Java多数据库操作示例：JDBC、HBase、Redis和MongoDB,-优快云博客

import java.sql.*;
public class mysqltest {
 
	/**
	 * @param args
	 */
	//JDBC DRIVER and DB
	static final String  DRIVER="com.mysql.jdbc.Driver";
	static final String DB="jdbc:mysql://localhost/test";
	//Database auth
	static final String USER="root";
	static final String PASSWD="12345678";
	
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Connection conn=null;
		Statement stmt=null;
		ResultSet rs=null;
		try {
			//加载驱动程序
			Class.forName(DRIVER);
			System.out.println("Connecting to a selected database...");
			//打开一个连接
			conn=DriverManager.getConnection(DB, USER, PASSWD);
			System.out.println(conn);
			//执行一个插入
//			stmt=conn.createStatement();
//			String sql="insert into student values('scofield',45,89,100)";
//			stmt.executeUpdate(sql);
//			System.out.println("Inserting records into the table successfully!");
			//执行一个查询
			stmt=conn.createStatement();
			String sql="select name,English from student where name='scofield' ";
			//获得结果集
			rs=stmt.executeQuery(sql);
			System.out.println("name"+"\t\t"+"English");
			while(rs.next())
			{
				System.out.print(rs.getString(1)+"\t\t");
				System.out.println(rs.getInt(2));
			}
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally
		{
			if(stmt!=null)
				try {
					stmt.close();
				} catch (SQLException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			if(conn!=null)
				try {
					conn.close();
				} catch (SQLException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
		}
	}
	}

import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.Admin;
import org.apache.hadoop.hbase.client.Connection;
import org.apache.hadoop.hbase.client.ConnectionFactory;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.Table;
import org.apache.hadoop.hbase.Cell;
import org.apache.hadoop.hbase.CellUtil;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.client.Get;
 
 
public class hbasetest {
 
	/**
	 * @param args
	 */
	  public static Configuration configuration;
      public static Connection connection;
      public static Admin admin;
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		init();
         try {
        	 //插入数据
//			insertRow("student","scofield","score","English","45");
// 		    insertRow("student","scofield","score","Math","89");
//			insertRow("student","scofield","score","Computer","100");
			//查询数据
			getData("student","scofield","score","English");
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
         close();
	}
	 public static void insertRow(String tableName,String rowKey,String colFamily,String col,String val) throws IOException {
         Table table = connection.getTable(TableName.valueOf(tableName));
         Put put = new Put(rowKey.getBytes());
         put.addColumn(colFamily.getBytes(), col.getBytes(), val.getBytes());
         table.put(put);
         table.close();
     }
	 public static void getData(String tableName,String rowKey,String colFamily,
			  String col)throws  IOException{
         Table table = connection.getTable(TableName.valueOf(tableName));
         Get get = new Get(rowKey.getBytes());
         get.addColumn(colFamily.getBytes(),col.getBytes());
         Result result = table.get(get);
         showCell(result);
         table.close();
     }
	  public static void showCell(Result result){
         Cell[] cells = result.rawCells();
         for(Cell cell:cells){
             System.out.println("RowName:"+new String(CellUtil.cloneRow(cell))+" ");
             System.out.println("Timetamp:"+cell.getTimestamp()+" ");
             System.out.println("column Family:"+new String(CellUtil.cloneFamily(cell))+" ");
             System.out.println("row Name:"+new String(CellUtil.cloneQualifier(cell))+" ");
             System.out.println("value:"+new String(CellUtil.cloneValue(cell))+" ");
         }
     }
	  
	  public static void init() {
		  configuration  = HBaseConfiguration.create();
	         configuration.set("hbase.rootdir","hdfs://localhost:9000/hbase");
	         try{
	             connection = ConnectionFactory.createConnection(configuration);
	             admin = connection.getAdmin();
	         }catch (IOException e){
	             e.printStackTrace();
	         }
	  }
	  
	  public static void close(){
            try{
                if(admin != null){
                    admin.close();
                }
                if(null != connection){
                    connection.close();
                }
            }catch (IOException e){
                e.printStackTrace();
            }
        }
}

import java.util.Map;
import redis.clients.jedis.Jedis;
 
public class redistest {
 
	/**
	 * @param args
	 */
	public static Jedis jedis;
	
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		jedis = new Jedis("localhost");
		//插入数据
//		test1();
		//查询数据
		test2();
	}
 
	public static void test1() {
		// TODO Auto-generated method stub
		jedis.hset("student.scofield", "English","45");
		jedis.hset("student.scofield", "Math","89");
		jedis.hset("student.scofield", "Computer","100");
		Map<String,String>  value = jedis.hgetAll("student.scofield");
		for(Map.Entry<String, String> entry:value.entrySet())
		{
			System.out.println(entry.getKey()+":"+entry.getValue());
		}
	}
	
	public static void test2() {
		// TODO Auto-generated method stub
		String value=jedis.hget("student.scofield", "English");
		System.out.println("scofield's English score is:    "+value);
	}
}

import java.util.ArrayList;
import java.util.List;
 
import org.bson.Document;
import com.mongodb.MongoClient;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;
import com.mongodb.client.MongoCursor;
 
public class mongotest {
 
	/**
	 * @param args
	 */
	public static MongoClient  mongoClient;
	public static MongoDatabase mongoDatabase;
	public static MongoCollection<Document> collection;
	
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		init();
		//插入数据
//		test1();
		//查询数据
		test2();
		
	}
 
	public static void test1() {
		// TODO Auto-generated method stub
		//实例化一个文档,内嵌一个子文档
		Document document=new Document("name","scofield").
				append("score", new Document("English",45).
						append("Math", 89).
						append("Computer", 100));
		List<Document> documents = new ArrayList<Document>();  
        documents.add(document);  
        //将文档插入集合中
        collection.insertMany(documents);  
        System.out.println("文档插入成功"); 
	}
	
	public static void test2() {
		// TODO Auto-generated method stub
		//进行数据查找,查询条件为name=scofield, 对获取的结果集只显示score这个域
				MongoCursor<Document>  cursor=collection.find( new Document("name","scofield")).
						projection(new Document("score",1).append("_id", 0)).iterator();
				while(cursor.hasNext())
					System.out.println(cursor.next().toJson());
		}
 
	public static void init() {
		// TODO Auto-generated method stub
		//实例化一个mongo客户端
		 mongoClient=new MongoClient("localhost",27017);
		//实例化一个mongo数据库
		mongoDatabase = mongoClient.getDatabase("student");
		//获取数据库中某个集合
		collection = mongoDatabase.getCollection("student");
	}
	
}

大数据技术实验四