資訊專欄INFORMATION COLUMN
摘要：每個(gè)條件必須引用一個(gè)屬性，并且還可以指定一種比較操作。如果省略比較操作符的話，那么這暗指是一種相等比較操作。
Spring-data對(duì)MongoDB進(jìn)行了很好的支持，接下來(lái)就講解一下關(guān)于Spring對(duì)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構(gòu)建
具體的工程代碼大家可以訪問(wèn)我的Github地址:https://github.com/zoeminghong/springmvc-javaconfig
①M(fèi)ongoDB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
// 啟用MongoDB的Repository功能，會(huì)對(duì)其Repositories自動(dòng)掃描
@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});
//還可以對(duì)端口進(jìn)行配置
return mongo;
}
// Mongo Template配置
@Bean
public MongoOperations mongoTemplate(Mongo mongo) {
//OrdersDB就是Mongo的數(shù)據(jù)庫(kù)
return new MongoTemplate(mongo, "OrdersDB");
}
}
為了訪問(wèn)數(shù)據(jù)庫(kù)的時(shí)候，我們可能還需要帳號(hào)密碼
MongoCredential credential=MongoCredential.createCredential(env.getProperty("mongo.username"), "OrdersDB",env.getProperty("mongo.password").toCharArray());
mongo.setCredentials(new MongoCredential[]{credential});
②為模型添加注解
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;
//這是文檔
@Document
public class Order {
//指定ID
@Id
private String id;
//為域重命名
@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 | 標(biāo)示映射到mongoDB文檔上的領(lǐng)域?qū)ο?/td> |
| @ID | 標(biāo)示某個(gè)為ID域 |
| @DbRef | 標(biāo)示某個(gè)域要引用其他的文檔，這個(gè)文檔有可能位于另外一個(gè)數(shù)據(jù)庫(kù)中 |
| @Field | 為文檔域指定自定義的元數(shù)據(jù) |
| @Version | 標(biāo)示某個(gè)屬性用作版本域 |
③使用MongoTemplate訪問(wèn)MongoDB若不使用@Field注解，域名就與Java屬性相同
上面之所以Item的Java類為什么沒有@Document注解，是因?yàn)槲覀儾粫?huì)多帶帶想Item持久化為文檔
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");
//第二個(gè)參數(shù)是文檔存儲(chǔ)的名稱
// mongo.save(order,"order");
// String orderId="1";
// Order order=mongo.findById(orderId, Order.class);
// System.out.println(order.getCustomer());
return "index";
}
}
在這里我們將MongoTemplate注入到一個(gè)類型為MongoOperations的屬性中。MongoOperations是MongoTemplate所實(shí)現(xiàn)的接口，MongoOperations中存在很多文檔操作方法
MongoOperations其實(shí)已經(jīng)能滿足很多需求了
如果還沒有滿足你的需求，接下來(lái)我就介紹一下，如何編寫MongoDB Repository
編寫MongoDB Repository
