网络加载框架Retrofit 相当于Okhttp的加强版，它也是一个网络加载框架。底层是使用OKHttp封装的。准确来说,网络请求的工作本质上是OkHttp完成，而 Retrofit 仅负责网络请求接口的封装。它的一个特点是包含了特别多注解，方便简化你的代码量。并且还支持很多的开源库(著名例子：Retrofit + RxJava)。
下面是Retrofit的GET请求：
首先加依赖：
implementation 'com.squareup.retrofit:retrofit:2.0.0-beta2'
implementation 'com.squareup.retrofit:converter-gson:2.0.0-beta2'网络请求：
<uses-permission android:name="android.permission.INTERNET"></uses-permission>定义一个Javabean的接口类：
JavaBean类：
package com.example.day12retrofit;
import java.util.List;
public class JavaBean {
/**
* ret : 1
* data : [{"id":"8289","title":"油焖大虾","pic":"http://www.qubaobei.com/ios/cf/uploadfile/132/9/8289.jpg","collect_num":"1665","food_str":"大虾 葱 生姜 植物油 料酒","num":1665},{"id":"2127","title":"四川回锅肉","pic":"http://www.qubaobei.com/ios/cf/uploadfile/132/3/2127.jpg","collect_num":"1590","food_str":"猪肉 青蒜 青椒 红椒 姜片","num":1590},{"id":"30630","title":"超简单芒果布丁","pic":"http://www.qubaobei.com/ios/cf/uploadfile/132/31/30630.jpg","collect_num":"1537","food_str":"QQ糖 牛奶 芒果","num":1537},{"id":"9073","title":"家常红烧鱼","pic":"http://www.qubaobei.com/ios/cf/uploadfile/132/10/9073.jpg","collect_num":"1423","food_str":"鲜鱼 姜 葱 蒜 花椒","num":1423},{"id":"10097","title":"家常煎豆腐","pic":"http://www.qubaobei.com/ios/cf/uploadfile/132/11/10097.jpg","collect_num":"1416","food_str":"豆腐 新鲜红椒 青椒 葱花 油","num":1416},{"id":"10509","title":"水煮肉片","pic":"http://www.qubaobei.com/ios/cf/uploadfile/132/11/10509.jpg","collect_num":"1339","food_str":"瘦猪肉 生菜 豆瓣酱 干辣椒 花椒","num":1339},{"id":"46968","title":"红糖苹果银耳汤","pic":"http://www.qubaobei.com/ios/cf/uploadfile/132/47/46968.jpg","collect_num":"1252","food_str":"银耳 苹果 红糖","num":1252},{"id":"10191","title":"麻婆豆腐","pic":"http://www.qubaobei.com/ios/cf/uploadfile/132/11/10191.jpg","collect_num":"1218","food_str":"豆腐 肉末 生抽 白糖 芝麻油","num":1218},{"id":"2372","title":"皮蛋瘦肉粥","pic":"http://www.qubaobei.com/ios/cf/uploadfile/132/3/2372.jpg","collect_num":"1150","food_str":"大米 皮蛋 猪肉 油条 香葱","num":1150},{"id":"2166","title":"蚂蚁上树","pic":"http://www.qubaobei.com/ios/cf/uploadfile/132/3/2166.jpg","collect_num":"1143","food_str":"红薯粉 肉 姜 蒜 花椒","num":1143},{"id":"2262","title":"糖醋肉","pic":"http://www.qubaobei.com/ios/cf/uploadfile/132/3/2262.jpg","collect_num":"1076","food_str":"猪肉 红椒 黄椒 洋葱 蛋清","num":1076},{"id":"9971","title":"鱼香豆腐","pic":"http://www.qubaobei.com/ios/cf/uploadfile/132/10/9971.jpg","collect_num":"1009","food_str":"豆腐 木耳 胡萝卜 香葱 番茄酱","num":1009},{"id":"10172","title":"干煸四季豆","pic":"http://www.qubaobei.com/ios/cf/uploadfile/132/11/10172.jpg","collect_num":"991","food_str":"四季豆 干辣椒 蒜头 酱油 糖","num":991},{"id":"2685","title":"胡萝卜肉末蒸蛋","pic":"http://www.qubaobei.com/ios/cf/uploadfile/132/3/2685.jpg","collect_num":"924","food_str":"胡萝卜 肉 蛋 生抽 盐","num":924},{"id":"9972","title":"虎皮青椒","pic":"http://www.qubaobei.com/ios/cf/uploadfile/132/10/9972.jpg","collect_num":"891","food_str":"青辣椒 大蒜 香醋 白糖 生抽","num":891},{"id":"10437","title":"叉烧排骨","pic":"http://www.qubaobei.com/ios/cf/uploadfile/132/11/10437.jpg","collect_num":"800","food_str":"排骨 李锦记叉烧酱 植物油 清水 油菜","num":800},{"id":"2892","title":"\u201c五行\u201d彩蔬汤","pic":"http://www.qubaobei.com/ios/cf/uploadfile/132/3/2892.jpg","collect_num":"758","food_str":"黑木耳 玉米 牛蒡 胡萝卜 西兰花","num":758},{"id":"33783","title":"美人豆浆","pic":"http://www.qubaobei.com/ios/cf/uploadfile/132/34/33783.jpg","collect_num":"756","food_str":"黄豆 红豆 绿豆 黑豆 黑米","num":756},{"id":"2348","title":"麻辣肉丝面","pic":"http://www.qubaobei.com/ios/cf/uploadfile/132/3/2348.jpg","collect_num":"755","food_str":"面条 肉丝 淀粉 酱油 辣椒","num":755},{"id":"10044","title":"土豆炖翅根","pic":"http://www.qubaobei.com/ios/cf/uploadfile/132/11/10044.jpg","collect_num":"754","food_str":"土豆 翅根 葱 姜 料酒","num":754}]
*/
private int ret;
/**
* id : 8289
* title : 油焖大虾
* pic : http://www.qubaobei.com/ios/cf/uploadfile/132/9/8289.jpg
* collect_num : 1665
* food_str : 大虾 葱 生姜 植物油 料酒
* num : 1665
*/
private List<DataBean> data;
public int getRet() {
return ret;
}
public void setRet(int ret) {
this.ret = ret;
}
public List<DataBean> getData() {
return data;
}
public void setData(List<DataBean> data) {
this.data = data;
}
@Override
public String toString() {
return "JavaBean{" +
"ret=" + ret +
", data=" + data +
'}';
}
public static class DataBean {
private String id;
private String title;
private String pic;
private String collect_num;
private String food_str;
private int num;
@Override
public String toString() {
return "DataBean{" +
"id='" + id + '\'' +
", title='" + title + '\'' +
", pic='" + pic + '\'' +
", collect_num='" + collect_num + '\'' +
", food_str='" + food_str + '\'' +
", num=" + num +
'}';
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public String getPic() {
return pic;
}
public void setPic(String pic) {
this.pic = pic;
}
public String getCollect_num() {
return collect_num;
}
public void setCollect_num(String collect_num) {
this.collect_num = collect_num;
}
public String getFood_str() {
return food_str;
}
public void setFood_str(String food_str) {
this.food_str = food_str;
}
public int getNum() {
return num;
}
public void setNum(int num) {
this.num = num;
}
}
}
主类：
