17 一个ContentProvider的例子

服务端(ContentProvider)

• 目录结构图:
  

• MainActivity.java:

  package com.qf.day17_contentprovider_words_demo2;
  
  import android.app.Activity;
  import android.database.Cursor;
  import android.os.Bundle;
  import android.view.View;
  import android.widget.EditText;
  import android.widget.ListView;
  import android.widget.SimpleCursorAdapter;
  
  import com.qf.day17_contentprovider_words_demo2.db.MyOpenHelper;
  
  public class MainActivity extends Activity {
  
      private EditText etWord,etChina;
      private ListView lv;
  
  
      private MyOpenHelper helper;
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_main);
  
          etWord  = (EditText) findViewById(R.id.et_word);
          etChina  = (EditText) findViewById(R.id.et_china);
          lv = (ListView) findViewById(R.id.lv);
  
          helper = new MyOpenHelper(MainActivity.this);
  
          getData();
      }
  
      //点击事件  提交按钮
      public void MyClick(View v){
  
          String strWord = etWord.getText().toString().trim();
          String strChina= etChina.getText().toString().trim();
          String sql = "insert into tb_words(word,detail)values(?,?)";
          helper.execData(sql, new String[]{strWord,strChina});
  
          getData();
  
      }
  
      public void getData(){
  
          String sql = "select * from tb_words";
          Cursor cursor = helper.queryData(sql, null);
  
          SimpleCursorAdapter adapter = new SimpleCursorAdapter(MainActivity.this,
                  R.layout.item, cursor, 
                  new String[]{"word","detail"}, 
                  new int[]{R.id.tv_word,R.id.tv_china}, SimpleCursorAdapter.FLAG_REGISTER_CONTENT_OBSERVER);
  
          lv.setAdapter(adapter);
      }
  
  
  
  
  }
  

• MyOpenHelper.java(数据库类):

  package com.qf.day17_contentprovider_words_demo2.db;
  
  import android.content.Context;
  import android.database.Cursor;
  import android.database.sqlite.SQLiteDatabase;
  import android.database.sqlite.SQLiteDatabase.CursorFactory;
  import android.database.sqlite.SQLiteOpenHelper;
  
  public class MyOpenHelper extends SQLiteOpenHelper {
  
      private static final String NAME = "db_words.db";
      private static final int VERSION = 1;
  
      private SQLiteDatabase db;
  
      public MyOpenHelper(Context context, String name, CursorFactory factory,
              int version) {
          super(context, name, factory, version);
          // TODO Auto-generated constructor stub
      }
      public MyOpenHelper(Context context) {
          super(context, NAME, null, VERSION);
          // TODO Auto-generated constructor stub
          db = getReadableDatabase();
      }
  
  
      /**
       * 查询
       * @param sql
       * @param selectionArgs
       * @return
       */
      public Cursor queryData(String sql, String[] selectionArgs){
  
          Cursor cursor = db.rawQuery(sql, selectionArgs);
          return cursor;
  
      }
  
      /**
       * 增加  修改  删除
       * @param sql
       * @param bindArgs
       */
      public  boolean execData(String sql,Object[] bindArgs){
          try {
              if(bindArgs ==null){
                  db.execSQL(sql);
              }else{
                  db.execSQL(sql, bindArgs);
              }
  
              return true;
  
          } catch (Exception e) {
              // TODO: handle exception
          }
          return false;
      }
  
      @Override
      public void onCreate(SQLiteDatabase db) {
          // TODO Auto-generated method stub
          String sql ="create table if not exists tb_words(_id integer primary key autoincrement,word,detail)";
          //此表无作用只作为一个示范
          String sql1 ="create table if not exists tb_newwords(_id integer primary key autoincrement,word,detail)";
          db.execSQL(sql);
          db.execSQL(sql1);
  
      }
  
      @Override
      public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
          // TODO Auto-generated method stub
  
      }
  
  }
  

• MyContentProvider

  package com.qf.day17_contentprovider_words_demo2;
  
  import com.qf.day17_contentprovider_words_demo2.db.MyOpenHelper;
  
  import android.content.ContentProvider;
  import android.content.ContentUris;
  import android.content.ContentValues;
  import android.content.UriMatcher;
  import android.database.Cursor;
  import android.database.sqlite.SQLiteDatabase;
  import android.net.Uri;
  
  public class MyContentProvider extends ContentProvider{
  
  
      private MyOpenHelper helper;
      private SQLiteDatabase db;
  
      //com.qf.contentprovider_words.mycontentprovider 用于匹配意图的uri 
      private static UriMatcher uriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
  
      static{
  
          /**第一个参数 :意图 和清单文件中的authorities 相同
           * 第二个参数 :路径 
           * 第三个参数:对应uri对应编码
           *  通配符 : * 任意文本  #数字
           *  
           * 例子uriMatcher.addURI("aa.bb","cc/#",1)
           * 例子uriMatcher.addURI("aa.bb","cc/*",2)
           * 
           * 如果 在ContentResolver 的意图uri为  aa.bb.cc/3 那么跳转uriMatcher.addURI("aa.bb","cc/#",1)
           * 
           */
          //在内容解析器中只需要 填写 uri即可 例子 ： com.qf.contentprovider_words.mycontentprovider/words/123
          //content://com.qf.contentprovider_words.mycontentprovider/words/h
          uriMatcher.addURI("com.qf.contentprovider_words.mycontentprovider", "words", 1);
          uriMatcher.addURI("com.qf.contentprovider_words.mycontentprovider", "newwords", 2);
          uriMatcher.addURI("com.qf.contentprovider_words.mycontentprovider", "words/*", 3);//*匹配任意文本
          uriMatcher.addURI("com.qf.contentprovider_words.mycontentprovider", "words_id/#", 4);//*匹配任意数字
          uriMatcher.addURI("com.qf.contentprovider_words.mycontentprovider", "words_zh/*", 5);//*匹配任意中文
  
      }
  
  
      @Override
      public boolean onCreate() {
          // TODO Auto-generated method stub
          helper =  new MyOpenHelper(getContext());
          db  = helper.getReadableDatabase();
          return false;
      }
  
  
  
      @Override
      public String getType(Uri uri) {
          // TODO Auto-generated method stub
          return null;
      }
  
  
      @Override
      public Cursor query(Uri uri, String[] projection, String selection,
              String[] selectionArgs, String sortOrder) {
          // TODO Auto-generated method stub
  
          Cursor cursor =null;
  
          switch (uriMatcher.match(uri)) {
          case 1:
              //tb_words表中所有数据
              cursor = db.query("tb_words", projection, selection, selectionArgs, null, null, sortOrder);
  
              break;
          case 2:
              //tb_newwords表中所有数据
              cursor = db.query("tb_newwords", projection, selection, selectionArgs, null, null, sortOrder);
  
              break;
          case 3:
              //tb_words表中符合条件  word
              String data = uri.getLastPathSegment();//获取Uri最后的参数
              cursor = db.query("tb_words", projection, "word like ?", new String[]{data+"%"}, null, null, sortOrder);
  
              break;
          case 4:
              //tb_words表中符合条件 _id
              String data1 = uri.getLastPathSegment();//获取Uri最后的参数
              cursor = db.query("tb_words", projection, "_id = ?", new String[]{data1+""}, null, null, sortOrder);
  
              break;
          case 5:
  
              //tb_words表中符合条件 detail
              String data2 = uri.getLastPathSegment();//获取Uri最后的参数
              cursor = db.query("tb_words", projection, "detail like ?", new String[]{data2+"%"}, null, null, sortOrder);
  
              break;
  
          default:
              break;
          }
  
          return cursor;
      }
  
      @Override
      public Uri insert(Uri uri, ContentValues values) {
          // TODO Auto-generated method stub
  
          Uri resultUri = null;
          switch (uriMatcher.match(uri)) {
          case 1:
  
              long l = db.insert("tb_words", null, values);
              /**
               * 两种皆可返回正确id
               */
  //          resultUri = Uri.parse("content://com.qf.contentprovider_words.mycontentprovider/words/"+l);
              resultUri = ContentUris.withAppendedId(uri, l);
              break;
          case 2:
              long l1 = db.insert("tb_newwords", null, values);
              /**
               * 两种皆可返回正确id
               */
  //          resultUri = Uri.parse("content://com.qf.contentprovider_words.mycontentprovider/newwords/"+l1);
              resultUri = ContentUris.withAppendedId(uri, l1);
              break;
  
          default:
              break;
          }
          return resultUri;
      }
  
  
  
  
      @Override
      public int update(Uri uri, ContentValues values, String selection,
              String[] selectionArgs) {
          // TODO Auto-generated method stub
          int num =0;
          switch (uriMatcher.match(uri)) {
          case 1:
              num = db.update("tb_words", values, selection, selectionArgs);
              break;
          case 2:
              num = db.update("tb_newwords", values, selection, selectionArgs);
              break;
  
          default:
              break;
          }
          return num;
      }
  
      @Override
      public int delete(Uri uri, String selection, String[] selectionArgs) {
          // TODO Auto-generated method stub
          int num =0;
          switch (uriMatcher.match(uri)) {
          case 1:
              num = db.delete("tb_words", selection, selectionArgs);
              break;
          case 2:
              num = db.delete("tb_newwords", selection, selectionArgs);
              break;
  
          default:
              break;
          }
          return num;
      }
  
  }
  

• layout布局文件：
  item

  <?xml version="1.0" encoding="utf-8"?>
  <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:orientation="vertical" >
  
      <TextView 
          android:id="@+id/tv_word"
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:textColor="#f00"
          android:textSize="20sp"
          android:text="hello"
          />
      <TextView 
          android:id="@+id/tv_china"
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:textColor="#00f"
          android:textSize="16sp"
          android:text="word"
          />
  
  
  </LinearLayout>
  

  activity_main.xml

  <LinearLayout 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"
      android:orientation="vertical"
      tools:context=".MainActivity" >
  
  
  
      <EditText
          android:id="@+id/et_word"
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:hint="请输入英文单词" />
      <EditText
          android:id="@+id/et_china"
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:hint="请输入对应的意思" />
  
      <Button 
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_margin="10dp"
          android:text="提交"
          android:onClick="MyClick"
          />
  
      <TextView 
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:background="#999900"
          android:text="以下显示单词列表"
          />
  
      <ListView 
          android:id="@+id/lv"
          android:layout_width="match_parent"
          android:layout_height="match_parent"
          android:divider="#f00"
          android:dividerHeight="1dp"
          ></ListView>
  
  </LinearLayout>
  

---

客户端

• 结构目录:
  

• MainActivity.java:

  package com.qf.day17_contentprovider_wordc_demo2;
  
  import java.util.regex.Pattern;
  
  import android.app.Activity;
  import android.content.ContentResolver;
  import android.content.ContentUris;
  import android.content.ContentValues;
  import android.database.Cursor;
  import android.net.Uri;
  import android.os.Bundle;
  import android.text.TextUtils;
  import android.view.View;
  import android.widget.EditText;
  import android.widget.ListView;
  import android.widget.SimpleCursorAdapter;
  
  public class MainActivity extends Activity {
  
      // //content://com.qf.contentprovider_words.mycontentprovider/words/
      // uriMatcher.addURI("com.qf.contentprovider_words.mycontentprovider",
      // "words", 1);
      // uriMatcher.addURI("com.qf.contentprovider_words.mycontentprovider",
      // "newwords", 2);
      // uriMatcher.addURI("com.qf.contentprovider_words.mycontentprovider",
      // "words/*", 3);//*匹配任意文本
      // uriMatcher.addURI("com.qf.contentprovider_words.mycontentprovider",
      // "words_id/#", 4);//*匹配任意数字
      // uriMatcher.addURI("com.qf.contentprovider_words.mycontentprovider",
      // "words_zh/*", 5);//*匹配任意中文
      //
  
      private EditText etSearch;
      private ListView lv;
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_main);
          etSearch = (EditText) findViewById(R.id.et_search);
          lv = (ListView) findViewById(R.id.lv);
      }
  
      public void MyClick(View v) {
          // 根据输入文本进行查询
          String strdata = etSearch.getText().toString().trim();
  
          getData(strdata);
  
      }
  
  
  
      // 查询方法
      public void getData(String strdata) {
  
          ContentResolver resolver = getContentResolver();
          Uri uriWords = Uri.parse("content://com.qf.contentprovider_words.mycontentprovider/words");
          Uri uriWordsId = Uri.parse("content://com.qf.contentprovider_words.mycontentprovider/words_id");
          Uri uriWordsZh = Uri.parse("content://com.qf.contentprovider_words.mycontentprovider/words_zh");
          Cursor cursor = null;
          if (TextUtils.isEmpty(strdata)) {// 什么也没输入 直接查询所有
              cursor = resolver.query(uriWords, null, null, null, null);
          } else {
              if (isNumber(strdata)) {// 输入的数据 是否是数值
                  // content://com.qf.contentprovider_words.mycontentprovider/words_id/45
                  // 拼接id 123
                  uriWordsId = ContentUris.withAppendedId(uriWordsId, Long.parseLong(strdata));
                  cursor = resolver.query(uriWordsId, null, null, null, null);
              } else {
                  if (isChina(strdata)) {// 是否是汉字
                      // 拼接中文 张
                      uriWordsZh = Uri.withAppendedPath(uriWordsZh, strdata);
                      cursor = resolver.query(uriWordsZh, null, null, null, null);
                  } else {
                      // 拼接英文字符串 
                      uriWords = Uri.withAppendedPath(uriWords, strdata);
                      cursor = resolver.query(uriWords, null, null, null, null);
                  }
  
              }
          }
  
          SimpleCursorAdapter adapter = new SimpleCursorAdapter(MainActivity.this, R.layout.item, cursor,
                  new String[] { "word", "detail" }, new int[] { R.id.tv_word, R.id.tv_china },
                  SimpleCursorAdapter.FLAG_REGISTER_CONTENT_OBSERVER);
  
          lv.setAdapter(adapter);
  
      }
  
      // 判断是否是数字
      public boolean isNumber(String data) {
          Pattern pattern = Pattern.compile("[0-9]+");
          return pattern.matcher(data).matches();
  
      }
  
      // 判断是否是中文
      public boolean isChina(String data) {
          Pattern pattern = Pattern.compile("[u4e00-u9fa5]+");
          return pattern.matcher(data).matches();
  
      }
  
  }
  

• layout布局:
  activity_main.xml:

  <LinearLayout 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"
      android:orientation="vertical"
      tools:context=".MainActivity" >
  
      <EditText
          android:id="@+id/et_search"
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:hint="请输入查询内容" />
  
      <Button 
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:text="提交"
          android:onClick="MyClick"
          />
  
      <TextView 
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:text="以下展示查询内容"
          android:background="#999900"
          />
      <ListView 
          android:id="@+id/lv"
          android:layout_width="match_parent"
          android:layout_height="match_parent"
          ></ListView>
  
  </LinearLayout>
  

  item.xml

  <?xml version="1.0" encoding="utf-8"?>
  <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:orientation="vertical" >
  
      <TextView 
          android:id="@+id/tv_word"
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:textColor="#f00"
          android:textSize="20sp"
          android:text="hello"
          />
      <TextView 
          android:id="@+id/tv_china"
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:textColor="#00f"
          android:textSize="16sp"
          android:text="word"
          />
  
  
  </LinearLayout>