package myPakage;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;public class Conn {
public static void main(String[] args)
{
Statement stmt=null;//语句对象
Connection conn=null;//连接对象
ResultSet rs=null;//结果集对象
String url="jdbc:mysql://localhost:3306/test";
String username="root";
String pwd="123456";
String sql=null;
try {
try {
Class.forName("com.mysql.jdbc.Driver").newInstance();
conn = DriverManager.getConnection(url, username, pwd);
System.out.println("连接成功O(∩_∩)O~");
} catch (InstantiationException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
stmt = conn.createStatement();//创建一个 Statement 对象来将 SQL 语句发送到数据库
System.out.println("请输入查询语句O(∩_∩)O~");
BufferedReader s= new BufferedReader(new InputStreamReader(System.in));
sql = (String)s.readLine();
rs = stmt.executeQuery(sql);//执行给定的 SQL 语句,该语句返回单个 ResultSet 对象
String[] columns;
if(sql.indexOf("*") > -1){
System.out.println("id" + "\tname"+" \t age");
while (rs.next()){
System.out.println(rs.getString("id")+"\t"+rs.getString("name")+" \t "+rs.getString("age"));
}
}
else{
int index2 = sql.indexOf(" from");
int index1 = sql.indexOf("select");
String column = sql.substring(index1 + 7,index2);
if(column.indexOf(",")>-1){
columns = column.split(",");
for(int i=0;i<columns.length;i++)
{
System.out.print(columns[i]+"\t");
}
System.out.println();
while (rs.next()){
for(int i=0;i<columns.length;i++)
{
System.out.print(rs.getString((String)columns[i])+"\t");
}
System.out.println();
}
}
else{
System.out.println(column);
while (rs.next()){
System.out.println(rs.getString(column));
}
}
}
}catch (Exception e){
System.out.println("语句错误,请重新输入!");
e.printStackTrace();
}
}
}将查询结果保存成xml格式的文件。
编写一个程序,读取xml格式的文件,解析该文件,输出练习一的结果。我是新手,没有接触过xml,时间紧迫,希望哪位前辈能帮我写完,让我通过程序来学习。谢谢!!
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;public class Conn {
public static void main(String[] args)
{
Statement stmt=null;//语句对象
Connection conn=null;//连接对象
ResultSet rs=null;//结果集对象
String url="jdbc:mysql://localhost:3306/test";
String username="root";
String pwd="123456";
String sql=null;
try {
try {
Class.forName("com.mysql.jdbc.Driver").newInstance();
conn = DriverManager.getConnection(url, username, pwd);
System.out.println("连接成功O(∩_∩)O~");
} catch (InstantiationException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
stmt = conn.createStatement();//创建一个 Statement 对象来将 SQL 语句发送到数据库
System.out.println("请输入查询语句O(∩_∩)O~");
BufferedReader s= new BufferedReader(new InputStreamReader(System.in));
sql = (String)s.readLine();
rs = stmt.executeQuery(sql);//执行给定的 SQL 语句,该语句返回单个 ResultSet 对象
String[] columns;
if(sql.indexOf("*") > -1){
System.out.println("id" + "\tname"+" \t age");
while (rs.next()){
System.out.println(rs.getString("id")+"\t"+rs.getString("name")+" \t "+rs.getString("age"));
}
}
else{
int index2 = sql.indexOf(" from");
int index1 = sql.indexOf("select");
String column = sql.substring(index1 + 7,index2);
if(column.indexOf(",")>-1){
columns = column.split(",");
for(int i=0;i<columns.length;i++)
{
System.out.print(columns[i]+"\t");
}
System.out.println();
while (rs.next()){
for(int i=0;i<columns.length;i++)
{
System.out.print(rs.getString((String)columns[i])+"\t");
}
System.out.println();
}
}
else{
System.out.println(column);
while (rs.next()){
System.out.println(rs.getString(column));
}
}
}
}catch (Exception e){
System.out.println("语句错误,请重新输入!");
e.printStackTrace();
}
}
}将查询结果保存成xml格式的文件。
编写一个程序,读取xml格式的文件,解析该文件,输出练习一的结果。我是新手,没有接触过xml,时间紧迫,希望哪位前辈能帮我写完,让我通过程序来学习。谢谢!!
既然是新手,就应该多看看教程是怎么弄得,我也是从新手过来的,那时候网上教程也少,都是自己闷头练出来的,多看多做多学~~~
//1.获取文档对象
SAXReader reader = new SAXReader();
Document document = reader.read(new File(fileName));
//2.获取根元素节点
Element element = doc.getRootElement();
//3.遍历节点
for ( Iterator i = root.elementIterator(); i.hasNext(); ) {
Element element = (Element) i.next();
// do something
}