使用Morphia访问MongoDB数据库

安装

要在ActFramework应用中使用Morphia，请在pom.xml文件中添加以下依赖:

  1. <dependency>
  2.     <groupId>org.actframework</groupId>
  3.     <artifactId>act-morphia</artifactId>
  4.     <version>0.1.1-SNAPSHOT</version>
  5. </dependency>

配置

简单的配置:

  1. db.uri=mongodb://localhost/mydb

小贴士 你甚至不需要任何配置. ActFramework会自动连接到本地MongoDB服务器的test数据库

稍微复杂一点的配置:

  1. db.url=mongodb://<username>:<password>@<host1>:<port1>,<host2>:<port2>,...,hostN:portN/dbname?replicaSet=...&connectTimeoutMS=...

域模型

下面创建一个简单的域模型，该模型有两个字段：

  1. name
  2. price
  1. package com.mycom.myprj;
  3. import org.mongodb.morphia.annotations.Entity;
  4. import act.db.morphia.MorphiaModel;
  6. @Entity("prod")
  7. public class Product extends MorphiaModel<Product> {
  8.     private String name;
  9.     private int price;
  11.     public String getName() {
  12.         return name;
  13.     }
  15.     public void setName(String name) {
  16.         this.name = name;
  17.     }
  19.     public int getPrice() {
  20.         return price;
  21.     }
  23.     public void setPrice(int price) {
  24.         this.price = price;
  25.     }
  26. }

数据访问对象和CRUD

以下代码演示如何使用MorphiaDao来进行CRUD操作:

  1. package com.mycom.myprj;
  3. import act.controller.Controller;
  4. import act.db.morphia.MorphiaDao;
  5. import org.bson.types.ObjectId;
  6. import org.osgl.mvc.annotation.GetAction;
  7. import org.osgl.mvc.annotation.PostAction;
  8. import org.osgl.mvc.annotation.PutAction;
  11. @Controller("/prod")
  12. public class ProductController extends Controller.Util {
  14.     private MorphiaDao<Product> dao = Product.dao();
  16.     @GetAction
  17.     public Iterable<Product> list() {
  18.         return dao.findAll();
  19.     }
  21.     @GetAction("/{id}")
  22.     public Product show(String id) {
  23.         return dao.findById(new ObjectId(id));
  24.     }
  26.     @PostAction
  27.     public void create(Product product) {
  28.         dao.save(product);
  29.     }
  31.     @PutAction("/{id}/name")
  32.     public void update(String id, String name) {
  33.         Product product = dao.findById(new ObjectId(id));
  34.         notFoundIfNull(product);
  35.         product.setName(name);
  36.         dao.save(product);
  37.     }
  39.     @DeleteAction
  40.     public void delete(String id) {
  41.         dao.deleteById(new ObjectId(id));
  42.     }
  43. }

查询操作

  1. // find by name
  2. Iterable<Product> products = dao.findBy("name", name);
  4. // find all that price is less than 10000
  5. Iterable<Product> products = dao.findBy("price <", 100000);
  7. // find by name and price
  8. Iterable<Product> products = dao.findBy("name, price <", name, 100000);
  10. // find by name using regular expression
  11. Iterable<Product> products = dao.findBy("name", Pattern.compile("laptop"));

使用扩展的DAO类

你可以根据需要扩展MorphiaDao类，并加入业务逻辑

  1. @Entity("prod")
  2. public class Product extends MorphiaModel<Product> {
  3.     private String name;
  4.     private int price;
  6.     public String getName() {
  7.         return name;
  8.     }
  10.     public void setName(String name) {
  11.         this.name = name;
  12.     }
  14.     public int getPrice() {
  15.         return price;
  16.     }
  18.     public void setPrice(int price) {
  19.         this.price = price;
  20.     }
  22.     public static class Dao extends MorphiaDao<Product> {
  24.         public static final int LOW_PRICE = 10000;
  25.         public static final int HIGH_PRICE = 999900;
  27.         public Dao() {
  28.             super(Product.class);
  29.         }
  31.         public Iterable findLowPriceProducts() {
  32.             return findBy("price <", LOW_PRICE);
  33.         }
  35.         public Iterable findHighPriceProducts() {
  36.             return findBy("price >", HIGH_PRICE);
  37.         }
  38.     }
  39. }

使用扩展的DAO类

假如你定义了扩展的DAO，你可以使用同样的接口来获取其实例:

  1. //private MorphiaDao<Product> dao = Product.dao();
  2. private Product.Dao dao = Product.dao();

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