（4）拥有Interceptors轻松处理请求与响应（自动处理GZip压缩）

OkHttp功能

（1）一般的get请求
（2）一般的post请求
（3）基于Http的文件上传
（4）文件下载
（5）上传下载的进度回调
（6）加载图片
（7）支持请求回调，直接返回对象、对象集合
（8）支持session的保持
（9）支持自签名网站https的访问，提供方法设置下证书就行
（10）支持取消某个请求

测试数据接口

package com.waves.controller;

import org.springframework.web.bind.annotation.*;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

@RestController
@RequestMapping("/dataApi")
public class ResponseDataController {

    @GetMapping("/getData")
    public Map<String,Object> getData(@RequestParam("pageIndex")String pageIndex){
        Map<String,Object>  map = new HashMap<>();
        map.put("username","小明");
        map.put("password","123456");
        map.put("age","18");
        map.put("endSchool","中国北京大学");
        List<Map<String,Object>> list = new ArrayList<>();
        list.add(map);
        Map<String,Object>  map2 = new HashMap<>();
        map2.put("total",list.size());
        map2.put("code",200);
        map2.put("data",list);

        return map2;
    }

    @PostMapping("/postData")
    public Map<String,Object> postData(@RequestBody  Map<String,Object> params){
        Map<String,Object>  map = new HashMap<>();
        map.put("username","小红");
        map.put("password","123456");
        map.put("age","18");
        map.put("school","中国北京大学");
        List<Map<String,Object>> list = new ArrayList<>();
        list.add(map);
        Map<String,Object>  map2 = new HashMap<>();
        map2.put("total",list.size());
        map2.put("code",200);
        map2.put("data",list);

        return map2;
    }
}

OkHttp POST请求接口

package com.waves.controller;

import com.alibaba.fastjson.JSONObject;
import okhttp3.MediaType;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;
import org.springframework.web.bind.annotation.*;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;


@RestController
@RequestMapping("/okHttpApi")
public class OkHttpController {

    @PostMapping("/okHttpPost")
    public Map<String,Object> okHttpPost(@RequestBody Map<String,Object> params){

        try {
            //json字符串的两种形式
            String k =  "{\n" +
                    "\t\"pageIndex\": \"1\",\n" +
                    "\t\"pageSize\": \"10\",\n" +
                    "\t\"userName\": \"xiaoming\"\n" +
                    "}";

            JSONObject json2 =  new JSONObject();
            json2.put("pageIndex","1");
            json2.put("pageSize","20");
            json2.put("userName","xiaoming");

            //创建一个OkHttpClient
            OkHttpClient client = new OkHttpClient();
            //设置请求头
            MediaType mediaType = MediaType.parse("application/json");
            //请求体
            okhttp3.RequestBody requestBody = okhttp3.RequestBody.create(mediaType,k);
            //创建一个request
            Request request = new Request.Builder()
                            .post(requestBody)
                            .url("http://localhost:8080/dataApi/postData")
                            .addHeader("content-type","application/json")
                            .build();
            //获得返回
            Response response = client.newCall(request).execute();
            if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);
            //获取返回值
            String responseData = response.body().string();
            //将json字符串转为JSONObject
            JSONObject data =   JSONObject.parseObject(responseData);
            //将jsonObject 转为Map
            Map<String,Object> map2 = data.toJavaObject(Map.class);
            return map2;
        }catch (Exception e){
            return new HashMap<>();
        }

    }

}

OkHttp GET方式请求接口

    @GetMapping("/okHttpGet")
    public Map<String,Object> okHttpGet(@RequestBody Map<String,Object> params){

        try {
            OkHttpClient client = new OkHttpClient();
            Request request = new Request.Builder()
                    .get()
                    .url("http://localhost:8080/dataApi/getData?pageIndex=1")
//                    .addHeader("content-type","application/json")
                    .build();
            Response response = client.newCall(request).execute();
            if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);
            //获取返回值
            String responseData = response.body().string();
            //将json字符串转为JSONObject
            JSONObject data =   JSONObject.parseObject(responseData);
            //将jsonObject 转为Map
            Map<String,Object> map2 = data.toJavaObject(Map.class);
            return map2;
        }catch (Exception e){
            return new HashMap<>();
        }

    }

项目所需pom（依赖）

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.waves</groupId>
    <artifactId>waves_okhttp</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>waves_okhttp</name>
    <description>Okhtp project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <spring-boot.version>2.3.7.RELEASE</spring-boot.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.72</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/com.squareup.okhttp3/okhttp -->
        <dependency>
            <groupId>com.squareup.okhttp3</groupId>
            <artifactId>okhttp</artifactId>
            <version>4.9.1</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>${spring-boot.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.8.1</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                    <encoding>UTF-8</encoding>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <version>2.3.7.RELEASE</version>
                <configuration>
                    <mainClass>com.waves.WavesOkhttpApplication</mainClass>
                </configuration>
                <executions>
                    <execution>
                        <id>repackage</id>
                        <goals>
                            <goal>repackage</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</project>