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Retrofit框架（一）

2018-01-27

Android

原CSDN博客已弃用，文章会逐渐迁移过来。

一、使用Retrofit框架请求网页

一、添加依赖

请见

https://blog.csdn.net/weimeig/article/details/78656178

二、建立接口文件

Service.java

package com.administrator.picassodemo;  

import retrofit2.Call;  
import retrofit2.http.GET;  

/** 
 * Created by Administrator on 2018/5/16. 
 */  

public interface Service {  
    @GET("/")//括号内可以不写，也可以写网页的子目录  
    Call<String> getBaidu();  
}

三、创建实例

MainActivity.java

package com.administrator.picassodemo;  

import android.support.v7.app.AppCompatActivity;  
import android.os.Bundle;  
import android.widget.TextView;  
import android.widget.Toast;  

import java.io.IOException;  
import java.lang.annotation.Annotation;  
import java.lang.reflect.Type;  

import okhttp3.ResponseBody;  
import retrofit2.Call;  
import retrofit2.Callback;  
import retrofit2.Converter;  
import retrofit2.Response;  
import retrofit2.Retrofit;  

public class MainActivity extends AppCompatActivity implements Callback<String> {  


    private TextView mTextView;  
    @Override  
    protected void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.activity_main);  
        mTextView = findViewById(R.id.tvContent);  
        //addConverterFactory()解析下载数据  
        Retrofit retrofit = new Retrofit.Builder()  
                .baseUrl("http://qq.com")  
                .addConverterFactory(new Converter.Factory() {  
                    @Override  
                    public Converter<ResponseBody, ?> responseBodyConverter(Type type, Annotation[] annotations, Retrofit retrofit) {  
                        return new Converter<ResponseBody, String>() {  
                            @Override  
                            public String convert(ResponseBody value) throws IOException {  
                                return value.string();  
                            }  
                        };  
                    }  
                }).build();  
        //用实例出来一个Service  
        Service service = retrofit.create(Service.class);  
        //用直接get出来一个请求  
        Call<String> call = service.getBaidu();  
//        异步请求  
        call.enqueue(this);  
    }  

//   ------得到两个反馈------  
    @Override  
    public void onResponse(Call<String> call, Response<String> response) {  
        mTextView.setText(response.body());  
    }  

    @Override  
    public void onFailure(Call<String> call, Throwable t) {  
        Toast.makeText(this,"请求失败"+call.request().url(),Toast.LENGTH_SHORT).show();  
        t.printStackTrace();  
    }  
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>  
<android.support.constraint.ConstraintLayout  
    xmlns:android="http://schemas.android.com/apk/res/android"  
    xmlns:tools="http://schemas.android.com/tools"  
    android:layout_width="match_parent"  
    android:layout_height="match_parent"  
    tools:context="com.administrator.picassodemo.MainActivity">  


    <ScrollView  
        android:layout_width="match_parent"  
        android:layout_height="match_parent">  
        <TextView  
        android:id="@+id/tvContent"  
        android:layout_width="match_parent"  
        android:layout_height="match_parent"  
        />  
    </ScrollView>  


</android.support.constraint.ConstraintLayout>

二、get请求和数据解析

(一)、添加依赖

dependencies {  
    compile 'com.squareup.retrofit2:retrofit:2.0.2'  
    compile 'com.squareup.retrofit2:converter-gson:2.0.0-beta3'  
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>  
<android.support.constraint.ConstraintLayout  
    xmlns:android="http://schemas.android.com/apk/res/android"  
    xmlns:tools="http://schemas.android.com/tools"  
    android:layout_width="match_parent"  
    android:layout_height="match_parent"  
    tools:context="com.administrator.picassodemo.MainActivity">  


    <ScrollView  
        android:layout_width="match_parent"  
        android:layout_height="match_parent">  
        <TextView  
        android:id="@+id/tvContent"  
        android:layout_width="match_parent"  
        android:layout_height="match_parent"  
        />  
    </ScrollView>  


</android.support.constraint.ConstraintLayout>

数据实体类

Cook.java

package com.administrator.picassodemo;  

import com.google.gson.annotations.SerializedName;  

/** 
 * Created by Administrator on 2018/5/16. 
 */  

public class Cook {  

    @SerializedName("id")  
    private int id;  
    @SerializedName("name")  
    private String name;  
    @SerializedName("food")  
    private String food;  
    @SerializedName("img")  
    private String img;  
    @SerializedName("images")  
    private String images;  
    @SerializedName("description")  
    private String description;  
    @SerializedName("keywords")  
    private String keywords;  
    @SerializedName("message")  
    private String message;  
    @SerializedName("count")  
    private int count;  
    @SerializedName("fcount")  
    private int fcount;  
    @SerializedName("rcount")  
    private int rcount;  

    public int getId() {  
        return id;  
    }  

    public void setId(int id) {  
        this.id = id;  
    }  

    public String getName() {  
        return name;  
    }  

    public void setName(String name) {  
        this.name = name;  
    }  

    public String getFood() {  
        return food;  
    }  

    public void setFood(String food) {  
        this.food = food;  
    }  

    public String getImg() {  
        return img;  
    }  

    public void setImg(String img) {  
        this.img = img;  
    }  

    public String getImages() {  
        return images;  
    }  

    public void setImages(String images) {  
        this.images = images;  
    }  

    public String getDescription() {  
        return description;  
    }  

    public void setDescription(String description) {  
        this.description = description;  
    }  

    public String getKeywords() {  
        return keywords;  
    }  

    public void setKeywords(String keywords) {  
        this.keywords = keywords;  
    }  

    public String getMessage() {  
        return message;  
    }  

    public void setMessage(String message) {  
        this.message = message;  
    }  

    public int getCount() {  
        return count;  
    }  

    public void setCount(int count) {  
        this.count = count;  
    }  

    public int getFcount() {  
        return fcount;  
    }  

    public void setFcount(int fcount) {  
        this.fcount = fcount;  
    }  

    public int getRcount() {  
        return rcount;  
    }  

    public void setRcount(int rcount) {  
        this.rcount = rcount;  
    }  
}

返回的数据有集合数据，所以建立集合数据实体类

Tngou.java

package com.administrator.picassodemo;  

import com.google.gson.annotations.SerializedName;  

import java.util.List;  

/** 
 * Created by Administrator on 2018/5/16. 
 */  

public class Tngou {  
    @SerializedName("status")  
    private boolean status;  
    @SerializedName("total")  
    private int total;  
    @SerializedName("tngou")  
    private List<Cook> list;  

    public boolean isStatus() {  
        return status;  
    }  

    public void setStatus(boolean status) {  
        this.status = status;  
    }  

    public int getTotal() {  
        return total;  
    }  

    public void setTotal(int total) {  
        this.total = total;  
    }  

    public List<Cook> getList() {  
        return list;  
    }  

    public void setList(List<Cook> list) {  
        this.list = list;  
    }  
}

建立接口文件

Service.java

package com.administrator.picassodemo;  

import retrofit2.Call;  
import retrofit2.http.GET;  
import retrofit2.http.Query;  

/** 
 * Created by Administrator on 2018/5/16. 
 */  

public interface Service {  
    @GET("/api/cook/list")//括号内可以不写，也可以写网页的子目录  
    Call<Tngou> getList(@Query("id") int id, @Query("page") int page,@Query("rows")  int rows);  
}

MainActivity.java

package com.administrator.picassodemo;  

import android.support.v7.app.AppCompatActivity;  
import android.os.Bundle;  
import android.widget.TextView;  
import java.util.List;  

import retrofit2.Call;  
import retrofit2.Callback;  
import retrofit2.GsonConverterFactory;  
import retrofit2.Response;  
import retrofit2.Retrofit;  

public class MainActivity extends AppCompatActivity implements Callback<Tngou> {  


    private TextView mTextView;  
    @Override  
    protected void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.activity_main);  
        mTextView = findViewById(R.id.tvContent);  
        //addConverterFactory()解析下载数据  
        Retrofit retrofit = new Retrofit.Builder().baseUrl("http://www.tngou.net")  
                .addConverterFactory(GsonConverterFactory.create())  
                .build();  
        Service service = retrofit.create(Service.class);  
        Call<Tngou> call = service.getList(0,1,20);  
        call.enqueue(this);  
    }  


    @Override  
    public void onResponse(Call<Tngou> call, Response<Tngou> response) {  
        List<Cook> list = response.body().getList();  
    }  

    @Override  
    public void onFailure(Call<Tngou> call, Throwable t) {  
        t.printStackTrace();  
    }  
}