package dao;import java.io.IOException;
import java.sql.CallableStatement;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.Timestamp;
import java.text.ParsePosition;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Date;
import java.util.List;import com.fasterxml.jackson.core.JsonParseException;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.JsonMappingException;
import com.fasterxml.jackson.databind.ObjectMapper;public class DBCon {private static String DBDRIVER="com.microsoft.sqlserver.jdbc.SQLServerDriver";private static String DBURL="jdbc:sqlserver://localhost:1433;databasename=改为数据库名称";private static String DBUID="登录账户";private static String DBPWD="登录密码";private static Connection conn = null;private static Statement stmt = null;//打开连接public static void open() {//加载驱动try {Class.forName(DBDRIVER);conn=DriverManager.getConnection(DBURL,DBUID,DBPWD);} catch (ClassNotFoundException e) {e.printStackTrace();} catch (SQLException e) {e.printStackTrace();}}//关闭连接public static void close() {try {if(stmt!=null)stmt.close();if(conn!=null && !conn.isClosed())conn.close();} catch (SQLException e) {// TODO Auto-generated catch block
             e.printStackTrace();}}//得到一个连接对象，当用户使用DBUtil无法解决个性问题时//可以通过本方法获得连接对象public static Connection getConnection() {try {if(conn==null ||conn.isClosed())open();} catch (SQLException e) {e.printStackTrace();}return conn;}//executeQuery//executeUpdate//execute//获得查询的数据集//select * from student where name='' and sex=''public static ResultSet executeQuery(String sql) {try {open();//保证连接是成功的stmt = conn.createStatement();return stmt.executeQuery(sql);} catch (SQLException e) {// TODO Auto-generated catch block
             e.printStackTrace();}return null;}//修改表格内容public static int executeUpdate(String sql) {int result = 0;try {open();//保证连接是成功的stmt = conn.createStatement();result = stmt.executeUpdate(sql);} catch (SQLException e) {// TODO Auto-generated catch block
             e.printStackTrace();} finally {close();}return result;}//如果执行的查询或存储过程，会返回多个数据集，或多个执行成功记录数//可以调用本方法，返回的结果，//是一个List<ResultSet>或List<Integer>集合public static Object execute(String sql) {boolean b=false;try {open();//保证连接是成功的stmt = conn.createStatement();b = stmt.execute(sql);            //true,执行的是一个查询语句，我们可以得到一个数据集//false,执行的是一个修改语句，我们可以得到一个执行成功的记录数if(b){return stmt.getResultSet();}else {return stmt.getUpdateCount();}} catch (SQLException e) {// TODO Auto-generated catch block
             e.printStackTrace();} finally {if(!b) {close();}}return null;}////select * from student where name=? and sex=?public static ResultSet executeQuery(String sql,Object[] in) {try {open();//保证连接是成功的PreparedStatement pst = conn.prepareStatement(sql);for(int i=0;i<in.length;i++)pst.setObject(i+1, in[i]);stmt = pst;//只是为了关闭命令对象pstreturn pst.executeQuery();} catch (SQLException e) {// TODO Auto-generated catch block
             e.printStackTrace();}return null;}public static int executeUpdate(String sql,Object[] in) {try {open();//保证连接是成功的PreparedStatement pst = conn.prepareStatement(sql);for(int i=0;i<in.length;i++)pst.setObject(i+1, in[i]);stmt = pst;//只是为了关闭命令对象pstreturn pst.executeUpdate();} catch (SQLException e) {// TODO Auto-generated catch block
             e.printStackTrace();}finally {close();}return 0;}public static Object execute(String sql,Object[] in) {boolean b=false;try {open();//保证连接是成功的PreparedStatement pst = conn.prepareStatement(sql);for(int i=0;i<in.length;i++)pst.setObject(i+1, in[i]);b = pst.execute();//true,执行的是一个查询语句，我们可以得到一个数据集//false,执行的是一个修改语句，我们可以得到一个执行成功的记录数if(b){System.out.println("----");/*List<ResultSet> list = new ArrayList<ResultSet>();list.add(pst.getResultSet());while(pst.getMoreResults()) {list.add(pst.getResultSet());}*/return pst.getResultSet();}else {System.out.println("****");List<Integer> list = new ArrayList<Integer>();list.add(pst.getUpdateCount());while(pst.getMoreResults()) {list.add(pst.getUpdateCount());}return list;}} catch (SQLException e) {// TODO Auto-generated catch block
             e.printStackTrace();} finally {if(!b) {System.out.println("====");close();}}return null;}//调用存储过程  proc_Insert(?,?,?)public static Object executeProcedure(String procName,Object[] in) {open();try {procName = "{call "+procName+"(";String link="";for(int i=0;i<in.length;i++) {procName+=link+"?";link=",";}procName+=")}";CallableStatement cstmt = conn.prepareCall(procName);for(int i=0;i<in.length;i++) {cstmt.setObject(i+1, in[i]);}if(cstmt.execute()){return cstmt.getResultSet();}else {return cstmt.getUpdateCount();}} catch (SQLException e) {// TODO Auto-generated catch block
             e.printStackTrace();}return null;}/** 调用存储过程，并有输出参数* @procName ，存储过程名称：proc_Insert(?,?)* @in ,输入参数集合* @output,输出参数集合* @type,输出参数类型集合* */public static Object executeOutputProcedure(String procName,Object[] in,Object[] output,int[] type){Object result = null;try {CallableStatement cstmt = conn.prepareCall("{call "+procName+"}");//设置存储过程的参数值int i=0;for(;i<in.length;i++){//设置输入参数cstmt.setObject(i+1, in[i]);//print(i+1);
             }int len = output.length+i;for(;i<len;i++){//设置输出参数cstmt.registerOutParameter(i+1,type[i-in.length]);//print(i+1);
             }boolean b = cstmt.execute();//获取输出参数的值for(i=in.length;i<output.length+in.length;i++)output[i-in.length] = cstmt.getObject(i+1);if(b) {result = cstmt.getResultSet();}else {result = cstmt.getUpdateCount();}} catch (SQLException e) {// TODO Auto-generated catch block
             e.printStackTrace();}return result;}public static String toJson(Object obj){String reuqest=null;//对象映射ObjectMapper mapper=new ObjectMapper();//设置时间格式SimpleDateFormat dateFormat=new SimpleDateFormat("yyyy年MM月dd日");mapper.setDateFormat(dateFormat);try {reuqest=mapper.writeValueAsString(obj);} catch (JsonProcessingException e) {// TODO Auto-generated catch block
                 e.printStackTrace();}return reuqest;}public static <T> T toObject(String src,Class<T> valueType){T request=null;//对象反射ObjectMapper mapper=new ObjectMapper();try {request=mapper.readValue(src, valueType);} catch (JsonParseException e) {// TODO Auto-generated catch block
             e.printStackTrace();} catch (JsonMappingException e) {// TODO Auto-generated catch block
             e.printStackTrace();} catch (IOException e) {// TODO Auto-generated catch block
             e.printStackTrace();}return request;}public static Date date(String date_str) {try {Calendar zcal = Calendar.getInstance();//日期类Timestamp timestampnow = new Timestamp(zcal.getTimeInMillis());//转换成正常的日期格式SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");//改为需要的东西ParsePosition pos = new ParsePosition(0);java.util.Date current = formatter.parse(date_str, pos);timestampnow = new Timestamp(current.getTime());return timestampnow;}catch (NullPointerException e) {return null;}}/*** 获取当前时间 yyyy-MM-dd HH:mm:ss* @param date* @return*/public static String newDate(String date){Date day=new Date();    SimpleDateFormat df = new SimpleDateFormat(date); return df.format(day); }}