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1、第8章习题答案一、选择题1 . C 2.A 3.B 4.BC 5.D二。、简答题2 .JDBC操作步骤(1)导入驱动程序(2)创立连接(3)创立 Statement(4)书写SQL语句(5)执行SQL语句获得结果(6)处理结果(7)关闭连接.列表对于数据类型Java数据类型SQL数据类型bytetiny intSshortsmall intintintlongbig intfloatnumberDoublenumberDatedata/time/datatimeStringvarchar.next方法工作流程,首先跳转进入结果集对象的下一行记录,如果记录不为空,返回值为 true,否那么返回值
2、为false。三、编程题.固定SQL语句方式:public int adminReg(String uname, String pswd) int result = -1;String driverclass = com.microsoft.sqlserver.jdbc.SQLServerDriver;String dbUrl = jdbc:sqlserver:/localhost:1433;databaseName=TestDB;Connection connection = null;Statement stmt = null;try(Class.forName(driverClass);
3、connection = DriverManager.getConnection(dbUrl, sa, sasa);stmt = connection.createStatement();String sql = insert into tb_admin(admin_name/admin_pswd) values ( + uname + 7 + pswd +result = stmt.executeUpdate(sql); catch (ClassNotFoundException e) e.printStackTrace(); catch (SQLException e) e.printSt
4、ackTrace();)finally if (stmt != null) trystmt.closeO; catch (Exception e) )if (connection != null)try(connection.closef); catch (Exception e) )return result;)预编译SQL语句方式:public int adminRegfString uname, String pswd) int result = -1;String driverClass = com.microsoft.sqlserver.jdbc.SQLServerDriver;St
5、ring dbUrl = jdbc:sqlserver:/localhost:1433;databaseName=TestDB;Connection connection = null;PreparedStatement pstmt = null;try (Class.forName(driverClass);connection = DriverManager.getConnection(dbUrlz sa, sasa);String sql = insert into tb_admin(admin_name,admin_pswd) values (?,?);pstmt = connecti
6、on.prepareStatement(sql);pstmt.setString(l, uname);pstmt.setString(2, pswd);result = pstmt.executellpdate(); catch (ClassNotFoundException e) e.printStackTrace(); catch (SQLException e) e.printStackTrace();)finally if (pstmt != null)try(pstmt.closef); catch (Exception e) )if (connection != null)try(
7、connection.close); catch (Exception e) )return result;).通用性很强的JDBC类import java.sql.Connection;import java.sql.DriverManager;import java.sql.ResultSet;import java.sql.SQLException;import java.sqLStatement;public class DBConn private final String className = com.microsoft.sqlserver.jdbc.SQLServerDrive
8、r;privatefinalStringconnectionllrljdbc:sqlserver:/localhost:1433;databaseName=TestDB;private final String username = sa;private final String password = sasa;private Connection connection;private Statement stmt;public DBConn() try(Class.forName(className);connection = DriverManager.getConnection(conn
9、ectionUrl, username, password);System.out.println(connection);stmt = connection.createStatement(); catch (Exception e) e.printStackTrace();)public int update(String sql) int r = -1;if (stmt != null) try(r = stmt.executellpdate(sql); catch (SQLException e) /TODO Auto-generated catch blocke.printStack
10、Trace();return r;public ResultSet queryfString sql) ResultSet rs = null;if (stmt != null) try(rs = stmt.executeQuery(sql); catch (SQLException e) / TODO Auto-generated catch block e.printStackTrace();) return rs;)public void close() if (connection != null) try(connection.close(); catch (SQLException
11、 e) / TODO Auto-generated catch block e.printStackTrace();)第9章习题答案一、选择题1. C 2.A 3.AB 4.AD 5,A 6.A7.B二、简答题1 .字节流是以直接的方式传送数据,字符流是以字符的方式传送数据。2 .读取操作步骤:(1)翻开文件,(2)声明缓存空间,(3)读取/写入,(4)关闭.构造方法:1) File (String pathname):通过给定路径创立一个新的File类对象。2) File(String parent, String chi Id):通过给定的文件夹目录和文件名创立一个新 的File类对象。3
12、) File(File parent, String child):通过给定的文件对象和文件名创立一个新的 File类对象。常用方法public String getName0 :返回文件对象的 XXXXXXX。1. public String getPathO :返回文件对象所在路径名。2. public String getAbsolutePath ():返回文件对象的绝对路径名。3. public String getParentO:返回文件对象所在父目录路径。如果文件对象没有父目录, 那么返回nullopublic boolean exists():判断文件对象所表示的文件或文件夹是否
13、存在,存在返回 true,不存在返回falseo4. public boolean isDirectory ():判断文件对象所表示的是否为目录(文件夹),如果是 返回true,否那么返回false。5. publ ic boolean isFi le():判断文件对象所表示的是否为一个标准文件,如果是,返回 true,否那么返回falseo三、编程题1. package p9_7;import java.io.FileWriter;import java.io.lOException;import java.util.Scanner;public class C97_l SuppressWa
14、rnings(resource)public static void main(String args) (请输入字符串:);Scanner scanner=new Scanner(System.in);String s=scanner.nextLine();String ss=s.tollpperCase();try (FileWriter writer=new FileWriterfa.txt); writer.write(ss);writer.close(); catch (lOException e) / TODO Auto-generated catch block e.printS
15、tackTrace();)2. package p9_7;import java.io.File;import java.io.FileWriter;import java.io.lOException;import java.util.Random;public class C97_2 public static void main(String args) File f=new File(test.txt); if(!f.exists() (try(f.createNewFile(); catch (lOException e) / TODO Auto-generated catch bl
16、ock e.printStackTrace();)Random r=new Random();StringBuffer sbf=new StringBuffer(); for(int i=l;i 0) String message = Thread.currentThread().getName() + 卖了 第+ ticket + ”票;System.out.println(message);ticket-;try(Thread.sleep(lOO); catch (InterruptedException e) / TODO Auto-generated catch block e.printStackTrace();) else break;