Morphia 地址：http://code.google.com/p/morphia/
教程：http://code.google.com/p/morphia/wiki/QuickStart
MongoDB 自己带的java API只能是保存 DBObject 对象的子类，类似BasicDBObject，如果对象有很多的字段，那是很繁琐的，需要一个个的put，地球人不爱干这样的事情，于是Morphia就出现了。
创建Meeting对象
package com.spell;
import java.util.Date;
import org.bson.types.ObjectId;
import com.google.code.morphia.annotations.Entity;
import com.google.code.morphia.annotations.Id;
@Entity
//默认是要持久所有对象的
public class Meeting {
@Id
private ObjectId id;
private static final long serialVersionUID = -4161545150796484674L;
// 标题
// @Transient //这个表示不持久，莫非
private String title;
// 地点
private String place;
// 时间
private Date time;
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public String getPlace() {
return place;
}
public void setPlace(String place) {
this.place = place;
}
public Date getTime() {
return time;
}
public void setTime(Date time) {
this.time = time;
}
public ObjectId getId() {
return id;
}
public void setId(ObjectId id) {
this.id = id;
}
}
用法示例：MeetingDaoTes.java
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package com.spell;
import java.util.Date;
import java.util.List;
import org.bson.types.ObjectId;
import com.google.code.morphia.Datastore;
import com.google.code.morphia.Morphia;
import com.mongodb.Mongo;
public class MeetingDaoTest {
public static void main(String[] args) throws Exception {
MeetingDaoTest test = new MeetingDaoTest();
// test.save();
test.queryList();
// test.getByObjectId();
}
public static Datastore getDatastore() throws Exception {
Mongo mongo = new Mongo("localhost", 27017);
Morphia morphia = new Morphia();
Datastore ds = morphia.createDatastore(mongo, "my_mongo", "spell",
"007".toCharArray());
return ds;
}
public void save() throws Exception {
Datastore ds = MeetingDaoTest.getDatastore();
Meeting m = new Meeting();
m.setTime(new Date());
m.setPlace("杭州");
m.setTitle("游玩");
ds.save(m);
System.out.println("save success");
}
public void queryList() throws Exception {
Datastore ds = MeetingDaoTest.getDatastore();
List<Meeting> list = ds.find(Meeting.class).asList();
/*
* 也可以有更加高级的查询 List<Meeting> list =
* ds.find(Meeting.class).field("place").endsWith("杭州").asList();
*/
for (Meeting m : list) {
System.out.println(m.getId() + " time:"
+ m.getTime().toLocaleString());
}
}
public void getByObjectId() throws Exception {
Datastore ds = MeetingDaoTest.getDatastore();
ObjectId id = new ObjectId("4d019b0e82ea26c308eea127");
Meeting m = ds.get(Meeting.class, id);
System.out.println(m.getTitle());
}
}
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Smile, the way to solve many problems;