首页 数据库 mysql教程 MongoDB之Java测试代码(DAO层)

MongoDB之Java测试代码(DAO层)

Jun 07, 2016 pm 04:06 PM
dao java mongodb 代码 测试

MongoInit.java是数据库初始化及连接类 MongoUtils.java是对mongodb的各种操作方法 MongoInit.java package com.wlwcloud.datatest;import java.io.File;import java.io.FileInputStream;import java.io.IOException;import java.net.UnknownHostException;i

MongoInit.java是数据库初始化及连接类

MongoUtils.java是对mongodb的各种操作方法

MongoInit.java

package com.wlwcloud.datatest;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.net.UnknownHostException;
import java.util.Properties;

import org.apache.log4j.Logger;

import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.Mongo;
import com.mongodb.MongoOptions;
import com.mongodb.ServerAddress;

/**
 * Mongo工具类:设计为单例模式,每当月份发生变化,数据库连接名称就会发生变化,这是业务规则 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(池大小默认为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,我们可以用以下方式保证一致性: DB mdb =mongo.getDB('dbname'); mdb.requestStart(); // 业务代码 mdb.requestDone();
 * DB和DBCollection是绝对线程安全的
 * @author undoner
 */
public class MongoInit {
	/** DB监听端口号 */
	private static int DBPort = 27017;
	/** DB连接URL */
	private static String DBUrl = "localhost";
	/** 连接DB库名称 */
	private static String DBName = "wlwdb";
	static Logger log = Logger.getRootLogger();
	private static Mongo mongo;
	private static DBCollection coll;
	private static DB db;

	static {
		try {
			DBproperties();
			MongoOptions options = new MongoOptions();
			options.autoConnectRetry = true;
			options.connectionsPerHost = 1000;
			options.maxWaitTime = 5000;
			options.socketTimeout = 0;
			options.connectTimeout = 15000;
			options.threadsAllowedToBlockForConnectionMultiplier = 5000;
			// 事实上,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了
			ServerAddress serverAddress = new ServerAddress(DBUrl, DBPort);
			mongo = new Mongo(serverAddress, options);
		} catch (UnknownHostException e) {
			log.info("get mongo instance failed");
		}
	}

	static void DBproperties() {
		// 读取配置文件config.properties中的属性值
		String myFilePath = MongoInit.class.getResource("/").getPath() + "MongoDBConfig.properties";
		Properties properties = new Properties();
		FileInputStream fileInputStream = null;
		try {
			   fileInputStream = new FileInputStream(myFilePath);
			   properties.load(fileInputStream);
			   DBPort = Integer.parseInt((String) properties.getProperty("DBPort"));
			   DBUrl = (String) properties.getProperty("DBUrl");
			   DBName = (String) properties.getProperty("DBName");
			  } catch (Exception e) {
			   e.printStackTrace();
			  } finally {
			   try {
			    fileInputStream.close();
			   } catch (IOException e) {
			    // TODO Auto-generated catch block
			    e.printStackTrace();
			   }
		}

	}

	public static DB getDB() {
		if (db == null) {
			db = mongo.getDB(DBName);
		}
		return db;
	}

	public static Mongo getMong() {
		return mongo;
	}

	public static DBCollection getColl(String collname) {
		return getDB().getCollection(collname);
	}

}
登录后复制

 

package com.wlwcloud.datatest;

import java.net.UnknownHostException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Set;
import java.util.regex.Pattern;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.ketayao.ketacustom.entity.main.User;
import com.ketayao.utils.SecurityUtils;
import com.mongodb.AggregationOutput;
import com.mongodb.BasicDBList;
import com.mongodb.BasicDBObject;
import com.mongodb.BasicDBObjectBuilder;
import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.DBCursor;
import com.mongodb.DBObject;
import com.mongodb.MapReduceCommand;
import com.mongodb.MapReduceOutput;
import com.mongodb.Mongo;
import com.mongodb.MongoException;
import com.mongodb.QueryBuilder;
import com.mongodb.WriteConcern;

public class MongoUtils {
	//DBCursor cursor = coll.find(condition).addOption(Bytes.QUERYOPTION_NOTIMEOUT);//设置游标不要超时  
     
    /** 
     * 获取所有数据库实例 
     */  
    public void testGetDBS() {  
        List<String> dbnames = MongoInit.getMong().getDatabaseNames();  
        for (String dbname : dbnames) {  
            System.out.println("dbname:" + dbname);  
        }  
    }  
  
     
    /** 
     * 删除数据库 
     */  
    public void dropDatabase(String dbname) {  
        MongoInit.getMong().dropDatabase(dbname);  
    }  
  
     
    /** 
     * 查询所有表名 
     */  
    public void getAllCollections() {  
        Set<String> colls = MongoInit.getDB().getCollectionNames();  
        for (String s : colls) {  
            System.out.println("Collections:"+s);  
        }  
    }  
  
    /** 
     * 删除一个表 
     */  
    public void dropCollection(String collection) {  
        MongoInit.getColl(collection).drop();  
    }  
  
    /** 
     * 添加一条记录 
     */  
     
    public void addData(String dbCollection,String dataID,String dataTime,String dataContent,String dataStatus) {  
        DBCollection coll = MongoInit.getColl(dbCollection);  
        BasicDBObject doc = new BasicDBObject();  
        doc.put("id", dataID);  
        doc.put("time", dataTime);  
        doc.put("data", dataContent);  
        doc.put("status", dataStatus);  
        coll.insert(doc);  
        // 设定write concern,以便操作失败时得到提示  
        coll.setWriteConcern(WriteConcern.SAFE);  
        findOne(dbCollection);
    }  
  
     
    /** 
     * 创建索引 
     */  
    public void createIndex(String collection) {  
        MongoInit.getColl(collection).createIndex(new BasicDBObject("index_id", 1));  
    }  
  
     
    /** 
     * 获取索引信息 
     */  
    public void getIndexInfo(String dbCollection) {  
        List<DBObject> list = MongoInit.getColl(dbCollection).getIndexInfo();  
        for (DBObject o : list) {  
            System.out.println(o);  
        }  
    }  
  
     
    /** 
     * 添加多条记录 
     */  
    public void addMultiData() {  
        for (int i = 0; i < 100; i++) {  
            MongoInit.getColl("wujintao").insert(  
                    new BasicDBObject().append("i", i));  
        }  
  
        List<DBObject> docs = new ArrayList<DBObject>();  
        for (int i = 0; i < 50; i++) {  
            docs.add(new BasicDBObject().append("i", i));  
        }  
        MongoInit.getColl("wujintao").insert(docs);  
        // 设定write concern,以便操作失败时得到提示  
        MongoInit.getColl("wujintao").setWriteConcern(WriteConcern.SAFE);  
    }  
  
     
    /** 
     * 查找第一条记录 
     */  
    public void findOne(String dbCollection) {  
        DBObject myDoc = MongoInit.getColl(dbCollection).findOne();  
        System.out.println(myDoc);  
    }  
  
     
    /** 
     * 获取表中所有记录条数 
     */  
    public void count(String dbCollection) {  
        System.out.println(MongoInit.getColl(dbCollection).getCount());  
        System.out.println(MongoInit.getColl(dbCollection).count());  
    }  
  
     
    /** 
     * 获取查询结果集的记录数 
     */  
    public void getCount(String dbCollection,String dataID) {  
        DBObject query = new BasicDBObject("id", dataID);  
        long count = MongoInit.getColl(dbCollection).count(query);  
        System.out.println(count);  
    }  
  
     
    /** 
     * 查询所有结果 
     */  
    public void getAllDocuments(String dbCollection) {  
        DBCursor cursor = MongoInit.getColl(dbCollection).find();  
        try {  
            while (cursor.hasNext()) {  
                System.out.println(cursor.next());  
            }  
        } finally {  
            cursor.close();  
        }  
    }  
  
     
    /** 
     * 按照一个条件查询 
     */  
    public void queryByConditionOne() {  
        BasicDBObject query = new BasicDBObject();  
        query.put("name", "MongoDB");  
        DBCursor cursor = MongoInit.getColl("wujintao").find(query);  
  
        try {  
            while (cursor.hasNext()) {  
                System.out.println(cursor.next());  
            }  
        } finally {  
            cursor.close();  
        }  
    }  
    public List<SensorData> queryById(String id) { 
    	User user = SecurityUtils.getLoginUser();
        BasicDBObject query = new BasicDBObject();  
        System.out.print(id);
        query.put("id", id);  
        String table="table_";
        DBCursor cursor = MongoInit.getColl("table_"+user.getUsername()).find(query);  
        List<DBObject> list=cursor.toArray();
        System.out.println(list.size());
        System.out.println("dao.."+list.toString());
        List<SensorData> sensordata=new ArrayList<SensorData>();
        for(int i=1;i<list.size();i++)
        {
        	String sid=(String)list.get(i).get("id");
        	String stime=(String)list.get(i).get("time");
        	String sdata=(String)list.get(i).get("data");
        	String status=(String)list.get(i).get("status");
        	String sstatus;
        	if(status.equals("0"))sstatus="正常";
        	else if(status.equals("1")) sstatus="删除";
        	else sstatus="未知状态";
            SensorData a=new SensorData(sid,stime,sdata,sstatus);
        //System.out.print(a.getData()+a.getId()+a.getStatus()+a.getTime());
        sensordata.add(a);
        }
        return sensordata;
       /* try {  
            while (cursor.hasNext()) {  
                System.out.println(cursor.next());  
            }  
        } finally {  
            cursor.close();  
        } */ 
    }  
     
    /** 
     * AND多条件查询,区间查询 
     */  
    public void queryMulti() {  
        BasicDBObject query = new BasicDBObject();  
        // 查询j不等于3,k大于10的结果集  
        query.put("j", new BasicDBObject("$ne", 3));  
        query.put("k", new BasicDBObject("$gt", 10));  
        DBCursor cursor = MongoInit.getColl("wujintao").find(query);  
        try {  
            while (cursor.hasNext()) {  
                System.out.println(cursor.next());  
            }  
        } finally {  
            cursor.close();  
        }  
    }  
  
     
    /** 
     * 区间查询 
     * select * from table where i >50 
     */  
    public void queryMulti2() {  
        BasicDBObject query = new BasicDBObject();  
        query = new BasicDBObject();  
        query.put("i", new BasicDBObject("$gt", 50)); // e.g. find all where i >  
        DBCursor cursor = MongoInit.getColl("wujintao").find(query);  
        try {  
            while (cursor.hasNext()) {  
                System.out.println(cursor.next());  
            }  
        } finally {  
            cursor.close();  
        }  
    }  
  
     
    /** 
     * 区间查询 
     * select * from table where 20 < i <= 30 
        //比较符    
        //"$gt": 大于    
        //"$gte":大于等于    
        //"$lt": 小于    
        //"$lte":小于等于    
        //"$in": 包含    
     */  
    public void queryMulti3() {  
        BasicDBObject query = new BasicDBObject();  
        query = new BasicDBObject();  
  
        query.put("i", new BasicDBObject("$gt", 20).append("$lte", 30));  
        DBCursor cursor = MongoInit.getColl("wujintao").find(query);  
        try {  
            while (cursor.hasNext()) {  
                System.out.println(cursor.next());  
            }  
        } finally {  
            cursor.close();  
        }  
    }  
  
    /** 
     * 组合in和and select * from test_Table where (a=5 or b=6) and (c=5 or d = 6) 
     */  
    public void queryMulti4() {  
        BasicDBObject query11 = new BasicDBObject();  
        query11.put("a", 1);  
        BasicDBObject query12 = new BasicDBObject();  
        query12.put("b", 2);  
        List<BasicDBObject> orQueryList1 = new ArrayList<BasicDBObject>();  
        orQueryList1.add(query11);  
        orQueryList1.add(query12);  
        BasicDBObject orQuery1 = new BasicDBObject("$or", orQueryList1);  
  
        BasicDBObject query21 = new BasicDBObject();  
        query21.put("c", 5);  
        BasicDBObject query22 = new BasicDBObject();  
        query22.put("d", 6);  
        List<BasicDBObject> orQueryList2 = new ArrayList<BasicDBObject>();  
        orQueryList2.add(query21);  
        orQueryList2.add(query22);  
        BasicDBObject orQuery2 = new BasicDBObject("$or", orQueryList2);  
  
        List<BasicDBObject> orQueryCombinationList = new ArrayList<BasicDBObject>();  
        orQueryCombinationList.add(orQuery1);  
        orQueryCombinationList.add(orQuery2);  
  
        BasicDBObject finalQuery = new BasicDBObject("$and",  
                orQueryCombinationList);  
        DBCursor cursor = MongoInit.getColl("wujintao").find(finalQuery);  
    }  
  
     
    /** 
     * IN查询 
     * if i need to query name in (a,b); just use { name : { $in : [&#39;a&#39;, &#39;b&#39;] } } 
     * select * from things where name=&#39;a&#39; or name=&#39;b&#39; 
     * @param coll 
     */  
    public void queryIn() {  
        BasicDBList values = new BasicDBList();  
        values.add("a");  
        values.add("b");  
        BasicDBObject in = new BasicDBObject("$in", values);  
        DBCursor cursor = MongoInit.getColl("wujintao").find(  
                new BasicDBObject("name", in));  
        try {  
            while (cursor.hasNext()) {  
                System.out.println(cursor.next());  
            }  
        } finally {  
            cursor.close();  
        }  
    }  
  
     
    /** 
     * 或查询 
     * select * from table where name  = &#39;12&#39; or title = &#39;p&#39; 
     * @param coll 
     */  
    public void queryOr() {  
        QueryBuilder query = new QueryBuilder();  
        query.or(new BasicDBObject("name", 12), new BasicDBObject("title", "p"));  
        DBCursor cursor = MongoInit.getColl("wujintao").find(query.get()).addSpecial("$returnKey", "");  
        try {  
            while (cursor.hasNext()) {  
                System.out.println(cursor.next());  
            }  
        } finally {  
            cursor.close();  
        }  
    }  
      
     
    public void customQueryField() throws UnknownHostException{  
        Mongo mongo = new Mongo("localhost", 27017);  
        DB db = mongo.getDB("zhongsou_ad");  
        BasicDBObjectBuilder bulder = new BasicDBObjectBuilder();  
        bulder.add("times",1);  
        bulder.add("aid",1);  
        DBCursor cusor =  db.getCollection("ad_union_ad_c_1").find(new BasicDBObject(),bulder.get());  
        for (DBObject dbObject : cusor) {  
            System.out.println(dbObject);  
        }  
    }  
      
     
    public void mapReduce() throws UnknownHostException{  
        Mongo mongo = new Mongo("localhost", 27017);  
        DB db = mongo.getDB("zhongsou_ad");  
        /*** 
         *  book1 = {name : "Understanding JAVA", pages : 100} 
         *  book2 = {name : "Understanding JSON", pages : 200} 
         *  db.books.save(book1) 
         *  db.books.save(book2) 
         *  book = {name : "Understanding XML", pages : 300} 
         *  db.books.save(book) 
         *  book = {name : "Understanding Web Services", pages : 400} 
         *  db.books.save(book) 
         *  book = {name : "Understanding Axis2", pages : 150} 
         *  db.books.save(book)   
         *   
        var map = function() { 
            var category; 
            if ( this.pages >= 250 ) 
                category = &#39;Big Books&#39;; 
            else 
                category = "Small Books"; 
            emit(category, {name: this.name}); 
        }; 
        var reduce = function(key, values) { 
            var sum = 0; 
            values.forEach(function(doc) { 
                sum += 1; 
            }); 
            return {books: sum}; 
        };        
        var count  = db.books.mapReduce(map, reduce, {out: "book_results"}); 
         */  
        try {  
  
            DBCollection books = db.getCollection("books");  
  
            BasicDBObject book = new BasicDBObject();  
            book.put("name", "Understanding JAVA");  
            book.put("pages", 100);  
            books.insert(book);  
              
            book = new BasicDBObject();    
            book.put("name", "Understanding JSON");  
            book.put("pages", 200);  
            books.insert(book);  
              
            book = new BasicDBObject();  
            book.put("name", "Understanding XML");  
            book.put("pages", 300);  
            books.insert(book);  
              
            book = new BasicDBObject();  
            book.put("name", "Understanding Web Services");  
            book.put("pages", 400);  
            books.insert(book);  
            
            book = new BasicDBObject();  
            book.put("name", "Understanding Axis2");  
            book.put("pages", 150);  
            books.insert(book);  
              
            String map = "function() { "+   
                      "var category; " +    
                      "if ( this.pages >= 250 ) "+    
                      "category = &#39;Big Books&#39;; " +  
                      "else " +  
                      "category = &#39;Small Books&#39;; "+    
                      "emit(category, {name: this.name});}";  
              
            String reduce = "function(key, values) { " +  
                                     "var sum = 0; " +  
                                     "values.forEach(function(doc) { " +  
                                     "sum += 1; "+  
                                     "}); " +  
                                     "return {books: sum};} ";  
              
            MapReduceCommand cmd = new MapReduceCommand(books, map, reduce,  
              null, MapReduceCommand.OutputType.INLINE, null);  
  
            MapReduceOutput out = books.mapReduce(cmd);  
  
            for (DBObject o : out.results()) {  
             System.out.println(o.toString());  
            }  
           } catch (Exception e) {  
             e.printStackTrace();  
           }  
    }  
      
     
    public void GroupByManyField() throws UnknownHostException{  
        //此方法没有运行成功  
        Mongo mongo = new Mongo("localhost", 27017);  
        DB db = mongo.getDB("libary");  
        DBCollection books = db.getCollection("books");  
        BasicDBObject groupKeys = new BasicDBObject();  
        groupKeys.put("total", new BasicDBObject("$sum","pages"));  
          
        BasicDBObject condition = new BasicDBObject();  
        condition.append("pages", new BasicDBObject().put("$gt", 0));  
     
          
        String reduce = "function(key, values) { " +  
                "var sum = 0; " +  
                "values.forEach(function(doc) { " +  
                "sum += 1; "+  
                "}); " +  
                "return {books: sum};} ";  
        /** 
         BasicDBList basicDBList = (BasicDBList)db.getCollection("mongodb中集合编码或者编码") 
                   .group(DBObject key,   --分组字段,即group by的字段 
                DBObject cond,        --查询中where条件 
                DBObject initial,     --初始化各字段的值 
                String reduce,        --每个分组都需要执行的Function 
                String finial         --终结Funciton对结果进行最终的处理 
         */  
        DBObject obj = books.group(groupKeys, condition,  new BasicDBObject(), reduce);  
        System.out.println(obj);  
          
        AggregationOutput ouput = books.aggregate(new BasicDBObject("$group",groupKeys));  
        System.out.println(ouput.getCommandResult());  
        System.out.println(books.find(new BasicDBObject("$group",groupKeys)));  
    }     
      
     
    /** 
     * 分页查询    
     */  
    public void pageQuery() {  
        DBCursor cursor = MongoInit.getColl("wujintao").find().skip(0)  
                .limit(10);  
        while (cursor.hasNext()) {  
            System.out.println(cursor.next());  
        }  
    }  
  
    /** 
     * 模糊查询 
     */  
    public void likeQuery() {  
        Pattern john = Pattern.compile("joh?n");  
        BasicDBObject query = new BasicDBObject("name", john);  
  
        // finds all people with "name" matching /joh?n/i  
        DBCursor cursor = MongoInit.getColl("wujintao").find(query);  
    }  
  
     
    /** 
     * 条件删除    
     */  
    public void delete(String dbCollection,String dataID) {  
        BasicDBObject query = new BasicDBObject();  
        query.put("id", dataID);  
        // 找到并且删除,并返回删除的对象  
        DBObject removeObj = MongoInit.getColl(dbCollection).findAndRemove(query);  
        System.out.println(removeObj);  
    }  
  
     
    /** 
     * 更新 
     */  
    public void update() {  
        BasicDBObject query = new BasicDBObject();  
        query.put("name", "liu");  
        DBObject stuFound = MongoInit.getColl("wujintao").findOne(query);  
        stuFound.put("name", stuFound.get("name") + "update_1");  
        MongoInit.getColl("wujintao").update(query, stuFound);  
    }  
	
    public void testGpsData() {  
    	try {
			//13862082455:117.13172:029.77659:131.2580
    		Date d = new Date(); 
			SimpleDateFormat  sdf =new SimpleDateFormat("yyyy-MM-dd HH:mm:ss SSS");
			String dateNowStr = sdf.format(d);  
			System.out.println(dateNowStr);
			
    		DBCollection coll = MongoInit.getColl("table_admin");  
            BasicDBObject doc = new BasicDBObject();  
            doc.put("id", "12345678");  
            doc.put("time", dateNowStr);  
            doc.put("data", "117.13172:029.77659:131.2580");  
            doc.put("status", "0");
            coll.insert(doc);  
            // 设定write concern,以便操作失败时得到提示  
            coll.setWriteConcern(WriteConcern.SAFE);  

			BasicDBObject dsort = new BasicDBObject();
			dsort.put("time", -1);
			
			BasicDBObject searchDevice = new BasicDBObject();
			searchDevice.put("id", "12345678");
			DBCursor cursor = coll.find(searchDevice).sort(dsort);		
			
			List<DBObject> list = cursor.toArray();
			//ArrayList<SensorData> listSensorData=new ArrayList<SensorData>(list.size());
			
			ObjectMapper mapper = new ObjectMapper();  
			String jsonfromList = null;
			try {
				//list转json
				jsonfromList = mapper.writeValueAsString(list);
			} catch (JsonProcessingException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}  
	        //System.out.println(jsonfromList);  
//			for(int i=0;i<list.size();i++)
//			{
//				System.out.println((String) list.get(i).get("time"));
			//}
			
			//System.out.println(list.size()+","+listSensorData);//list的长度
//		    System.out.println(cursor.count());//计算结果的数量,类似于(mysql count()函数),不受limit的影响
			
//			while (cursor.hasNext()) {
//				System.out.println(cursor.next());
//			}
			System.out.println("The Search Query has Executed!");
		} catch (MongoException e) {
			e.printStackTrace();
		}
    }  
    
    public static void main(String[] args) {
    	String dbname="wlwdb";
    	String dbCollection="table_admin";
    	String dbCollection1="15257102317";
    	String dataID="12345678";
		MongoUtils tb=new MongoUtils();
		tb.testGetDBS();//查询所有数据库
		tb.getAllCollections();//查询所有表
//		
//		tb.findOne(dbCollection);//查找第一条记录
		tb.testGpsData();
		tb.getAllDocuments(dbCollection);//获取制定表明的所有数据
		//tb.dropDatabase(dbname);//删除指定数据库
		//tb.delete(dbCollection,dataID);//删除制定表明和设备ID的数据
		//tb.dropCollection(dbCollection);// 删除一个表
		
		//tb.createIndex(dbCollection1);//创建索引
		//tb.getIndexInfo(dbCollection1);//获得表中所有索引
	}
}
登录后复制
#端口设置
DBPort=27017
#URL
DBUrl=localhost
#URL
DBName=wlwdb
登录后复制

本站声明
本文内容由网友自发贡献,版权归原作者所有,本站不承担相应法律责任。如您发现有涉嫌抄袭侵权的内容,请联系admin@php.cn

热AI工具

Undresser.AI Undress

Undresser.AI Undress

人工智能驱动的应用程序,用于创建逼真的裸体照片

AI Clothes Remover

AI Clothes Remover

用于从照片中去除衣服的在线人工智能工具。

Undress AI Tool

Undress AI Tool

免费脱衣服图片

Clothoff.io

Clothoff.io

AI脱衣机

AI Hentai Generator

AI Hentai Generator

免费生成ai无尽的。

热门文章

R.E.P.O.能量晶体解释及其做什么(黄色晶体)
2 周前 By 尊渡假赌尊渡假赌尊渡假赌
R.E.P.O.最佳图形设置
2 周前 By 尊渡假赌尊渡假赌尊渡假赌
R.E.P.O.如果您听不到任何人,如何修复音频
3 周前 By 尊渡假赌尊渡假赌尊渡假赌

热工具

记事本++7.3.1

记事本++7.3.1

好用且免费的代码编辑器

SublimeText3汉化版

SublimeText3汉化版

中文版,非常好用

禅工作室 13.0.1

禅工作室 13.0.1

功能强大的PHP集成开发环境

Dreamweaver CS6

Dreamweaver CS6

视觉化网页开发工具

SublimeText3 Mac版

SublimeText3 Mac版

神级代码编辑软件(SublimeText3)

Java 中的完美数 Java 中的完美数 Aug 30, 2024 pm 04:28 PM

Java 完美数指南。这里我们讨论定义,如何在 Java 中检查完美数?,示例和代码实现。

Java 中的随机数生成器 Java 中的随机数生成器 Aug 30, 2024 pm 04:27 PM

Java 随机数生成器指南。在这里,我们通过示例讨论 Java 中的函数,并通过示例讨论两个不同的生成器。

Java中的Weka Java中的Weka Aug 30, 2024 pm 04:28 PM

Java 版 Weka 指南。这里我们通过示例讨论简介、如何使用weka java、平台类型和优点。

Java 中的史密斯数 Java 中的史密斯数 Aug 30, 2024 pm 04:28 PM

Java 史密斯数指南。这里我们讨论定义,如何在Java中检查史密斯号?带有代码实现的示例。

Java Spring 面试题 Java Spring 面试题 Aug 30, 2024 pm 04:29 PM

在本文中,我们保留了最常被问到的 Java Spring 面试问题及其详细答案。这样你就可以顺利通过面试。

突破或从Java 8流返回? 突破或从Java 8流返回? Feb 07, 2025 pm 12:09 PM

Java 8引入了Stream API,提供了一种强大且表达力丰富的处理数据集合的方式。然而,使用Stream时,一个常见问题是:如何从forEach操作中中断或返回? 传统循环允许提前中断或返回,但Stream的forEach方法并不直接支持这种方式。本文将解释原因,并探讨在Stream处理系统中实现提前终止的替代方法。 延伸阅读: Java Stream API改进 理解Stream forEach forEach方法是一个终端操作,它对Stream中的每个元素执行一个操作。它的设计意图是处

创造未来:面向零基础的 Java 编程 创造未来:面向零基础的 Java 编程 Oct 13, 2024 pm 01:32 PM

Java是热门编程语言,适合初学者和经验丰富的开发者学习。本教程从基础概念出发,逐步深入讲解高级主题。安装Java开发工具包后,可通过创建简单的“Hello,World!”程序实践编程。理解代码后,使用命令提示符编译并运行程序,控制台上将输出“Hello,World!”。学习Java开启了编程之旅,随着掌握程度加深,可创建更复杂的应用程序。

Java 变得简单:编程能力的初学者指南 Java 变得简单:编程能力的初学者指南 Oct 11, 2024 pm 06:30 PM

JavaMadeSimple:ABeginner'sGuidetoProgrammingPower简介Java是一种强大的编程语言,广泛应用于从移动应用程序到企业级系统的各种领域。对于初学者来说,Java的语法简洁易懂,是学习编程的理想选择。基本语法Java使用基于类的面向对象编程范式。类是将相关数据和行为组织在一起的模板。以下是一个简单的Java类示例:publicclassPerson{privateStringname;privateintage;

See all articles