之所以把Hilt 归类到Dagger2 文章系列，原因是，Hilt 是专门为Android设计，设计团队专门找到Dagger2团队合作，为Android设计了这套注入框架Hilt。底层api其实还是高度还原Dagger语法。
1. Hilt 注入框架
1.1特点
Hilt就是Android团队联系了Dagger2团队，一起开发出来的一个专门面向Android的依赖注入框架。
相比于Dagger2，Hilt最明显的特征就是：1. 简单。2. 提供了Android专属的API。
Hilt做的优化包括
无需编写大量的Component代码
Scope也会与Component自动绑定
预定义绑定，例如 Application与Activity
预定义的限定符，例如@ApplicationContext与@ActivityContext
1.2基本配置
apply plugin: 'dagger.hilt.android.plugin'
//hilt
implementation "com.google.dagger:hilt-android:2.28-alpha"
annotationProcessor "com.google.dagger:hilt-android-compiler:2.28-alpha"
//kotlin
//katp "com.google.dagger:hilt-android-compiler:2.28-alpha"
------
//支持java8
compileOptions {
sourceCompatibility JavaVersion.VERSION_1_8
targetCompatibility JavaVersion.VERSION_1_8
}
------
Hilt 目前支持以下 Android 类：
Application
Activity
Fragment
View
Service
BroadcastReceiver
1.3基本使用
1.提供一个对象
public class HttpObject {
}
2.编写Module
@InstallIn(ActivityComponent.class)
@Module
public class HttpModule {
@Provides
public HttpObject getHttpObject(){
return new HttpObject();
}
}
3.注入到Activity
@AndroidEntryPoint
public class MainActivity extends AppCompatActivity {
@Inject
HttpObject httpObject;
@Inject
HttpObject httpObject2;
4.Application中注册
@HiltAndroidApp
public class MyApplication extends Application {
}
5.全局单例使用
@InstallIn(ApplicationComponent.class)
@Module
public class HttpModule {
@Provides
@Singleton
public HttpObject getHttpObject(){
return new HttpObject();
}
}
注意：Hilt注入的字段是不可以声明成private
为接口注入实例
public interface AnalyticsService {
void analyticsMethods();
}
-------
public class AnalyticsServiceImpl implements AnalyticsService {
...
@Inject
AnalyticsServiceImpl(...) {
...
}
}
------
@Module
@InstallIn(ActivityComponent.class)
public abstract class AnalyticsModule {
@Binds
public abstract AnalyticsService bindAnalyticsService(
AnalyticsServiceImpl analyticsServiceImpl
);
}
1.4 Component与Scope
Hilt 提供了以下组件：
Hilt组件.png
组件生命周期
生命周期.png
同时还提供了相应的作用域
作用域.png
1.5 注意事项
实现有使用gradle插件做字节码插桩
类似路径
windows
C:\Users\Administrator\.gradle\caches\modules-2\files-2.1\com.google.dagger\hilt-android-gradle-plugin\2.28-alpha\eb33a043b2bbdc7cdee3c851d0f8532bfd3645a5\hilt-android-gradle-plugin-2.28-alpha-sources\dagger\hilt\android\plugin
mac
/Users/zcw/.gradle/caches/modules-2/files-2.1/com.google.dagger/hilt-android-gradle-plugin/2.28.1-alpha/898bcdda64bf6f48581dbb24e555505bb66c1acf/hilt-android-gradle-plugin-2.28.1-alpha-sources.jar
2 网络请求隔离层应用
2.1设计具有网络访问能力的接口
package top.zcwfeng.httpprocessor_java_hilt;
public interface IHttpProcessor {
// 网络访问能力
void post(String url, Map<String,Object> params,ICallback callback);
void get(String url, Map<String,Object> params,ICallback callback);
}
2.2顶层的回调接口
将来可能是，json，xml，Protobuf
package top.zcwfeng.httpprocessor_java_hilt;
public interface ICallback {
void onSuccess(String result);
void onFailure(String e);
}
2.3核心回调接口一种实现
将来可以用其他方式实现
/**
* 回调接口的一种实现 new HttpCallback<JavaBean>
*/
public abstract class HttpCallback<Result> implements ICallback {
@Override
public void onSuccess(String result) {
//result 就是网络访问第三方框架返回的字符串
// 1. 得到调用者用什么样的JavaBean接受数据
Class<?> clz = analysisClassInfo(this);
// 2. 把result转换成对应的javabean
Gson gson = new Gson();
Result objResult = (Result) gson.fromJson(result, clz);
// 3.objResult 交给程序员使用
onSuccess(objResult);
}
public abstract void onSuccess(Result objResult);
private Class<?> analysisClassInfo(Object object){
// getGenericSuperclass
// 得到包含原始类型，参数化类型，数组，类型变量，进本数据类型
Type type = object.getClass().getGenericSuperclass();
Type[] params = ((ParameterizedType) type).getActualTypeArguments();
return (Class<?>) params[0];
}
@Override
public void onFailure(String e) {
}
}
2.4 定义接口bean
public class ResponceData {
/**
* result : null
* reason : 当前可请求的次数不足
* error_code : 10012
* resultcode : 112
*/
private String result;
private String reason;
private int error_code;
private String resultcode;
public void setResult(String result) {
this.result = result;
}
public void setReason(String reason) {
this.reason = reason;
}
public void setError_code(int error_code) {
this.error_code = error_code;
}
public void setResultcode(String resultcode) {
this.resultcode = resultcode;
}
public String getResult() {
return result;
}
public String getReason() {
return reason;
}
public int getError_code() {
return error_code;
}
public String getResultcode() {
return resultcode;
}
}
2.5三种请求实现
用我们之前的hilt注入基础，用@Inject 构造方法注入完成
OkHttpProcessor
package top.zcwfeng.httpprocessor_java_hilt;
import android.os.Handler;
import java.io.IOException;
import java.util.Map;
import javax.inject.Inject;
import okhttp3.Call;
import okhttp3.Callback;
import okhttp3.FormBody;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.RequestBody;
import okhttp3.Response;
public
class OkHttpProcessor implements IHttpProcessor {
private OkHttpClient mOkHttpClient;
private Handler mHandler;
@Inject
public OkHttpProcessor() {
mOkHttpClient = new OkHttpClient();
mHandler = new Handler();
}
@Override
public void post(String url, Map<String, Object> params, ICallback callback) {
final RequestBody requestBody=appendBody(params);
Request request=new Request.Builder()
.url(url)
.post(requestBody)
.build();
mOkHttpClient.newCall(request).enqueue(new Callback() {
@Override
public void onResponse(Call call, Response response) throws IOException {
final String result=response.body().string();
if(response.isSuccessful()){
mHandler.post(new Runnable() {
@Override
public void run() {
callback.onSuccess(result);
}
});
}else{
mHandler.post(new Runnable() {
@Override
public void run() {
callback.onFailure(result);
}
});
}
}
@Override
public void onFailure(Call call, IOException e) {
mHandler.post(new Runnable() {
@Override
public void run() {
callback.onFailure("onFailure");
}
});
}
});
}
@Override
public void get(String url, Map<String, Object> params, ICallback callback) {
}
private RequestBody appendBody(Map<String, Object> params){
FormBody.Builder body=new FormBody.Builder();
if(params==null || params.isEmpty()){
return body.build();
}
for(Map.Entry<String, Object> entry:params.entrySet()){
body.add(entry.getKey(),entry.getValue().toString());
}
return body.build();
}
}
VolleyProcessor
package top.zcwfeng.httpprocessor_java_hilt;
import android.content.Context;
import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.StringRequest;
import com.android.volley.toolbox.Volley;
import java.util.Map;
import javax.inject.Inject;
import dagger.hilt.android.qualifiers.ApplicationContext;
public
class VolleyProcessor implements IHttpProcessor {
private static RequestQueue mQueue = null;
@Inject
public VolleyProcessor(@ApplicationContext Context context) {
mQueue = Volley.newRequestQueue(context);
}
@Override
public void post(String url, Map<String, Object> params, ICallback callback) {
StringRequest stringRequest = new StringRequest(Request.Method.POST,
url,
new Response.Listener<String>() {
@Override
public void onResponse(String response) {
callback.onSuccess(response);
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
}
});
mQueue.add(stringRequest);
}
@Override
public void get(String url, Map<String, Object> params, ICallback callback) {
}
}
XUtilsProcessor
package top.zcwfeng.httpprocessor_java_hilt;
import android.app.Application;
import org.xutils.common.Callback;
import org.xutils.http.RequestParams;
import org.xutils.x;
import java.util.Map;
import javax.inject.Inject;
public
class XUtilsProcessor implements IHttpProcessor {
@Inject
public XUtilsProcessor(Application app) {
x.Ext.init((MyApplication)app);
}
@Override
public void post(String url, Map<String, Object> params, ICallback callback) {
RequestParams requestParams = new RequestParams(url);
x.http().post(requestParams, new Callback.CommonCallback<String>() {
@Override
public void onSuccess(String result) {
callback.onSuccess(result);
}
@Override
public void onError(Throwable ex, boolean isOnCallback) {
}
@Override
public void onCancelled(CancelledException cex) {
}
@Override
public void onFinished() {
}
});
}
@Override
public void get(String url, Map<String, Object> params, ICallback callback) {
}
}
2.6 定义请求的Module，注入管理
package top.zcwfeng.httpprocessor_java_hilt;
import javax.inject.Singleton;
import dagger.Binds;
import dagger.Module;
import dagger.hilt.InstallIn;
import dagger.hilt.android.components.ApplicationComponent;
import top.zcwfeng.httpprocessor_java_hilt.annotation.BindOkHttp;
import top.zcwfeng.httpprocessor_java_hilt.annotation.BindVolley;
import top.zcwfeng.httpprocessor_java_hilt.annotation.BindXUtils;
@Module
@InstallIn(ApplicationComponent.class)
public abstract class HttpProcessorModule {
@BindOkHttp
@Singleton
@Binds
abstract IHttpProcessor bindOKHttp(OkHttpProcessor okHttpProcessor);
@BindVolley
@Singleton
@Binds
abstract IHttpProcessor bindVolley(VolleyProcessor okHttpProcessor);
@BindXUtils
@Singleton
@Binds
abstract IHttpProcessor bindXUtils(XUtilsProcessor okHttpProcessor);
}
为了区分我们@Binds的注入，我们添加三个annotation
BindOkHttp,BindVolley,BindXUtils 实现相同名字不同
package top.zcwfeng.httpprocessor_java_hilt.annotation;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import javax.inject.Qualifier;
@Qualifier
@Retention(RetentionPolicy.RUNTIME)
public @interface BindOkHttp {
}
2.7 全局注入Application使用
package top.zcwfeng.httpprocessor_java_hilt;
import android.app.Application;
import javax.inject.Inject;
import dagger.hilt.android.HiltAndroidApp;
import top.zcwfeng.httpprocessor_java_hilt.annotation.BindOkHttp;
@HiltAndroidApp
public class MyApplication extends Application {
@BindOkHttp
@Inject
IHttpProcessor iHttpProcessor;
public IHttpProcessor getiHttpProcessor(){
return iHttpProcessor;
}
}
2.8 MainActivity 进行测试
package top.zcwfeng.httpprocessor_java_hilt;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Toast;
import androidx.appcompat.app.AppCompatActivity;
import java.util.HashMap;
import dagger.hilt.android.AndroidEntryPoint;
import top.zcwfeng.httpprocessor_java_hilt.bean.ResponceData;
@AndroidEntryPoint
public class MainActivity extends AppCompatActivity {
//全局注入
IHttpProcessor iHttpProcessor;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
iHttpProcessor = ((MyApplication)getApplication()).getiHttpProcessor();
}
public void click(View view) {
Log.e("zcwfeng", "11111111");
String url="https://v.juhe.cn/historyWeather/citys";
HashMap<String,Object> params=new HashMap<>();
//https://v.juhe.cn/historyWeather/citys?&province_id=2&key=bb52107206585ab074f5e59a8c73875b
params.put("province_id","2");
params.put("key","bb52107206585ab074f5e59a8c73875b");
iHttpProcessor.post(url, params, new HttpCallback<ResponceData>() {
@Override
public void onSuccess(ResponceData objResult) {
Log.e("zcwfeng", "click(View view) ==== onSuccess");
Toast.makeText(MainActivity.this, objResult.getResultcode(), Toast.LENGTH_SHORT).show();
}
});
}
}
