验证 Loader 行为

heyblood · Jan 26, 2021 · ca58a71 · ca58a71
1 parent 732b6ca
commit ca58a71
Show file tree

Hide file tree

Showing 3 changed files with 18 additions and 6 deletions.
diff --git a/app/src/main/java/com/example/quakereport/EarthquakeActivity.java b/app/src/main/java/com/example/quakereport/EarthquakeActivity.java
@@ -17,13 +17,11 @@
 
 import android.content.Intent;
 import android.net.Uri;
-import android.os.AsyncTask;
 import android.os.Bundle;
 import android.util.Log;
 import android.view.View;
 import android.widget.AdapterView;
 import android.widget.ListView;
-import android.widget.Toast;
 
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
@@ -58,6 +56,8 @@ public class EarthquakeActivity extends AppCompatActivity implements LoaderManag
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
+        Log.i(LOG_TAG, "TEST: onCreate() called ...");
+
         super.onCreate(savedInstanceState);
         setContentView(R.layout.earthquake_activity);
 
@@ -96,18 +96,23 @@ public void onItemClick(AdapterView<?> adapterView, View view, int position, lon
         // 初始化 loader。传递上面定义的整数 ID 常量并作为捆绑
         // 传递 null。为 LoaderCallbacks 参数（由于
         // 此活动实现了 LoaderCallbacks 接口而有效）传递此活动。
+        Log.i(LOG_TAG, "TEST: loaderManager.initLoader() called ...");
         loaderManager.initLoader(EARTHQUAKE_LOADER_ID, null, this);
     }
 
     @NonNull
     @Override
     public Loader<List<Earthquake>> onCreateLoader(int id, @Nullable Bundle args) {
+        Log.i(LOG_TAG, "TEST: onCreateLoader() called ...");
+
         // 为给定 URL 创建新 loader
         return new EarthquakeLoader(this, USGS_REQUEST_URL);
     }
 
     @Override
     public void onLoadFinished(@NonNull Loader<List<Earthquake>> loader, List<Earthquake> earthquakes) {
+        Log.i(LOG_TAG, "TEST: onLoadFinished() called ...");
+
         // 清除之前地震数据的适配器
         earthquakeAdapter.clear();
 
@@ -120,8 +125,10 @@ public void onLoadFinished(@NonNull Loader<List<Earthquake>> loader, List<Earthq
 
     @Override
     public void onLoaderReset(@NonNull Loader<List<Earthquake>> loader) {
+        Log.i(LOG_TAG, "TEST: onLoaderReset() called ...");
+
         // 重置 Loader，以便能够清除现有数据。
         earthquakeAdapter.clear();
     }
-    
+
 }
diff --git a/app/src/main/java/com/example/quakereport/EarthquakeLoader.java b/app/src/main/java/com/example/quakereport/EarthquakeLoader.java
@@ -1,6 +1,7 @@
 package com.example.quakereport;
 
 import android.content.Context;
+import android.util.Log;
 
 import androidx.loader.content.AsyncTaskLoader;
 
@@ -35,6 +36,9 @@ public EarthquakeLoader(Context context, String url) {
 
     @Override
     protected void onStartLoading() {
+        Log.i(LOG_TAG, "TEST: onStartLoading() called ...");
+
+        // Loader 初始化完成后，立即强制启动
         forceLoad();
     }
 
@@ -43,6 +47,8 @@ protected void onStartLoading() {
      */
     @Override
     public List<Earthquake> loadInBackground() {
+        Log.i(LOG_TAG, "TEST: loadInBackground() called ...");
+
         if (null == url) {
             return null;
         }

diff --git a/app/src/main/java/com/example/quakereport/QueryUtils.java b/app/src/main/java/com/example/quakereport/QueryUtils.java
@@ -11,13 +11,10 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
-import java.io.Reader;
 import java.net.HttpURLConnection;
 import java.net.MalformedURLException;
 import java.net.URL;
-import java.text.SimpleDateFormat;
 import java.util.ArrayList;
-import java.util.Date;
 import java.util.List;
 
 /**
@@ -184,6 +181,8 @@ private static List<Earthquake> extractFeatureFromJson(String earthquakeJSON) {
      * 查询 USGS 数据集并返回 {@link Earthquake} 对象的列表。
      */
     public static List<Earthquake> fetchEarthquakeData(String requestUrl) {
+        Log.i(LOG_TAG, "TEST: fetchEarthquakeData() called ...");
+
         // 创建 URL 对象
         URL url = createUrl(requestUrl);