一、简介
一、代码
1.xml
(1)main.xml
1 <?xml version="1.0" encoding="utf-8"?> 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 3 android:orientation="vertical" android:layout_width="fill_parent" 4 android:layout_height="fill_parent"> 5 <Button android:id="@+id/insertButton" android:layout_width="fill_parent" 6 android:layout_height="wrap_content" android:text="insert" /> 7 <Button android:id="@+id/queryButton" android:layout_width="fill_parent" 8 android:layout_height="wrap_content" android:text="query" /> 9 </LinearLayout>
(2)AndroidManifest.xml.xml
1 <?xml version="1.0" encoding="utf-8"?> 2 <manifest xmlns:android="http://schemas.android.com/apk/res/android" 3 package="com.example.s01_original_e16_textcp" 4 android:versionCode="1" 5 android:versionName="1.0" > 6 7 <uses-sdk 8 android:minSdkVersion="8" 9 android:targetSdkVersion="21" /> 10 11 <application 12 android:allowBackup="true" 13 android:icon="@drawable/ic_launcher" 14 android:label="@string/app_name" 15 android:theme="@style/AppTheme" > 16 <activity 17 android:name=".CPActivity" 18 android:label="@string/app_name" > 19 <intent-filter> 20 <action android:name="android.intent.action.MAIN" /> 21 22 <category android:name="android.intent.category.LAUNCHER" /> 23 </intent-filter> 24 </activity> 25 <provider android:name="com.example.s01_original_e16_textcp.FirstContentProvider" 26 android:authorities="tony.cp.FirstContentProvider" /> 27 </application> 28 29 </manifest>
2.java
(1)CPActivity.java
1 package com.example.s01_original_e16_textcp;
2
3 import android.app.Activity;
4 import android.content.ContentValues;
5 import android.database.Cursor;
6 import android.net.Uri;
7 import android.os.Bundle;
8 import android.view.View;
9 import android.widget.Button;
10
11 import com.example.s01_original_e16_textcp.FirstProviderMetaData.UserTableMetaData;
12
13 public class CPActivity extends Activity {
14 /** Called when the activity is first created. */
15 private Button insertButton = null;
16 private Button queryButton = null;
17
18 @Override
19 public void onCreate(Bundle savedInstanceState) {
20 super.onCreate(savedInstanceState);
21 setContentView(R.layout.main);
22 insertButton = (Button) findViewById(R.id.insertButton);
23 insertButton.setOnClickListener(new View.OnClickListener() {
24
25 @Override
26 public void onClick(View v) {
27 ContentValues values = new ContentValues();
28 values.put(FirstProviderMetaData.UserTableMetaData.USER_NAME,
29 "zhangsan");
30 Uri uri = getContentResolver().insert(
31 FirstProviderMetaData.UserTableMetaData.CONTENT_URI,
32 values);
33 System.out.println("uri ---> " + uri.toString());
34 }
35 });
36 queryButton = (Button) findViewById(R.id.queryButton);
37 queryButton.setOnClickListener(new View.OnClickListener() {
38
39 @Override
40 public void onClick(View v) {
41 Cursor c = getContentResolver().query(
42 FirstProviderMetaData.UserTableMetaData.CONTENT_URI,
43 null, null, null, null);
44 while (c.moveToNext()) {
45 System.out.println(c.getString(c
46 .getColumnIndex(UserTableMetaData.USER_NAME)));
47 }
48
49 }
50 });
51 }
52 }
(2)FirstContentProvider.java
1 package com.example.s01_original_e16_textcp;
2
3 import java.util.HashMap;
4
5 import android.content.ContentProvider;
6 import android.content.ContentUris;
7 import android.content.ContentValues;
8 import android.content.UriMatcher;
9 import android.database.Cursor;
10 import android.database.SQLException;
11 import android.database.sqlite.SQLiteDatabase;
12 import android.database.sqlite.SQLiteQueryBuilder;
13 import android.net.Uri;
14 import android.text.TextUtils;
15
16 import com.example.s01_original_e16_textcp.FirstProviderMetaData.UserTableMetaData;
17
18 public class FirstContentProvider extends ContentProvider {
19
20 // UriMatcher用来检查URI是否合法
21 public static final UriMatcher uriMatcher;
22 public static final int INCOMING_USER_COLLECTION = 1;
23 public static final int INCOMING_USER_SINGLE = 2;
24
25 private DatabaseHelper dh;
26
27 static {
28 uriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
29 uriMatcher.addURI(FirstProviderMetaData.AUTHORITY, "users",
30 INCOMING_USER_COLLECTION);
31 uriMatcher.addURI(FirstProviderMetaData.AUTHORITY, "users/#",
32 INCOMING_USER_SINGLE);
33 }
34
35 //相当于给sql的列起别名
36 public static HashMap<String, String> userProjectionMap;
37 static {
38 userProjectionMap = new HashMap<String, String>();
39 userProjectionMap.put(UserTableMetaData._ID, UserTableMetaData._ID);
40 userProjectionMap.put(UserTableMetaData.USER_NAME,
41 UserTableMetaData.USER_NAME);
42 }
43
44 @Override
45 public int delete(Uri arg0, String arg1, String[] arg2) {
46 // TODO Auto-generated method stub
47 System.out.println("delete...");
48 return 0;
49 }
50
51 // 根据传入的URI，返回该URI所表示的数据类型
52 @Override
53 public String getType(Uri uri) {
54 System.out.println("getType...");
55 switch (uriMatcher.match(uri)) {
56 case INCOMING_USER_COLLECTION:
57 return UserTableMetaData.CONTENT_TYPE;
58 case INCOMING_USER_SINGLE:
59 return UserTableMetaData.CONTENT_TYPE_ITEM;
60 default:
61 throw new IllegalArgumentException("Unknow URI " + uri);
62 }
63 }
64
65 /**
66 * 该函数的返回值是一个Uri，这个Uri表示的是刚刚那使用这个函数所插入的数据
67 * content://ycitss.cp.firstContentProivder/users/1
68 */
69 @Override
70 public Uri insert(Uri uri, ContentValues values) {
71 System.out.println("insert...");
72 SQLiteDatabase db = dh.getWritableDatabase();
73 long rowId = db.insert(UserTableMetaData.TABLE_NAME, null, values);
74 if (rowId > 0) {
75 Uri insertedUserUri = ContentUris.withAppendedId(
76 UserTableMetaData.CONTENT_URI, rowId);
77 // 通知监听器，数据已经修改
78 getContext().getContentResolver().notifyChange(insertedUserUri,
79 null);
80 return insertedUserUri;
81 }
82 throw new SQLException("Failed to insert row into " + uri);
83 }
84
85 // 是一个回调方法，所以说在ContentProvider创建的时候执行
86 @Override
87 public boolean onCreate() {
88 dh = new DatabaseHelper(getContext(),
89 FirstProviderMetaData.DATABASE_NAME);
90 System.out.println("onCreate...");
91 return true;
92 }
93
94 @Override
95 public Cursor query(Uri uri, String[] projection, String selection,
96 String[] selectionArgs, String sortOrder) {
97 SQLiteQueryBuilder qb = new SQLiteQueryBuilder();
98 switch (uriMatcher.match(uri)) {
99 case INCOMING_USER_COLLECTION:
100 qb.setTables(UserTableMetaData.TABLE_NAME);
101 qb.setProjectionMap(userProjectionMap);
102 break;
103 case INCOMING_USER_SINGLE:
104 qb.setTables(UserTableMetaData.TABLE_NAME);
105 qb.setProjectionMap(userProjectionMap);
106 qb.appendWhere(UserTableMetaData._ID + "="
107 + uri.getPathSegments().get(1));
108 break;
109 }
110 String orderBy;
111 if (TextUtils.isEmpty(sortOrder)) {
112 orderBy = UserTableMetaData.DEFAULT_SORT_ORDER;
113 } else {
114 orderBy = sortOrder;
115 }
116 SQLiteDatabase db = dh.getWritableDatabase();
117 Cursor c = qb.query(db, projection, selection, selectionArgs, null,
118 null, orderBy);
119 c.setNotificationUri(getContext().getContentResolver(), uri);
120 System.out.println("query...");
121 return c;
122 }
123
124 @Override
125 public int update(Uri uri, ContentValues values, String selection,
126 String[] selectionArgs) {
127 System.out.println("update...");
128 return 0;
129 }
130
131 }
(3)FirstProviderMetaData.java
1 package com.example.s01_original_e16_textcp;
2
3 import android.net.Uri;
4 import android.provider.BaseColumns;
5
6 public class FirstProviderMetaData {
7 // 必需与AndroidManifest.xml中定义的android:authorities一致
8 public static final String AUTHORITY = "tony.cp.FirstContentProvider";
9 // 数据库名称
10 public static final String DATABASE_NAME = "FirstProvider.db";
11 // 数据库版本
12 public static final int DATABASE_VERSION = 1;
13 // 表名
14 public static final String USERS_TABLE_NAME = "users";
15
16 public static final class UserTableMetaData implements BaseColumns {
17 // 表名
18 public static final String TABLE_NAME = "users";
19 // 访问该ContentProvider的URI
20 public static final Uri CONTENT_URI = Uri.parse("content://"
21 + AUTHORITY + "/users");
22 // 该contentProvider所返回的数据类型的定义
23 public static final String CONTENT_TYPE = "vnd.android.cursor.dir/vnd.firstprovider.user";//访问整张表
24 public static final String CONTENT_TYPE_ITEM = "vnd.android.cursor.item/vnd.firstprovider.user";//取一条数据
25 // 列名
26 public static final String USER_NAME = "name";
27 // 默认的排序方法
28 public static final String DEFAULT_SORT_ORDER = "_id desc";
29 }
30 }
(4)DatabaseHelper.java
1 package com.example.s01_original_e16_textcp;
2
3 import android.content.Context;
4 import android.database.sqlite.SQLiteDatabase;
5 import android.database.sqlite.SQLiteDatabase.CursorFactory;
6 import android.database.sqlite.SQLiteOpenHelper;
7
8 public class DatabaseHelper extends SQLiteOpenHelper {
9 private static final int VERSION = 1;
10
11 public DatabaseHelper(Context context, String name, CursorFactory factory,
12 int version) {
13 super(context, name, factory, version);
14 // TODO Auto-generated constructor stub
15 }
16
17 public DatabaseHelper(Context context, String name, int version) {
18 this(context, name, null, version);
19 }
20
21 public DatabaseHelper(Context context, String name) {
22 this(context, name, VERSION);
23 }
24
25 // 该函数是在第一次创建数据库的时候执行，实际上是在第一次得到SQLiteDAtabase对象的时候，才会调用这个方法
26 @Override
27 public void onCreate(SQLiteDatabase db) {
28 System.out.println("cteate a Database");
29 // execSQL函数用于执行SQL语句
30 db.execSQL("create table " + FirstProviderMetaData.USERS_TABLE_NAME
31 + "(" + FirstProviderMetaData.UserTableMetaData._ID
32 + " INTEGER_PARIMARY_AUTOINCREMENT,"
33 + FirstProviderMetaData.UserTableMetaData.USER_NAME
34 + " varchar(20))");
35 }
36
37 @Override
38 public void onUpgrade(SQLiteDatabase db, int arg1, int arg2) {
39 System.out.println("update a Database");
40 }
41
42 }
时间： 2024-10-03 09:43:23