【Java】okHttp3 简单使用

之前用的RestTemplate，发现一个multipart的http请求始终发不成功，后面就试了下okHttp，发现真的好用，api太清爽了，记录一下使用：

package com.liyao;

import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;

import org.jetbrains.annotations.NotNull;
import org.junit.Test;

import okhttp3.Call;
import okhttp3.Callback;
import okhttp3.FormBody;
import okhttp3.MediaType;
import okhttp3.MultipartBody;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.RequestBody;
import okhttp3.Response;


public class OhHttpTest {

    private static final String host = "http://localhost.charlesproxy.com:8080";
    // 最好用单例
    private static OkHttpClient okHttpClient = new OkHttpClient();

    @Test
    public void post1() throws IOException {
        // RequestBody 有三种构建方式:
        // 1.  FormBody.Builder，构建application/x-www-form-urlencoded类型的post表单
        // 2.  MultipartBody.Builder，构建multipart类型的body，多个内容合成到一个body里
        // 3.  RequestBody.create方法构建body体，传入两个参数：类型和内容
        RequestBody body = new FormBody.Builder()
                .add("key1", "value1")
                .add("key1", "value1&key2=value2")
                .addEncoded("key3", "value3?&=") // 这俩方法没看出啥区别，都会urlencode
                .build();

        Request request = new Request.Builder()
                .url(host + "/rest/n/testApi/path")
                .post(body)
                .build();

        Call call = okHttpClient.newCall(request);
        call.execute();
    }

    @Test
    public void post2() throws IOException {
        RequestBody body = RequestBody.create("{}", MediaType.parse("application/json"));

        Request request = new Request.Builder()
                .url(host + "/rest/n/testApi/path")
                .post(body)
                .build();

        Call call = okHttpClient.newCall(request);
        call.execute();
    }

    @Test
    public void multipart() throws IOException {
        InputStream inputStream = new FileInputStream("src/test/resources/mapping.xlsx");
        byte[] bs = inputStream.readAllBytes();

        // 随便读一个excel文件，当做二进制流处理呗
        RequestBody part1 = RequestBody.create(bs, MediaType.parse("application/octet-stream"));

        // 通过构造方法指定boundary，一般不需要，只是知道有这么个用法
        RequestBody multipart = new MultipartBody.Builder("MyBoundary")
                .setType(MultipartBody.MIXED)
                .addFormDataPart("m1", "v1")
                .addFormDataPart("m2", "v2", part1)
                .build();

        Request request = new Request.Builder()
                .url(host + "/rest/n/testApi/path")
                .post(multipart)
                .build();

        Call call = okHttpClient.newCall(request);
        call.execute();
    }

    @Test
    public void get1() {
        // get没有body
        Request request = new Request.Builder()
                .url(host + "/rest/n/testApi/hello")
                .get()
                .build();

        Call call = okHttpClient.newCall(request);

        // sync
        try {
            Response response = call.execute();
            // process response
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    @Test
    public void get2() {
        Request request = new Request.Builder()
                .url(host + "/rest/n/testApi/hello")
                .get()
                .build();

        Call call = okHttpClient.newCall(request);

        // async
        call.enqueue(new Callback() {
            @Override
            public void onFailure(@NotNull Call call, @NotNull IOException e) {
                // process error
            }

            @Override
            public void onResponse(@NotNull Call call, @NotNull Response response) throws IOException {
                // process response
            }
        });

        // wait async result
        try {
            Thread.sleep(100000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}