- PageBaen 分页工具类
package com.strurts.utli;
import java.util.Map;
import javax.servlet.http.HttpServletRequest;
public class PageBean {
private int page = 1;// 页码
private int rows = 2;// 行数/页大小
private int total = 0;// 总记录数
private boolean pagination = true;// 默认分页
private String url;// 上一次请求的地址
private Map<String, String[]> parameterMap;// 上一次请求的所有参数
public PageBean() {
super();
}
/**
* 对分页bean进行初始化
*
* @param request
*/
public void setRequest(HttpServletRequest request) {
// 公共参数
this.setPage(request.getParameter("page"));
this.setRows(request.getParameter("rows"));
this.setPagination(request.getParameter("pagination"));
// 请求地址和请求参数
this.setUrl(request.getContextPath() + request.getServletPath());
this.setParameterMap(request.getParameterMap());
}
public String getUrl() {
return url;
}
public void setUrl(String url) {
this.url = url;
}
public Map<String, String[]> getParameterMap() {
return parameterMap;
}
public void setParameterMap(Map<String, String[]> parameterMap) {
this.parameterMap = parameterMap;
}
public int getPage() {
return page;
}
public void setPage(int page) {
this.page = page;
}
public void setPage(String page) {
if (null != page && !"".equals(page.trim())) {
this.page = Integer.parseInt(page);
}
}
public int getRows() {
return rows;
}
public void setRows(int rows) {
this.rows = rows;
}
public void setRows(String rows) {
if (null != rows && !"".equals(rows.trim())) {
this.rows = Integer.parseInt(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;
}
public void setPagination(String pagination) {
if ("false".equals(pagination)) {
this.pagination = false;
}
}
/**
* 下一页
*
* @return
*/
public int getNextPage() {
int nextPage = page + 1;
if (nextPage > this.getMaxPage()) {
nextPage = this.getMaxPage();
}
return nextPage;
}
/**
* 上一页
*
* @return
*/
public int getPreviousPage() {
int previousPage = page - 1;
if (previousPage < 1) {
previousPage = 1;
}
return previousPage;
}
/**
* 最大页码
*
* @return
*/
public int getMaxPage() {
return total % rows == 0 ? total / rows : total / rows + 1;
}
/**
* 起始记录的下标
*
* @return
*/
public int getStartIndex() {
return (page - 1) * rows;
}
@Override
public String toString() {
return "PageBean [page=" + page + ", rows=" + rows + ", total=" + total + ", pagination=" + pagination + "]";
}
}
- StringUtils 判断字符串是否为空的类
package com.hibernateSql.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);
}
}
- Hibernate 查询通用BaseDao
package com.hibernateSql.dao;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import org.hibernate.Session;
import org.hibernate.query.Query;
import com.hibernateSql.util.PageBean;
/**
* jdbc：
* executeQuery(pagebean,sql,clz)
* sql: select * from book where book_name '%?%'
* select * from book where book_name '%xx%'
*
* 分页：1.sql-->countSql-->total-->pagebaen
* 2.sql-->pagesql-->result
* 3.处理结果集
*
* hibername
* 分页：
* 1.hql-->countHql-->total-->pagebaen
* 2.Hql-->pageHql-->result
*
* @author Administrator
*
*/
public class BaseDao {
/**
* 如果有带参数，
* 命名参数 ：赋值
*
* @param query
* @param hql
*/
public void setParameters(Query<?> query,Map<String, Object> map) {
if(map == null || map.size()==0) {
return ;
}
else {
//创建map的视图
Object values=null;
for (Map.Entry<String, Object> entry : map.entrySet()) {
values=entry.getValue();
//判断它的数据类型
if(values instanceof Collection) {
query.setParameterList(entry.getKey(), (Collection) values);
}
else if(values instanceof Object[]) {
query.setParameterList(entry.getKey(), (Object[]) values);
}
else {
query.setParameter(entry.getKey(), values);
}
}
}
}
/**
* 拼接Hqlcount语句
*/
public String getcountHql(String hql) {
int index = hql.toUpperCase().indexOf("FROM");
return "select count(*) "+ hql.substring(index);
}
/**
*
*/
public List<?> executeQuery(String hql,Map<String, Object> map,PageBean pageBean,Session session){
//判断它是否分页
if(pageBean != null && pageBean.isPagination()) {
//如果分页
String countHql = getcountHql(hql);
//查询出总页数
Query<?> query = session.createQuery(countHql);
//给这个countHql中的命名参数赋值
setParameters(query, map);
String total = query.getSingleResult().toString();
//放入pageBeau
pageBean.setTotal(total);
//开始查询数据
Query<?> pageQuery = session.createQuery(hql);
//给命名参数赋值
this.setParameters(pageQuery, map);
//设置分页
pageQuery.setFirstResult(pageBean.getStartIndex());
pageQuery.setMaxResults(pageBean.getRows());
return pageQuery.list();
}
else {
//不分页的时候
Query<?> query = session.createQuery(hql);
//给参数赋值
setParameters(query, map);
return query.list();
}
}
}
- 获取Map , 根据传递过来到key获取里面到值
package com.strurts.utli;
import java.util.Arrays;
import java.util.Map;
public class JsonUtil {
/**
* 获取Map , 根据传递过来到key获取里面到值
* @param map
* @param key
* @return
*/
public static String getParamMapVal(Map<String, String[]> map,String key) {
if(map!=null&&map.size()>0) {
String[] vals = map.get(key);
if(vals!=null&&vals.length>0) {
String val = Arrays.toString(vals);
return val.substring(1, val.length()-1);
}
}
return "";
}
}
- BaseDao 利用oop思想进行增强的一个通用查询分页类
package com.zking.util;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;
/**
* 利用oop思想进行增强的一个通用查询分页类
* @author Administrator
*
* @param <T>
*/
public class BaseDao<T> {
/**
* 沿用的思想类似于ajax
* success：function{
* }
* @author Administrator
*
*/
public abstract class CallBack{
public abstract List<T> forEach(ResultSet rst,Connection con) throws SQLException, InstantiationException, IllegalAccessException;
}
/**
*
* @param sql
* @param pageBean
* @param callBack
* @return
* @throws SQLException
* @throws InstantiationException
* @throws IllegalAccessException
*/
public List<T> executeQuery(String sql, PageBean pageBean,CallBack callBack) throws SQLException, InstantiationException, IllegalAccessException {
Connection con = DBAccess.getConnection();
if(pageBean.isPagination()) {
String countSql = getCountSql(sql);
PreparedStatement pst = con.prepareStatement(countSql);
ResultSet rst = pst.executeQuery();
if(rst.next()) {
pageBean.setTotal(rst.getObject(1).toString());
}
}
String pageSql = getPageSql(sql,pageBean);
PreparedStatement pst = con.prepareStatement(pageSql);
ResultSet rst = pst.executeQuery();
return callBack.forEach(rst, con);
}
/**
* 拼装分页的sql语句
* @param sql
* @param PageBean
* @return
*/
private String getPageSql(String sql, PageBean pageBean) {
int page = pageBean.getPage();
int rows = pageBean.getRows();
int startIndex = (page - 1) * rows;
return pageBean.isPagination() ? (sql + " limit "+ startIndex +"," + rows) : sql;
}
/**
* 获取符合记录数的sql语句
* @param sql
* @return
*/
private String getCountSql(String sql) {
return "select count(*) from ("+ sql +") t;";
}
}
- EntityBaseDao 利用反射对通用分页查询进行二次增强
package com.zking.util;
import java.lang.reflect.Field;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
/**
* 利用反射对通用分页查询进行二次增强
* @author Administrator
*
* @param <T>
*/
public class EntityBaseDao<T> extends BaseDao<T> {
public List<T> executeQuery(String sql, PageBean pageBean, Class<T> clz) throws SQLException, InstantiationException, IllegalAccessException{
return super.executeQuery(sql, pageBean, new CallBack() {
@Override
public List<T> forEach(ResultSet rst,Connection con) throws SQLException, InstantiationException, IllegalAccessException {
List<T> list = new ArrayList<>();
while(rst.next()) {
// 1、实例化一个具体的类对象出来
// 2、给具体的哪一个类对象赋值（用于页面展示）
// 3、要通过类对象的属性从ResultSet拿到数据
// 4、把装有数据的实体类添加给list
// list.add(new Book(rst.getInt("bid"), rst.getString("bname"), rst.getFloat("price")));
T t = (T) clz.newInstance();
Field[] declaredFields = clz.getDeclaredFields();
for (Field field : declaredFields) {
field.setAccessible(true);
field.set(t, rst.getObject(field.getName()));
}
list.add(t);
}
return list;
}
});
}
/**
* 通用的增删改方法
* @param sql 增删改的sql语句
* @param attrs 要个sql语句的那个表字段进行赋值，需要调用方传递过来
* @param t 具体要给哪个对象进行增删改操作
* @return
* @throws SQLException
* @throws InstantiationException
* @throws IllegalAccessException
* @throws SecurityException
* @throws NoSuchFieldException
*/
public int executeUpdate(String sql, String[] attrs, T t) throws SQLException, InstantiationException, IllegalAccessException, NoSuchFieldException, SecurityException{
Connection con = DBAccess.getConnection();
PreparedStatement pst = con.prepareStatement(sql);
// 给sql语句预定义对象赋值
for (int i = 0; i < attrs.length; i++) {
Field attrField = t.getClass().getDeclaredField(attrs[i]);
attrField.setAccessible(true);
int j = i+1;
pst.setObject(j, attrField.get(t));
}
return pst.executeUpdate();
}
}
- JsonBaseDao json格式的通用查询
package com.zking.util;
import java.lang.reflect.Field;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* json格式的通用查询
* @author Administrator
*
*/
public class JsonBaseDao extends BaseDao<Map<String, Object>>{
public List<Map<String, Object>> executeQuery(String sql, PageBean pageBean)
throws SQLException, InstantiationException, IllegalAccessException {
return super.executeQuery(sql, pageBean, new CallBack() {
@Override
public List<Map<String, Object>> forEach(ResultSet rst,Connection con)
throws SQLException, InstantiationException, IllegalAccessException {
List<Map<String, Object>> list=new ArrayList<>();
ResultSetMetaData md=rst.getMetaData();
int columnCount = md.getColumnCount();
Map<String, Object> map=null;
while(rst.next()) {
map=new HashMap<>();
for (int i = 1; i <=columnCount; i++) {
map.put(md.getColumnName(i), rst.getObject(i));
}
list.add(map);
}
con.close();
return list;
}
});
}
/**
* 通用增删改
*/
public int executeUpdate(String sql, String[] keys,Map<String, String[]> map) throws SQLException, InstantiationException, IllegalAccessException, NoSuchFieldException, SecurityException{
Connection con = DBAccess.getConnection();
PreparedStatement pst = con.prepareStatement(sql);
// 给sql语句预定义对象赋值
for (int i = 0; i < keys.length; i++) {
pst.setObject(i+1, JsonUtil.getParamMapVal(map,keys[i]));
}
return pst.executeUpdate();
}
}