import android.net.Uri;import android.provider.BaseColumns;/** * @author 郭宏志 * 通讯录常量类 */public final class Employees {// 授权常量 public static final String AUTHORITY = "com.amaker.provider.Employees"; private Employees() {} // 内部类 public static final class Employee implements BaseColumns { // 构造方法 private Employee() {} // 访问Uri public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/employee"); // 内容类型 public static final String CONTENT_TYPE = "vnd.android.cursor.dir/vnd.amaker.employees"; public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/vnd.amaker.employees"; // 默认排序常量 public static final String DEFAULT_SORT_ORDER = "name DESC";// 按姓名排序 // 表字段常量 public static final String NAME = "name";// 姓名 public static final String GENDER= "gender";// 性别 public static final String AGE = "age"; // 年龄 }}
package com.amaker.ch10.app;import android.content.Context;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteOpenHelper;import com.amaker.ch10.app.Employees.Employee;/** * * @author 郭宏志 * 数据库工具类 */public class DBHelper extends SQLiteOpenHelper{ // 数据库名称常量 private static final String DATABASE_NAME = "Employees.db"; // 数据库版本常量 private static final int DATABASE_VERSION = 1; // 表名称常量 public static final String EMPLOYEES_TABLE_NAME = "employee";// 构造方法public DBHelper(Context context) {// 创建数据库super(context, DATABASE_NAME,null, DATABASE_VERSION);}// 创建时调用public void onCreate(SQLiteDatabase db) { db.execSQL("CREATE TABLE " + EMPLOYEES_TABLE_NAME + " (" + Employee._ID + " INTEGER PRIMARY KEY," + Employee.NAME + " TEXT," + Employee.GENDER + " TEXT," + Employee.AGE + " INTEGER" + ");");}// 版本更新时调用public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {// 删除表db.execSQL("DROP TABLE IF EXISTS employee"); onCreate(db);}}package com.amaker.ch10.app;import java.util.HashMap;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.database.sqlite.SQLiteQueryBuilder;import android.net.Uri;import android.text.TextUtils;import com.amaker.ch10.app.Employees.Employee;public class EmployeeProvider extends ContentProvider{// 数据库帮助类private DBHelper dbHelper; // Uri工具类 private static final UriMatcher sUriMatcher; // 查询、更新条件 private static final int EMPLOYEE = 1; private static final int EMPLOYEE_ID = 2; // 查询列集合 private static HashMap<String, String> empProjectionMap; static { // Uri匹配工具类 sUriMatcher = new UriMatcher(UriMatcher.NO_MATCH); sUriMatcher.addURI(Employees.AUTHORITY, "employee", EMPLOYEE); sUriMatcher.addURI(Employees.AUTHORITY, "employee/#", EMPLOYEE_ID); // 实例化查询列集合 empProjectionMap = new HashMap<String, String>(); // 添加查询列 empProjectionMap.put(Employee._ID, Employee._ID); empProjectionMap.put(Employee.NAME, Employee.NAME); empProjectionMap.put(Employee.GENDER, Employee.GENDER); empProjectionMap.put(Employee.AGE, Employee.AGE); }// 创建是调用public boolean onCreate() {// 实例化数据库帮助类dbHelper = new DBHelper(getContext());return true;}// 添加方法public Uri insert(Uri uri, ContentValues values) {// 获得数据库实例SQLiteDatabase db = dbHelper.getWritableDatabase();// 插入数据，返回行IDlong rowId = db.insert(DBHelper.EMPLOYEES_TABLE_NAME, Employee.NAME, values);// 如果插入成功返回uri if (rowId > 0) { Uri empUri = ContentUris.withAppendedId(Employee.CONTENT_URI, rowId); getContext().getContentResolver().notifyChange(empUri, null); return empUri; }return null;}// 删除方法public int delete(Uri uri, String selection, String[] selectionArgs) {// 获得数据库实例SQLiteDatabase db = dbHelper.getWritableDatabase(); // 获得数据库实例 int count; switch (sUriMatcher.match(uri)) { // 根据指定条件删除 case EMPLOYEE: count = db.delete(DBHelper.EMPLOYEES_TABLE_NAME, selection, selectionArgs); break; // 根据指定条件和ID删除 case EMPLOYEE_ID: String noteId = uri.getPathSegments().get(1); count = db.delete(DBHelper.EMPLOYEES_TABLE_NAME, Employee._ID + "=" + noteId + (!TextUtils.isEmpty(selection) ? " AND (" + selection + ')' : ""), selectionArgs); break; default: throw new IllegalArgumentException("错误的 URI " + uri); } getContext().getContentResolver().notifyChange(uri, null); return count;}// 获得类型public String getType(Uri uri) {return null;}// 查询方法public Cursor query(Uri uri, String[] projection, String selection,String[] selectionArgs, String sortOrder) { SQLiteQueryBuilder qb = new SQLiteQueryBuilder(); switch (sUriMatcher.match(uri)) { // 查询所有 case EMPLOYEE: qb.setTables(DBHelper.EMPLOYEES_TABLE_NAME); qb.setProjectionMap(empProjectionMap); break; // 根据ID查询 case EMPLOYEE_ID: qb.setTables(DBHelper.EMPLOYEES_TABLE_NAME); qb.setProjectionMap(empProjectionMap); qb.appendWhere(Employee._ID + "=" + uri.getPathSegments().get(1)); break; default: throw new IllegalArgumentException("Uri错误！ " + uri); } // 使用默认排序 String orderBy; if (TextUtils.isEmpty(sortOrder)) { orderBy = Employee.DEFAULT_SORT_ORDER; } else { orderBy = sortOrder; } // 获得数据库实例 SQLiteDatabase db = dbHelper.getReadableDatabase(); // 返回游标集合 Cursor c = qb.query(db, projection, selection, selectionArgs, null, null, orderBy); c.setNotificationUri(getContext().getContentResolver(), uri); return c;}// 更新方法public int update(Uri uri, ContentValues values, String selection,String[] selectionArgs) { // 获得数据库实例 SQLiteDatabase db = dbHelper.getWritableDatabase(); int count; switch (sUriMatcher.match(uri)) { // 根据指定条件更新 case EMPLOYEE: count = db.update(DBHelper.EMPLOYEES_TABLE_NAME, values, selection, selectionArgs); break; // 根据指定条件和ID更新 case EMPLOYEE_ID: String noteId = uri.getPathSegments().get(1); count = db.update(DBHelper.EMPLOYEES_TABLE_NAME, values, Employee._ID + "=" + noteId + (!TextUtils.isEmpty(selection) ? " AND (" + selection + ')' : ""), selectionArgs); break; default: throw new IllegalArgumentException("错误的 URI " + uri); } getContext().getContentResolver().notifyChange(uri, null); return count;}}
