本文实例讲述了java 数据库连接与增删改查操作。分享给大家供大家参考，具体如下：

1、设置数据库的基本配置信息

package mysql;//数据库配置资源连接public final class DbConfig { //数据库资源 指定所使用的数据库类型 地址 端口 数据库名称 编码格式 public final static String dbUrl = "jdbc:mysql://localhost:3306/database_name?useUnicode=true&characterEncodong=utf-8"; //数据库用户名 public final static String dbUser= "xxxxxx"; //数据库密码 public final static String dbPwd = "xxxxxx";}

2、数据库连接类 用户获取数据库连接

package mysql;import java.sql.SQLException;import java.sql.Connection;import java.sql.DriverManager;public class Conn { //保存住默认数据库连接 private static Connection conn = null; //数据库连接 private static Connection getDbConn(String dbUurl,String dbUser,String dbPwd) { Connection dbConn; try{ //载入mysql 工具包 Class.forName("com.mysql.jdbc.Driver"); dbConn = DriverManager.getConnection(dbUurl,dbUser,dbPwd); }catch(ClassNotFoundException | SQLException e){ dbConn = null; e.printStackTrace(); } return dbConn; } //获得第三方数据库链接 public static Connection getConn(String dbUrl,String dbUser,String dbPwd) { return getDbConn(DbConfig.dbUrl,DbConfig.dbUser,DbConfig.dbPwd); } //获得本地默认数据库连接 public static Connection getConn() { if(conn == null){ conn = getDbConn(DbConfig.dbUrl,DbConfig.dbUser,DbConfig.dbPwd); } return conn; }}

3、数据库测试类 检验获得的数据库连接是否有效

import Demo.Demo;import mysql.*;import java.sql.Connection;import java.sql.SQLException;import java.sql.ResultSet;import java.sql.ResultSetMetaData;import java.sql.PreparedStatement;public class Index { public static void main(String[] args) { index1(); //分隔符 System.out.println("----------------------------------------------"); System.out.println("----------------------------------------------"); System.out.println("----------------------------------------------"); index2(); } //自定义数据库连接方式 public static void index1() { //获取数据库连接 Connection conn = Conn.getConn(DbConfig.dbUrl,DbConfig.dbUser,DbConfig.dbPwd); //测试该数据库连接是否有效 index3(conn); } //默认方式获取数据库连接 public static void index2() { //获取数据库连接 Connection conn = Conn.getConn(); //测试该数据库连接是否有效 index3(conn); } /** * 测试数据库连接是否有效 * @param * Connection conn 数据库连接 * */ public static void index3(Connection conn) { //定义要执行的sql语句 String sql = "select * from table_name where id = ?"; try { //对sql语句进行预处理 PreparedStatement pre = conn.prepareStatement(sql); //变量数据填充 填充后的sql为 select * from table_name where id = "xxxxxxx" pre.setString(1,"xxxxx"); //执行sql语句 发挥执行的结果 ResultSet result = pre.executeQuery(); //返回的结果是否是空数据 if(!result.next()) { System.out.println("没有查询到响应的数据"); return; } //获取返回结果的元数据，列名 ResultSetMetaData meta = result.getMetaData(); //打印输出 int metaLength = meta.getColumnCount(); do{ for(int forInt = 1;forInt <= metaLength;forInt++) { String keyName = meta.getColumnName(forInt); System.out.println(keyName + " => " + result.getString(keyName)); } }while(result.next()); }catch(SQLException e){ e.printStackTrace(); } }}

获取到Connection 连接后看到执行一个sql语句获得返回结果还要这么多的处理操作，以下是自己封装的mysql操作类

数据库接口类，针对数据库操作的类，都得实现这个类。不管以后更换了什么数据库，该数据库的操作类都得实现这个接口所规定的方法，然后我们不需要任何的改动，只需要变更该接口的实现就可以了。

package standard.db.operation;import java.sql.Connection;import java.util.List;import java.util.Map;import spring.beans.db.realization.mysql.DataType;public interface DbOper{ /** * 数据库连接 * */ public void setConnection(Connection conn); public Connection getConnection(); /** * 查询所有数据 * @param * String 要执行的sql语句 * @param * String[] keyVal 映射数组 * @return * List<Map<String,String>> result 查询结果集 * */ public List<Map<String,String>> query(String sql,String[] keyVal); public List<Map<String,String>> query(String sql); /** * 查询单行数据 * @param * String 要执行的sql语句 * @param * String[] keyVal 映射数组 * @return * Map<String,String> result 查询结果集 * */ public Map<String,String> find(String sql,String[] keyVal); public Map<String,String> find(String sql); /** * 更新数据 * @param * String 要执行的sql语句 * @param * String[] keyVal 映射数组 * @return * int resultInt 受影响的行数 * */ public int update(String sql,String[] keyVal); public int update(String sql); /** * 新增数据 * @param * String 要执行的sql语句 * @param * String[] keyVal 映射数组 * @return * int resultInt 新增成功行数 * */ public int insert(String sql,String[] keyVal); public int insert(String sql); /** * 删除数据库 * @param * String 要执行的sql语句 * @param * String[] keyVal 映射数组 * @return * boolean 删除时候成功 * */ public boolean delete(String sql,String[] keyVal); public boolean delete(String sql); /** * 调用存储过程 * @param * String callFunc 存储过程名称 * List<Map<String,String>> 存储过程参数值 如：Map<"int","22"> * */ public List<Map<String,String>> callResult(String callFunc,List<DataType> keyVal); public List<Map<String,String>> callResult(String callFunc);}

针对DbOper接口的实现

package spring.beans.db.realization.mysql;import java.sql.Connection;import java.util.List;import java.util.ArrayList;import java.util.Map;import java.util.HashMap;import java.sql.CallableStatement; import java.sql.SQLException;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.ResultSetMetaData;import javax.annotation.PostConstruct;import javax.annotation.PreDestroy;import javax.sql.DataSource;import org.springframework.beans.factory.annotation.Value;import org.springframework.context.annotation.Scope;import org.springframework.stereotype.Repository;import standard.db.operation.DbOper;/** * mysql 操作实现类 - 容器 * author : 谭勇 * create_date : 2017-04-13 * */@Repository("db_connection")@Scope("request")public final class MysqlRealization implements DbOper{ private Connection conn; /** * 对象初始化 * */ @PostConstruct public void initDb() { } @Override public void setConnection(Connection conn) { this.conn = conn; } @Value(value="#{mysql_driver_manager_dataSource}") public void setConnection(DataSource dataSource) { try{ setConnection(dataSource.getConnection()); }catch(SQLException e) { } } @Override public Connection getConnection() { return this.conn; } @Override public List<Map<String, String>> query(String sql, String[] keyVal) { PreparedStatement pre = null; ResultSet result = null; ResultSetMetaData meta = null; try{ pre = conn.prepareStatement(sql); if(keyVal != null) { //映射到问号 for(int i=1;i<=keyVal.length;i++) { pre.setString(i, keyVal[i-1]); } } result = pre.executeQuery(); if (result.next()) { meta = result.getMetaData(); result.last(); List<Map<String,String>> list = new ArrayList<Map<String,String>>(result.getRow()); result.first(); int propertiesLength = meta.getColumnCount(); do{ Map<String,String> map = new HashMap<String,String>(propertiesLength); for(int i=1;i<=propertiesLength;i++) { String keyName = meta.getColumnName(i); map.put(keyName, result.getString(keyName)); } list.add(map); }while(result.next()); return list; } }catch(SQLException e) { e.printStackTrace(); }finally{ closePreparedStatement(pre); closeResultSet(result); } return null; } @Override public List<Map<String, String>> query(String sql) { return query(sql,null); } @Override public Map<String, String> find(String sql, String[] keyVal) { PreparedStatement pre = null; ResultSet result = null; ResultSetMetaData meta = null; try{ pre = conn.prepareStatement(sql); if(keyVal != null) { //映射到问号 for(int i=1;i<=keyVal.length;i++) { pre.setString(i, keyVal[i-1]); } } result = pre.executeQuery(); if (result.next()) { meta = result.getMetaData(); int propertiesLength = meta.getColumnCount(); Map<String,String> map = new HashMap<String,String>(propertiesLength); for(int i=1;i<=propertiesLength;i++) { String keyName = meta.getColumnName(i); map.put(keyName, result.getString(keyName)); } return map; } }catch(SQLException e) { e.printStackTrace(); }finally{ closePreparedStatement(pre); closeResultSet(result); } return null; } @Override public Map<String, String> find(String sql) { return find(sql,null); } @Override public int update(String sql, String[] keyVal) { PreparedStatement pre = null; try{ pre = conn.prepareStatement(sql); if(keyVal != null) { //映射到问号 for(int i=1;i<=keyVal.length;i++) { pre.setString(i, keyVal[i-1]); } } return pre.executeUpdate(); }catch(SQLException e) { e.printStackTrace(); }finally{ closePreparedStatement(pre); } return 0; } @Override public int update(String sql) { return update(sql,null); } @Override public int insert(String sql, String[] keyVal) { PreparedStatement pre = null; try{ pre = conn.prepareStatement(sql); if(keyVal != null) { //映射到问号 for(int i=1;i<=keyVal.length;i++) { pre.setString(i, keyVal[i-1]); } } return pre.executeUpdate(); }catch(SQLException e) { e.printStackTrace(); }finally{ closePreparedStatement(pre); } return 0; } @Override public int insert(String sql) { return insert(sql,null); } @Override public boolean delete(String sql, String[] keyVal) { PreparedStatement pre = null; try{ pre = conn.prepareStatement(sql); if(keyVal != null) { //映射到问号 for(int i=1;i<=keyVal.length;i++) { pre.setString(i, keyVal[i-1]); } } return pre.executeUpdate() > 0 ? true:false; }catch(SQLException e) { e.printStackTrace(); }finally{ closePreparedStatement(pre); } return false; } @Override public boolean delete(String sql) { return delete(sql,null); } /** * 调用存储过程 * @param * String callFunc 存储过程名 * */ public List<Map<String,String>> callResult(String callFunc,List<DataType> keyVal) { String call = "{call " + callFunc + "}"; ResultSetMetaData meta = null; CallableStatement callableStatement= null; ResultSet result = null; try{ callableStatement = conn.prepareCall(call); if(keyVal != null) { for(int i=1;i<=keyVal.size();i++) { DataType data = keyVal.get(i-1); switch(data.getType()) { case ValueTypeSource.STRING: callableStatement.setString(i, String.valueOf(data.getValue())); break; case ValueTypeSource.INT: callableStatement.setInt(i, Integer.valueOf(data.getValue())); break; case ValueTypeSource.LONG: callableStatement.setLong(i, Long.valueOf(data.getValue())); break; case ValueTypeSource.DOUBLE: callableStatement.setDouble(i, Double.valueOf(data.getValue())); break; default: callableStatement.setString(i,String.valueOf(data.getValue())); } } } callableStatement.execute(); result = callableStatement.getResultSet(); meta = result.getMetaData(); result.last(); List<Map<String,String>> list = new ArrayList<Map<String,String>>(result.getRow()); result.first(); int propertiesLength = meta.getColumnCount(); do{ Map<String,String> map = new HashMap<String,String>(propertiesLength); for(int i=1;i<=propertiesLength;i++) { String keyName = meta.getColumnName(i); map.put(keyName, result.getString(keyName)); } list.add(map); }while(result.next()); return list; }catch(SQLException e) { e.printStackTrace(); return null; }finally{ closeCallableStatement(callableStatement); closeResultSet(result); } } @Override public List<Map<String,String>> callResult(String callFunc) { return callResult(callFunc,null); } /** * 关闭资源链接 * */ private void closePreparedStatement(PreparedStatement pre) { if(pre != null) { try { pre.close(); }catch(SQLException e) { e.printStackTrace(); } } } private void closeResultSet(ResultSet result) { if(result != null) { try { result.close(); }catch(SQLException e) { e.printStackTrace(); } } } private void closeCallableStatement(CallableStatement call) { if(call != null) { try { call.close(); }catch(SQLException e) { e.printStackTrace(); } } } private void closeConnection(Connection conn) { if(conn != null) { try { conn.close(); }catch(SQLException e) { e.printStackTrace(); } } } /** * 对象注销 * */ @PreDestroy public void closeDb() { closeConnection(conn); }}

以下用于调用存储过程使用的工具类

package spring.beans.db.realization.mysql;public final class DataType { private String keyName; private String value; private int type; public DataType(){} public DataType(String keyName,String value,int type) { setKeyName(keyName); setValue(value); setType(type); } public void setKeyName(String keyName) { this.keyName = keyName; } public void setValue(String value) { this.value = value; } public void setType(int type) { this.type = type; } public String getKeyName() { return keyName; } public String getValue() { return value; } public int getType() { return type; }}package spring.beans.db.realization.mysql;public enum ValueType { INT(ValueTypeSource.INT), STRING(ValueTypeSource.STRING), DOUBLE(ValueTypeSource.DOUBLE), CHAR(ValueTypeSource.CHAR), DATE(ValueTypeSource.DATE), BLOB(ValueTypeSource.BLOB), LONG(ValueTypeSource.LONG); private int type; private ValueType(int type) { this.type = type; } public int getType() { return type; }}package spring.beans.db.realization.mysql;public final class ValueTypeSource { public final static int INT=1, STRING=2, DOUBLE=3, CHAR=4, DATE=5, LONG=6, BLOB=7;}

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希望本文所述对大家java程序设计有所帮助。