Java集成mongodb有很多方式，可以直接用mongodb的java驱动程序来发送语句到mongodb服务器，也可以用第三方的工具包来做。

(1) 选择版本

今天我选择的就是springdata集成的mongodb（spring-data-mongodb）

1.1 spring-data-mongodb版本

gradle坐标：

org.springframework.data:spring-data-mongodb:1.7.2.RELEASE

maven 坐标

<dependency><groupId>org.springframework.data</groupId><artifactId>spring-data-mongodb</artifactId><version>1.7.2.RELEASE</version>
</dependency>

1.2 java驱动器版本

gradle坐标：

org.mongodb:mongo-java-driver:3.2.0

maven 坐标

<dependency><groupId>org.mongodb</groupId><artifactId>mongo-java-driver</artifactId><version>3.2.0</version>
</dependency>

(2) 集成

2.1 spring 配置文件

新建文件 mongodb-context.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"xmlns:mongo="http://www.springframework.org/schema/data/mongo"xsi:schemaLocation="http://www.springframework.org/schema/context   http://www.springframework.org/schema/context/spring-context-3.0.xsd   http://www.springframework.org/schema/data/mongo   http://www.springframework.org/schema/data/mongo/spring-mongo-1.0.xsd   http://www.springframework.org/schema/beans   http://www.springframework.org/schema/beans/spring-beans-3.0.xsd"><!-- mongodb 的基本配置 --><mongo:mongo id="mongo"  host="192.168.1.202" port="27017"  /><!-- 权限配置 --><bean id="userCredentials" class="org.springframework.data.authentication.UserCredentials"><constructor-arg name="username"  value="root"/><constructor-arg name="password"  value="root"/></bean><!-- template 配置 --><bean id="mongoTemplate" class="org.springframework.data.mongodb.core.MongoTemplate"><constructor-arg ref="mongo" /><!-- 数据库名称 --><constructor-arg value="demodb" /><!-- 权限  --><constructor-arg ref="userCredentials" /></bean></beans>

集成到spring的基础配置文件中即可
spring的主配置文件插入如下代码

    <!-- 导入mongodb的配置文件 --><import resource="mongodb-context.xml"/>

(3) 编写基础类

3.1 Dao 基础操作类 MongodbDao

其他的dao类都可以继承改类

import java.util.List;import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Sort;
import org.springframework.data.domain.Sort.Direction;
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.stereotype.Repository;import com.github.pagehelper.PageInfo;/*** mongodb 基础操作类* @author chenpengye 2015年12月21日 下午11:33:06* @param <T>*/
@Repository
public class MongodbDao<T extends IdEntity> {private static final Logger logger = LoggerFactory.getLogger(MongodbDao.class);private static final int DEFAULT_SKIP = 0;private static final int DEFAULT_LIMIT = 200;@Autowiredprotected MongoTemplate mongoTemplate;// ＝＝＝＝＝＝＝ 增 ＝＝＝＝＝＝＝＝＝＝＝＝public void save(T t) {mongoTemplate.save(t);logger.debug("save entity: {}", t);}public void insertAll(List<T> list) {mongoTemplate.insertAll(list);}// ＝＝＝＝＝＝＝ 删 ＝＝＝＝＝＝＝＝＝＝＝＝/*** 删除对象* * @param t*/public void delete(T t) {mongoTemplate.remove(t);}/*** 根据id 删除对象* * @param id*/public void deleteById(String id) {Criteria criteria = Criteria.where("id").is(id);Query query = new Query(criteria);mongoTemplate.remove(query, this.getEntityClass());}/*** 根据条件删除*/public void delete(Query query) {mongoTemplate.remove(query, this.getEntityClass());}/*** 删除该collection 的所有的数据*/public void deleteAll() {mongoTemplate.dropCollection(this.getEntityClass());}// ＝＝＝＝＝＝＝ 改 ＝＝＝＝＝＝＝＝＝＝＝＝public void update(Query query, Update update) {mongoTemplate.findAndModify(query, update, this.getEntityClass());}// ＝＝＝＝＝＝＝ 查 ＝＝＝＝＝＝＝＝＝＝＝＝public List<T> findAll(){return mongoTemplate.findAll(this.getEntityClass());}/*** 根据查询query 查找list* * @param query* @return*/public List<T> find(Query query) {return mongoTemplate.find(query, this.getEntityClass());}/*** 按照字段排序 － 顺序  <br/>* @param query        查询条件  <br/>* @param properties   排序字段  <br/>* @return*/public List<T> findWithOrderAsc(Query query, String... properties){Sort sort = new Sort(Direction.ASC, properties);query.with(sort);return mongoTemplate.find(query, this.getEntityClass());}/*** 按照字段排序 － 逆序 <br/>* @param query        查询条件  <br/>* @param properties   排序字段  <br/>* @return*/public List<T> findWithOrderDesc(Query query, String... properties){Sort sort = new Sort(Direction.DESC, properties);query.with(sort);return mongoTemplate.find(query, this.getEntityClass());}/*** 根据查询query 查找一个对象* * @param query* @return*/public T findOne(Query query) {return mongoTemplate.findOne(query, this.getEntityClass());}/*** 根据 id 查询对象* * @param id* @return*/public T findById(String id) {return mongoTemplate.findById(id, this.getEntityClass());}/*** 根据id 和 集合名字查询对象* * @param id* @param collectionName* @return*/public T findById(String id, String collectionName) {return mongoTemplate.findById(id, this.getEntityClass(), collectionName);}/*** 查询分页  tips：［不要skip 太多的页数，如果跳过太多会严重影响效率。最大不要skip 20000页］* @param page* @param query* @return*/public PageInfo<T> findPage(PageInfo<T> page, Query query) {long count = this.count(query);page.setTotal(count);int pageNumber = page.getPageNum();int pageSize = page.getPageSize();query.skip((pageNumber - 1) * pageSize).limit(pageSize);List<T> list = this.find(query);page.setList(list);return page;}public long count(Query query) {return mongoTemplate.count(query, this.getEntityClass());}/*** 获取需要操作的实体类class <br/>* 例如: StudentScoreDao extends MongodbDao <b>&lt;StudentScore&gt;</b> <br/>* 返回的是 <b>StudentScore</b> 的Class* * @return*/private Class<T> getEntityClass() {return ReflectionUtils.getSuperClassGenricType(getClass());}/*** 获取collection的名字，默认是dao范型T的名字 <br/>* 例如: StudentScoreDao extends MongodbDao <b>&lt;StudentScore&gt;</b> <br/>* 则返回的名字是：<b>StudentScore</b>* * @return*/private String getCollectionName() {return getEntityClass().getSimpleName();}}

由于现行项目使用mybatis，并且分页采用了pagehelper:pagehelper:4.0.3，因此这里的分页类也采用里pagehelper里面的分页类。如果要分页，请也引入pagehelper的jar包
gradle坐标

    compile 'com.github.jsqlparser:jsqlparser:0.9.4'compile 'com.github.pagehelper:pagehelper:4.0.3'

maven坐标

<dependency><groupId>com.github.jsqlparser</groupId><artifactId>jsqlparser</artifactId><version>0.9.4</version>
</dependency><dependency><groupId>com.github.pagehelper</groupId><artifactId>pagehelper</artifactId><version>4.0.3</version>
</dependency>

3.2 工具类 ReflectionUtils

import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;import org.apache.commons.lang.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.util.Assert;/*** 反射工具类.* * 提供访问私有变量,获取泛型类型Class, 提取集合中元素的属性, 转换字符串到对象等Util函数.* */
public class ReflectionUtils {private static Logger logger = LoggerFactory.getLogger(ReflectionUtils.class);/*** 调用Getter方法.*/public static Object invokeGetterMethod(Object obj, String propertyName) {String getterMethodName = "get" + StringUtils.capitalize(propertyName);return invokeMethod(obj, getterMethodName, new Class[] {}, new Object[] {});}/*** 调用Setter方法.使用value的Class来查找Setter方法.*/public static void invokeSetterMethod(Object obj, String propertyName, Object value) {invokeSetterMethod(obj, propertyName, value, null);}/*** 调用Setter方法.* * @param propertyType 用于查找Setter方法,为空时使用value的Class替代.*/public static void invokeSetterMethod(Object obj, String propertyName, Object value, Class<?> propertyType) {Class<?> type = propertyType != null ? propertyType : value.getClass();String setterMethodName = "set" + StringUtils.capitalize(propertyName);invokeMethod(obj, setterMethodName, new Class[] { type }, new Object[] { value });}/*** 直接读取对象属性值, 无视private/protected修饰符, 不经过getter函数.*/public static Object getFieldValue(final Object obj, final String fieldName) {Field field = getAccessibleField(obj, fieldName);if (field == null) {throw new IllegalArgumentException("Could not find field [" + fieldName + "] on target [" + obj + "]");}Object result = null;try {result = field.get(obj);} catch (IllegalAccessException e) {logger.error("不可能抛出的异常{}", e.getMessage());}return result;}/*** 直接设置对象属性值, 无视private/protected修饰符, 不经过setter函数.*/public static void setFieldValue(final Object obj, final String fieldName, final Object value) {Field field = getAccessibleField(obj, fieldName);if (field == null) {throw new IllegalArgumentException("Could not find field [" + fieldName + "] on target [" + obj + "]");}try {field.set(obj, value);} catch (IllegalAccessException e) {logger.error("不可能抛出的异常:{}", e.getMessage());}}/*** 循环向上转型, 获取对象的DeclaredField,   并强制设置为可访问.* * 如向上转型到Object仍无法找到, 返回null.*/public static Field getAccessibleField(final Object obj, final String fieldName) {Assert.notNull(obj, "object不能为空");Assert.hasText(fieldName, "fieldName");for (Class<?> superClass = obj.getClass(); superClass != Object.class; superClass = superClass.getSuperclass()) {try {Field field = superClass.getDeclaredField(fieldName);field.setAccessible(true);return field;} catch (NoSuchFieldException e) {//NOSONAR// Field不在当前类定义,继续向上转型}}return null;}/*** 直接调用对象方法, 无视private/protected修饰符.* 用于一次性调用的情况.*/public static Object invokeMethod(final Object obj, final String methodName, final Class<?>[] parameterTypes,final Object[] args) {Method method = getAccessibleMethod(obj, methodName, parameterTypes);if (method == null) {throw new IllegalArgumentException("Could not find method [" + methodName + "] on target [" + obj + "]");}try {return method.invoke(obj, args);} catch (Exception e) {throw convertReflectionExceptionToUnchecked(e);}}/*** 循环向上转型, 获取对象的DeclaredMethod,并强制设置为可访问.* 如向上转型到Object仍无法找到, 返回null.* * 用于方法需要被多次调用的情况. 先使用本函数先取得Method,然后调用Method.invoke(Object obj, Object... args)*/public static Method getAccessibleMethod(final Object obj, final String methodName,final Class<?>... parameterTypes) {Assert.notNull(obj, "object不能为空");for (Class<?> superClass = obj.getClass(); superClass != Object.class; superClass = superClass.getSuperclass()) {try {Method method = superClass.getDeclaredMethod(methodName, parameterTypes);method.setAccessible(true);return method;} catch (NoSuchMethodException e) {//NOSONAR// Method不在当前类定义,继续向上转型}}return null;}/*** 通过反射, 获得Class定义中声明的父类的泛型参数的类型.* 如无法找到, 返回Object.class.* eg.* public UserDao extends HibernateDao<User>** @param clazz The class to introspect* @return the first generic declaration, or Object.class if cannot be determined*/@SuppressWarnings({ "unchecked", "rawtypes" })public static <T> Class<T> getSuperClassGenricType(final Class clazz) {return getSuperClassGenricType(clazz, 0);}/*** 通过反射, 获得Class定义中声明的父类的泛型参数的类型.* 如无法找到, 返回Object.class.* * 如public UserDao extends HibernateDao<User,Long>** @param clazz clazz The class to introspect* @param index the Index of the generic ddeclaration,start from 0.* @return the index generic declaration, or Object.class if cannot be determined*/@SuppressWarnings("rawtypes")public static Class getSuperClassGenricType(final Class clazz, final int index) {Type genType = clazz.getGenericSuperclass();if (!(genType instanceof ParameterizedType)) {logger.warn(clazz.getSimpleName() + "'s superclass not ParameterizedType");return Object.class;}Type[] params = ((ParameterizedType) genType).getActualTypeArguments();if (index >= params.length || index < 0) {logger.warn("Index: " + index + ", Size of " + clazz.getSimpleName() + "'s Parameterized Type: "+ params.length);return Object.class;}if (!(params[index] instanceof Class)) {logger.warn(clazz.getSimpleName() + " not set the actual class on superclass generic parameter");return Object.class;}return (Class) params[index];}/*** 将反射时的checked exception转换为unchecked exception.*/public static RuntimeException convertReflectionExceptionToUnchecked(Exception e) {if (e instanceof IllegalAccessException || e instanceof IllegalArgumentException|| e instanceof NoSuchMethodException) {return new IllegalArgumentException("Reflection Exception.", e);} else if (e instanceof InvocationTargetException) {return new RuntimeException("Reflection Exception.", ((InvocationTargetException) e).getTargetException());} else if (e instanceof RuntimeException) {return (RuntimeException) e;}return new RuntimeException("Unexpected Checked Exception.", e);}
}

3.3 基础实体类 IdEntity

import java.io.Serializable;/*** mongodb 基础id类，id都是字符串型的* @author chenpengye* 2015年12月21日 下午4:53:45*/
public class IdEntity implements Serializable {private static final long serialVersionUID = 33633625616087044L;private String id;public String getId() {return id;}public void setId(String id) {this.id = id;}}

3.4 实体类 StudentScore

import java.io.Serializable;
import java.util.List;/*** 测试实体类* @author chenpengye* 2015年12月21日 下午11:59:02*/
public class StudentScore extends IdEntity implements Serializable {private static final long serialVersionUID = 8743196073520676022L;/*** 学生姓名*/private String username;/*** 学生成绩*/private List<Double> scoreList;public String getUsername() {return username;}public void setUsername(String username) {this.username = username;}public List<Double> getScoreList() {return scoreList;}public void setScoreList(List<Double> scoreList) {this.scoreList = scoreList;}}

3.5 实体类的dao操作类 StudentScoreDao

import org.springframework.stereotype.Repository;/*** 继承MongodbDao<br/>* 此类对StudentScore对增删改查和分页方法都已经有了<br/>* @author chenpengye* 2016年1月4日 下午10:04:25*/
@Repository
public class StudentScoreDao extends MongodbDao<StudentScore> {}

有需要的同学可以参考我的上一篇博客，关于mongodb的安装
－－－（1）在ubuntu上安装mongodb －－－－－－

欢迎探讨，如有疑问请发邮件到chenpengye1861@163.com