JDBC自定义连接池

最近学习了JDBC的相关知识，写一下自定义连接池

一些说明：

本代码参考了部分别人的代码！！！

JDBCCon类具体创建了连接；

MyConnection类集成了Connection类用来管理连接与池，其中的close方法必须pool.add()；

MyDataSource则是具体实现连接池。

具体步骤：

1、导mysql的jar包

2、配置db.propertites

driver = com.mysql.cj.jdbc.Driver
url = jdbc:mysql://localhost:3306/test?serverTimezone=GMT
username = root
password = root

3、JDBCCon

package com.nick.util;

import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Properties;

public class JDBCCon {

    private static String driver; 
    private static String url;
    private static String username;
    private static String password;
    
    
    static {
        
        try {
            ClassLoader classLoader = JDBCCon.class.getClassLoader();
            InputStream is = classLoader.getResourceAsStream("db.properties");
            Properties props = new Properties();
            props.load(is);
            driver = props.getProperty("driver");
            url = props.getProperty("url");
            username = props.getProperty("username");
            password = props.getProperty("password");
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        
    }
    
    public static Connection getConnection() {
        Connection connection = null;
        try {
            Class.forName(driver);
            connection = DriverManager.getConnection(url, username, password);
        } catch (Exception e) {
            // TODO: handle exception
        }
        return connection;
        
    }
    
    public static void release(Connection conn, PreparedStatement pstmt, ResultSet rs) {
        if(rs != null) {
            try {
                rs.close();
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        if(pstmt != null) {
            try {
                pstmt.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();
            }
        }
        
    }
    
}

4、MyConnection

package com.nick.dataSource;

import java.sql.Array;
import java.sql.Blob;
import java.sql.CallableStatement;
import java.sql.Clob;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.NClob;
import java.sql.PreparedStatement;
import java.sql.SQLClientInfoException;
import java.sql.SQLException;
import java.sql.SQLWarning;
import java.sql.SQLXML;
import java.sql.Savepoint;
import java.sql.Statement;
import java.sql.Struct;
import java.util.LinkedList;
import java.util.Map;
import java.util.Properties;
import java.util.concurrent.Executor;

public class MyConnection implements Connection{

    private Connection connection = null;
    private LinkedList<Connection> pool = null;
    public MyConnection(Connection connection, LinkedList<Connection> pool) {
        this.connection = connection;
        this.pool = pool;
    }
    
    @Override
    public void close() throws SQLException {
        // TODO Auto-generated method stub
        pool.add(connection);
    }
    
    @Override
    public <T> T unwrap(Class<T> iface) throws SQLException {
        // TODO Auto-generated method stub
        return null;
    }
    @Override
    public boolean isWrapperFor(Class<?> iface) throws SQLException {
        // TODO Auto-generated method stub
        return false;
    }
    @Override
    public Statement createStatement() throws SQLException {
        // TODO Auto-generated method stub
        return null;
    }
    @Override
    public PreparedStatement prepareStatement(String sql) throws SQLException {
        // TODO Auto-generated method stub
        return null;
    }
    @Override
    public CallableStatement prepareCall(String sql) throws SQLException {
        // TODO Auto-generated method stub
        return null;
    }
    @Override
    public String nativeSQL(String sql) throws SQLException {
        // TODO Auto-generated method stub
        return null;
    }
    @Override
    public void setAutoCommit(boolean autoCommit) throws SQLException {
        // TODO Auto-generated method stub
        
    }
    @Override
    public boolean getAutoCommit() throws SQLException {
        // TODO Auto-generated method stub
        return false;
    }
    @Override
    public void commit() throws SQLException {
        // TODO Auto-generated method stub
        
    }
    @Override
    public void rollback() throws SQLException {
        // TODO Auto-generated method stub
        
    }
    
    @Override
    public boolean isClosed() throws SQLException {
        // TODO Auto-generated method stub
        return false;
    }
    @Override
    public DatabaseMetaData getMetaData() throws SQLException {
        // TODO Auto-generated method stub
        return null;
    }
    @Override
    public void setReadOnly(boolean readOnly) throws SQLException {
        // TODO Auto-generated method stub
        
    }
    @Override
    public boolean isReadOnly() throws SQLException {
        // TODO Auto-generated method stub
        return false;
    }
    @Override
    public void setCatalog(String catalog) throws SQLException {
        // TODO Auto-generated method stub
        
    }
    @Override
    public String getCatalog() throws SQLException {
        // TODO Auto-generated method stub
        return null;
    }
    @Override
    public void setTransactionIsolation(int level) throws SQLException {
        // TODO Auto-generated method stub
        
    }
    @Override
    public int getTransactionIsolation() throws SQLException {
        // TODO Auto-generated method stub
        return 0;
    }
    @Override
    public SQLWarning getWarnings() throws SQLException {
        // TODO Auto-generated method stub
        return null;
    }
    @Override
    public void clearWarnings() throws SQLException {
        // TODO Auto-generated method stub
        
    }
    @Override
    public Statement createStatement(int resultSetType, int resultSetConcurrency) throws SQLException {
        // TODO Auto-generated method stub
        return null;
    }
    @Override
    public PreparedStatement prepareStatement(String sql, int resultSetType, int resultSetConcurrency)
            throws SQLException {
        // TODO Auto-generated method stub
        return null;
    }
    @Override
    public CallableStatement prepareCall(String sql, int resultSetType, int resultSetConcurrency) throws SQLException {
        // TODO Auto-generated method stub
        return null;
    }
    @Override
    public Map<String, Class<?>> getTypeMap() throws SQLException {
        // TODO Auto-generated method stub
        return null;
    }
    @Override
    public void setTypeMap(Map<String, Class<?>> map) throws SQLException {
        // TODO Auto-generated method stub
        
    }
    @Override
    public void setHoldability(int holdability) throws SQLException {
        // TODO Auto-generated method stub
        
    }
    @Override
    public int getHoldability() throws SQLException {
        // TODO Auto-generated method stub
        return 0;
    }
    @Override
    public Savepoint setSavepoint() throws SQLException {
        // TODO Auto-generated method stub
        return null;
    }
    @Override
    public Savepoint setSavepoint(String name) throws SQLException {
        // TODO Auto-generated method stub
        return null;
    }
    @Override
    public void rollback(Savepoint savepoint) throws SQLException {
        // TODO Auto-generated method stub
        
    }
    @Override
    public void releaseSavepoint(Savepoint savepoint) throws SQLException {
        // TODO Auto-generated method stub
        
    }
    @Override
    public Statement createStatement(int resultSetType, int resultSetConcurrency, int resultSetHoldability)
            throws SQLException {
        // TODO Auto-generated method stub
        return null;
    }
    @Override
    public PreparedStatement prepareStatement(String sql, int resultSetType, int resultSetConcurrency,
            int resultSetHoldability) throws SQLException {
        // TODO Auto-generated method stub
        return null;
    }
    @Override
    public CallableStatement prepareCall(String sql, int resultSetType, int resultSetConcurrency,
            int resultSetHoldability) throws SQLException {
        // TODO Auto-generated method stub
        return null;
    }
    @Override
    public PreparedStatement prepareStatement(String sql, int autoGeneratedKeys) throws SQLException {
        // TODO Auto-generated method stub
        return null;
    }
    @Override
    public PreparedStatement prepareStatement(String sql, int[] columnIndexes) throws SQLException {
        // TODO Auto-generated method stub
        return null;
    }
    @Override
    public PreparedStatement prepareStatement(String sql, String[] columnNames) throws SQLException {
        // TODO Auto-generated method stub
        return null;
    }
    @Override
    public Clob createClob() throws SQLException {
        // TODO Auto-generated method stub
        return null;
    }
    @Override
    public Blob createBlob() throws SQLException {
        // TODO Auto-generated method stub
        return null;
    }
    @Override
    public NClob createNClob() throws SQLException {
        // TODO Auto-generated method stub
        return null;
    }
    @Override
    public SQLXML createSQLXML() throws SQLException {
        // TODO Auto-generated method stub
        return null;
    }
    @Override
    public boolean isValid(int timeout) throws SQLException {
        // TODO Auto-generated method stub
        return false;
    }
    @Override
    public void setClientInfo(String name, String value) throws SQLClientInfoException {
        // TODO Auto-generated method stub
        
    }
    @Override
    public void setClientInfo(Properties properties) throws SQLClientInfoException {
        // TODO Auto-generated method stub
        
    }
    @Override
    public String getClientInfo(String name) throws SQLException {
        // TODO Auto-generated method stub
        return null;
    }
    @Override
    public Properties getClientInfo() throws SQLException {
        // TODO Auto-generated method stub
        return null;
    }
    @Override
    public Array createArrayOf(String typeName, Object[] elements) throws SQLException {
        // TODO Auto-generated method stub
        return null;
    }
    @Override
    public Struct createStruct(String typeName, Object[] attributes) throws SQLException {
        // TODO Auto-generated method stub
        return null;
    }
    @Override
    public void setSchema(String schema) throws SQLException {
        // TODO Auto-generated method stub
        
    }
    @Override
    public String getSchema() throws SQLException {
        // TODO Auto-generated method stub
        return null;
    }
    @Override
    public void abort(Executor executor) throws SQLException {
        // TODO Auto-generated method stub
        
    }
    @Override
    public void setNetworkTimeout(Executor executor, int milliseconds) throws SQLException {
        // TODO Auto-generated method stub
        
    }
    @Override
    public int getNetworkTimeout() throws SQLException {
        // TODO Auto-generated method stub
        return 0;
    }
}

5、MyDataSource

package com.nick.dataSource;

import java.sql.Connection;
import java.util.LinkedList;

import com.nick.util.JDBCCon;

public class MyDataSource {

    private static LinkedList<Connection> pool = new LinkedList<Connection>();
    
    static {
        //
        for(int i = 0; i < 5; i++) {
            Connection connection = JDBCCon.getConnection();
            pool.add(connection);
        }
    }
    
    public static Connection getConnection() {
        if(pool.size() == 0) {
            for(int i = 0; i < 5; i++) {
                Connection connection = JDBCCon.getConnection();
                MyConnection myConnection = new MyConnection(connection, pool);
                pool.add(myConnection);
            }
        }
        Connection connection = pool.remove(0);
        return connection;
        
    } 
}

6、检测代码

package com.nick.test;

import java.sql.Connection;
import java.sql.PreparedStatement;

import org.junit.jupiter.api.Test;

import com.nick.dataSource.MyDataSource;
import com.nick.util.JDBCCon;

public class TestDemo01 {

    @Test
    public void t1() {
        Connection connection = null;
        PreparedStatement pstmt = null;
        MyDataSource myDataSource = new MyDataSource();
        try {
            connection = myDataSource.getConnection();
            String sql = "insert into student values (?,?,?,?)";
            PreparedStatement prepareStatement = connection.prepareStatement(sql);
            prepareStatement.setInt(1, 10);
            prepareStatement.setString(2, "吕布");
            prepareStatement.setString(3, "男");
            prepareStatement.setInt(4, 100);
            int rows = prepareStatement.executeUpdate();
            if(rows > 0) {
                System.out.println("OK");
            }else {
                System.out.println("NO");
            }
        } catch (Exception e) {
            // TODO: handle exception
        }
    }
}

以上即全部代码。