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:gitee.com/javaaier/Ha…

• 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.

1. 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:

作者：人工智能姬

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