002 使用鸿蒙WebView创建简单浏览器 step 2 - HarmonyOS技术社区 - 电子技术论坛

人工智能姬

2021-04-19 21:45:54

002 使用鸿蒙WebView创建简单浏览器 step 2

通过DataAbility给简易浏览器增加历史记录存储

学习鸿蒙的点滴记录在Gitee上面:https://gitee.com/javaaier/HarmonyOSNotes

注:本次笔记及代码中使用了发发老师(钟洪发)视频的配套代码.侵删.

添加数据库类
@Database(entities = {WebViewHistory.class, WebViewFavorite.class}, version = 1)
public abstract class WebViewStore extends OrmDatabase {
}
添加历史记录类
@Entity(tableName = "WebViewHistory",
indices = {@Index(value = {"historyId"}, name = "historyId_index", unique = true)})
public class WebViewHistory extends OrmObject{
@PrimaryKey(autoGenerate = true)
private Integer historyId;
private Long browseTime;
private String url;
private String title;
... 省略了 getters setters toString方法
}
添加Data Ability,并实现增加和查询的方法
public class WebViewHistoryAbility extends Ability {
private static final HiLogLabel LABEL_LOG = new HiLogLabel(3, 0xD001100, "Demo");
private OrmContext ormContext = null;

@Override
public void onStart(Intent intent) {
      super.onStart(intent);
      HiLog.info(LABEL_LOG, "WebViewHistoryAbility onStart");
      DatabaseHelper databaseHelper = new DatabaseHelper(this);
      ormContext = databaseHelper.getOrmContext("WebViewStore", "WebViewStore.db", WebViewStore.class, null);
}

@Override
public ResultSet query(Uri uri, String[] columns, DataAbilityPredicates predicates) {
      HiLog.info(LABEL_LOG, "WebViewHistoryAbility query");
      if (ormContext == null) {
         return null;
      }
      System.out.println("----------------------------开始获取数据--------------------------");
      //真正查询数据的语句
      OrmPredicates ormPredicates = DataAbilityUtils.createOrmPredicates(predicates, WebViewHistory.class);
      ResultSet rs = ormContext.query(ormPredicates, columns);
      return rs;
}

@Override
public int insert(Uri uri, ValuesBucket value) {
      HiLog.info(LABEL_LOG, "WebViewHistoryAbility insert");
      if (ormContext == null) {
         return -1;
      }
      System.out.println("----------------------------开始写入数据--------------------------");
      WebViewHistory history = new WebViewHistory();
      history.setBrowseTime(value.getLong("browseTime"));
      history.setTitle(value.getString("title"));
      history.setUrl(value.getString("url"));
      boolean insert = ormContext.insert(history);
      if (!insert) {
         return -1;
      }
      boolean flush = ormContext.flush();
      if (!flush) {
         return -1;
      }
      int id = Math.toIntExact(history.getRowId());
      System.out.println("----------------------------写入数据完成--------------------------");
      return id;

}
在config.json文件中添加权限
  "reqPermissions": [
   {
      "name": "ohos.permission.INTERNET"
   },
   {
      "name": "ohos.permission.GET_DISTRIBUTED_DEVICE_INFO"
   },
   {
      "name": "ohos.permission.DISTRIBUTED_DATASYNC"
   },
   {
      "name": "ohos.permission.READ_USER_STORAGE"
   },
   {
      "name": "com.javaaier.family.huawei.DataAbilityShellProvider.PROVIDER"
   }
],
"defPermissions": [
   {
      "name": "com.javaaier.family.huawei.DataAbilityShellProvider.PROVIDER",
      "grantMode": "system_grant"
   }
]
修改WebView界面,增加查看历史记录的按钮(本次笔记只记录输出历史记录到控制台)
//定义历史记录Data Ability的Uri
historyUri = Uri.parse("dataability:///com.javaaier.family.huawei.WebViewHistoryAbility");

//新增历史记录
ValuesBucket values = new ValuesBucket();
            values.putLong("browseTime", System.currentTimeMillis());
            values.putString("url", "url");
            values.putString("title", webView.getTitle());
            try {
                  int insertRowId = helper.insert(historyUri, values);
            } catch (DataAbilityRemoteException e) {
                  e.printStackTrace();
            }

// 查看历史记录
  case ResourceTable.Id_button_webView_viewHistory: {
                  try {
                     DataAbilityPredicates dap = new DataAbilityPredicates();
                     dap.orderByDesc("browseTime");
                     ResultSet rs = helper.query(historyUri,
                              new String[]{"historyId", "browseTime", "url", "title"},
                              dap);
                     Utils.showTip(SimpleWebViewAbilitySlice.this, "已读取数据");
                     if (rs.getRowCount() > 0) {
                        rs.goToFirstRow();
                        for (int i = 0; i < rs.getRowCount(); i++) {
                              System.out.println("查询出来的数据："
                                    + rs.getInt(rs.getColumnIndexForName("historyId")) + "," +
                                    rs.getLong(rs.getColumnIndexForName("browseTime")) + "," +
                                    rs.getString(rs.getColumnIndexForName("url")) + "," +
                                    rs.getString(rs.getColumnIndexForName("title")));
                              rs.goToNextRow();
                        }
                     }
                  } catch (DataAbilityRemoteException e) {
                     e.printStackTrace();
                  }
            }
运行及验证是否正确
最终记录和读取的历史记录如下图所示:

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[文章]002 使用鸿蒙WebView创建简单浏览器 step 2

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