android：kotlin语言使用greendao3

buildscript {

ext.kotlin_version = ‘1.1.50’

repositories {

mavenCentral()

google()

jcenter()

}

dependencies {

classpath ‘com.android.tools.build:gradle:3.0.0-beta7’

classpath “org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version”

classpath ‘org.greenrobot:greendao-gradle-plugin:3.2.0’

// NOTE: Do not place your application dependencies here; they belong

// in the individual module build.gradle files

}

}

步骤二、创建Student实体类

---

package tsou.com.simple.greendaoforkotlin.bean;

import android.support.annotation.Keep;

import org.greenrobot.greendao.annotation.Entity;

import org.greenrobot.greendao.annotation.Id;

import org.greenrobot.greendao.annotation.Generated;

@Entity(generateConstructors = false)

public class Student {

@Id

private Long id;

private String name;

private int age;

public Student() {

}

@Keep

public Student(String name, int age) {

this.name = name;

this.age = age;

}

public Student(Long id, String name, int age) {

this.id = id;

this.name = name;

this.age = age;

}

@Keep

public Long getId() {

return id;

}

@Keep

public void setId(Long id) {

this.id = id;

}

@Keep

public String getName() {

return name;

}

@Keep

public void setName(String name) {

this.name = name;

}

@Keep

public int getAge() {

return age;

}

@Keep

public void setAge(int age) {

this.age = age;

}

@Keep

@Override

public boolean equals(Object o) {

if (this == o) return true;

if (!(o instanceof Student)) return false;

Student student = (Student) o;

return name.equals(student.name);

}

@Keep

@Override

public int hashCode() {

return (int) (id ^ (id >>> 32));

}

@Keep

@Override

public String toString() {

return “Student{” +

“id=” + id +

“, name='” + name + ‘’’ +

“, age=” + age +

‘}’;

}

}

步骤三、修复一下工程，自动生成greendao包下的类（就是点击一下小锤子），你会自动生成greendao包中的类。

---

步骤四、开始使用，创建管理类

---

package tsou.com.simple.greendaoforkotlin.manager

import android.content.Context

import android.database.sqlite.SQLiteDatabase

import tsou.com.simple.greendaoforkotlin.greendao.DaoMaster

import tsou.com.simple.greendaoforkotlin.greendao.DaoSession

class DbManager private constructor(mContext: Context) {

private val DB_NAME = “test.db”

private var mDevOpenHelper: DaoMaster.DevOpenHelper? = null

private var mDaoMaster: DaoMaster? = null

private var mDaoSession: DaoSession? = null

init {

// 初始化数据库信息

mDevOpenHelper = DaoMaster.DevOpenHelper(mContext, DB_NAME)

getDaoMaster(mContext)

getDaoSession(mContext)

}

companion object {

@Volatile

var instance: DbManager? = null

fun getInstance(mContext: Context): DbManager? {

if (instance == null) {

synchronized(DbManager::class) {

if (instance == null) {

instance = DbManager(mContext)

}

}

}

return instance

}

}

/**

• 获取可读数据库

• @param context

• @return

*/

fun getReadableDatabase(context: Context): SQLiteDatabase? {

if (null == mDevOpenHelper) {

getInstance(context)

}

return mDevOpenHelper?.getReadableDatabase()

}

/**

• 获取可写数据库

• @param context

• @return

*/

fun getWritableDatabase(context: Context): SQLiteDatabase? {

if (null == mDevOpenHelper) {

getInstance(context)

}

return mDevOpenHelper?.getWritableDatabase()

}

/**

• 获取DaoMaster

• @param context

• @return

*/

fun getDaoMaster(context: Context): DaoMaster? {

if (null == mDaoMaster) {

synchronized(DbManager::class.java) {

if (null == mDaoMaster) {

mDaoMaster = DaoMaster(getWritableDatabase(context))

}

}

}

return mDaoMaster

}

/**

• 获取DaoSession

• @param context

• @return

*/

fun getDaoSession(context: Context): DaoSession? {

if (null == mDaoSession) {

synchronized(DbManager::class.java) {

mDaoSession = getDaoMaster(context)?.newSession()

}

}

return mDaoSession

}

}

步骤五、增删改查，

---

package tsou.com.simple.greendaoforkotlin.dao

import android.content.Context

import tsou.com.simple.greendaoforkotlin.bean.Student

import tsou.com.simple.greendaoforkotlin.greendao.StudentDao

import tsou.com.simple.greendaoforkotlin.manager.DbManager

class StudentDaoOpe private constructor() {

private object mHolder {

val instance = StudentDaoOpe()

}

companion object {

fun getInstance(): StudentDaoOpe {

return mHolder.instance

}

}

/**

• 添加数据至数据库

• @param context

• @param stu

*/

fun insertData(context: Context?, stu: Student) {

DbManager.getInstance(context!!)?.getDaoSession(context)?.getStudentDao()?.insert(stu)

}

/**

• 将数据实体通过事务添加至数据库

• @param context

• @param list

*/

fun insertData(context: Context?, list: List?) {

if (null == list || list.size <= 0) {

return

}

DbManager.getInstance(context!!)?.getDaoSession(context)?.getStudentDao()?.insertInTx(list)

}

/**

• 添加数据至数据库，如果存在，将原来的数据覆盖

• 内部代码判断了如果存在就update(entity);不存在就insert(entity)；

• @param context

• @param student

*/

fun saveData(context: Context?, student: Student) {

DbManager.getInstance(context!!)?.getDaoSession(context)?.getStudentDao()?.save(student)

}

/**

• 删除数据至数据库

• @param context

• @param student 删除具体内容

*/

fun deleteData(context: Context?, student: Student) {

DbManager.getInstance(context!!)?.getDaoSession(context)?.getStudentDao()?.delete(student)

}

/**

• 根据id删除数据至数据库

• @param context

• @param id 删除具体内容

*/

fun deleteByKeyData(context: Context?, id: Long) {

DbManager.getInstance(context!!)?.getDaoSession(context)?.getStudentDao()?.deleteByKey(id)

}

/**

• 删除全部数据

• @param context

*/

fun deleteAllData(context: Context?) {

DbManager.getInstance(context!!)?.getDaoSession(context)?.getStudentDao()?.deleteAll()

}

/**

• 更新数据库

• @param context

• @param student

*/

fun updateData(context: Context?, student: Student) {

DbManager.getInstance(context!!)?.getDaoSession(context)?.getStudentDao()?.update(student)

}

/**

• 查询所有数据

• @param context

• @return

*/

fun queryAll(context: Context?): MutableList? {

val builder = DbManager.getInstance(context!!)?.getDaoSession(context)?.getStudentDao()?.queryBuilder()

return builder?.build()?.list()

}

/**

• 根据id，其他的字段类似

• @param context

• @param id

• @return

*/

fun queryForId(context: Context?, id: Long): MutableList? {

val builder = DbManager.getInstance(context!!)?.getDaoSession(context)?.getStudentDao()?.queryBuilder()

/**

• 返回当前id的数据集合,当然where(这里面可以有多组，做为条件);

• 这里build.list()；与where(StudentDao.Properties.Id.eq(id)).list()结果是一样的；

• 在QueryBuilder类中list()方法return build().list();

*/

// Query build = builder.where(StudentDao.Properties.Id.eq(id)).build();

// List list = build.list();

return builder?.where(StudentDao.Properties.Id.eq(id))?.list()

}

}

步骤六、mainactivity布局

---

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout xmlns:android=“http://schemas.android.com/apk/res/android”

xmlns:tools=“http://schemas.android.com/tools”

android:id=“@+id/activity_main”

android:layout_width=“match_parent”

android:layout_height=“match_parent”

tools:context=“.MainActivity”>

<LinearLayout

android:layout_width=“match_parent”

android:layout_height=“wrap_content”

android:orientation=“horizontal”>

<Button

android:id=“@+id/add”

android:layout_width=“0dp”

android:layout_height=“wrap_content”

android:layout_weight=“1”

android:text=“增” />

<Button

android:id=“@+id/delete”

android:layout_width=“0dp”

android:layout_height=“wrap_content”

android:layout_weight=“1”

android:text=“删” />

<Button

android:id=“@+id/updata”

android:layout_width=“0dp”

android:layout_height=“wrap_content”

android:layout_weight=“1”

android:text=“改” />

<Button

android:id=“@+id/check”

android:layout_width=“0dp”

android:layout_height=“wrap_content”

android:layout_weight=“1”

android:text=“查” />

<Button

android:id=“@+id/deleteAll”

android:layout_width=“wrap_content”

android:layout_height=“wrap_content”

android:layout_centerInParent=“true”

android:layout_weight=“1”

android:text=“删除全部” />

<Button

android:id=“@+id/check_id”

android:layout_width=“wrap_content”

android:layout_height=“wrap_content”

android:layout_above=“@id/deleteAll”

android:layout_centerInParent=“true”

android:text=“根据id查” />

步骤七、mainActivity

---

package tsou.com.simple.greendaoforkotlin

import android.content.Context

import android.os.Bundle

import android.support.v7.app.AppCompatActivity

import android.util.Log

import kotlinx.android.synthetic.main.activity_main.*

import tsou.com.simple.greendaoforkotlin.bean.Student

import tsou.com.simple.greendaoforkotlin.dao.StudentDaoOpe

class MainActivity : AppCompatActivity() {

private var mContext: Context? = null

private var student: Student? = null

override fun onCreate(savedInstanceState: Bundle?) {