mvc03

package com.zhulinjun.util;
import java.lang.reflect.Field;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;
/**
 * 所有Dao层的父类
 *  BookDao
 *  UserDao
 *  OrderDao
 *  ...
 * @author Administrator
 *
 * @param <T>
 */
public class BaseDao<T> {
  /**
   * 通用的增删改方法
   * @param book
   * @return 
   * @throws Exception
   */
  public int executeUpdate(String sql, T t, String[] attrs) throws Exception {
//    String[] attrs = new String[] {"bid", "bname", "price"};
    Connection con = DBAccess.getConnection();
    PreparedStatement pst = con.prepareStatement(sql);
//    pst.setObject(1, book.getBid());
//    pst.setObject(2, book.getBname());
//    pst.setObject(3, book.getPrice());
    /*
     * 思路：
     *  1.从传进来的t中读取属性值
     *  2.往预定义对象中设置了值
     *  
     *  t->book
     *  f->bid
     */
    for (int i = 0; i < attrs.length; i++) {
      Field f = t.getClass().getDeclaredField(attrs[i]);
      f.setAccessible(true);
      pst.setObject(i+1, f.get(t));
    }
    return pst.executeUpdate();
  }
  /**
   * 通用分页查询
   * @param sql
   * @param clz
   * @return
   * @throws Exception
   */
  public List<T> executeQuery(String sql,Class<T> clz,PageBean pageBean) throws Exception{
    List<T> list = new ArrayList<T>();
    Connection con = DBAccess.getConnection();;
    PreparedStatement pst = null;
    ResultSet rs = null;
    /*
     * 是否需要分页？
     *  无需分页（项目中的下拉框，查询条件教员下拉框，无须分页）  
     *  必须分页（项目中列表类需求、订单列表、商品列表、学生列表...）
     */
    if(pageBean != null && pageBean.isPagination()) {
//      必须分页（列表需求）
      String countSQL = getCountSQL(sql);
      pst = con.prepareStatement(countSQL);
      rs = pst.executeQuery();
      if(rs.next()) {
        pageBean.setTotal(String.valueOf(rs.getObject(1)));
      }
//      挪动到下面，是因为最后才处理返回的结果集
//      -- sql=SELECT * FROM t_mvc_book WHERE bname like '%圣墟%'
//      -- pageSql=sql limit (page-1)*rows,rows   对应某一页的数据
//      -- countSql=select count(1) from (sql) t  符合条件的总记录数
      String pageSQL = getPageSQL(sql,pageBean);//符合条件的某一页数据
      pst = con.prepareStatement(pageSQL);
      rs = pst.executeQuery();
    }else {
//      不分页（select需求）
      pst = con.prepareStatement(sql);//符合条件的所有数据
      rs = pst.executeQuery();
    }
    while (rs.next()) {
      T t = clz.newInstance();
      Field[] fields = clz.getDeclaredFields();
      for (Field f : fields) {
        f.setAccessible(true);
        f.set(t, rs.getObject(f.getName()));
      }
      list.add(t);
    }
    return list;
  }
  /**
   * 将原生SQL转换成符合条件的总记录数countSQL
   * @param sql
   * @return
   */
  private String getCountSQL(String sql) {
//    -- countSql=select count(1) from (sql) t  符合条件的总记录数
    return "select count(1) from ("+sql+") t";
  }
  /**
   * 将原生SQL转换成pageSQL
   * @param sql
   * @param pageBean
   * @return
   */
  private String getPageSQL(String sql,PageBean pageBean) {
//    (this.page - 1) * this.rows
//    pageSql=sql limit (page-1)*rows,rows
    return sql + " limit "+ pageBean.getStartIndex() +","+pageBean.getRows();
  }
}
========================================================================================
package com.zhulinjun.util;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;
/**
 * 提供了一组获得或关闭数据库对象的方法
 * 
 */
public class DBAccess {
  private static String driver;
  private static String url;
  private static String user;
  private static String password;
  static {// 静态块执行一次，加载 驱动一次
    try {
      InputStream is = DBAccess.class
          .getResourceAsStream("config.properties");
      Properties properties = new Properties();
      properties.load(is);
      driver = properties.getProperty("driver");
      url = properties.getProperty("url");
      user = properties.getProperty("user");
      password = properties.getProperty("pwd");
      Class.forName(driver);
    } catch (Exception e) {
      e.printStackTrace();
      throw new RuntimeException(e);
    }
  }
  /**
   * 获得数据连接对象
   * 
   * @return
   */
  public static Connection getConnection() {
    try {
      Connection conn = DriverManager.getConnection(url, user, password);
      return conn;
    } catch (SQLException e) {
      e.printStackTrace();
      throw new RuntimeException(e);
    }
  }
  public static void close(ResultSet rs) {
    if (null != rs) {
      try {
        rs.close();
      } catch (SQLException e) {
        e.printStackTrace();
        throw new RuntimeException(e);
      }
    }
  }
  public static void close(Statement stmt) {
    if (null != stmt) {
      try {
        stmt.close();
      } catch (SQLException e) {
        e.printStackTrace();
        throw new RuntimeException(e);
      }
    }
  }
  public static void close(Connection conn) {
    if (null != conn) {
      try {
        conn.close();
      } catch (SQLException e) {
        e.printStackTrace();
        throw new RuntimeException(e);
      }
    }
  }
  public static void close(Connection conn, Statement stmt, ResultSet rs) {
    close(rs);
    close(stmt);
    close(conn);
  }
  public static boolean isOracle() {
    return "oracle.jdbc.driver.OracleDriver".equals(driver);
  }
  public static boolean isSQLServer() {
    return "com.microsoft.sqlserver.jdbc.SQLServerDriver".equals(driver);
  }
  public static boolean isMysql() {
    return "com.mysql.cj.jdbc.Driver".equals(driver);
  }
  public static void main(String[] args) {
    Connection conn = DBAccess.getConnection();
    System.out.println(conn);
    DBAccess.close(conn);
    System.out.println("isOracle：" + isOracle());
    System.out.println("isSQLServer：" + isSQLServer());
    System.out.println("isMysql：" + isMysql());
    System.out.println("数据库连接(关闭)成功");
  }
}
================================================================================
package com.zhulinjun.util;
import java.io.IOException;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
 * 中文乱码处理
 * 
 */
@WebFilter("*.action")
public class EncodingFiter implements Filter {
  private String encoding = "UTF-8";// 默认字符集
  public EncodingFiter() {
    super();
  }
  public void destroy() {
  }
  public void doFilter(ServletRequest request, ServletResponse response,
      FilterChain chain) throws IOException, ServletException {
    HttpServletRequest req = (HttpServletRequest) request;
    HttpServletResponse res = (HttpServletResponse) response;
    // 中文处理必须放到 chain.doFilter(request, response)方法前面
    res.setContentType("text/html;charset=" + this.encoding);
    if (req.getMethod().equalsIgnoreCase("post")) {
      req.setCharacterEncoding(this.encoding);
    } else {
      Map map = req.getParameterMap();// 保存所有参数名=参数值(数组)的Map集合
      Set set = map.keySet();// 取出所有参数名
      Iterator it = set.iterator();
      while (it.hasNext()) {
        String name = (String) it.next();
        String[] values = (String[]) map.get(name);// 取出参数值[注：参数值为一个数组]
        for (int i = 0; i < values.length; i++) {
          values[i] = new String(values[i].getBytes("ISO-8859-1"),
              this.encoding);
        }
      }
    }
    chain.doFilter(request, response);
  }
  public void init(FilterConfig filterConfig) throws ServletException {
    String s = filterConfig.getInitParameter("encoding");// 读取web.xml文件中配置的字符集
    if (null != s && !s.trim().equals("")) {
      this.encoding = s.trim();
    }
  }
}
===================================================================================
package com.zhulinjun.util;
import java.util.HashMap;
import java.util.Map;
import javax.servlet.http.HttpServletRequest;
/**
 * 分页工具类
 *
 */
public class PageBean {
  private int page = 1;// 页码
  private int rows = 10;// 页大小
  private int total = 0;// 总记录数
  private boolean pagination = true;// 是否分页
  private String url; //保存上一次请求的URL
  private Map<String,String[]> paramMap = new HashMap<>();// 保存上一次请求的参数
  /**
   * 初始化pagebean的，保存上一次请求的重要参数
   * @param req
   */
  public void setRequest(HttpServletRequest req) {
//    1.1 需要保存上一次请求的URL
    this.setUrl(req.getRequestURL().toString());
//    1.2 需要保存上一次请求的参数  bname、price
    this.setParamMap(req.getParameterMap());
//    1.3 需要保存上一次请求的分页设置  pagination
    this.setPagination(req.getParameter("pagination"));
//    1.4 需要保存上一次请求的展示条目数
    this.setRows(req.getParameter("rows"));
//    1.5  初始化请求的页码 page
    this.setPage(req.getParameter("page"));
  }
  public void setPage(String page) {
    if(StringUtils.isNotBlank(page))
      this.setPage(Integer.valueOf(page));
  }
  public void setRows(String rows) {
    if(StringUtils.isNotBlank(rows))
      this.setRows(Integer.valueOf(rows));
  }
  public void setPagination(String pagination) {
//    只有在前台jsp填写了pagination=false，才代表不分页
    if(StringUtils.isNotBlank(pagination))
      this.setPagination(!"false".equals(pagination));
  }
  public String getUrl() {
    return url;
  }
  public void setUrl(String url) {
    this.url = url;
  }
  public Map<String, String[]> getParamMap() {
    return paramMap;
  }
  public void setParamMap(Map<String, String[]> paramMap) {
    this.paramMap = paramMap;
  }
  public PageBean() {
    super();
  }
  public int getPage() {
    return page;
  }
  public void setPage(int page) {
    this.page = page;
  }
  public int getRows() {
    return rows;
  }
  public void setRows(int rows) {
    this.rows = rows;
  }
  public int getTotal() {
    return total;
  }
  public void setTotal(int total) {
    this.total = total;
  }
  public void setTotal(String total) {
    this.total = Integer.parseInt(total);
  }
  public boolean isPagination() {
    return pagination;
  }
  public void setPagination(boolean pagination) {
    this.pagination = pagination;
  }
  /**
   * 获得起始记录的下标
   * 
   * @return
   */
  public int getStartIndex() {
    return (this.page - 1) * this.rows;
  }
  /**
   * 最大页
   * @return
   */
  public int maxPage() {
//    total % rows == 0 ? total / rows : total / rows +1
    return this.total % this.rows == 0 ? this.total / this.rows : this.total / this.rows + 1;
  }
  /**
   * 下一页
   * @return
   */
  public int nextPage() {
//    如果当前页小于最大页，那就下一页为当前页+1；如果不小于，说明当前页就是最大页，那就无需+1
    return this.page < this.maxPage() ? this.page + 1 : this.page;
  }
  /**
   * 上一页
   * @return
   */
  public int previousPage() {
    return this.page > 1 ? this.page - 1 : this.page;
  }
  @Override
  public String toString() {
    return "PageBean [page=" + page + ", rows=" + rows + ", total=" + total + ", pagination=" + pagination + "]";
  }
}
==================================================================================
package com.zhulinjun.util;
public class StringUtils {
  // 私有的构造方法，保护此类不能在外部实例化
  private StringUtils() {
  }
  /**
   * 如果字符串等于null或去空格后等于""，则返回true，否则返回false
   * 
   * @param s
   * @return
   */
  public static boolean isBlank(String s) {
    boolean b = false;
    if (null == s || s.trim().equals("")) {
      b = true;
    }
    return b;
  }
  /**
   * 如果字符串不等于null或去空格后不等于""，则返回true，否则返回false
   * 
   * @param s
   * @return
   */
  public static boolean isNotBlank(String s) {
    return !isBlank(s);
  }
}
==================================================================================
#oracle9i
#driver=oracle.jdbc.driver.OracleDriver
#url=jdbc:oracle:thin:@localhost:1521:ora9
#user=test
#pwd=test
#sql2005
#driver=com.microsoft.sqlserver.jdbc.SQLServerDriver
#url=jdbc:sqlserver://localhost:1423;DatabaseName=test
#user=sa
#pwd=sa
#sql2000
#driver=com.microsoft.jdbc.sqlserver.SQLServerDriver
#url=jdbc:microsoft:sqlserver://localhost:1433;databaseName=unit6DB
#user=sa
#pwd=888888
#mysql5
#driver=com.mysql.jdbc.Driver
#url=jdbc:mysql://127.0.0.1:3306/mybatis_ssm?useUnicode=true&characterEncoding=utf8&serverTimezone=GMT
#user=mybatis_ssm
#pwd=xiaoli
#mysql8
driver=com.mysql.cj.jdbc.Driver
url=jdbc:mysql://127.0.0.1:3306/mybatis_ssm?useUnicode=true&characterEncoding=utf8&serverTimezone=GMT&useSSL=true
user=root
pwd=123456