说明：
代码语言：txt复制 主要功能：对mongoDB的集合做增删改查。 项目的运行环境：tomcat6、jdk8。 所用技术：mongoDB、jsp/servlet、前端bootstrap。mongoDB工具类：
代码语言：txt复制 定义一个MongoDBUtil的枚举类，枚举类中定义一个instance实例。 MongoDB工具类 Mongo实例代表了一个数据库连接池，即使在多线程的环境中，一个Mongo实例对我们来说已经足够。 注意Mongo已经实现了连接池，并且是线程安全的。 设计为单例模式， 因 MongoDB的Java驱动是线程安全的，对于一般的应用，只要一个Mongo实例即可。 Mongo有个内置的连接池（默认为10个） 对于有大量写和读的环境中，为了确保在一个Session中使用同一个DB时，DB和DBCollection是绝对线程安全的。public enum MongoDBUtil {
/**
* 定义一个枚举的元素，它代表此类的一个实例
*/
instance;
} 在MongoDBUtil类中，定义一个MongoClient对象，并根据IP和端口获得该对象。private MongoClient mongoClient;
static {
System.out.println("===MongoDBUtil初始化===");
// 从配置文件中获取属性值
String ip = "localhost";
int port = 27017;
instance.mongoClient = new MongoClient(ip, port);
} 根据MongoClient对象，得到MongoDataBase对象和MongoConnection<Document>对象。/**
* 获取DB实例 - 指定DB
*
* @param dbName
* @return
*/
public MongoDatabase getDB(String dbName) {
if (dbName != null && !"".equals(dbName)) {
MongoDatabase database = mongoClient.getDatabase(dbName);
return database;
}
return null;
}
/**
* 获取collection对象 - 指定Collection
*
* @param collName
* @return
*/
public MongoCollection<Document> getCollection(String dbName, String collName) {
if (null == collName || "".equals(collName)) {
return null;
}
if (null == dbName || "".equals(dbName)) {
return null;
}
MongoCollection<Document> collection = mongoClient.getDatabase(dbName).getCollection(collName);
return collection;
} 工具类的查询、插入、更新、删除方法。/**条件查询*/
public MongoCursor<Document> find(MongoCollection<Document> coll, Bson filter) {
if(null!=filter){
return coll.find(filter).iterator();
}else{
return coll.find().iterator();
}
}
/**插入一条数据*/
public void insert(MongoCollection<Document> coll,Document doc){
coll.insertOne(doc);
}
/**更新一条数据*/
public void update(MongoCollection<Document> coll,Document querydoc,Document updatedoc){
coll.updateMany(querydoc, updatedoc);
}
/**删除一条数据*/
public void delete(MongoCollection<Document> coll,Document doc){
coll.deleteMany(doc);
}项目中的增删改查：
插入：对应MongoDB中脚本的db.getCollection('person').insert({"name":"ryan1","age":21})
代码语言：txt复制 插入功能的servletString name = request.getParameter("name");
Double age = Double.valueOf(request.getParameter("age"));
String dbName = "personmap";
String collName = "person";
MongoCollection<Document> coll = MongoDBUtil.instance.getCollection(dbName, collName);
Document doc = new Document();
doc.put("name", name);
doc.put("age", age);
MongoDBUtil.instance.insert(coll, doc);
PrintWriter out = response.getWriter();
out.write("insert success!"); 插入功能的jsp<div class="panel panel-warning" style="width:20%">
<div class="panel-heading">删除文档</div>
<div class="panel-body">
<form action="InsertPerson">
<input type="text" name="name" class="form-control" placeholder="name" aria-describedby="basic-addon1">
<br/>
<input type="text" name="age" class="form-control" placeholder="age" aria-describedby="basic-addon1">
<br/>
<button type="submit" class="btn btn-default">插入</button>
</form>
</div>
</div>
更新：对应MongoDB中脚本的db.getCollection('person').update({"name":"ryan1"}{"$set":{"age":22}})
代码语言：txt复制 更新功能的servletString queryname = request.getParameter("queryname");
Double updateage = Double.valueOf(request.getParameter("updateage"));
String dbName = "personmap";
String collName = "person";
MongoCollection<Document> coll = MongoDBUtil.instance.getCollection(dbName, collName);
Document querydoc = new Document();
querydoc.put("name", queryname);
Document updatedoc = new Document();
updatedoc.put("name", queryname);
updatedoc.put("age", updateage);
MongoDBUtil.instance.update(coll, querydoc , new Document("$set",updatedoc));
PrintWriter out = response.getWriter();
out.write("update success!"); 更新功能的jsp<div class="panel panel-warning" style="width:20%">
<div class="panel-heading">根据name更新age</div>
<div class="panel-body">
<form action="UpdatePerson">
<input type="text" name="queryname" class="form-control" placeholder="queryname" aria-describedby="basic-addon1">
<br/>
<input type="text" name="updateage" class="form-control" placeholder="updateage" aria-describedby="basic-addon1">
<br/>
<button type="submit" class="btn btn-default">更新</button>
</form>
</div>
</div>
删除：对应MongoDB中脚本的db.getCollection('person').remove({"name":"ryan1"})
代码语言：txt复制 删除功能的servletString name = request.getParameter("name");
String dbName = "personmap";
String collName = "person";
MongoCollection<Document> coll = MongoDBUtil.instance.getCollection(dbName, collName);
Document doc = new Document();
doc.put("name", name);
MongoDBUtil.instance.delete(coll, doc);
PrintWriter out = response.getWriter();
out.write("delete success!"); 删除功能的jsp<div class="panel panel-warning" style="width:20%">
<div class="panel-heading">删除文档</div>
<div class="panel-body">
<form action="DeletePerson">
<input type="text" name="name" class="form-control" placeholder="name" aria-describedby="basic-addon1">
<br/>
<button type="submit" class="btn btn-default">删除</button>
</form>
</div>
</div>
**查找**：对应MongoDB中脚本的db.getCollection('person').find({}) 查找功能的servletString dbName = "personmap";
String collName = "person";
MongoCollection<Document> coll = MongoDBUtil.instance.getCollection(dbName, collName);
List<Person> personList = new ArrayList<Person>();
// 查询所有
//Bson filter = Filters.eq("name", "ryan1");
Bson filter = null;
MongoCursor<Document> cursor = MongoDBUtil.instance.find(coll, filter);
while(cursor.hasNext()){
Document tempdoc = cursor.next();
Person person = new Person();
person.set_id(tempdoc.get("_id").toString());
person.setName(tempdoc.get("name").toString());
person.setAge(Double.valueOf(tempdoc.get("age").toString()));
personList.add(person);
}
Gson gson = new Gson();
PrintWriter out = response.getWriter();
out.write(gson.toJson(personList)); 查找功能的jsp<div class="panel panel-warning" style="width:50%">
<div class="panel-heading">查找全部数据</div>
<div class="panel-body">
<table data-toggle="table"
data-url="FindPerson"
data-classes="table table-hover table-condensed"
data-striped="true">
<thead>
<tr>
<th class="col-xs-2" data-field="_id">_id</th>
<th class="col-xs-2" data-field="name">name</th>
<th class="col-xs-2" data-field="age">age</th>
</tr>
</thead>
</table>
</div>
</div>
