1.mysql_jdbc.properties配置文件
mysql_url=jdbc:mysql://192.168.1.2:3306/test mysql_username=test mysql_password=test
2.JDBCDBUtils .java
/** * */ package com.dh.imsi.utils; import java.io.File; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.ResultSetMetaData; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; /** * @title : DBUtils.java * @author : tao * @date : 2017-6-8 上午9:49:46 * @version V1.0 */ public class JDBCDBUtils { private static String url = "jdbc:mysql://127.0.0.1/test"; private static String driverName = "com.mysql.jdbc.Driver"; private static String user = "root"; private static String password = "root"; private Connection conn; // 数据库连接 private PreparedStatement preStat; // 预编译 private ResultSet rstSet; // 结果集 static { try { String path = System.getProperty("user.dir"); String confPath = path + File.separator + "bin" + File.separator + "mysql_jdbc.properties"; Map<String, String> map = PropertiesUtils.readProperties(confPath); if (map != null && map.size() > 0) { url = CommonFunc.checkNull(map.get("mysql_url")); user = CommonFunc.checkNull(map.get("mysql_username")); password = CommonFunc.checkNull(map.get("mysql_password")); } Class.forName(driverName);//指定连接类型 } catch (Exception e) { System.out.println("加载数据库配置文件时异常, e = " + e); e.printStackTrace(); } } /** * 创建连接 */ private void createConn() { try { conn = DriverManager.getConnection(url, user, password); } catch (Exception e) { System.out.println("创建Connection时异常, e = " + e); e.printStackTrace(); } } /** * 释放 * @param flag */ public void freeAll(boolean flag) { try { if (flag && conn != null) { conn.commit(); } else if (conn != null) { conn.rollback(); } if (rstSet != null) { rstSet.close(); rstSet = null; } if (preStat != null) { preStat.close(); preStat = null; } if (conn != null) { conn.close(); conn = null; } } catch (Exception exception1) { } } /** * 查询 * @param sql * @param values * @return */ public List<Map<String, Object>> query(String sql, Object[] values) { List<Map<String, Object>> list = new ArrayList<Map<String, Object>>(); try { if (conn == null) { createConn(); } // 初始化PreparedStatement preStat = conn.prepareStatement(sql); for (int i = 0; i < values.length; i++) { preStat.setObject((i + 1), values[i]); } rstSet = preStat.executeQuery(); /* * 遍历结果集 */ if (rstSet != null) { ResultSetMetaData rsmd = rstSet.getMetaData(); int columnCount = rsmd.getColumnCount(); // 列数 while (rstSet.next()) { Map<String, Object> map = new HashMap<String, Object>(); /* * 根据列数遍历 */ for (int j = 1; j < columnCount + 1; j++) { Object obj = rstSet.getObject(j); if (obj != null) { map.put(rsmd.getColumnName(j).toLowerCase(), obj); } else { map.put(rsmd.getColumnName(j).toLowerCase(), null); } } list.add(map); } } } catch (Exception e) { e.printStackTrace(); } finally { freeAll(false); } return list; } public static void main(String[] args){ try { /*Properties pro = new Properties(); InputStream in = DBUtils.class.getResourceAsStream("/mysql_jdbc.properties"); pro.load(in); in.close(); String val = PropertiesUtils.readValue(pro, "mysql_url"); System.out.println("val = " + val);*/ /*String path = System.getProperty("user.dir"); String confPath = path + File.separator + "bin" + File.separator + "mysql_jdbc.properties"; //System.out.println("confPath = " + confPath); Map<String, String> map = PropertiesUtils.readProperties(confPath); Iterator<Entry<String, String>> it = map.entrySet().iterator(); while(it.hasNext()){ Map.Entry<String, String> entry = it.next(); System.out.println(entry.getKey() + " = " + entry.getValue()); }*/ JDBCDBUtils dbUtils = new JDBCDBUtils(); String sql = "select * from sys_user where USERACC=? "; Object[] values = new Object[]{"00000000"}; List<Map<String, Object>> list = dbUtils.query(sql, values); Map<String, Object> map = list.get(0); System.out.println("useracc = " + CommonFunc.checkNull(map.get("useracc"))); } catch (Exception e) { e.printStackTrace(); } } }
3. CommonFunc .java
/** * */ package com.dh.imsi.utils; /** * @title : CommonFunc.java * @author : tao * @date : 2017-6-8 上午10:05:18 * @version V1.0 */ public class CommonFunc { /** * 判空字符串 * * @param obj * @return */ public static String checkNull(Object obj) { if (obj == null) { return ""; } return obj.toString().trim(); } /** * 判断字符串是否为大于等于0的整数 * @param str 待操作的字符串 * @param defaultVal 默认值 * @return */ public static int checkNum(String str, int defaultVal){ if("".equals(checkNull(str))){ return defaultVal; } int rstVal = defaultVal; String pattern = "^[0-9]+$"; // 匹配大于等于0的整数 if(str.matches(pattern)){ rstVal = Integer.parseInt(str); } return rstVal; } public static void main(String[] args){ String str = "a123sf"; System.out.println("str == " + checkNum(str, -1)); } }
4.PropertiesUtils.java
/** * */ package com.dh.imsi.utils; import java.io.BufferedInputStream; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.util.Enumeration; import java.util.HashMap; import java.util.Iterator; import java.util.Map; import java.util.Properties; import java.util.Set; /** * @title : PropertiesUtils.java * @author : tao * @date : 2017-6-8 上午10:03:22 * @version V1.0 */ public class PropertiesUtils { /** * 读取Properties文件中key的值 * @param filePath * @param key * @return */ public static String readValue(String filePath, String key) { Properties props = new Properties(); String value = ""; try { File file = new File(filePath); if (file.exists()) { InputStream in = new BufferedInputStream(new FileInputStream( filePath)); props.load(in); value = props.getProperty(key); // System.out.println(key+"="+value); in.close(); // 关闭流 } } catch (Exception e) { e.printStackTrace(); } return value; } /** * 读取Properties文件中key的值 * @param props * @param key * @return */ public static String readValue(Properties props, String key) { String value = ""; try { if (props != null) { value = CommonFunc.checkNull(props.getProperty(key)); // System.out.println(key+"="+value); } } catch (Exception e) { e.printStackTrace(); } return value; } /** * * @param filePath * @return */ @SuppressWarnings("rawtypes") public static Map<String, String> readProperties(String filePath) { Properties props = null; HashMap<String, String> map = new HashMap<String, String>(); try { File file = new File(filePath); if (file.exists()) { props = new Properties(); InputStream in = new BufferedInputStream(new FileInputStream( filePath)); props.load(in); Enumeration en = props.propertyNames(); while (en.hasMoreElements()) { String key = (String) en.nextElement(); String value = props.getProperty(key); map.put(key, CommonFunc.checkNull(value)); // System.out.println(key+Property); } in.close(); } } catch (Exception e) { e.printStackTrace(); } return map; } /** * 向Properties配置文件中写数据 * @param filePath * @param map */ public static void writeProperties(String filePath, HashMap<String, String> map) { Properties prop = new Properties(); Set<Map.Entry<String, String>> set = map.entrySet(); Iterator<Map.Entry<String, String>> it = set.iterator(); try { InputStream fis = new FileInputStream(filePath); prop.load(fis); OutputStream fos = new FileOutputStream(filePath); while (it.hasNext()) { Map.Entry<String, String> me = it.next(); prop.setProperty(me.getKey(), me.getValue()); prop.store(fos, "Update '" + me.getKey() + "' value"); } } catch (IOException e) { // System.err.println("Visit "+filePath+" for updating "+parameterName+" value error"); } } }
