Java-编写一个jdbc操作类
时间：2021-07-01 10:21:17
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数据库操作类;
/* * Db.java
Created on 2007年8月20日, 上午 8:37
*/
import java.io.*
;
import java.sql.*
;
import java.util.Properties;
public class DB {
private String driver;
private String url;
private String user;
private String password;
private Connection conn;
private Statement stm;
private ResultSet rs;
public DB(){
this("DBConf.properties"
);
}
public DB(String conf) {
loadProperties(conf);
setConn();
}
public Connection getConn(){
return this.conn;
}
//handle the properties file to get the informations for connection
private void loadProperties(String conf){
Properties props =
new Properties();
try {
props.load(new FileInputStream(conf));
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
this.driver = props.getProperty("driver"
);
this.url = props.getProperty("url"
);
this.user = props.getProperty("user"
);
this.password = props.getProperty("password"
);
}
//implement the Connection
private void setConn(){
try {
Class.forName(driver);
this.conn =
DriverManager.getConnection(url,user,password);
} catch(ClassNotFoundException classnotfoundexception) {
classnotfoundexception.printStackTrace();
System.err.println("db: " +
classnotfoundexception.getMessage());
} catch(SQLException sqlexception) {
System.err.println("db.getconn(): " +
sqlexception.getMessage());
}
}
public void doInsert(String sql) {
try {
Statement statement =
conn.createStatement();
int i =
stm.executeUpdate(sql);
} catch(SQLException sqlexception) {
System.err.println("db.executeInset:" +
sqlexception.getMessage());
}
}
public void doDelete(String sql) {
try {
stm =
conn.createStatement();
int i =
stm.executeUpdate(sql);
} catch(SQLException sqlexception) {
System.err.println("db.executeDelete:" +
sqlexception.getMessage());
}
}
public void doUpdate(String sql) {
try {
stm =
conn.createStatement();
int i =
stm.executeUpdate(sql);
} catch(SQLException sqlexception) {
System.err.println("db.executeUpdate:" +
sqlexception.getMessage());
}
}
public ResultSet doSelect(String sql) {
try {
stm =
conn.createStatement(java.sql.ResultSet.TYPE_SCROLL_INSENSITIVE,java.sql.ResultSet.CONCUR_READ_ONLY);
rs =
stm.executeQuery(sql);
} catch(SQLException sqlexception) {
System.err.println("db.executeQuery: " +
sqlexception.getMessage());
}
return rs;
}
public static void main(String[] args){
try{
DB db =
new DB();
Connection conn =
db.getConn();
if(conn !=
null && !
conn.isClosed()) {
System.out.println("連結成功"
);
ResultSet rs = db.doSelect("select * from content"
);
while(rs.next()){
System.out.println(rs.getString(1)+":"+rs.getString(2)+":"+rs.getString(3
));
}
rs.close();
conn.close();
}
}catch(SQLException e) {
e.printStackTrace();
}
}
}
Java-编写一个jdbc操作类
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