項目框架結構
添加依賴
在pom.xml文件中添加依賴:
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>3.1.0</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.17</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.44</version>
</dependency>
由此引入數據庫和log4j的jar包
Properties
db.properties:
db.username=root
db.password=root
db.url=jdbc:mysql://192.168.77.14/test
log4j.properties:
# DEBUG\u8BBE\u7F6E\u8F93\u51FA\u65E5\u5FD7\u7EA7\u522B\uFF0C\u7531\u4E8E\u4E3ADEBUG\uFF0C\u6240\u4EE5ERROR\u3001WARN\u548CINFO \u7EA7\u522B\u65E5\u5FD7\u4FE1\u606F\u4E5F\u4F1A\u663E\u793A\u51FA\u6765
log4j.rootLogger=DEBUG,Console,RollingFile
#\u5C06\u65E5\u5FD7\u4FE1\u606F\u8F93\u51FA\u5230\u63A7\u5236\u53F0
log4j.appender.Console=org.apache.log4j.ConsoleAppender
log4j.appender.Console.layout=org.apache.log4j.PatternLayout
log4j.appender.Console.layout.ConversionPattern= [%-5p]-[%d{yyyy-MM-dd HH:mm:ss}] -%l -%m%n
#\u5C06\u65E5\u5FD7\u4FE1\u606F\u8F93\u51FA\u5230\u64CD\u4F5C\u7CFB\u7EDFD\u76D8\u6839\u76EE\u5F55\u4E0B\u7684log.log\u6587\u4EF6\u4E2D
log4j.appender.RollingFile=org.apache.log4j.DailyRollingFileAppender
log4j.appender.RollingFile.File=E://log.log
log4j.appender.RollingFile.layout=org.apache.log4j.PatternLayout
log4j.appender.RollingFile.layout.ConversionPattern=%d [%t] %-5p %-40.40c %X{traceId}-%m%n
寫出相應工具類
PropertiesTool:
package com.zzu.tool;
import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;
public class PropertiesTool {
private static Properties properties = new Properties();
static {
InputStream inputStream = PropertiesTool.class.getClassLoader().getResourceAsStream("db.properties");//將db.properties變爲javaIO流對象
try {
properties.load(inputStream);
} catch (IOException e) {
e.printStackTrace();
}
}
public static String getValue(String key) {
String value = properties.getProperty(key);
return value;
}
}
DBLink:
package com.zzu.tool.db;
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 org.apache.log4j.Logger;
import com.zzu.tool.PropertiesTool;
/**
* 數據庫工具類
*
* @author Administrator
*/
public class DBLink {
private Logger logger = Logger.getLogger(DBLink.class);
/**
* 獲取數據庫鏈接
* @return
*/
private Connection getConnection() {
try {
Class.forName("com.mysql.jdbc.Driver");//加載驅動
String userName = PropertiesTool.getValue("db.username");
String passWord = PropertiesTool.getValue("db.password");
String url = PropertiesTool.getValue("db.url");
return DriverManager.getConnection(url ,userName,passWord);
} catch (Exception e) {
logger.debug(e.getMessage(), e);
}
return null;
}
/**
* 判斷sql語句是否存在數據
* @param sql
* @return
*/
public boolean exist(String sql) {
Connection connection = null;
Statement statement = null;
ResultSet resultSet = null;
try {
connection = getConnection();
statement = connection.createStatement();
resultSet = statement.executeQuery(sql);
return resultSet.next();
} catch (Exception e) {
logger.debug(e.getMessage(), e);
}finally {
close(resultSet, statement, connection);
}
return false;
}
public boolean exist(String sql,Object ...params) {
Connection connection = null;
PreparedStatement preparedStatement = null;
ResultSet resultSet = null;
try {
connection = getConnection();
preparedStatement = connection.prepareStatement(sql);
for (int i = 0; i < params.length; i++) {
preparedStatement.setObject(i+1, params[i]);
}
resultSet = preparedStatement.executeQuery();
return resultSet.next();
} catch (Exception e) {
logger.debug(e.getMessage(), e);
}finally {
close(resultSet, preparedStatement, connection);
}
return false;
}
/**
* 查詢數據
* @param sql
* @param rowMapper
*/
public void select(String sql, IRowMapper rowMapper) {//接口無法創建對象,所以rowMapper參數一定指向IRowMapper接口實現類對象
Connection connection = null;
Statement statement = null;
ResultSet resultSet = null;
try {
connection = getConnection();
statement = connection.createStatement();
resultSet = statement.executeQuery(sql);
rowMapper.rowMapper(resultSet);
} catch (Exception e) {
logger.debug(e.getMessage(), e);
}finally {
close(resultSet, statement, connection);
}
}
/**
* 查詢數據
* @param sql
* @param rowMapper
*/
public void select(String sql, IRowMapper rowMapper,Object ...params) {//接口無法創建對象,所以rowMapper參數一定指向IRowMapper接口實現類對象
Connection connection = null;
PreparedStatement preparedStatement = null;
ResultSet resultSet = null;
try {
connection = getConnection();
preparedStatement = connection.prepareStatement(sql);//含有?佔位符的sql
for (int i = 0; i < params.length; i++) {
preparedStatement.setObject(i + 1, params[i]);//爲?賦值
}
resultSet = preparedStatement.executeQuery();//執行sql
rowMapper.rowMapper(resultSet);
} catch (Exception e) {
logger.debug(e.getMessage(), e);
}finally {
close(resultSet, preparedStatement, connection);
}
}
/**
* 修改(insert、update、delete)數據
* @param sql
* @return
*/
public boolean update(String sql) {
Connection connection = null;
Statement statement = null;
try {
connection = getConnection();
System.out.println(connection);
statement = connection.createStatement();//獲取statement對象
int result = statement.executeUpdate(sql);//執行sql語句,返回受影響的行數
return result>0;
} catch (Exception e) {
logger.debug(e.getMessage(), e);
}finally {
close(statement, connection);
}
return false;
}
/**
* 修改(insert、update、delete)數據
* @param sql
* @return
*/
public boolean update(String sql,Object ...params) {
Connection connection = null;
PreparedStatement prepareStatement = null;
try {
connection = getConnection();
prepareStatement = connection.prepareStatement(sql);
for (int i = 0; i < params.length; i++) {
prepareStatement.setObject(i+1, params[i]);//爲?賦值
}
return prepareStatement.executeUpdate()>0;
} catch (Exception e) {
logger.debug(e.getMessage(), e);
}finally {
close(prepareStatement, connection);
}
return false;
}
/**
* 釋放資源
* @param statement
* @param connection
*/
private void close(Statement statement,Connection connection) {
try {
if(statement!=null) {
statement.close();
}
} catch (SQLException e) {
logger.debug(e.getMessage(), e);
}
try {
if(connection!=null) {
connection.close();
}
} catch (SQLException e) {
logger.debug(e.getMessage(), e);
}
}
/**
* 釋放資源
* @param statement
* @param connection
*/
private void close(ResultSet resultSet,Statement statement,Connection connection) {
try {
if(resultSet!=null) {
resultSet.close();
}
} catch (SQLException e) {
logger.debug(e.getMessage(), e);
}
try {
if(statement!=null) {
statement.close();
}
} catch (SQLException e) {
logger.debug(e.getMessage(), e);
}
try {
if(connection!=null) {
connection.close();
}
} catch (SQLException e) {
logger.debug(e.getMessage(), e);;
}
}
}
IRowMapper:
package com.zzu.tool.db;
import java.sql.ResultSet;
public interface IRowMapper {
void rowMapper(ResultSet rs);
}
程序主體
package com.zzu.client;
import java.util.Scanner;
import com.zzu.tool.db.DBLink;
public class Main {
private static DBLink db = new DBLink();
public static void main(String[] args) {
System.out.println("*********************************");
System.out.println("*\t\t\t\t*");
System.out.println("*\t歡迎使用學生信息管理系統\t*");
System.out.println("*\t\t\t\t*");
System.out.println("*********************************");
while (true) {
menu();
}
}
static void menu() {
System.out.println("1、添加學生信息");
System.out.println("2、刪除學生信息");//學號
System.out.println("3、修改學生信息");//地址傳遞
System.out.println("4、查詢學生信息");//name
System.out.println("請輸入操作,以Enter鍵結束:");
Scanner scanner = new Scanner(System.in);
int option = scanner.nextInt();
switch (option) {
case 1:{
System.out.println("請輸入學號:");
String id = scanner.next();
String sql = "select name from student where id=?";
if(db.exist(sql, id)) {
System.out.println("學號已存在,添加失敗!");
return;
}
System.out.println("請輸入姓名:");
String name = scanner.next();
System.out.println("請輸入手機號:");
String mobile = scanner.next();
System.out.println("請輸入地址:");
String address = scanner.next();
sql = "insert into student (id,name,mobile,address) value(?,?,?,?)";
if(db.update(sql, id,name,mobile,address)) {
System.out.println("添加成功!");
return;
}
System.out.println("添加失敗!");
break;
}
case 2:{
System.out.println("請輸入學號:");
String id = scanner.next();
String sql = "select name from student where id=?";
if(!db.exist(sql, id)) {
System.out.println("該學號不存在,刪除失敗!");
return;
}
sql = "delete from student where id=?";
if(db.update(sql, id)) {
System.out.println("刪除成功!");
return;
}
System.out.println("刪除失敗!");
break;
}
case 3:{
System.out.println("請輸入學號:");
String id =scanner.next();
String sql = "select name from student where id=?";
if(!db.exist(sql, id)) {
System.out.println("該學號不存在,修改失敗!");
return;
}
System.out.println("請輸入新的姓名:");
String name =scanner.next();
System.out.println("請輸入新的手機號:");
String mobile = scanner.next();
System.out.println("請輸入新的地址:");
String address = scanner.next();
sql = "update student set name=?,mobile=?,address=? where id=?";
if(db.update(sql,name,mobile,address,id)) {
System.out.println("修改成功!");
return;
}
System.out.println("修改失敗!");
break;
}
case 4:{
System.out.println("請輸入學號:");
String id = scanner.next();
String sql = "select name from student where id=?";
if(!db.exist(sql,id)) {
System.out.println("該學號不存在,查詢失敗!");
return;
}
sql = "select id,name,mobile,address from student where id=?";
//普通寫法
/*class RowMapper implements IRowMapper{
public void rowMapper(ResultSet rs) {
try {
if(rs.next()) {
String name = rs.getString("name");
String mobile = rs.getString("mobile");
String address = rs.getString("address");
System.out.println("id="+id+" ,name="+name+" ,mobile="+mobile+" ,address="+address);
return;
}
System.out.println("沒有找到該學號學生的信息");
} catch (Exception e) {
e.printStackTrace();
}
}
}*/
//Lambda表達式寫法
/*IRowMapper rowMapper = (rs)->{
try {
if(rs.next()) {
String name = rs.getString("name");
String mobile = rs.getString("mobile");
String address = rs.getString("address");
System.out.println("id="+id+" ,name="+name+" ,mobile="+mobile+" ,address="+address);
return;
}
System.out.println("沒有找到該學號學生的信息");
} catch (Exception e) {
e.printStackTrace();
}
};*/
//最簡寫法
db.select(sql, (rs)->{
try {
if(rs.next()) {
String name = rs.getString("name");
String mobile = rs.getString("mobile");
String address = rs.getString("address");
System.out.println("id="+id+" ,name="+name+" ,mobile="+mobile+" ,address="+address);
return;
}
System.out.println("沒有找到該學號學生的信息");
} catch (Exception e) {
e.printStackTrace();
}
}, id);
break;
}
default:
System.out.println("I'm Sorry,there is not the "+option+" option,please try again.");
}
}
}