android数据库操作(一)
为了以后的项目使用Android数据库更方便，自已写了一个小的应用框架，不知道算不算称得上框架，反正自已用起来觉得还是挺方便的，参考Hibernate了应用思想。
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业务介绍
1、建一个数据库madfiger.db
2、建一个用户表UserInfo,包含一些用户基本字段
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好了那么我们现在来实现吧
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1、新建UserInfo实体类，继承AbstractBaseModel，UserInfo的类名为数据库表名，字段分别为实现了Get与Set方式的实性字段;
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UserInfo代码如下：
package cn.company.android.project.model;import java.util.Calendar;import java.util.Date;import java.util.Locale;import cn.madfinger.android.core.AbstractBaseModel;import cn.madfinger.android.core.util.DateUtils;public class UserInfo extends AbstractBaseModel{private static final long serialVersionUID = -7079062473198239915L;private String id;private String username;private String password;private String birthday;private int gender;private float weight;private Date createTime=DateUtils.long2Date(Calendar.getInstance(Locale.CHINESE).getTimeInMillis());public UserInfo(){super();}public String getId() {return id;}public void setId(String id) {this.id = id;}public String getUsername() {return username;}public void setUsername(String username) {this.username = username;}public String getPassword() {return password;}public void setPassword(String password) {this.password = password;}public String getBirthday() {return birthday;}public void setBirthday(String birthday) {this.birthday = birthday;}public int getGender() {return gender;}public void setGender(int gender) {this.gender = gender;}public float getWeight() {return weight;}public void setWeight(float weight) {this.weight = weight;}public Date getCreateTime() {return createTime;}public void setCreateTime(Date createTime) {this.createTime = createTime;}}?
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AbstractBaseModel代码如下：
package cn.madfinger.android.core;import java.io.Serializable;import java.lang.reflect.Method;import java.util.HashMap;import java.util.Iterator;import java.util.Map;import java.util.Set;import org.json.JSONObject;import android.util.Log;/** * 实体模型基类 * * @author wiley */public abstract class AbstractBaseModel implements Serializable {private static final long serialVersionUID = -4685989463430616599L;private static String TAG = AbstractBaseModel.class.getSimpleName();private static Map<String, String> TYPES = new HashMap<String, String>();static {TYPES.put("date", "TEXT");TYPES.put("string", "TEXT");TYPES.put("integer", "INTEGER");TYPES.put("int", "INTEGER");TYPES.put("short", "INTEGER");TYPES.put("long", "INTEGER");TYPES.put("float", "REAL");TYPES.put("double", "REAL");}public AbstractBaseModel() {TAG = this.getClass().getSimpleName();}public abstract String getId();public abstract void setId(String id);public Set<String> toFieldSet(){return this.toFieldMap().keySet();}public Map<String, String> toFieldMap() {Map<String, String> fieldMap = new HashMap<String, String>();Method[] methods = this.getClass().getMethods();try {String propertyName;String typeString;for (Method method : methods) {String methodName = method.getName();if (!methodName.startsWith("get")|| methodName.equalsIgnoreCase("getClass")|| methodName.equalsIgnoreCase("get"))continue;typeString = method.getReturnType().getSimpleName();propertyName = methodName.substring(3);fieldMap.put(propertyName, typeString);}} catch (Exception e) {Log.e(TAG, e.getMessage());}return fieldMap;}public String toCreateTableString() {StringBuilder sb = new StringBuilder();sb.append("CREATE TABLE ");sb.append(this.getClass().getSimpleName());sb.append(" (");int i = 0;Map<String, String> fieldMap = toFieldMap();Iterator<String> it = fieldMap.keySet().iterator();while (it.hasNext()) {String field = (String) it.next();String type = fieldMap.get(field).toLowerCase();if (i++ != 0)sb.append(",");sb.append(field.toUpperCase());sb.append(" " + (TYPES.containsKey(type)?TYPES.get(type):"NONE"));if (field.equalsIgnoreCase("id"))sb.append(" PRIMARY KEY");}sb.append(");");return sb.toString();}public String toJSONString() {return this.toJSON().toString();}public JSONObject toJSON() {Method[] methods = this.getClass().getMethods();JSONObject json = new JSONObject();Object propertyValue;String propertyName;try {for (Method method : methods) {String methodName = method.getName();if (!methodName.startsWith("get")|| methodName.equalsIgnoreCase("getClass")|| methodName.equalsIgnoreCase("get"))continue;propertyValue = method.invoke(this, new Object[] {});propertyName = methodName.substring(3);propertyName = Character.toLowerCase(propertyName.charAt(0))+ propertyName.substring(1);json.put(propertyName, propertyValue);}} catch (Exception e) {Log.e(TAG, e.getMessage());}return json;}}?
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实体类新建后配置Sqlite.xml,此文件位与res/string下
<?xml version="1.0" encoding="utf-8"?><resources><!-- 数据库版本 --><string name="database_version">1</string><!-- 数据库名称 --> <string name="database_name">madfinger.db</string> <!-- 数据表对应实列 --> <string-array name="model_beans"> <item>cn.company.android.project.model.UserInfo</item> </string-array></resources>
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?在软件启动时new SqlitHelper,那么在数据库与表将被自动新建,若需要新建多张表的话只需要新建多个继承AbstractBaseModel类的实体类，并添加至sqlite.xml中即可
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下面我再将sqlitHelper贴出来
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package cn.madfinger.android.core;import java.util.LinkedList;import java.util.List;import android.content.Context;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteOpenHelper;import android.util.Log;import cn.company.android.project.R;import cn.madfinger.android.core.util.StrUtils;/** * 数据库初始化 * @author wiley * */public class SqliteHelper {private static final String TAG = SqliteHelper.class.getSimpleName();private static SQLiteDatabase mWriterHandler;private static SQLiteDatabase mReaderHandler;private static int mVersion;private static String mDatabase;public static List<Class<? extends AbstractBaseModel>> mBeanList = new LinkedList<Class<? extends AbstractBaseModel>>();private DatabaseHelper mDBHelper;@SuppressWarnings("unchecked")public SqliteHelper(Context context) {Log.i(TAG, "new SqliteHelper");mVersion=StrUtils.str2int(context.getResources().getString(R.string.database_version), 1);mDatabase=StrUtils.null2string(context.getResources().getString(R.string.database_name), "madfinger.db");String[] modelBeans=context.getResources().getStringArray(R.array.model_beans);if(null!=modelBeans){for(String modelBean:modelBeans){try {mBeanList.add((Class<? extends AbstractBaseModel>)Class.forName(modelBean));} catch (ClassNotFoundException e) {Log.d(TAG, "",e);}}}//初始化数据库if(null!=mBeanList&&mBeanList.size()>0){mDBHelper = new DatabaseHelper(context);mWriterHandler=mDBHelper.getWritableDatabase();}}public SQLiteDatabase getWriterHandler() {if(null==mWriterHandler)mWriterHandler=mDBHelper.getWritableDatabase();return mWriterHandler;}public SQLiteDatabase getReaderHandler() {if(null==mReaderHandler)mReaderHandler=mDBHelper.getWritableDatabase();return mReaderHandler;}public void release() {if (null != mWriterHandler) {mWriterHandler.close();mWriterHandler = null;}if(null!=mReaderHandler){mReaderHandler.close();mReaderHandler=null;}}private static class DatabaseHelper extends SQLiteOpenHelper {DatabaseHelper(Context context) {super(context,mDatabase , null, mVersion);}@Overridepublic void onCreate(SQLiteDatabase db) {Log.i(TAG, "onCreate ");createTable(db);}@Overridepublic void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {Log.i(TAG, "Upgrading database from version " + oldVersion + " to "+ newVersion + ", which will destroy all old data");// 删除旧表格deleteTable(db);// 创建新表createTable(db);}@Overridepublic void onOpen(SQLiteDatabase db) {super.onOpen(db);Log.i(TAG, "onOpen ");}/* * 创建所有表 */private void createTable(SQLiteDatabase db) {Log.i(TAG, "createTable begin");for(Class<? extends AbstractBaseModel> clazz:mBeanList){try {String sqlString = clazz.newInstance().toCreateTableString();Log.i(TAG, sqlString);db.execSQL(sqlString);} catch (IllegalAccessException e) {Log.e(TAG, "",e);} catch (InstantiationException e) {Log.e(TAG, "",e);}}Log.i(TAG, "createTable end");}/* * 删除所有表 */private void deleteTable(SQLiteDatabase db) {Log.i(TAG, "deleteTable begin");String sql = "DROP TABLE IF EXISTS ";for(Class<? extends AbstractBaseModel> clazz:mBeanList){Log.i(TAG, sql + clazz.getSimpleName());db.execSQL(sql + clazz.getSimpleName());}Log.i(TAG, "deleteTable end");}}}?
?数据库操作将在后一章节中分享给大家