摘要：每个条件必须引用一个属性，并且还可以指定一种比较操作。如果省略比较操作符的话，那么这暗指是一种相等比较操作。
Spring-data对MongoDB进行了很好的支持，接下来就讲解一下关于Spring对MongoDB的配置和一些正常的使用
我下面的工程使用的是Spring的Java配置的方式和Maven构建
具体的工程代码大家可以访问我的Github地址:https://github.com/zoeminghong/springmvc-javaconfig
①MongoDB的必要配置package springmvc.rootconfig;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.mongodb.core.MongoClientFactoryBean;
import org.springframework.data.mongodb.core.MongoOperations;
import org.springframework.data.mongodb.core.MongoTemplate;
import org.springframework.data.mongodb.repository.config.EnableMongoRepositories;
import com.mongodb.Mongo;
@Configuration
// 启用MongoDB的Repository功能，会对其Repositories自动扫描
@EnableMongoRepositories(basePackages = "springmvc.orders.db")
public class MongoConfig {
// MongoClient配置
@Bean
public MongoClientFactoryBean mongo() {
MongoClientFactoryBean mongo = new MongoClientFactoryBean();
mongo.setHost("localhost");
//MongoCredential credential=MongoCredential.createCredential(env.getProperty("mongo.username"), "OrdersDB",env.getProperty("mongo.password").toCharArray());
// mongo.setCredentials(new MongoCredential[]{credential});
//还可以对端口进行配置
return mongo;
}
// Mongo Template配置
@Bean
public MongoOperations mongoTemplate(Mongo mongo) {
//OrdersDB就是Mongo的数据库
return new MongoTemplate(mongo, "OrdersDB");
}
}
为了访问数据库的时候，我们可能还需要帐号密码
MongoCredential credential=MongoCredential.createCredential(env.getProperty("mongo.username"), "OrdersDB",env.getProperty("mongo.password").toCharArray());
mongo.setCredentials(new MongoCredential[]{credential});
②为模型添加注解
package springmvc.bean;
import java.util.Collection;
import java.util.LinkedHashSet;
import org.springframework.data.annotation.Id;
import org.springframework.data.mongodb.core.mapping.Document;
import org.springframework.data.mongodb.core.mapping.Field;
//这是文档
@Document
public class Order {
//指定ID
@Id
private String id;
//为域重命名
@Field("client")
private String customer;
private String type;
private Collection- items=new LinkedHashSet
- ();
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getCustomer() {
return customer;
}
public void setCustomer(String customer) {
this.customer = customer;
}
public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
public Collection
- getItems() {
return items;
}
public void setItems(Collection
- items) {
this.items = items;
}
}
package springmvc.bean;
public class Item {
private Long id;
private Order order;
private String product;
private double price;
private int quantity;
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public Order getOrder() {
return order;
}
public void setOrder(Order order) {
this.order = order;
}
public String getProduct() {
return product;
}
public void setProduct(String product) {
this.product = product;
}
public double getPrice() {
return price;
}
public void setPrice(double price) {
this.price = price;
}
public int getQuantity() {
return quantity;
}
public void setQuantity(int quantity) {
this.quantity = quantity;
}
}
| 注解 | 描述 |
|---|---|
| @Document | 标示映射到mongoDB文档上的领域对象 |
| @ID | 标示某个为ID域 |
| @DbRef | 标示某个域要引用其他的文档，这个文档有可能位于另外一个数据库中 |
| @Field | 为文档域指定自定义的元数据 |
| @Version | 标示某个属性用作版本域 |
③使用MongoTemplate访问MongoDB若不使用@Field注解，域名就与Java属性相同
上面之所以Item的Java类为什么没有@Document注解，是因为我们不会多带带想Item持久化为文档
package springmvc.web;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.mongodb.core.MongoOperations;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import springmvc.bean.Order;
import springmvc.orders.db.OrderRepository;
@Controller
public class HomeController {
@Autowired
MongoOperations mongo;
@RequestMapping(value = { "/", "index" }, method = RequestMethod.GET)
public String index() {
long orderCount=mongo.getCollection("order").count();
System.out.println(orderCount);
// Order order = new Order();
// order.setId("1");
// order.setCustomer("gg");
// order.setType("2");
//第二个参数是文档存储的名称
// mongo.save(order,"order");
// String orderId="1";
// Order order=mongo.findById(orderId, Order.class);
// System.out.println(order.getCustomer());
return "index";
}
}
在这里我们将MongoTemplate注入到一个类型为MongoOperations的属性中。MongoOperations是MongoTemplate所实现的接口，MongoOperations中存在很多文档操作方法
MongoOperations其实已经能满足很多需求了
如果还没有满足你的需求，接下来我就介绍一下，如何编写MongoDB Repository
编写MongoDB Repository
