在我们的开发中，为了提高开发效率，我们一般都会使用到框架，ormilte则是我们必不可少的数据库框架。
对于ORMLite我也是今天才刚刚接触，我们先从一个简单的项目来了解它吧。
ORMLite jar
要想使用ormlite，我们要先下载其jar包。
下载方法：
我们可以到官网去下载：http://ormlite.com/releases/
下载的时候，我们要下载一个core的jar和android的jar，本人用的是ormlite-android-5.0.jar和ormlite-core-5.0.jar
然后把我们下载好的jar放在我项目中的lib下，然后加载到项目中即可
编写Bean类
1 package com.example.bean;
2
3 import com.j256.ormlite.field.DatabaseField;
4 import com.j256.ormlite.table.DatabaseTable;
5
6 @DatabaseTable(tableName="t_student")
7 public class student {
8
9 //generatedId表示该字段名为主键，却自增长
10 @DatabaseField(generatedId=true)
11 private int stuId;
12 @DatabaseField(columnName="stuName")
13 private String stuName;
14 @DatabaseField(columnName="age")
15 private int age;
16 public int getStuId() {
17 return stuId;
18 }
19 public void setStuId(int stuId) {
20 this.stuId = stuId;
21 }
22 public String getStuName() {
23 return stuName;
24 }
25 public void setStuName(String stuName) {
26 this.stuName = stuName;
27 }
28 public int getAge() {
29 return age;
30 }
31 public void setAge(int age) {
32 this.age = age;
33 }
34
35 }
@DatabaseTable(tableName = "tb_user")，标明这是数据库中的一张表
@DatabaseField(columnName = "name") ，columnName的值为该字段在数据中的列名
@DatabaseField(generatedId = true) ，generatedId 表示id为主键且自动生成
编写ORMilte的dao包
package com.example.ormlitetest;
import java.sql.SQLException;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.util.Log;
import com.example.bean.student;
import com.j256.ormlite.android.apptools.OrmLiteSqliteOpenHelper;
import com.j256.ormlite.dao.Dao;
import com.j256.ormlite.support.ConnectionSource;
import com.j256.ormlite.table.TableUtils;
public class DataBaseHelp extends OrmLiteSqliteOpenHelper{
private static final int version = 1;
private static final String DB_NAME = "text_data.db";
//每张表对应一个
private Dao<student,Integer> studao ;
public Dao<student,Integer> getDao() throws SQLException{
if(studao == null){
studao = getDao(student.class);
}
return studao;
}
public DataBaseHelp(Context context) {
super(context, DB_NAME, null, version);
// TODO Auto-generated constructor stub
}
@Override
public void onCreate(SQLiteDatabase db, ConnectionSource connectionSource) {
try {
TableUtils.createTable(connectionSource, student.class);
Log.i("tag", "创建数据库success");
} catch (Exception e) {
Log.i("tag", "错误");
}
}
@Override
public void onUpgrade(SQLiteDatabase arg0, ConnectionSource arg1, int arg2,
int arg3) {
// TODO Auto-generated method stub
}
@Override
public void close() {
// TODO Auto-generated method stub
super.close();
studao = null;
}
}
这里我们需要继承OrmLiteSqliteOpenHelper，其实就是间接继承了SQLiteOpenHelper
然后需要实现两个方法：
1、onCreate(SQLiteDatabase database,ConnectionSource connectionSource)
创建表，我们直接使用ormlite提供的TableUtils.createTable(connectionSource, User.class);进行创建~
2、onUpgrade(SQLiteDatabase database, ConnectionSource connectionSource, int oldVersion, int newVersion)
更新表，使用ormlite提供的TableUtils.dropTable(connectionSource, User.class, true);进行删除操作~
删除完成后，别忘了，创建操作：onCreate(database, connectionSource);
MainActivity类通用数据库
1 package com.example.ormlitetest;
2
3 import java.sql.SQLException;
4 import java.util.*;
5
6 import com.example.bean.student;
7
8 import android.app.Activity;
9 import android.database.sqlite.SQLiteDatabase;
10 import android.os.Bundle;
11 import android.util.Log;
12 import android.view.LayoutInflater;
13 import android.view.View;
14 import android.view.ViewGroup;
15 import android.widget.BaseAdapter;
16 import android.widget.ListView;
17 import android.widget.TextView;
18
19 public class MainActivity extends Activity {
20
21
22 private SQLiteDatabase db;
23 private ListView lv;
24 private List<student> stulist = new ArrayList<student>();
25
26 @Override
27 protected void onCreate(Bundle savedInstanceState) {
28 super.onCreate(savedInstanceState);
29 setContentView(R.layout.activity_main);
30
31 DataBaseHelp help = new DataBaseHelp(MainActivity.this);
32
33 for (int i = 0; i < 100; i++) {
34 student s = new student();
35 s.setStuName("好无聊" + i);
36 s.setAge(i);
37 try {
38 help.getDao().create(s);
39 } catch (SQLException e) {
40 // TODO Auto-generated catch block
41 e.printStackTrace();
42 }
43 }
44 try {
45 stulist = help.getDao().queryForAll();
46 } catch (SQLException e) {
47 // TODO Auto-generated catch block
48 e.printStackTrace();
49 }
50 lv = (ListView) findViewById(R.id.listView1);
51 lv.setAdapter(new BaseAdapter() {
52
53 public View getView(int position, View convertView, ViewGroup parent) {
54 View view = null;
55 if (convertView == null) {
56 Log.i("info:", "没有缓存，重新生成" + position);
57 LayoutInflater inflater = MainActivity.this
58 .getLayoutInflater();
59 // 因为getView()返回的对象，adapter会自动赋给ListView
60 view = inflater
61 .inflate(R.layout.list_item, null);
62 } else {
63 Log.i("info:", "有缓存，不需要重新生成" + position);
64 view = convertView;
65 }
66 student s = stulist.get(position);
67
68 TextView tv_userName = (TextView) view
69 .findViewById(R.id.tv_stuName);
70 tv_userName.setText(s.getStuName());
71 tv_userName.setTextSize(15);
72
73 TextView tv_lastMessage = (TextView) view
74 .findViewById(R.id.tv_age);
75 tv_lastMessage.setText(s.getAge()+"");
76 tv_lastMessage.setTextSize(12);
77
78 return view;
79 }
80
81 @Override
82 public long getItemId(int arg0) {
83 // TODO Auto-generated method stub
84 return 0;
85 }
86
87 @Override
88 public Object getItem(int arg0) {
89 // TODO Auto-generated method stub
90 return null;
91 }
92
93 @Override
94 public int getCount() {
95 // TODO Auto-generated method stub
96 return stulist.size();
97 }
98 });
99 help.close();
100 }
101
102 }
然后我们运行一下程序看一下
好了， 这就是本人对于ORMLite的初步了解。
时间： 2024-08-02 15:10:52