安卓ORM框架greenDAO
greenDAO ormlite的性能对比：
上面可以看到，greeendao的insert和update效率要比ormlite快两倍左右，load更是夸张到4倍多。
我们可以在官网（http://search.maven.org/#search%7Cga%7C1%7Cg%3A%22de.greenrobot%22%20AND%20a%3A%22greendao-generator%22）上直接下来，也可去github项目主页上下载源码。
下面新建一个java工程，注意是java工程不是android工程,工程名GreenDaoExample。并手动在工程中新建src-gen文件夹。导入freemaker.jar和greendao-generator.jar，加入到build path。建一个如下的类：
import de.greenrobot.daogenerator.DaoGenerator;
import de.greenrobot.daogenerator.Entity;
import de.greenrobot.daogenerator.Property;
import de.greenrobot.daogenerator.Schema;
import de.greenrobot.daogenerator.ToMany;
/**
* Generates entities and DAOs for the example project DaoExample.
*
* Run it as a Java application (not Android).
*
* @author Markus
*/
public class ExampleDaoGenerator
{
public static void main(String[] args) throws Exception
{
Schema schema = new Schema(3, "com.young.do");
addNote(schema);
addCustomerOrder(schema);
new DaoGenerator().generateAll(schema, "../DaoExample/src-gen");
}
private static void addNote(Schema schema)
{
Entity note = schema.addEntity("Note");
note.addIdProperty();
note.addStringProperty("text").notNull();
note.addStringProperty("comment");
note.addDateProperty("date");
}
private static void addCustomerOrder(Schema schema)
{
Entity customer = schema.addEntity("Customer");
customer.addIdProperty();
customer.addStringProperty("name").notNull();
Entity order = schema.addEntity("Order");
order.setTableName("ORDERS"); // "ORDER" is a reserved keyword
order.addIdProperty();
Property orderDate = order.addDateProperty("date").getProperty();
Property customerId = order.addLongProperty("customerId").notNull().getProperty();
order.addToOne(customer, customerId);
ToMany customerToOrders = customer.addToMany(order, customerId);
customerToOrders.setName("orders");
customerToOrders.orderAsc(orderDate);
}
}
直接运行，代码生成
自动生成model和dao，随便看一个model类：
package com.young.do;
// THIS CODE IS GENERATED BY greenDAO, DO NOT EDIT. Enable "keep" sections if you want to edit.
/**
* Entity mapped to table "NOTE".
*/
public class Note {
private Long id;
/** Not-null value. */
private String text;
private String comment;
private java.util.Date date;
public Note() {
}
public Note(Long id) {
this.id = id;
}
public Note(Long id, String text, String comment, java.util.Date date) {
this.id = id;
this.text = text;
this.comment = comment;
this.date = date;
}
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
/** Not-null value. */
public String getText() {
return text;
}
/** Not-null value; ensure this value is available before it is saved to the database. */
public void setText(String text) {
this.text = text;
}
public String getComment() {
return comment;
}
public void setComment(String comment) {
this.comment = comment;
}
public java.util.Date getDate() {
return date;
}
public void setDate(java.util.Date date) {
this.date = date;
}
}
在安卓中使用greenDAO
首先加入greendao.jar包，并把java工程中生成的类复制到安卓工程中。然后就可以进行增删改查了，具体代码如下。
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
DevOpenHelper helper = new DaoMaster.DevOpenHelper(this,
"greendao_test.db", null);
SQLiteDatabase db = helper.getWritableDatabase();
DaoMaster daoMaster = new DaoMaster(db);
DaoSession daoSession = daoMaster.newSession();
final NoteDao noteDao = daoSession.getNoteDao();
// noteDao.insertInTx(new ArrayList<Note>(), true);
findViewById(R.id.but).setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Note note = new Note();
note.setDate(new Date());
note.setId(System.currentTimeMillis());
note.setText("ttteesstt");
noteDao.insert(note);
}
});
findViewById(R.id.get).setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
List<Note> l = noteDao.loadAll();
StringBuilder builder = new StringBuilder();
for (Note note : l) {
builder.append(note.getId()).append(" ")
.append(note.getText()).append(" ")
.append(note.getDate()).append("\n");
}
Toast.makeText(getApplicationContext(), builder, 1).show();
}
});
}
}
由于NoteDao继承自AbstractDao，所以可以直接调用各种增删改查方法