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。

 

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

 

好了那么我们现在来实现吧

 

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;

 

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;
	}
}

 

 

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;
	}
}

 

 

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>

 

 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

 

下面我再将sqlitHelper贴出来

 

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);
		}

		@Override
		public void onCreate(SQLiteDatabase db) {
			Log.i(TAG, "onCreate ");
			createTable(db);
		}

		@Override
		public 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);
		}

		@Override
		public 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