在QMaster分类里记录的相关源码是个人认为写得比较好、比较有用（可复用程度比较高）的一部分，并非QMaster的全部源码。欢迎评论。
dbconfig.xml
<?xml version=”1.0″ encoding=”GB2312″?>
<!–数据库配置文件–>
<dbconfig>
<jdbcdriver>com.mysql.jdbc.Driver</jdbcdriver><!–JDBC Driver–>
<jdbcurl>jdbc:mysql://localhost:3306/questionnaire</jdbcurl><!–JDBC URL–>
<dbuser>root</dbuser><!–数据库用户名–>
<dbpwd>yarpee19890607</dbpwd><!–数据库密码–>
</dbconfig>
DBConfig.java
/**
* 功能：解析dbconfig.xml文件，提供数据库配置。
*/
package db;
import java.io.IOException;
import java.io.InputStream;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;
public class DBConfig {
//对应dbconfig.xml中的配置
private String jdbcDriver;
private String jdbcUrl;
private String dbUser;
private String dbPwd;
DBConfig() throws ParserConfigurationException, SAXException, IOException {
DocumentBuilderFactory docBuildFac = DocumentBuilderFactory.newInstance();//生成一个DOM解析器工厂
InputStream is = this.getClass().getClassLoader().getResourceAsStream(“dbconfig.xml”);//相对位置src/dbconfig.xml
Document doc = docBuildFac.newDocumentBuilder().parse(is);//生成一个DOM解析器，并解析dbconfig.xml生成Doc。
Element root = doc.getDocumentElement();//根结点
NodeList nodeList = root.getChildNodes();//根结点的子结点链表
for(int i = 0; i < nodeList.getLength(); i++) {
Node node = nodeList.item(i);//子结点
if(node.getNodeType() == Node.ELEMENT_NODE) {
if(node.getNodeName().equals(“jdbcdriver”)) {
jdbcDriver = node.getFirstChild().getNodeValue();//DOM把<node>value</node>当成两层结点
} else if(node.getNodeName().equals(“jdbcurl”)) {
jdbcUrl = node.getFirstChild().getNodeValue();
} else if(node.getNodeName().equals(“dbuser”)) {
dbUser = node.getFirstChild().getNodeValue();
} else if(node.getNodeName().equals(“dbpwd”)) {
dbPwd = node.getFirstChild().getNodeValue();
}
}
}
}
public String getDbPwd() {
return dbPwd;
}
public String getDbUser() {
return dbUser;
}
public String getJdbcDriver() {
return jdbcDriver;
}
public String getJdbcUrl() {
return jdbcUrl;
}
}
DB.java
/**
* 功能：连接、关闭数据库
*/
package db;
import java.io.IOException;
import java.sql.*;
import javax.xml.parsers.ParserConfigurationException;
import org.xml.sax.SAXException;
public class DB {
private DBConfig config = null;
private Connection conn = null;
public DB() throws ClassNotFoundException, ParserConfigurationException, SAXException, IOException {
config = new DBConfig();
Class.forName(config.getJdbcDriver());
}
public Connection getConnection() throws SQLException {
conn = DriverManager.getConnection(config.getJdbcUrl(), config.getDbUser(), config.getDbPwd());
return conn;
}
public void close() throws SQLException {
if(conn != null)
conn.close();
}
}
DBBak.java
/**
* 功能：备份、还原数据库
*/
package db;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.util.Calendar;
import javax.xml.parsers.ParserConfigurationException;
import org.xml.sax.SAXException;
public class DBBak {
private DBConfig config = null;
public DBBak() throws ParserConfigurationException, SAXException, IOException {
config = new DBConfig();
}
public String getFileName() {
Calendar today = Calendar.getInstance();
String year = String.valueOf(today.get(Calendar.YEAR));
String month = String.valueOf(today.get(Calendar.MONTH) + 1);//0~11表示1~12月
String date = String.valueOf(today.get(Calendar.DATE));
String time = String.valueOf(today.getTimeInMillis());
return year + “-” + month + “-” + date + “-” + time + “.sql”;
}
public void backUp(String path) {
try {
String jdbcUrl = config.getJdbcUrl();
int pos = jdbcUrl.lastIndexOf(“/”);
String dbName = jdbcUrl.substring(pos+1);
String cmd = “mysqldump -u” + config.getDbUser() + ” -p” + config.getDbPwd() + ” ” + dbName;
Runtime rt = Runtime.getRuntime();
Process child = rt.exec(cmd);
InputStream in = child.getInputStream();
InputStreamReader xx = new InputStreamReader(in, “ISO-8859-1″);
String inStr;
StringBuffer sb = new StringBuffer(“”);
String outStr;
BufferedReader br = new BufferedReader(xx);
while ((inStr = br.readLine()) != null) {
sb.append(inStr + “/r/n”);
}
outStr = new String(sb.toString().getBytes(“ISO-8859-1″), “UTF-8″);
FileOutputStream fout = new FileOutputStream(path);
OutputStreamWriter writer = new OutputStreamWriter(fout,”UTF-8″);
writer.write(outStr);
writer.flush();
in.close();
xx.close();
br.close();
writer.close();
fout.close();
}
catch (Exception e) {
e.printStackTrace();
}
}
public void load(String path){
try{
File f = new File(path);
FileInputStream fis = new FileInputStream(f);
String jdbcUrl = config.getJdbcUrl();
int pos = jdbcUrl.lastIndexOf(“/”);
String dbName = jdbcUrl.substring(pos+1);
String cmd = “mysql -u” + config.getDbUser() + ” -p” + config.getDbPwd() + ” ” + dbName;
Runtime rt = Runtime.getRuntime();
Process child = rt.exec(cmd);
OutputStream out = child.getOutputStream();
String inStr;
StringBuffer sb = new StringBuffer(“”);
String outStr;
BufferedReader br = new BufferedReader(new InputStreamReader(fis, “UTF-8″));
while ((inStr = br.readLine()) != null) {
sb.append(inStr + “/r/n”);
}
outStr =new String(sb.toString().getBytes(“UTF-8″), “ISO-8859-1″);
OutputStreamWriter writer = new OutputStreamWriter(out, “ISO-8859-1″);
writer.write(outStr);
writer.flush();
out.close();
br.close();
writer.close();
fis.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
FileList.java
/**
* 功能：列出数据库备份文件
*/
package db;
import java.io.File;
import java.util.ArrayList;
public class FileList {
public ArrayList tree(File f) {//传入目录
ArrayList files = new ArrayList();
File[] list = f.listFiles();
if(list != null){
for(int i = 0; i < list.length; i++) {
if(list[i].isFile()) {
if(list[i].getName().endsWith(“.sql”)) {
files.add(list[i].getName());
}
}
}
}
return files;
}
}