一、mongonDB基本介绍
什么是MongoDB ?
MongoDB 是由C++语言编写的，是一个基于分布式文件存储的开源数据库系统。
在高负载的情况下，添加更多的节点，可以保证服务器性能。
MongoDB 旨在为WEB应用提供可扩展的高性能数据存储解决方案。
MongoDB 将数据存储为一个文档，数据结构由键值(key=>value)对组成。MongoDB 文档类似于 JSON 对象。字段值可以包含其他文档，数组及文档数组。
主要特点
- MongoDB的提供了一个面向文档存储，操作起来比较简单和容易。
- 你可以在MongoDB记录中设置任何属性的索引 (如：FirstName="Sameer",Address="8 Gandhi Road")来实现更快的排序。
- 你可以通过本地或者网络创建数据镜像，这使得MongoDB有更强的扩展性。
- 如果负载的增加（需要更多的存储空间和更强的处理能力） ，它可以分布在计算机网络中的其他节点上这就是所谓的分片。
- Mongo支持丰富的查询表达式。查询指令使用JSON形式的标记，可轻易查询文档中内嵌的对象及数组。
- MongoDb 使用update()命令可以实现替换完成的文档（数据）或者一些指定的数据字段 。
- Mongodb中的Map/reduce主要是用来对数据进行批量处理和聚合操作。
- Map和Reduce。Map函数调用emit(key,value)遍历集合中所有的记录，将key与value传给Reduce函数进行处理。
- Map函数和Reduce函数是使用Javascript编写的，并可以通过db.runCommand或mapreduce命令来执行MapReduce操作。
- GridFS是MongoDB中的一个内置功能，可以用于存放大量小文件。
- MongoDB允许在服务端执行脚本，可以用Javascript编写某个函数，直接在服务端执行，也可以把函数的定义存储在服务端，下次直接调用即可。
- MongoDB支持各种编程语言:RUBY，PYTHON，JAVA，C++，PHP，C#等多种语言。
- MongoDB安装简单。
一、java操作mongonDB示例
1、新建maven工程springboot-mongodb，工程结构如下：
2、引入springboot和mongodb的依赖
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.springboot.mongodb</groupId> <artifactId>springboot-mongodb</artifactId> <version>0.0.1-SNAPSHOT</version> <name>springboot-mongodb</name> <description>springboot-mongodb</description> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.4.1.RELEASE</version> </parent> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-mongodb</artifactId> </dependency> </dependencies> </project>
3、建立springboot主类
package com.springboot; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; @SpringBootApplication public class Application { public static void main(String[] args) throws Exception { SpringApplication.run(Application.class, args); } }
4、在src/main/resource下添加mongodb的数源据配置application.yml
spring:
data:
mongodb:
uri: mongodb://hzb:hzb@172.16.63.208:27017/hzb_test?readPreference=secondaryPreferred
数据库名 hzb_test ，用户hzb，密码hzb
5、实体类
Student:
package com.springboot.model; public class Student { private String name; private String sex; private Integer age; private String des; private StudentScore studentScore; public String getName() { return name; } public void setName(String name) { this.name = name; } public String getSex() { return sex; } public void setSex(String sex) { this.sex = sex; } public Integer getAge() { return age; } public void setAge(Integer age) { this.age = age; } public StudentScore getStudentScore() { return studentScore; } public void setStudentScore(StudentScore studentScore) { this.studentScore = studentScore; } public String getDes() { return des; } public void setDes(String des) { this.des = des; } }
StudentScore:
package com.springboot.model; public class StudentScore { private String chinese; private String english; private String des; public String getChinese() { return chinese; } public void setChinese(String chinese) { this.chinese = chinese; } public String getEnglish() { return english; } public void setEnglish(String english) { this.english = english; } public String getDes() { return des; } public void setDes(String des) { this.des = des; } }
6、操作mongondb的dao
package com.springboot.dao; import java.util.List; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.data.mongodb.core.MongoTemplate; import org.springframework.data.mongodb.core.query.Criteria; import org.springframework.data.mongodb.core.query.Query; import org.springframework.data.mongodb.core.query.Update; import org.springframework.data.mongodb.repository.MongoRepository; import org.springframework.data.repository.query.Param; import org.springframework.stereotype.Component; import com.springboot.model.Student; @Component public class StudentDao{ @Autowired private MongoTemplate mongoTemplate; /** * 保存一个Student信息到student集合里 * @param stu */ public void save(Student stu){ try { mongoTemplate.save(stu,"student"); } catch (Exception e) { // TODO: handle exception } } /** * 查询所有的Student信息 * @return */ public List<Student> findAll(){ return mongoTemplate.findAll(Student.class,"student"); } /** * 通过Student.name查询document * @param name * @return */ public List<Student> findByName(String name){ List<Student> list=null; try { Query query=new Query(Criteria.where("name").is(name)); list=mongoTemplate.find(query, Student.class,"student"); } catch (Exception e) { // TODO: handle exception } return list; } /** * 通过Student.StudentScore.des查询document * @param des * @return */ public List<Student> findByStudentScoreDes(String des){ List<Student> list=null; try { Query query=new Query(Criteria.where("studentScore.des").is(des)); list=mongoTemplate.find(query, Student.class,"student"); } catch (Exception e) { // TODO: handle exception } return list; } /** * 通过Student.name和Student.des查询document * @param name * @param des * @return */ public List<Student> searchByNameAndDes(String name,String des){ List<Student> list=null; try { Query query=new Query(Criteria.where("name").is(name).and("des").is(des)); list=mongoTemplate.find(query, Student.class,"student"); } catch (Exception e) { // TODO: handle exception } return list; } /** * 通过Student.name和Student.Student.des查询document * @param name * @param des * @return */ public List<Student> searchByNameAndStudentScoreDes(String name,String des){ List<Student> list=null; try { Query query=new Query(Criteria.where("name").is(name).and("studentScore.des").is(des)); list=mongoTemplate.find(query, Student.class,"student"); } catch (Exception e) { // TODO: handle exception } return list; } /** * 更新 * @param stu */ public void update(Student stu){ try { Query query=new Query(Criteria.where("name").is(stu.getName())); Update update= new Update().set("des", stu.getDes()).set("studentScore.des", stu.getStudentScore().getDes()); //更新查询返回结果集的第一条 mongoTemplate.updateFirst(query,update,Student.class,"student"); //更新查询返回结果集的所有 // mongoTemplate.updateMulti(query,update,Student.class); } catch (Exception e) { // TODO: handle exception } } /** * 删除 * @param name */ public void remove(String name){ Query query=new Query(Criteria.where("name").is(name)); mongoTemplate.remove(query, Student.class,"student"); } }
7、controller
package com.springboot.controller; import java.util.List; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.data.mongodb.core.MongoTemplate; import org.springframework.data.mongodb.core.query.Criteria; import org.springframework.data.mongodb.core.query.Query; import org.springframework.web.bind.annotation.DeleteMapping; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.PostMapping; import org.springframework.web.bind.annotation.PutMapping; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; import com.springboot.dao.StudentDao; import com.springboot.model.Student; import com.springboot.model.StudentScore; @RestController @RequestMapping("/mongo") public class StudentController { @Autowired private StudentDao studentDao; /** * 向mongondb添加一个document对象 */ @PostMapping("/add") public void add() { Student student=new Student(); student.setName("hzb"); student.setSex("man"); student.setAge(31); student.setDes("hzb_father"); StudentScore score=new StudentScore(); score.setChinese("88"); score.setEnglish("93"); score.setDes("hzb_child"); student.setStudentScore(score); Student student1=new Student(); student1.setName("xiaweihu"); student1.setSex("man"); student1.setAge(31); student1.setDes("xiaweihu_father"); StudentScore score1=new StudentScore(); score1.setChinese("66"); score1.setEnglish("54"); score1.setDes("xiaweihu_child"); student1.setStudentScore(score1); Student student2=new Student(); student2.setName("hzb"); student2.setSex("man"); student2.setAge(31); student2.setDes("hzb_father"); StudentScore score2=new StudentScore(); score2.setChinese("77"); score2.setEnglish("99"); score2.setDes("hzb_child2"); student2.setStudentScore(score2); studentDao.save(student); studentDao.save(student1); studentDao.save(student2); } /** * 查询mongodb当中的所有document * @return */ @GetMapping("/findAll") public List<Student> findAll() { List<Student> list= studentDao.findAll(); return list; } /** * 通过名字查询document * @return */ @GetMapping("/findByName") public List<Student> findByName() { List<Student> student=studentDao.findByName("hzb"); return student; } /** * 通过Student.Student.des查询document * @param des * @return */ @GetMapping("/findByStudentScoreDes") public List<Student> findByStudentScore_Des(String des){ List<Student> student=studentDao.findByStudentScoreDes("hzb_child2"); return student; } /** * 通过Student.name和Student.des查询document * @param des * @return */ @GetMapping("/findByNameAndDes") public List<Student> findByNameAndDes(String des){ List<Student> student=studentDao.searchByNameAndDes("hzb","hzb_father"); return student; } /** * 通过Student.name和Student.Student.des查询document * @param des * @return */ @GetMapping("/findByNameAndStudentScoreDes") public List<Student> findByNameAndStudentScoreDes(String des){ List<Student> student=studentDao.searchByNameAndStudentScoreDes("hzb","hzb_child2"); return student; } /** * 更新document */ @PutMapping("/updateByName") public void ubdateByName(){ List<Student> students=studentDao.findByName("xiaweihu"); Student student=students.get(0); student.setDes("aaaaaaaaaaaaaaaaaaaa"); student.getStudentScore().setDes("bbbbbbbbbbbbbbbbbbbbb"); studentDao.update(student); } /** * 删除document */ @DeleteMapping("/deleteByName") public void deleteByName(){ studentDao.remove("xiaweihu"); } }
7、运行结果
1）当执行 http://localhost:8080/mongo/add
用Robomongo 1.0查看mongodb数据库，可以看到插入了三条记录
/* 1 */ { "_id" : ObjectId("5922792f48a5d132a48886f2"), "_class" : "com.springboot.model.Student", "name" : "hzb", "sex" : "man", "age" : 31, "des" : "hzb_father", "studentScore" : { "chinese" : "88", "english" : "93", "des" : "hzb_child" } } /* 2 */ { "_id" : ObjectId("5922792f48a5d132a48886f3"), "_class" : "com.springboot.model.Student", "name" : "xiaweihu", "sex" : "man", "age" : 31, "des" : "xiaweihu_father", "studentScore" : { "chinese" : "66", "english" : "54", "des" : "xiaweihu_child" } } /* 3 */ { "_id" : ObjectId("5922792f48a5d132a48886f4"), "_class" : "com.springboot.model.Student", "name" : "hzb", "sex" : "man", "age" : 31, "des" : "hzb_father", "studentScore" : { "chinese" : "77", "english" : "99", "des" : "hzb_child2" } }
2）查询所有的Student记录，http://localhost:8080/mongo/add
[ { "name": "hzb", "sex": "man", "age": 31, "des": "hzb_father", "studentScore": { "chinese": "88", "english": "93", "des": "hzb_child" } }, { "name": "xiaweihu", "sex": "man", "age": 31, "des": "xiaweihu_father", "studentScore": { "chinese": "66", "english": "54", "des": "xiaweihu_child" } }, { "name": "hzb", "sex": "man", "age": 31, "des": "hzb_father", "studentScore": { "chinese": "77", "english": "99", "des": "hzb_child2" } } ]
3）查询名字为“hzb”的Student记录，http://localhost:8080/mongo/findByName
[ { "name": "hzb", "sex": "man", "age": 31, "des": "hzb_father", "studentScore": { "chinese": "88", "english": "93", "des": "hzb_child" } }, { "name": "hzb", "sex": "man", "age": 31, "des": "hzb_father", "studentScore": { "chinese": "77", "english": "99", "des": "hzb_child2" } } ]
4）查询名字为studentScore.des为hzb_child2的Student记录，http://localhost:8080/mongo/findByStudentScoreDes
[ { "name": "hzb", "sex": "man", "age": 31, "des": "hzb_father", "studentScore": { "chinese": "77", "english": "99", "des": "hzb_child2" } } ]
5）查询名字为name为hzb，des为hzb_father的Student记录，http://localhost:8080/mongo/findByNameAndDes
[ { "name": "hzb", "sex": "man", "age": 31, "des": "hzb_father", "studentScore": { "chinese": "88", "english": "93", "des": "hzb_child" } }, { "name": "hzb", "sex": "man", "age": 31, "des": "hzb_father", "studentScore": { "chinese": "77", "english": "99", "des": "hzb_child2" } } ]
6）查询名字为name为hzb，studentScore.des为hzb_child2的Student记录，http://localhost:8080/mongo/findByNameAndStudentScoreDes
[ { "name": "hzb", "sex": "man", "age": 31, "des": "hzb_father", "studentScore": { "chinese": "77", "english": "99", "des": "hzb_child2" } } ]
7)执行http://localhost:8080/mongo/updateByName后再执行http://localhost:8080/mongo/findAll
[ { "name": "hzb", "sex": "man", "age": 31, "des": "hzb_father", "studentScore": { "chinese": "88", "english": "93", "des": "hzb_child" } }, { "name": "xiaweihu", "sex": "man", "age": 31, "des": "aaaaaaaaaaaaaaaaaaaa", "studentScore": { "chinese": "66", "english": "54", "des": "bbbbbbbbbbbbbbbbbbbbb" } }, { "name": "hzb", "sex": "man", "age": 31, "des": "hzb_father", "studentScore": { "chinese": "77", "english": "99", "des": "hzb_child2" } } ]
8)执行http://localhost:8080/mongo/deleteByName后再执行http://localhost:8080/mongo/findAll
[ { "name": "hzb", "sex": "man", "age": 31, "des": "hzb_father", "studentScore": { "chinese": "88", "english": "93", "des": "hzb_child" } }, { "name": "hzb", "sex": "man", "age": 31, "des": "hzb_father", "studentScore": { "chinese": "77", "english": "99", "des": "hzb_child2" } } ]